NASA/TP–2013–217511

International VLBI Service for

Geodesy and Astrometry 2012

Annual Report

Karen D. Baver (ed.)

NVI, Inc., Greenbelt, Maryland

Dirk Behrend (ed.)

NVI, Inc., Greenbelt, Maryland

Kyla L. Armstrong (ed.)

NVI, Inc., Greenbelt, Maryland

National Aeronautics and

Space Administration

Goddard Space Flight Center

Greenbelt, Maryland 20771-0001

June 2013
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Preface

This volume of reports is the 2012 Annual Report of the International VLBI Service for Geodesy

and Astrometry (IVS). The individual reports were contributed by VLBI groups in the international geodetic and astrometric community who constitute the permanent components of IVS.

The IVS 2012 Annual Report documents the work of the IVS components for the calendar year

2012, our fourteenth year of existence. The reports describe changes, activities, and progress of

the IVS. Many thanks to all IVS components who contributed to this Annual Report.

With the exception of the first section and parts of the last section (described below), the

contents of this Annual Report also appear on the IVS Web site at

http://ivscc.gsfc.nasa.gov/publications/ar2012

This book and the Web site are organized as follows:

• The first section contains general information about IVS, a map showing the location of the

components, information about the Directing Board members, and the annual report of the

IVS Chair.

• The second section holds four special reports. The first report, “Short Report of IVS Working

Group 5 (WG5) on Space Science Applications”, presents the work of Working Group 5,

which was established in 2009 to examine ways in which IVS and other VLBI networks can

support planetary and space science missions to the mutual benefit of all participants. The

WG5 report considers several types of spacecraft, evaluating VLBI’s suitability for observing

them and the expected benefits, and the report assesses the availablity of IVS observing

sessions for this purpose. The second and third reports concern comparisons of two related

VLBI system components — down-converters, which convert analog radio frequencies (RF) to

intermediate frequencies (IF), and digital backends (DBE), which convert IF into channelized

digital data that can be correlated. “VLBI Digital-Backend Intercomparison Test Report”

discusses the results of the October 2012 2nd DBE intercomparison workshop, which tested

and compared five DBE systems. “VLBI2010 Receiver Back End Comparison” presents

tables that summarize information about two flexible down-converters and nine DBE systems

as of mid-January 2013. Finally, the fourth report, “VLBI2010 Feed Comparison”, presents

a table and a figure that compare two VLBI2010-compliant broadband feeds and a table that

compares two triband feeds that are non-compliant but can be used during the transition to

VLBI2010 and also to support X/Ka CRF observations.

• The next seven sections hold the reports from the Coordinators and the reports from the IVS

Permanent Components: Network Stations, Operation Centers, Correlators, Data Centers,

Analysis Centers, and Technology Development Centers.

• The next section contains a compilation of publications in the field of geodetic and astrometric

VLBI during 2012.

• The last section includes reference information about IVS: the Terms of Reference, the lists of

Member and Affiliated organizations, the IVS Associate Member list, a complete list of IVS

components, the list of institutions that contributed to this report, and a list of acronyms.

iii

Table of Contents

Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii

About IVS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

IVS Organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

IVS Component Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

IVS Directing Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

IVS Chair’s Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Special Reports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Short Report of IVS Working Group 5 (WG5) on Space Science Applications . . . . . . . . . . . . . . . . . . . . . . . . . 13

VLBI Digital-Backend Intercomparison Test Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

VLBI2010 Receiver Back End Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

VLBI2010 Feed Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

IVS Coordination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Coordinating Center Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Analysis Coordinator Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Network Coordinator Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

IVS Technology Coordinator Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .68

Network Stations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

Badary Radio Astronomical Observatory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

Fortaleza Station Report for 2012 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

Goddard Geophysical and Astronomical Observatory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

Hartebeesthoek Radio Astronomy Observatory (HartRAO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86

AuScope VLBI Project and Hobart 26-m Antenna . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

Kashima 34-m Radio Telescope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .94

Kashima and Koganei 11-m VLBI Stations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98

Kokee Park Geophysical Observatory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .102

Matera CGS VLBI Station . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106

The Medicina Station Status Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110

Mets ̈ahovi Radio Observatory - IVS Network Station . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112

VERA Geodetic Activities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116

Noto Station Status Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120

Ny- ̊Alesund Geodetic Observatory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123

German Antarctic Receiving Station (GARS) O’Higgins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126

Onsala Space Observatory – IVS Network Station . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130

Parkes 2012 IVS Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .134

Korea Geodetic VLBI Station, Sejong . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135

Sheshan VLBI Station Report for 2012 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139

Simeiz VLBI Station - Geodetic and Astrophysical Study . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .142

Svetloe Radio Astronomical Observatory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146

JARE Syowa Station 11-m Antenna, Antarctica . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150

Status of the TIGO VLBI Station in Concepci ́on . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154

Tsukuba 32-m VLBI Station . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157

Warkworth 12-m VLBI Station: WARK12M . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161

Westford Antenna . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165

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Geodetic Observatory Wettzell - 20-m Radio Telescope and Twin Telescope . . . . . . . . . . . . . . . . . . . . . . . . . 169

Instituto Geogr ́afico Nacional of Spain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173

Zelenchukskaya Radio Astronomical Observatory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177

Operation Centers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181

The Bonn Geodetic VLBI Operation Center . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183

CORE Operation Center Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185

NEOS Operation Center . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189

Correlators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191

The Bonn Astro/Geo Correlator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193

Haystack Observatory VLBI Correlator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197

IAA Correlator Center . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201

VLBI Correlators in Kashima . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204

Shanghai VLBI Correlator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208

Tsukuba VLBI Correlator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212

Washington Correlator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216

Data Centers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219

BKG Data Center . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221

CDDIS Data Center Summary for the IVS 2012 Annual Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223

Italy INAF Data Center Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226

Data Center at NICT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227

Paris Observatory (OPAR) Data Center . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231

Analysis Centers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235

Analysis Center of Saint Petersburg University . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237

Geoscience Australia Analysis Center . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239

Report for 2012 from the Bordeaux IVS Analysis Center . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241

BKG/DGFI Combination Center Annual Report 2012 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245

Matera CGS VLBI Analysis Center . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249

DGFI Analysis Center Annual Report 2012 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251

GFZ Analysis Center . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255

The BKG/IGGB VLBI Analysis Center . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257

GSFC VLBI Analysis Center . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261

Haystack Analysis Center . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265

IAA VLBI Analysis Center Report 2012 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 269

Italy INAF Analysis Center Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271

JPL VLBI Analysis Center Report for 2012 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273

KASI Combination Center Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277

KTU-GEOD IVS Analysis Center Annual Report 2012 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281

IVS Analysis Center at Main Astronomical Observatory of National Academy of Sciences of Ukraine 285

Analysis Center at National Institute of Information and Communications Technology . . . . . . . . . . . . . . . 287

NMA Analysis Center . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291

Paris Observatory Analysis Center (OPAR): Report on Activities, January - December 2012 . . . . . . . . . 294

Onsala Space Observatory – IVS Analysis Center . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .298

PMD IVS Analysis Center . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 302

Pulkovo IVS Analysis Center (PUL) 2012 Annual Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .305

SAI VLBI Analysis Center Report 2012 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 309

SHAO Analysis Center 2012 Annual Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 311

Tsukuba VLBI Analysis Center . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315

vi
U.S. Naval Observatory VLBI Analysis Center . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 319

USNO Analysis Center for Source Structure Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323

Vienna Special Analysis Center Annual Report 2012 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325

Technology Development Centers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329

Canadian VLBI Technology Development Center . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 331

GSFC Technology Development Center Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332

Haystack Observatory Technology Development Center . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335

IAA Technology Development Center Report 2012 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 339

Technology Development Center at NICT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 342

Onsala Space Observatory – IVS Technology Development Center . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 346

Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 351

Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 353

IVS Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 371

IVS Terms of Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 373

IVS Member Organizations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 383

IVS Affiliated Organizations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 385

IVS Associate Members . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 386

IVS Permanent Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 398

Addresses of Institutions of Authors Contributing to this Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 403

List of Acronyms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .411

vii

About IVS
2

IVS Organization

Objectives

IVS is an international collaboration of organizations which 

operate or support Very Long Baseline Interferometry 

(VLBI) components. The goals are:

1. To provide a service to support geodetic, geophysical 

and astrometric research and operational activities.

2. To promote research and development activities in 

all aspects of the geodetic and astrometric VLBI 

technique.

3. To interact with the community of users of VLBI 

products and to integrate VLBI into a global Earth 

observing system.

The IVS

• Interacts closely with the IERS, which is tasked by 

IAU and IUGG with maintaining the international 

celestial and terrestrial reference frames (ICRF

and ITRF),

• coordinates VLBI observing programs, 

• sets performance standards for the observing stations, 

• establishes conventions for data formats and products, 

• issues recommendations for analysis software,

• sets standards for analysis documentation,

• institutes appropriate product delivery methods in 

order to insure suitable product quality and timeliness.

Realization And Status Of IVS

IVS consists of

• 33 Network Stations, acquiring high performance 

VLBI data,

• 3 Operation Centers, coordinating the activities of a 

network of Network Stations,

• 7 Correlators, processing the acquired data, providing feedback to the stations and providing processed 

data to analysts,

• 6 Data Centers, distributing products to users, 

providing storage and archiving functions,

• 27 Analysis Centers, analyzing the data and producing 

the results and products,

• 6 Technology Development Centers, developing new 

VLBI technology,

• 1 Coordinating Center, coordinating daily and long 

term activities.

Altogether

• 83 Permanent Components, representing 43 institutions in 21 countries,

• ~280 Associate Members.

In addition the IVS has:

• Directing Board, determining policies, standards and 

goals; the board is composed of 15 members (elected 

and ex officio), including

• Coordinators for the network, analysis and technology.

ORGANIZATION OF INTERNATIONAL VLBI SERVICE
3

IVS Affiliated Organizations

The following organizations cooperate with IVS on issues 

of common interest, but do not support an IVS component. 

Affiliated Organizations express an interest in establishing 

and maintaining a strong working association with IVS to 

mutual benefit. Listed alphabetically by country. 

Products

The VLBI technique contributes uniquely to

• Definition and realization of the International Celestial 

Reference Frame (ICRF)

• Monitoring of Universal Time (UT1) and length of day 

(LOD)

• Monitoring the coordinates of the celestial pole (nutation and precession)

Further significant products are

• All components of Earth Orientation Parameters at 

regular intervals

• Station coordinates and velocity vectors for the realization and maintenance of the International Terrestrial 

Reference Frame (ITRF)

All VLBI data and results in appropriate formats are archived in data centers and publicly available for research 

in related areas of geodesy, geophysics and astrometry.

IVS Member Organizations

The following organizations contribute to IVS by supporting 

one or more IVS components. They are considered IVS 

Members. Listed alphabetically by country.

Organization Country

Geoscience Australia Australia

University of Tasmania Australia

CSIRO Australia

Vienna University of Technology Austria

Centro de Rádio Astronomia e Aplicações 

Espaciais

Brazil

Geodetic Survey Division, Natural 

Resources Canada

Canada

Dominion Radio Astrophysical 

Observatory

Canada

Universidad de Concepción Chile

Instituto Geográfico Militar Chile

Chinese Academy of Sciences China

Finnish Geodetic Institute, Aalto University Finland

Observatoire de Paris France

Laboratoire d’Astrophysique de Bordeaux France

Deutsches Geodätisches 

Forschungsinstitut

Germany

Bundesamt für Kartographie und Geodäsie Germany

Institut für Geodäsie und Geoinformation 

der Universität Bonn

Germany

Forschungseinrichtung Satellitengeodäsie, 

TU-Munich

Germany

Max-Planck-Institut für Radioastronomie Germany

GeoForschungsZentrum Potsdam Germany

Istituto di Radioastronomia INAF Italy

Agenzia Spaziale Italiana Italy

Politecnico di Milano DIIAR Italy

Geospatial Information Authority of Japan Japan

National Institute of Information and 

Communications Technology

Japan

National Astronomical Observatory of 

Japan

Japan

National Institute of Polar Research Japan

Auckland University of Technology New 

Zealand

Norwegian Mapping Authority Norway

Astronomical Institute of St.-Petersburg 

University

Russia

Institute of Applied Astronomy Russia

Pulkovo Observatory Russia

Sternberg Astronomical Institute of 

Moscow State University

Russia

Organization Country

Hartebeesthoek Radio Astronomy 

Observatory

South 

Africa

Korea Astronomy and Space Science 

Institute

South 

Korea

National Geographic Information Institute S. Korea

Instituto Geográfico Nacional Spain

Chalmers University of Technology Sweden

Karadeniz Technical University Turkey

Main Astronomical Observatory, 

National Academy of Sciences, Kiev

Ukraine

Laboratory of Radioastronomy of Crimean 

Astrophysical Observatory

Ukraine

NASA Goddard Space Flight Center USA

U. S. Naval Observatory USA

Jet Propulsion Laboratory USA

Organization Country

Australian National University Australia

University of New Brunswick Canada

FÖMI Satellite Geodetic Observatory Hungary

Joint Institute for VLBI in Europe (JIVE) Netherlands

Westerbork Observatory Netherlands

National Radio Astronomy Observatory USA
4

IVS Component Map

IVS Components by Country

Country Qty.

Australia 3

Austria 1

Brazil 1

Canada 1

Chile 1

China 4

Finland 1

France 3

Germany 9

Italy 8

Japan 13

New Zealand 1

Norway 2

Russia 9

South Africa 1

South Korea 2

Spain 1

Sweden 3

Turkey 1

Ukraine 2

USA 16

Total 83

A complete list of IVS Permanent

Components is in the IVS Information

section of this volume.

Network Station

Former Station

Operation Center

Correlator

Data Center

Analysis Center

Technology Development Center

Coordinating Center

O’Higgins

TIGO

Fortaleza

Haystack

Canadian VLBI

Algonquin

Yellowknife

Gilmore Creek

JPL

Kokee Park

GGAO

NEOS

GSFC

USNO
5

GSI

NICT

Kashima 34

Kashima 11

Koganei

Katherine

Parkes

GA

Hobart

Warkworth

Yarragadee

Hartebeesthoek

Syowa

Mizusawa

Tsukuba

KASI

Shanghai

Seshan

Sejong

Nanshan

Badary

Zelenchukskaya

KTU

Simeiz

SAI

IAA

AIStPbU

Svetloe

NMA

GFZ

Metsähovi

Onsala

IGGB

Paris

FGS(BKG,IGGB)

Bordeaux

Wettzell

TU Vienna

Medicina

Matera

Noto PMD

Yebes

INAF

DGFI

PUL

BKG MAO

Ny Alesund
6

IVS Directing Board

NAME: Hayo Hase

AFFILIATION: Bundesamt für 

Kartographie und Geodäsie/

TIGO, Germany/Chile

POSITION: Networks 

Representative

TERM: Feb 2011 to Feb 2015

NAME: Rüdiger Haas

AFFILIATION: Chalmers 

University of Technology, 

Sweden

POSITION: Technology Development Centers Representative

TERM: Feb 2009 to Feb 2013

NAME: Dirk Behrend

AFFILIATION: NVI, Inc./Goddard 

Space Flight Center, USA

POSITION: Coordinating Center 

Director

TERM: ex officio

NAME: Harald Schuh

AFFILIATION: Vienna University 

of Technology, Austria

POSITION: Acting Chair and IAG 

Representative

TERM: ex officio

NAME: Jesús Gómez González

AFFILIATION: National 

Geographic Institute of Spain

POSITION: At Large Member

TERM: Feb 2011 to Feb 2013

NAME: Patrick Charlot

AFFILIATION: Bordeaux 

Observatory, France

POSITION: IAU Representative

TERM: ex officio

NAME: Alessandra Bertarini

AFFILIATION: University 

of Bonn, Germany

POSITION: Correlators

and Operation Centers

Representative

TERM: Feb 2011 to Feb 2015
7

NAME: Shinobu Kurihara

AFFILIATION: Geospatial 

Information Authority, Japan

POSITION: At Large Member

TERM: (Feb 2011) to Feb 2013

NAME: Gino Tuccari

AFFILIATION: Istituto di

Radioastronomia, Italy

POSITION: Networks

Representative

TERM: Feb 2009 to Feb 2013

NAME: Axel Nothnagel

AFFILIATION: University 

of Bonn, Germany

POSITION: Analysis

Coordinator

TERM: permanent

NAME: Chopo Ma

AFFILIATION: NASA Goddard 

Space Flight Center, USA

POSITION: IERS Representative

TERM: ex officio

NAME: Fengchun Shu

AFFILIATION: Shanghai 

Astronomical Observatory, 

China

POSITION: At Large Member

TERM: Feb 2011 to Feb 2013

NAME: Alan Whitney

AFFILIATION: Haystack

Observatory, USA

POSITION: Technology

Coordinator

TERM: permanent

NAME: Oleg Titov

AFFILIATION: Geoscience 

Australia, Australia

POSITION: Analysis and 

Data Centers Representative

TERM: Feb 2009 to Feb 2013

NAME: Ed Himwich

AFFILIATION: NVI, Inc./Goddard 

Space Flight Center, USA

POSITION: Network

Coordinator

TERM: permanent
8

IVS Chair’s Report

Harald Schuh

Helmholtz Centre Potsdam - GFZ German Research 

Centre for Geosciences

With the 2012 Annual Report the IVS components report 

about their progress and activities which were conducted 

during the service’s fourteenth year of existence. I would 

like to thank all IVS Associate Members for their contributions over the course of the year, in particular for providing 

their reports in time. Timely appearance of the Annual 

Report is always an ambitious goal and is highly appreciated for maintaining this volume as a real information 

exchange tool for the community and related groups. I 

thank the editors for the timely release.

In 2012 IVS observing activities remained at the same 

high level as in previous years, testament to the optimized coordination by the Coordinating Center and 

strong support from all components despite the limited 

resources and failures at a few aging radio telescopes. I 

would like to thank the staff of the Coordinating Center 

who bear much responsibility and carry a heavy burden 

for the entire service activities. Day-to-day work is done 

continuously by the Network Stations, the Correlators, 

the Data Centers, and the Analysis Centers and is the 

basis for the regular provision of precise and reliable IVS 

products. Here I would like to emphasize those activities 

performed in 2012 that go beyond the normal work load.

IVS Contribution to the Global Geodetic 

Observing System (GGOS)

In 2005 the intergovernmental Group on Earth Observations (GEO) was formed. This group initiated the creation 

of a Global Earth Observing System of Systems (GEOSS) 

for monitoring and understanding global change. The International Association of Geodesy (IAG) contributes to 

this multi-national and multi-institutional effort with the 

Global Geodetic Observing System (GGOS). Based on 

the well-established, international space-geodetic services GGOS will provide the most precise terrestrial and 

celestial reference frames that are needed as a stable 

reference to monitor any kind of changes on Earth and 

in space. 

Integration and combination in the framework of GGOS 

is the main challenge for the international geodesy in 

this decade. GGOS goes beyond the integration of the 

geometric techniques (VLBI, SLR, GNSS, DORIS) as it 

includes also techniques measuring terrestrial gravity, the 

global Earth gravity field, sea level, and also the magnetic 

field. Thus, a consistent combination of all geometric and 

physical techniques will be required. GGOS plays an essential role in helping to solve environmental and societal 

problems. Many tasks such as establishing a unified global 

height system or open questions related to global change, 

sea level rise, or the prevention of natural hazards need 

precise reference frames and exact geodetic measurements. VLBI can give a critical contribution to GGOS by 

its relation to a quasi-inertial celestial reference frame and 

its unique ability to measure long-term UT1-UTC and precession/nutation. One of the IVS main tasks in 2012 was 

to continue its contribution as an efficient partner within 

GGOS. Several GGOS events were attended in 2012 with 

presentations about the IVS, its next generation VLBI2010 

system, and the new IVS network called VGOS (VLBI2010 

Global Observing System). 

VLBI2010 Committee (V2C), VLBI2010 

Project Executive Group (V2PEG), and 

VGOS (VLBI2010 Global Observing 

System)

In recent years the IVS has developed the concept and 

specifications of a next generation VLBI system called 

VLBI2010. The goals of the new system are to achieve 

(on scales up to the size of the Earth): 

• 1 mm position accuracy, 

• 0.1 mm/yr velocity accuracy,

• continuous observations, and 

• results available in near real-time. 

The VLBI2010 Committee (V2C), chaired by Bill Petrachenko, was established in 2005. It is tasked with promoting the goals set by the VLBI2010 Report released by 

the IVS Working Group 3 “VLBI2010: Current and Future 

Requirements for Geodetic VLBI Systems.” All results 

have been summarized in the excellent VLBI2010 Progress Report with recommendations that can be used as 

a benchmark for new VLBI systems. Since the VLBI2010 

Progress Report was finalized in spring 2009 and put on 

the IVS Web site (ftp://ivscc.gsfc.nasa.gov/pub/misc/V2C/

TM-2009-214180.pdf ) the V2C activities have continued 

with a lot of further simulations and technical studies. 

I would like to thank all members of the V2C for taking 

over the responsible leading role in the realization of the 

VLBI2010 visions.
9

IVS Working Group 5 on “Space Science 

Applications” 

The mandate of the WG5 comprises the following tasks: 

1. To investigate synergies in scientific and technological areas between the IVS core activities and VLBI 

experiments in application to planetary and space 

science missions.

2. To determine areas of VLBI support of planetary and 

space science missions where experiments conducted by the IVS (possibly together with other VLBI 

networks) can be mutually beneficial.

3. To investigate desirability and feasibility of establishing 

a mission-specific liaison between IVS and appropriate space agencies and organizations involved in 

planetary and space science missions.

Due to cancellations or postponement of several relevant 

space missions the work of WG5 was delayed, but it is 

anticipated to be closed in spring 2013 as the final report 

describing the state-of-the-art and future perspectives is 

about to be published.

IVS Working Group 6 on “VLBI Education 

and Training” 

The IVS Directing Board established in March 2009 the 

Working Group 6 on “Education and Training” chaired by 

Rüdiger Haas. The general aim of IVS WG6 is to support 

education and training in the field of geodetic and astrometric VLBI, in order to pass on and maintain expertise 

in this field for the next generations.

The Terms of Reference of IVS WG6 are:

1. To establish contacts to education institutions in geodesy and geosciences worldwide with the aim to raise 

interest in geodetic VLBI among students.

2. To develop ideas for education material that can be 

distributed to education institutions.

3. To seek funding to organize training in form of, for 

instance, IVS summer schools for Master and PhD 

students.

Proposals for a VLBI school were already submitted in 

2011 and it was very successfully organized in Helsinki, 

Finland in March 2013.

VLBI2010 is supposed to develop not only the visions but 

also very detailed specifications for future VLBI systems. 

Now, the task for the IVS is the realization of the VLBI2010 

concept. To support the implementation of VLBI2010 and 

to actively contact governmental entities and funding organizations the VLBI2010 Project Executive Group (V2PEG) 

under the leadership of Hayo Hase continued its activities 

in 2012. Several letters of support were sent to government bodies and funding agencies all over the world and 

an update of the so-called station survey was requested 

from the IVS network stations in December 2011. Based 

on this questionnaire very useful information was obtained 

about the status of the planning process concerning the 

transition to VLBI2010 at the various observing stations. 

In the last years several countries have decided to develop 

or purchase new VLBI systems. We highly appreciate that 

agencies in the following countries got approval of new 

VLBI2010-type radio telescopes so far: Australia, China, 

Finland, Germany, Japan, New Zealand, Norway, Portugal, 

Russia, Spain, South Korea, and Sweden. Thus, already 

nineteen VLBI2010 antennas have been approved with 

more proposals under consideration or even in review in 

countries like France, Poland, and Saudi Arabia. With new 

antennas the global coverage of geodetic VLBI is getting 

better, but it is still far from being optimal; in particular 

more VLBI sites in the south-eastern quadrant would be 

more than welcome. 

IVS Working Group 4 on “VLBI Data 

Structures”

The IVS Working Group on “VLBI Data Structures” chaired 

by John Gipson was established in September 2007 as a 

response to the strong need for new, common VLBI data 

structures. This Working Group examines the data structure currently used in VLBI data processing and develops 

the data structure needed in the future. WG4 is getting 

closed soon as all its goals w.r.t. the new data format have 

been achieved. What remains is the implementation into 

the various existing VLBI software packages.
10

Events and Highlights in 2012

In early March 2012, the 7th IVS General Meeting under 

the theme “Launching the Next-Generation IVS Network” 

was held in Madrid (Spain), i.e. in the country where presently the establishment of four new VLBI radio telescopes 

is taking place in the frame of the Spanish/Portuguese 

RAEGE project, chaired by Prof. Jesús Gómez-González 

(Instituto Geográfico Nacional, IGN). In conjunction with 

the General Meeting, an IVS Analysis Workshop, a V2C 

meeting, a V2PEG meeting, and the 27th Directing Board 

Meeting were organized. I would like to thank the Local Organizing Committee, Francisco Colomer (Chair), Susana 

García-Espada, Álvaro Santamaría, Pablo de Vicente, 

and Marta Calvo for the excellent organization. I thank 

also the session conveners and all other individuals who 

contributed to the great success of the meeting. The IGN 

is deeply acknowledged for providing the meeting facilities. We very much appreciated the great hospitality we 

received from our Spanish colleagues. A special highlight 

was certainly the official ‘launch’ of the new VGOS, the 

VLBI2010 Global Observing System, in the closing session of the 7th General Meeting. 

Other highlights in terms of 2012 meetings to be mentioned here are the IVS VLBI2010 Workshop on Technical Specifications (TecSpec), in Bad Kötzting/Wettzell 

(Germany), March 1–2, 2012, http://www.fs.wettzell.de/ 

veranstaltungen/vlbi/tecspec2012/index.html and the 1st 

International VLBI Technology Workshop, at MIT Haystack 

Observatory, October 22–24, 2012, http://www.haystack.

mit.edu/workshop/ivtw/.

In 2012 we were able to welcome several new components to the IVS family. Metsähovi Observatory (Finland) 

and Sejong Station (South Korea) became new Network 

Stations of the IVS. Shanghai Astronomical Observatory 

(SHAO, China) was approved as an IVS Correlator facility, while GFZ Potsdam (Germany) was approved as IVS 

Associate Analysis Center. I would like to thank all new 

components for their support and commitment.

Summary information about all IVS events and activities is available on the IVS homepage http://ivscc.gsfc.

nasa.gov and in the IVS Newsletters 32, 33, and 34. The 

Newsletter is an excellent means to transfer information 

to everybody. The editor team, Dirk Behrend, Hayo Hase, 

and Heidi Johnson, presented interesting and up-to-date 

information. They once again did an excellent job, which 

is highly appreciated. 

The “IVS Live” tool has been further refined. It provides 

excellent information about ongoing VLBI sessions and 

can be accessed at http://ivslive.obs.u-bordeaux1.fr/. 

Many thanks to the Laboratoire d’Astrophysique de 

Bordeaux and, in particular, to Arnaud Collioud for the 

continued support.

Personal remarks at the end

In November 2012 I moved from Vienna, where I have 

worked for about 13 years, to a new position as Head 

of Department 1 ‘Geodesy and Remote Sensing’ at 

Helmholtz Centre Potsdam – German Research Centre 

for Geosciences (usually called ‘GFZ Potsdam’). Being 

still full professor at TU Wien (on leave) I am now also a 

full professor and Head of Section ‘Satellite Geodesy’ at 

TU Berlin. At GFZ we have already started to establish a 

VLBI group chaired by Robert Heinkelmann which was 

approved as a new IVS Associate Analysis Center in 

December 2012. Our main goals are VLBI observation 

of satellites and spacecraft as well as co-location in 

space (i.e., VLBI, GNSS, SLR, and DORIS on the same 

satellite). As was already agreed in 2011 my duty as 

Acting IVS Chair would finish at the first IVS Directing 

Board (DB) meeting after the next IVS election (which 

took place at the end of 2012). Thus at the DB meeting 

in Metsähovi in March 2013 I completed my time as IVS 

Chair. Axel Nothnagel (University of Bonn, Germany) 

got elected as new IVS Chair. I wish him and the whole 

IVS family a lot of success for the future. 

Harald Schuh

IVS Chair’s Report Continued
Special Reports

13

Short Report of IVS Working Group 5 (WG5)

on Space Science Applications

- An IVS Perspective -

Axel Nothnagel1, Patrick Charlot2, Veronique Dehant3, Agnes Fienga4, Hayo Hase5, Lucia 

Plank6, Harald Schuh7

1

Institute of Geodesy and Geoinformation, University of Bonn, Germany

2Observatoire de Bordeaux, Bordeaux, France

3Royal Observatory of Belgium, Brussels, Belgium 

4Université de Franche-Comté, Institut UTINAM, Besançon, France

5

Bundesamt für Kartographie und Geodäsie, Germany

6Department of Geodesy and Geoinformation, Vienna University of Technology, Austria

7Department of Geodesy and Remote Sensing, GFZ German Research Centre for Geosciences, 

Potsdam, Germany

1. Introduction and Charter of WG5

The IVS Working Group on Space Science Applications (WG5) was established by the IVS 

Directing Board at its meeting in Bordeaux on 23 March 2009. The mandate of the WG5, its 

membership, and chairmanship have been reviewed by the IVS Board at its regular meetings.

The current mandate of the WG5 comprises the following tasks (from the charter for WG5):

 To investigate synergies in scientific and technological areas between the IVS core 

activities and VLBI experiments in application to planetary and space science missions.

 To determine areas of VLBI support of planetary and space science missions where 

experiments conducted by the IVS (possibly together with other VLBI networks) can be 

mutually beneficial.

 To investigate desirability and feasibility of establishing a mission-specific liaison 

between IVS and appropriate space agencies and organizations involved in planetary 

and space science missions.

 The WG5 is to be co-chaired by a member of the IVS Directing Board and an external 

expert. The WG5 is to be composed of up to 16 persons, at least half of which should be 

affiliated with IVS institutes.

The mandate of the WG5 was originally approved for the period of one year starting from April 

2009. Continuation of the activities of the WG5 beyond March 2010 has been suggested by the 

IVS Directing Board.

A summary of the studies and discussions within WG5 done so far will be given here.
14

2. Preamble

Observations of satellites and spacecraft by VLBI radio telescopes in general and the IVS 

network in particular will be important contributions to several scientific disciplines depending on 

their general missions and flight paths. The methods of observing these objects are based on 

either group delay or phase delay measurements, predominantly in differential VLBI (D-VLBI) 

mode or with the astrometric phase referencing method. 

Earth orbiters normally do not require observations by VLBI but these can be used in an ideal 

fashion to link the dynamical reference frames of the satellites with terrestrial and, most 

importantly, to the celestial reference frame as defined by the positions of quasars. Spacecraft 

en-route to the moon and subsequently orbiting the moon and possibly also landing on the moon 

can be and have been observed by VLBI with great success already (e.g., Goossens et al. 

2011). The same applies to various spacecraft and missions to planets and outer space, mainly 

observed by the NASA Deep Space Network (e.g., Border 2009).

This summary describes the perspectives of future missions, possible implications, and the 

potential involvement of the IVS. The activities of the IVS in this field are not limited to providing 

the observations and initial data processing but also contain scientific data analysis and 

interpretation.

3. Missions

3.1 Artificial Earth Orbiters

A variety of spacecraft is in orbit around the Earth for a multitude of applications. All of them 

communicate on radio frequency links and may be observable with radio telescopes, thus, also 

being candidates for VLBI observations. Satellites with dedicated transmitters or even quasarlike beacons are another class of targets to be considered, e.g. GRASP (Nerem et al. 2011) or 

MicroGEM (Wickert et al. 2008, Brieß et al. 2009).

Observing these satellites with VLBI will provide invaluable information for geodetic and 

astrometric applications. The geodetic challenges of artificial Earth orbiters are closely related to 

the establishment and maintenance of reference systems. While in geodetic practice, station 

coordinates are usually provided in the kinematic International Terrestrial Reference Frame 

(ITRF) and radio source coordinates in the International Celestial Reference Frame (ICRF), 

positioning of space probes or the determination of planetary ephemerides rests upon dynamical 

theories. The link between these systems can only be established and maintained with VLBI 

observations of the spacecraft and preferably relative to radio sources of the ICRF.

As most of the modern geodetic techniques make use of sensors and targets in extra-terrestrial 

space, the main challenges for applications on Earth today are to interlink the underlying 

reference frames to guarantee accuracies at the mm-level with a stability of better than 0.1 

mm/y. For example, orbits of GNSS (Global Navigation Satellite Systems) satellites are linked to 

a certain ITRF realization of observing stations on the Earth’s surface. To avoid inconsistencies 

and errors during measurement and calculation procedures, exact frame ties between quasiinertial, kinematic, and dynamic reference frames have to be secured. By observing space 

probes alternately to radio sources with the differential Very Long Baseline Interferometry (DVLBI) method, the relative positions of the targets to each other on the sky can be determined. 

As the directions to the radio sources are well known in the ICRF, it is possible with such 

observational configurations to link the bodies within our solar system with the ICRF. While the 

Earth orientation parameters (EOP), which are regularly provided by the International Earth 
15

Rotation and Reference Systems Service (IERS), practically link the ICRF to the ITRF, the ties 

with the dynamic frames will be established by D-VLBI observations. 

Dynamic reference frames are typically realized for each individual satellite or satellite 

constellation by numerical orbit integration. When it comes to the combination of various 

missions or follow-on satellites (e.g., the various altimetry missions), precise ties between the 

various frames are essential for correct and reliable results over long time periods, needed, for 

instance, for monitoring global change and climate variation. A typical example for such a need 

of consistency is the derivation of sea level heights from the altimetry missions Topex/Poseidon, 

Jason-1, and Jason-2, which contain a bias for each satellite that has to be removed before 

trends of global sea level can be determined. Today, altimeter satellites are tracked by Satellite 

Laser Ranging (SLR) ground stations and D-VLBI observations can provide complementary 

information.

3.1.1 Low Height Earth Orbiters

From a VLBI observational point of view, near-Earth orbiters are rather challenging since mutual 

visibility depends on the altitude of the satellite and the separation of the radio telescopes. 

Furthermore the satellites travel through the field of view very fast requiring radio telescopes with 

sufficient speed, which will, however, be guaranteed by usage of radio telescopes of the 

VLBI2010 class. For these satellites, continental-size VLBI observing networks are essential.

3.1.2 Medium Height Earth Orbiters

Global Navigation Satellite Systems (GNSS) are the overall representatives of medium height 

Earth orbiters. They have been observed with VLBI successfully in recent years (Tornatore and 

Haas 2009, Tornatore et al. 2011) and will permit a direct link between the terrestrial, the 

dynamical, and the celestial reference frames. The common field of view of two or more radio 

telescopes is extended for medium height Earth orbiters.

3.1.3 Geostationary Orbiters

Normally, geostationary orbiters do not have noteworthy importance in geodetic applications. 

However, in terms of reference frames, these satellites also deserve a closer look and some 

efforts to evaluate their importance in reference frame studies and time transfer applications. 

Observations and analysis of geostationary orbiters are hampered by frequent maneuvers to 

keep the orbiter in its preset box in the sky. Thus, the orbits themselves cannot be considered as 

being smooth over time.

3.2 Missions to the Moon

VLBI observations of orbiters of the moon have contributed important information for the 

determination of orbits and trajectories of spacecraft in the vicinity of the moon. In the future, 

VLBI will also help to position landers on the moon. As for Earth orbiters, these observations will 

be used to map the Moon into the known hierarchy of the established reference systems. All the 

lunar missions mentioned below may have valuable VLBI observation components.
16

SMART-1 was ESA's first mission to the moon. The purpose of tracking this satellite with VLBI 

methods was a demonstration of its capabilities in space applications during critical events, like 

the precise timing and location determination of the impact on September 3, 2006 (JIVE , 2008).

KAGUYA/SELENE. A significant milestone in lunar geodesy has been reached with the 

successful implementation of the Japanese SELENE (SELenological and ENgineering Explorer) 

mission, launched on September 14, 2007. SELENE consists of three satellites: a main satellite 

(MS), a relay satellite (RS), and a VLBI sub-satellite (VS), all three inserted in a coplanar orbit 

with an inclination near 90°. The MS had an initial 100-km-altitude circular orbit controlled by 

attitude maneuvers, while the RS and VS are free flyers on highly eccentric orbits with 100/880 

km and 100/2400 km perigee and apogee, respectively. Besides other observing methods, 

same-beam differential VLBI tracking (projected accuracy 1 mm integrated over 100 sec) 

between RS and VS was used to precisely determine the RS orbit, which serves as the 

reference for the four-way Doppler measurements. 

The overall goal of Kaguya/Selene is to derive an improved version of the lunar gravity field. 

After successfully orbiting the moon for 1 year and 8 months, the main orbiter was intentionally 

crashed onto the lunar surface on June 10, 2009. Data analysis is still continuing to this day 

(e.g., Ando et al. 2012).

For the future, a so-called inverse VLBI experiment is proposed (where artificial radio sources 

are located either in two landers or in one lander and the orbiter) for the lunar landing mission 

SELENE-2 (Kikuchi et al., 2010). 

Lunar Reconnaissance Orbiter Mission. NASA’s Lunar Reconnaissance Orbiter (LRO) was 

launched on June 18, 2009, and began its nominal mission on September 15. The spacecraft is 

orbiting the moon in a circular polar orbit at a mean altitude of 50 km through its one-year 

“primary mission”, followed by a multi-year “science mission” in a modified elliptic orbit. Accurate 

lunar 3D-orbits of such orbiters are a prerequisite for the processing of imaging or altimetry data. 

Although techniques exist to improve lunar orbits from camera data and altimetry crossovers, in 

general the quality of the orbits plays a significant role in the realization of the lunar reference 

frame (http://lro.gsfc.nasa.gov/).

GRAIL. The US-mission GRAIL (Gravity Recovery and Interior Laboratory), launched on 

September 10, 2011, realizes the concept of inter-satellite, high-precision ranging in a planetary 

orbit for the first time. GRAIL’s science objectives include the mapping of the gravity field for 

studies of lunar interior, thermal evolution, and tidal dynamics (Zuber et al., 2008). GRAIL 

consists of two spacecraft in lunar orbit, tracked by S-band from Earth and connected by Kaband ranging derived from the GRACE concept. 

LEO, Lunar version of GRACE. In 2007, DLR (German Aerospace Center) suggested to 

establish the German lunar-orbiting mission LEO (Lunar Explorations Orbiter, Jaumann et al., 

2007) for comprehensive studies of the Moon, including for mapping of lunar magnetic and 

gravity fields. Flechtner et al. (2007, 2008) proposed to include a GRACE-type experiment with 

LEO, consisting of two sub-satellites to be released from LEO in lunar orbit and to be tracked 

from Earth by the two-way, two-frequency (X/S-band) precise range and range-rate (PRARE-L) 

system. Moreover, Ka-band ranging was chosen to realize a high-precision (projected accuracy 

2.5 μm/s) link between the sub-satellites. Aside from the lunar gravity field, the science 
17

objectives of this experiment included geophysical parameters like crustal density, Love 

numbers and contributions to the reference system. The LEO mission has not been realized yet.

Remark: The US-German twin-satellite mission GRACE (Gravity Recovery and Climate 

Experiment) may be used as a predecessor for lunar and planetary missions applying similar 

concepts. GRACE (Tapley and Reigber, 2001) has two identical spacecraft using an 

intersatellite K-band ranging link with μm-accuracy. It was primarily designed to map the static 

and time-variable gravity field and has provided excellent results allowing the determination of 

mass transport within system Earth. The GRACE Follow-on satellites have been approved and 

according to present schedule will be launched in 2017.

3.3 Missions to Planets, Comets, and Other Bodies

Since the 1980s the National Aeronautics and Space Administration (NASA), the European 

Space Agency (ESA), and recently also the Japan Aerospace Exploration Agency (JAXA) have 

performed D-VLBI observations during their (deep) space missions, generating data that can 

also be used to establish precise frame ties to major celestial frames (e.g. Hildebrand et al., 

1994). Another potential network to carry out D-VLBI and suitable for spacecraft navigation is the 

Very Long Baseline Array (VLBA); see Lanyi et al. (2005). An interesting development is the 

plan of the Deep Space Network to move to the 32 GHz band for spacecraft tracking (which 

provides higher telemetry rates) while the astrometric community is also considering to adopt 

higher observing frequencies (up to 43 GHz) yielding better accuracies due to reduced source 

structure effects (Lanyi et al. 2010, Charlot et al. 2010, García-Miró et al. 2012). Some efforts in 

the development and application of phase-connection techniques are also of interest (Marti-Vidal 

et al., 2008).

The term D-VLBI comprises the determination of a relative position using differential 

observations in order to minimize common error sources like atmospheric propagation delays, 

antenna-specific delays, and station position inaccuracies. The configuration of the character of 

the spacecraft tone, the observed frequency, the antenna size, the observation network, and the 

achieved accuracy vary between different realizations of D-VLBI, as described by Lanyi et al. 

(2007). A very well developed technique performed routinely by NASA and ESA is the so-called 

Delta Differential One-way Ranging (ΔDOR) employing antennas of the Deep Space Network 

(DSN). Mainly used to support precise spacecraft navigation at the level of some nrad (e.g., 

Martin-Mur et al., 2006), Mars spacecraft VLBI measurements (Mars Global Surveyor, Mars 

Odyssey, Mars Reconnaissance Orbiter) tie the planetary ephemerides to the ICRF with an 

accuracy better than 1 mas (= 5 nrad) (Folkner, 2008). The reliance on special DOR-tones 

transmitted by the spacecraft, the need of big antennas with special receiving units, and an 

accuracy regulated by the group delay measurement disqualifies ΔDOR for many observations 

other than to deep space probes. Recent successful D-VLBI observations using the phase 

referencing technique of, for instance, ESA’s Huygens probe landing on Titan (van ’t Klooster, 

2005) or within JAXA’s lunar gravity mission SELENE (Liu et al., 2010) managed to overcome 

those restrictions. This opened up a wide range of new applications and initiated further 

research in D-VLBI. With the Planetary Radio Interferometry and Doppler Experiment (PRIDE), 

an initiative by the Joint Institute for VLBI in Europe (JIVE), Duev et al. (2012) present the VLBI 

spacecraft technique which has been successfully tested observing ESA’s Venus Express 

Spacecraft. Working with almost any phase-stable radio signal from a spacecraft, observed in 

phase referencing mode, the PRIDE approach is applicable to virtually any deep space mission, 

as well as to planetary science missions and near-Earth targets (Duev et al., 2012). 
18

VLBI tracking of Cassini, VenusExpress or MarsExpress have been already successfully used 

for the orbit reconstruction of the spacecraft during their flyby or orbital phases. As demonstrated 

by Folkner et al. (1994), the relative positions of the spacecraft observed in the projected vicinity 

of an extragalactic radio source with its position defined in the ICRF provide strong angular 

constraints for the spacecraft orbit but also for the planetary ephemerides. VLBI S/C

observations are used in the adjustment of the planetary ephemerides. Even if very few VLBI 

data are used so far (about 0.25% of the total amount), they are the only accurate link between 

the orbits of the planets and the ICRF. Because of this, they are absolutely crucial for the 

construction of planetary ephemerides in the ICRF as required by the International Astronomical 

Union.

3.4 Spacecraft in Transit to Outer Space

Flybys of planets by spacecraft in transit to outer space are also a good source of information. 

Owing to the vicinity of the probe and its accurate tracking during this crucial phase of the 

mission, together with VLBI tracking, it is possible to deduce very accurate positions of the 

planet as the probe passes by. For gas planets, this type of observations puts a major constraint 

on their orbits (flybys of Jupiter and Saturn, mainly). Even if they are not numerous (less than 

0.5% of the data sample), they impose 50% of the constraints brought to the Jupiter and Saturn 

orbits. As an example, the New Horizons mission flew by Jupiter at a distance closer than that 

achieved by Cassini from which the positions of Jupiter have been deduced in late 2000 by JPL. 

The analysis of the New Horizons radio science data during its flyby of Jupiter with an accuracy 

below 10 meters in geocentric distances and 5 mas in right ascension and declination give new 

very accurate constraints for the Jupiter orbit.

Precise ephemerides of the planets have been computed at various different institutions 

(Development Ephemeris (DE), JPL, see Folkner et al. 2008, Ephemerides of Planets and the 

Moon (EPM), IAA, see Pitjeva 2005, Integration Numerique Planetaire de l’Observatoire de Paris 

(INPOP), see Fienga et al. 2008) and are updated in current projects using tracking or 

navigation data from orbiting spacecraft or from flybys. These observations are also essential 

tools for monitoring the gravitational and non-gravitational forces affecting the spacecraft 

trajectory. These data enable the determination of planetary gravity fields with their time 

variations and the interpretation of the results in terms of geophysics and dynamics of solar 

system objects. 

4. Involvement of the IVS in Space Missions

The operation of the IVS observing network and the distribution of the correlator load are 

controlled by the IVS Observing Program Committee (OPC). The OPC decides on observing 

proposals on the basis of scientific and operational merit according to the general rules of the 

IVS as set forth in the IVS Terms of Reference. Furthermore, the OPC discusses with the 

observatories and correlators involved whether observations can be carried out for the specific 

purpose of the proposal.

It is expected that proposals for future VLBI observing campaigns related to space science 

applications which require the involvement of one or more of the IVS components will be 

handled in the same objective resource-responsible manner. The benefits of scientific or 

possibly also economic developments which may help to maintain the IVS’s infrastructure will 

remain the driving force behind any decision.
19

5. Concluding Remarks

The application of the VLBI technique for observing spacecraft is a valuable contribution to 

support space science applications as has been demonstrated by completed and ongoing 

projects. In the future, forthcoming missions will also draw from the strengths of the VLBI 

technique in general and from the expertise of VLBI scientists in particular. Geodetic and 

astrometric VLBI bears good chances for further developments in the area of space sciences 

and will provide ample opportunities for synergies. On the other hand, VLBI itself will benefit 

from space science applications due to external demand for technical progress and due to 

increased visibility in the science community.

6. References

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Noda H, Liu Q, Oyama KI, Yamamoto Z, Saito A; Dual-spacecraft radio occultation measurement of 

the electron density near the lunar surface by the SELENE mission; JGR Vol. 117, A8, DOI: 

10.1029/2011JA017141, 2012.

Border JS; Innovations in delta differential one-way range: from Viking to Mars Science Laboratory. Proc. 

21st Int. Sym. Space Flight Dynamics, Toulouse, France;

http://issfd.org/ISSFD_2009/OrbitDeterminationI/Border.pdf, 2009.

Brieß K, Kornemann G, Wickert J; MicroGEM – Microsatellites for GNSS Earth Monitoring, 

Abschlussbericht Phase 0/A, Helmholtz-Zentrum Potsdam Deutsches GeoForschungsZentum GFZ 

und Technische Universit ̈at Berlin, 2009.

Charlot P, Boboltz DA, Fey AL, Fomalont EB, Geldzahler B, Gordon D, Jacobs CS, Lanyi GE, Ma C, 

Naudet CJ, Romney JD, Sovers OJ, Zhang LD; The Celestial Reference Frame at 24 and 43 GHz: II. 

Imaging, Astron. J., 139, 1713-1770, 2010.

Duev DA, Molera Calvés G, Progrebenko SV, Gurvits LI, Gimó G, Bocanegra Bahamon T; Spacecraft 

VLBI and Doppler tracking: algorithms and implementation. A&A 541, A43, 2012.

Fienga A, Manche H, Laskar J, Gastineau M; NPOP06: a new numerical planetary ephemeris, A&A Vol. 

477, p. 315-327, 2008.

Folkner WM, Charlot P, Finger MH, Williams JG, Sovers OJ, Newhall XX, Standish EM Jr.; Determination 

of the extragalactic-planetary frame tie from joint analysis of radio interferometric and lunar laser 

ranging measurements. A&A, 287, 279-289, 1994.

Folkner WM, Williams JG, Boggs DH; The Planetary and Lunar Ephemeris DE421. Memorandum IOM 

343R-08-003, Jet Propulsion Laboratory, 2008.

García-Miró C, Clark JE, Horiuchi S, Jacobs CS, Romero-Wolf A, Snedeker LG, Sotuela I; The X/Ka-band 

Extragalactic Reference Frame, IVS 2012 General Meeting Proceedings, Eds. Dirk Behrend and Karen 

D. Baver, NASA/CP-2012-217504, p. 347-351, 2012.

Goossens S, Matsumoto K, Rowlands D, Lemoine FG, Noda H, Araki H; Orbit determination of the 

SELENE satellites using multi-satellite data types and evaluation of SELENE gravity field models. J 

Geod 85:487-504, 2011.

Hildebrand CE, Iijima BA, Kroger PM, Folkner WM, Edwards CD; Radio-Planetary Frame Tie From 

Phobos-2 VLBI Data. In TDA Progress Report, Jet Propulsion Laboratory, Pasadena, 42-119, 1994.

JIVE Research Note #0011: VLBI Observations of the Huygens Probe, 2008.

Kikuchi, F., et al., Picosecond accuracy VLBI of the two subsatellites of SELENE (KAGUYA) using 

multifrequency and same beam methods. In Radio Science, 44, RS2008, doi:10.1029/2008RS003997, 

2009.
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Lanyi G, Border J, Benson J, Dhawan V, Fomalont E, Martin-Mur T, McElrath T, Romney J, Walker C;

Determination of Angular Separation Between Spacecraft and Quasars with the Very Long Baseline 

Array. In IPN Progress Report, Jet Propulsion Laboratory, Pasadena, 42-162, 2005. 

Lanyi G, Bagri D, Border J; Angular Position Determination of Spacecraft by Radio Interferometry. In Proc 

IEEE, Vol. 95(11), 2193-2201, 2007.

Lanyi GE, Boboltz DA, Charlot P, Fey AL, Fomalont EB, Geldzahler B, Gordon D, Jacobs CS, Ma C, 

Naudet CJ, Romney JD, Sovers OJ, Zhang LD; The Celestial Reference Frame at 24 and 43 GHz: I. 

Astrometry, Astron. J., 139, 1695-1712, 2010.

Liu Q, et al., Same-beam VLBI observations of SELENE for improving lunar gravity field model. In Radio 

Science, 45, RS2004, doi:10.1029/2009RS004203, 2010.

Martin-Mur T, Antreasian P, Border J, Benson J, Dhawan V, Fomalont E, Graat E, Jacobson R, Lanyi G, 

McElrath T, Romney J, Walker C; Use of very long baseline interferometric data for spacecraft 

navigation. In Proc 25th Int. Symp. Space Technol. Sci. (ISTS)/19th Int. Symp. Space Flight Dyn. 

(ISSFD), Kanazawa, Japan, Jun. 4-11, paper 2006-d-50, 2006. 

Marti-Vidal I, Marcaide JM, Guirado JC, Perez-Torres MA, Ros E; Absolute kinematics of radio source 

components in the complete S5 polar cap sample. III. First wide-field high-precision astrometry at 15.4 

GHz. In Astronomy and Astrophysics, Vol. 478, Issue 1, pp. 267-275, Jan. IV 2008.

Nerem R, Bar-Sever YE, Grasp Team; The Geodetic Reference Antenna in Space (GRASP) - A Mission 

to Enhance the Terrestrial Reference Frame; American Geophysical Union, Fall Meeting 2011, 

abstract #G51B-04; 2011AGUFM.G51B..04N, 2011.

Pitjeva EV; High-Precision Ephemerides of Planets - EPM and Determination of Some Astronomical

Constants, SoSyR, Vol. 1, p. 176-186, 2005. 

Tornatore V, Haas R; Considerations on the observation of GNSS-signals with the VLBI2010 system. 

Proceedings of the 19th European VLBI for Geodesy and Astrometry Working Meeting, 24-25 March 

2009, Bordeaux, pp. 151-155, 2009. 

Tornatore V, Haas R, Duev D, Pogrebenko S, Casey S, Molera-Calves G, Keimpema A; Single baseline 

GLONASS observations with VLBI: data processing and first results. Proceedings of the 20th Meeting 

of the European VLBI Group for Geodesy and Astrometry, Schriftenreihe des Inst. f. Geodäsie u. 

Geoinformation, 22, Bonn, 162-165, 2011. 

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Kilometer Distance. In 2005 5th International Conference on Antenna Theory and Techniques, 24-27 

May, Kiev, 2005. 

Wickert J, Arras C, Ao CO, Beyerle G, Falck C, Grunwaldt L, Healy SB, Heise S, Helm A, Huang CY, 

Jakowski N, König R, Mannucci T, Mayer C, Michalak G, Poli P, Rothacher M, Schmidt T, Stosius R,

Tapley B; CHAMP, GRACE, SAC-C, TerraSAR-X/TanDEM-X: Science results, status and future 

prospects; GRAS SAF Workshop on Applications of GPSRO Measurements, 16-18 June 2008, 43-52.
MIT Haystack Observatory VLBI DBE Test Report

VLBI Digital-Backend Intercomparison Test Report

Alan Whitney, Christopher Beaudoin, Roger Cappallo, Arthur Niell, Bill Petrachenko,

Chester A. Ruszczyk, Mike Titus

Abstract

Issues related to digital-backend (DBE) systems can be difficult to evaluate in either local tests

or actual VLBI experiments. The 2nd DBE intercomparison workshop at Haystack Observatory on

25-26 October 2012 provided a forum to explicitly address validation and interoperability issues among

independent global developers of DBE equipment. This special report discusses the workshop. It

identifies DBE systems that were tested at the workshop, describes the test objectives and procedures,

and reports and discusses the results of the testing.

1. Introduction

As VLBI expands the scope of digital signal-processing in VLBI systems, it is important that

each sub-system be validated for proper function and interoperability. While every VLBI developer

strives to ensure that these criteria are met, it is often only by comparison that problems can be

uncovered. One area of particular interest is digital-backend (DBE) systems, where some issues are

difficult to evaluate in either local tests or actual VLBI experiments. The 2nd DBE intercomparison

workshop at Haystack Observatory on 25-26 October 2012 provided a forum to explicitly address

validation and interoperability issues among independent global developers of DBE equipment,

and it built on the work of the first such workshop held at Haystack Observatory in May 2009.

The 2012 workshop took advantage of the completion of a new Instrumentation Lab at Haystack

Observatory that provided the space and signal connections needed to efficiently support the

comparison exercise.

2. The DBE Systems

Five systems were assembled at Haystack for testing1:

1. The European ‘DBBC’ system, configured as a polyphase filter bank (PFB) converter2,

hereafter referred to as ‘DBBC-PFB’.

2. The Chinese VLBI Data Acquisition System (CDAS) configured as 16 tunable DDCs, hereafter referred to as ‘CDAS-DDC’.

3. The CDAS with polyphase filter-bank signal processing, hereafter referred to as ‘CDAS-PFB’.

The CDAS-PFB is a separate hardware unit from the CDAS-DDC.

4. The Japanese ‘ADS3000+’ system configured with 16 tunable DDC processors.

1The DBBC was accompanied by Gino Tuccari of INAF/IRA and Michael Wunderlich of MPIfR. The CDAS

units were designed by Drs. Hong Xiaoyu, Zhang Xiuzhong, Wei Wenrun, Xiang Ying, Li Bin, Shu Fengchun, Zhu

Renjie, Zhao Rongbing, Ling Quanbao, Wu Yajun, Wang Jinqing, Xue Zhuhe, Luo Jintao (all SHAO), and Chen

Lan (now at Shanghai Institute of Technology). The ADS3000+ was accompanied by Hiroshi Takeuchi of JAXA

and Kazuhiro Takefuji of National Institute of Information and Communications Technology. The RDBE-H was

overseen by Haystack staff Chester Ruszczyk, Russ McWhirter, and Arthur Niell.

2The DBBC system can also be configured in a DDC configuration, which was successfully tested at the 2009

DBE intercomparison workshop but was not tested at this workshop.

IVS 2012 Annual Report 21
VLBI DBE Test Report MIT Haystack Observatory

5. The Haystack ‘RDBE-H’ PFB system, with hardware designed by UCBerkeley and NRAOSocorro, and with firmware from Haystack and NRAO. The RDBE was configured with

FPGA code version 1.4.

A detailed comparison of the systems under test, based on information gathered by Bill Petrachenko, is found in Table 1.

3. Test Objectives

The test objective was to ensure, as much as possible, that all DBE units were operating

properly, including both functional and interoperability criteria. This was done by providing all

units with a common frequency reference, 1pps timing signal, and broadband noise source spanning

approximately 100 MHz to 2 GHz. For some testing, embedded test tones at IF frequencies 575

MHz and 961 MHz were added to the broadband noise source. The testing was divided into three

specific phases:

1. Verification of compatibility with laboratory interfaces, command and control functionality,

and digital-output format compatibility.

2. Single baseline cross-correlation test of each unit paired with RDBE-H unit; all station autocorrelations.

3. Simultaneous four-station zero-baseline cross-correlation of all six possible station pairs; all

station auto-correlations.

4. Test Procedures

4.1. DBE Unit Setup First Day (Day 299)

Initial setup included basic testing of the compatibility of lab interfaces with equipment under

test, including test recordings and verifications of recorded format, etc. Nearly the full first day of

testing was devoted to this type of activity, but it resulted in the successful interfacing of all the

units and successful basic operation of all units.

Prior to any testing, the units under test were set up as follows:

1. All units were supplied with a common 5 or 10 MHz reference frequency, as required.

2. All units were synchronized to a common TTL 1pps timing reference.

3. All units were set to identical UT times, as required.

4. IF levels were set appropriately by adjusting the amplification or attenuation to each unit

under test.

5. Temporary test tones at 575 MHz and 961 MHz were injected into the IF as test markers

(which were subsequently turned off after it was determined that the marker frequencies were

appearing in the expected output channels via auto-correlation processing).

6. The CDAS-PFB and CDAS-DDC units were each connected to a Mark 5B+ with a VSI-H

interface operating at a 64 MHz clock rate.

22 IVS 2012 Annual Report
MIT Haystack Observatory VLBI DBE Test Report

7. The RDBE-H produced 10GigE data in Mark 5B data format and was connected to a Mark

5C.

8. The DBBC produced Mark 5B data format over either a VSI-H interface to a Mark 5B+

recorder or a 10GigE interface (via Fila10G card) to a Mark 5C.

9. The ADS3000+ was connected to a K5 recorder and recorded in K5 format. The data were

software-converted to Mark 5B format prior to correlation.

Each DBE unit under test included at its input a 512-to-1024 MHz anti-aliasing filter to place

the recorded signal in the second Nyquist zone of the DBEs. The sampling clock for all units was

1024 MHz.

Figure 1. Relationship between input IF and digital output channels for PFB units.

4.2. Pairwise Zero-baseline Cross-correlation Tests - First Day

Following successful setup, auto-correlation and single-baseline cross-correlation tests were conducted with each unit using the RDBE-H as a reference unit. (The DBBC was tested separately

with both VSI-H and Fila10G output formats.) The DBEs using a polyphase filter bank, namely

RDBE, DBBC and CDAS-PFB, were configured to produce 15 useful 32 MHz baseband channels,

each of which was lower sideband (LSB) with respect to the input IF (i.e. sky frequency increases

in opposite direction to the IF). The frequencies that appear at DC for the 15 good channels were

1008,..., 528 MHz in steps of 32 MHz (see Figure 1). The PFB algorithm causes the 0th channel

to be unusable, as indicated in Figure 1. The DBEs with flexible LOs, namely CDAS-DDC and

ADS3000+ were set up with compatible channels.

For each pairwise test, ∼30 seconds of data were recorded, followed by e-transfer to standard

Linux files, followed by auto-correlation and cross-correlation processing on the Haystack DiFX

correlator. For each station pair, auto-correlation spectra were created for each station, as well as

the zero-baseline cross-correlation results.

IVS 2012 Annual Report 23
VLBI DBE Test Report MIT Haystack Observatory

4.3. Four-station Zero-baseline Cross-correlation Tests - Second Day (Day 300)

A four-station zero-baseline cross-correlation test captured simultaneous data using the common broadband IF noise source to all systems under test. The setup is shown in Figure 2, where

the broadband noise input is labeled ‘IF’ and Nyquist zone 2 filters are assumed to be internal to

the individual DBE units.

Figure 2. Setup for the zero-baseline inter-comparison test.

As before, 30 seconds of data were recorded from all four units simultaneously (with the DBBC

unit operating in DDC mode with 10GigE output). No test tones were injected into the IF. The

data were again e-transferred to standard Linux files, and the six cross-correlation pairs were

processed on the DiFX correlator.

5. Results and Discussion

5.1. Auto-correlation Results (Figures 3 through 7)

All auto-correlation scans shown were with all test tones turned off.

Auto-correlation results shown for RDBE-H, ADS3000+ and DBBC are from Day 300 (scan

300-1657). Auto-correlation results for CDAS-DDC and CDAS-PFB are from Day 2993

The only significant difference between the auto-correlation results of the four units under test

are the amplitude and spacing of ripples in the auto-correlation spectra, as well as the sharpness

of the cutoffs at the top and bottom of the bands. These differences should not present any

3The CDAS-DDC was not active on Day 300. Auto-correlation results for RDBE-H, ADS3000+, and DBBC-PFB

units are from the four-station scan 300-1657; auto-correlation results for CDAS-PFB for scan 300-1657 (not shown)

contain a number of anomalous ‘birdies’ (though these ‘birdies’, as expected, do not propagate to the associated

zero-baseline cross-correlation spectra). The cause of the ‘birdies’ is not known, but they were not present in the

CDAS-PFB Day 299 data and may not be intrinsic to the CDAS-PFB. Hence we have elected to show the Day 299

auto-correlation for the CDAS-PFB unit. Further testing will be required to investigate the cause of these ‘birdies’

in the CDAS-PFB spectra for scan 300-1657.

24 IVS 2012 Annual Report
MIT Haystack Observatory VLBI DBE Test Report

problems for geodetic-VLBI operation or analysis, and can, in any case, be calibrated and removed

if necessary.

The only problems in the set of auto-correlation of Figures 3 through 7 are in the CDASDDC spectra (Figure 7) that show a ‘birdie’ at mid-point in the auto-correlation spectra and a

drop in amplitude of channel h (which covers IF frequency range 752-784; see Figure 1); separate

processing of each 32 MHz output channel shows the ‘birdie’ to be only in channel h, which causes

the apparent spectra amplitude to drop. We speculate that this problem may be due to a rounding

bias in an interpolation step in the processing of that channel, but further testing is necessary to

fully understand this problem.

5.2. Cross-correlation Results (Figures 8 through 14)

All zero-baseline cross-correlation results look quite nominal except for the Day 299 singlebaseline result from the RDBE to CDAS-DDC (Figure 8), for which both correlation amplitudes

and phases differ widely from channel to channel. Further investigation of this result has been

inconclusive; post-correlation processing of single channels shows similarly low cross-correlation

amplitudes as well as channel-to-channel delay differences spanning a range of almost 30 nsec,

whereas equivalent delay differences among all other units (Figures 10-14) are all under ∼2 nsec.

It is possible that the RDBE unit was malfunctioning on the day of the test, but we have no

way to test this with only the single baseline of available data, and the RDBE unit behaved

well on the second day of testing. At this point, we can only suggest that perhaps some sort

of sampler jitter or digital-oscillator phase jitter in the CDAS-DDC may be responsible for the

low correlation amplitudes, and varying internal signal path lengths may be responsible for the

observed channel-to-channel delays; further testing is necessary. On the other hand, the CDASPFB unit, cross-correlated against DBBC-DDC, ADS3000+, and RDBE-H (as shown in Figures

10, 12 and 14, respectively) on Day 300 performed well despite observed ‘birdies’ in the CDAS-PFB

data in scan3.

6. Summary

After several weeks of preparation and two long days of testing, including correcting various

misunderstandings, fixing some hardware, and overcoming some internal networking problems, the

testing was quite successful. Only one unit was found to have apparent significant problems, and

another to have possible, more minor issues, and we hope that the results of this testing will help

to understand and fix these problems, allowing more confidence of proper results as these DBEs

move into routine VLBI observations.

This report is also available on-line at:

http://www.haystack.mit.edu/workshop/ivtw/2012.12.17 DBE testing memo final.pdf

Acknowledgements

We thank everyone who participated. We hope that this exercise was useful for all of the

participants, and we at Haystack were happy to be able to help support this effort.

IVS 2012 Annual Report 25
VLBI DBE Test Report MIT Haystack Observatory

Figure 3. Auto-correlation results for RDBE-H version 1.4 (PFB algorithm).

26 IVS 2012 Annual Report
MIT Haystack Observatory VLBI DBE Test Report

Figure 4. Auto-correlation results for DBBC-PFB w/Fila10G.

IVS 2012 Annual Report 27
VLBI DBE Test Report MIT Haystack Observatory

Figure 5. Auto-correlation results for ADS3000+ (DDC algorithm).

28 IVS 2012 Annual Report
MIT Haystack Observatory VLBI DBE Test Report

Figure 6. Auto-correlation results for CDAS-PFB.

IVS 2012 Annual Report 29
VLBI DBE Test Report MIT Haystack Observatory

Figure 7. Auto-correlation results for CDAS-DDC.

30 IVS 2012 Annual Report
MIT Haystack Observatory VLBI DBE Test Report

Figure 8. Zero-baseline cross-correlation results between RDBE-H and CDAS-DDC.

IVS 2012 Annual Report 31
VLBI DBE Test Report MIT Haystack Observatory

Figure 9. Zero-baseline cross-correlation results between RDBE-H and ADS3000+

32 IVS 2012 Annual Report
MIT Haystack Observatory VLBI DBE Test Report

Figure 10. Zero-baseline cross-correlation results between DBBC-PFB w/Fila10G and CDAS-PFB

IVS 2012 Annual Report 33
VLBI DBE Test Report MIT Haystack Observatory

Figure 11. Zero-baseline cross-correlation results between DBBC-PFB w/Fila10G and ADS3000+.

34 IVS 2012 Annual Report
MIT Haystack Observatory VLBI DBE Test Report

Figure 12. Zero-baseline cross-correlation results between CDAS-PFB and ADS3000+.

IVS 2012 Annual Report 35
VLBI DBE Test Report MIT Haystack Observatory

Figure 13. Zero-baseline cross-correlation results between RDBE-H and DBBC-PFB w/Fila10G.

36 IVS 2012 Annual Report
MIT Haystack Observatory VLBI DBE Test Report

Figure 14. Zero-baseline cross-correlation results between RDBE-H and CDAS-PFB.

IVS 2012 Annual Report 37
VLBI DBE Test Report MIT Haystack Observatory

Table 1. DBE Feature Comparison.

Feature RDBE-H DBBC2010-8H8C CDAS ADS3000+

FPGA code version tested 1.4 14 1.0(PFB)/2.0(DDC) 10.06

IF’s/Unit 2 8 4 4

Ref Freq (MHz) 5 10 5 10

Sampler resolution(bits) 8 10 at ADC 8 10 at ADC/8 at FPGA

Input Gain Set Internal Internal Internal Select 4 bits

Sampler BW (MHz) 0-1536 0-3500 50 -1024 0-2500 (-3dB@1800)

Input BW (MHz) 512 1024 512 4 × 512

2 × 1024

1 × 2048

PFB - Channel BW (MHz) 32 32/64 32 -

PFB - Max # channels per IF 15 usable 31/15 usable 15 usable -

PFB - Channel selection Flexible (16 max) Flexible No (but planned) -

DDC - Channel BW (MHz) - 1/2/4/8/16 1/2/4/8/16/32 4/8/16/32

DDC - # per unit - 32 UL 16 16

DDC - Frequency resolution - 104(1e6/2

20)Hz 10kHz 1Hz

Requantization threshold (bits) 2 1, 2 or 4 1, 2 or 4 2 or 4

Real / Complex Data Output Yes / No Yes / Yes Yes / No Yes / Yes

Pcal / Total Pwr No/Yes Yes/Yes Yes/Yes No/No

Data Rate/Unit (Gbps) 2 32 2 2

Output Layer 10GigE 10GigE/VSI-H VSI-H VSI-H

Availability Commercial Commercial Small number Commercial

Availability Date Now Now Now Now

Upgradable Yes Yes No No

Cost/Unit US$18K 98.6K euros US$50K (DDC) US$40K

US$10K (PFB)

38 IVS 2012 Annual Report
39

VLBI2010 Receiver Back End Comparison

Bill Petrachenko

January 21, 2013

Introduction.

VLBI2010 requires a receiver back-end to convert analog RF signals from the 

receiver front end into channelized digital data streams to be recorded or 

transmitted electronically. The back end functions are typically performed in two 

steps: conversion of analog RF inputs into IF bands (see Table 2), and 

conversion of IF bands into channelized digital data streams (see Tables 1a, 1b 

and 1c). The latter IF systems are now completely digital and generically referred 

to as digital back ends (DBEs). 

In Table 2 two RF conversion systems are compared, and in Tables 1a, 1b, and 

1c nine DBE systems are compared. Since DBE designs are advancing rapidly, 

the data in these tables are only guaranteed to be current near the update date 

of this document.

DBE Comparison Table (Tables 1a, 1b, 1c)

In Tables 1a, 1b and 1c nine DBEs are compared. These include:

 Roach-based Digital Back End (RDBE): This DBE is the joint product of 

Haystack Observatory and the National Radio Astronomy Observatory 

(NRAO) with Haystack being responsible for the Polyphase Filter Bank 

(PFB) personality and NRAO for the Direct Digital Converter (DDC) 

personality. In the near term additional development work on the PFB 

personality continues at Haystack to add features such as PCAL detection 

and GNSS tick offset monitoring and to make a transition from real to 

complex mode and from Mk5B to VDIF output. In the longer term a 

bandwidth increase from 512 to 1024 MHz is planned in order to raise the 

VLBI2010 compliance from Half to Full. More information can be obtained 

from:

o Arthur Niell, Haystack Observatory, aniell@haystack.mit.edu

o Jon Romney, NRAO, jromney@aoc.nrao.edu

 DBBC2010-8L8C, DBBC2010-8H8C: This is an extension of the familiar 

DBBC2 developed by Gino Tuccari at INAF with boards added to handle 

the increased number of IF inputs specified for VLBI2010. The 8L8C 

version handles 512 MHz IF inputs, while the 8H8C version handles 1024 

MHz IF inputs. More information can be obtained from:

o Gino Tuccari, INAF/IRA, g.tuccari@ira.inaf.it

 CDAS-DDC and CDAS-PFB: These have been developed by a team led 

by Xiuzhong Zhang at Shanghai Astronomical Observatory. Work 

continues on both systems to improve compatibility with VLBI2010. In 

particular plans exist to increase the efficiency of the CDAS-DDC for 
40

VLBI2010. There is no planned commercial availability of the CDAS, but 

manufacture of a small number of units for use outside China may be 

possible. More information can be obtained from:

o Xiuzhong Zhang, Shanghai Astronomical Observatory, 

xzhang@shao.ac.cn

 ADS3000+: The ADS3000+ is a joint development of NICT, JAXA/ISAS, 

and COSMO RESEARCH Corp. It is a DDC based system but has modes 

compatible with VLBI2010 if enough systems are used. More information 

can be obtained from:

o Hiroshi Takeuchi, JAXA, takeuchi@isas.jaxa.jp

o Kazuhiro Takefuji, NICT, takefuji@nict.go.jp

 Russian Broadband Acquisition System (BRAS): The BRAS DBE is 

being developed at IAA by Evgeny Nosov. It outputs the entire 512 MHz 

input IF as a single 512 MHz wide channel. More information can be 

obtained from:

o Evgeny Nosov. E84@mail.ru

 JPL DBE: This DBE is being developed at JPL. It is mainly intended to 

support JPL VLBI activities related to deep space tracking in the Deep 

Space Network (DSN) including support of the X/Ka CRF. It has a unique 

two step channelization process where a 500 MHz input band sampled at 

1280 MHz uses a PFB to produce 8 160 MHz bands which are further 

subdivided using DDC to channels with programmable bandwidths of less 

than 32 MHz. More information can be obtained from:

o Eric Clark, JPL, jec@jpl.nasa.gov

 XCube StreamX-VLBI (VLBI-In-a-Box): This is a commercial system 

adapted to VLBI with support from NRAO and CSIRO and others. This 

system is a digital backend and data recorder in a single box. The system 

is configurable in terms of number of IO channels and FPGA and GPU 

compute resources. The base system has 4 bands at 512MHz with a PFB 

filter bank dividing it to 16, 32MHz bands. The system also has a RAW 

mode, and a GPU for software processing. It can be extended to 8 

Channels with an additional sampler card. The recorder part can operate 

up to 24Gbit/s recording to removable media, or send data over Ethernet. 

As a recorder the StreamX VLBI is compatible with other DBE. A DDC 

mode and a larger PFB, 16MHz bands, are planned. In addition, data 

monitoring, real-time spectrometer and more are available. More 

information can be obtained from:

o Mikael Taveniku, mtaveniku@x3-c.com

 It is possible that other DBEs exist that might be applicable to VLBI2010. 

However, at the time of preparation of this comparison, data were only 

available for these nine DBE’s.
41

Heading descriptions:

 VLBI2010 compliant: DBEs were qualified as either Half or Full

VLBI2010 compliant. Half compliant implies at least eight IF inputs of 512 

MHz, at least eight 32 MHz channel outputs per IF, and a total output data 

rate of at least 8 Gbps. Full implies at least eight IF inputs of 1024 MHz 

(could be 2*512 MHz), at least sixteen 32 MHz channels per IF, and a 

total output data rate of at least 16 Gbps.

 IF’s/Unit. This is the number of IF inputs per unit. It is one of the factors 

that determine the number of units needed per VLBI2010 system.

 Units/VLBI2010. This the number of units required for a VLBI2010 system 

(either Half or Full).

 Sampler Resolution (bits). This is the number of bits resolution per 

sample.

 Input Gain Set. This is either internal or external depending on whether or 

not digitally controlled variable attenuators are built into the system. [Note: 

In the case of the ADS3000+, the gain setting is done inside the FPGA by 

selecting the best 4 of 8 bits to continue in the processing.]

 Sampler Bandwidth (GHz). This is the maximum frequency that can be 

input into the sampler without significant degradation. It determines the 

highest Nyquist zone that can be used.

 Input Bandwidth (GHz). This is the bandwidth of each Nyquist zone, i.e. 

the bandwidth that is actually processed.

The next three inputs are applicable only for systems with PFB personalities. 

If a PFB personality does not exist, they are left blank.

 PFB – Channel Bandwidth (MHz). This is the bandwidth of each output 

channel.

 PFB – Max # of channels per IF. This is the maximum number of output 

channels. This should normally be calculated according to Input 

bandwidth/PFB Channel bandwidth.

 PFB – Channel Selection. This refers to the degree of flexibility in 

selecting channels to be routed to the output.

The next three inputs are applicable only for systems with DDC personalities. 

If a DDC personality does not exist, they are left blank.

 DDC – Channel Bandwidth (MHz). This is the bandwidth of each output 

channel.

 DDC – # per unit. This is the number of DDC output channels per unit.

 DDC – Frequency resolution. This refers to the degree of flexibility in 

selecting channels to be routed to the output.

 Requantization Threshold. How many bits per output sample.

 Real/Complex. Is the output available in real or complex format or both.

 PCAL/Total Power. Is there a Pcal and/or total power function.

 Total Data Rate. This is the total data rate for all units making up the 

VLBI2010 system.

 Output layer. VSI-H or 10GE
42

 VDIF. Is VDIF output format provided? [Note. In the case of the DBE’s 

with VSI-H outputs it is possible to generate VDIF output if these DBE’s 

are interfaced with a VDIF-compatible recorder of 10GE converter (e.g. K5 

recorder).]

 Availability. Is the DBE commercially available?

 Availability Date. At what date will the DBE be commercially available

 Upgradable. Can the VLBI2010 DBE be produced by upgrading a 

previous version of the DBE.

 Cost. Separated into the cost for a Full and/or Half system
43

Table 1a RDBE DBBC2010-

8L8C DBBC2010-8H8C

VLBI2010 

Compliant Half Half Full

IF’s/Unit 2 8 8

Units/VLBI2010 4 1 1

Sampler 

resolution (bits) 8 8

10 at ADC/

8 at FPGA

Input Gain Set Internal Internal Internal

Sampler BW 

(MHz) 0-1536 0-2200 0-3500

Input BW (MHz) 512 512 1024

PFB - Channel 

BW (MHz) 32 32 32/4

PFB – Max # 

channels per IF 

15 

(16 per unit)

15

(128 per unit)

31/15

(256/128 per unit)

PFB - Channel 

selection Flexible Flexible Flexible

DDC - Channel 

BW (MHz)

1/2/4/8/16/

32/64/128 1/2/4/8/16 1/2/4/8/16

DDC - # per unit 4/4/4/4/4/4/2/1 32 UL 32 UL

DDC – Frequency 

resolution (Hz)

250K

(15.625K)

10K

(1024e6/2^31)

10K

(2048e6/2^31)

Requantization 

threshold 2-bit 1-, 2-, or 4-bit 1-, 2-, or 4-bit

Real/Complex Yes/Yes(2013) Yes/Yes Yes/Yes

Pcal/Total Pwr Yes(2013)/Yes Yes/Yes Yes/Yes

Data Rate/Unit 

(Gbps) 2 16 32

Total Data Rate 

(Gbps) 8 16 32

Output Layer 10GE 10GE/VSI-H 10GE/VSI-H

VDIF (2013) Yes Yes

Availability Commercial Commercial Commercial

Availability Date Now Now Now

Upgradable Yes Yes Yes

Cost/Unit $18K 84.7K€ 98.6K€

Cost 

(Half VLBI2010) $72K 84.7K€ -

(Full VLBI2010) - - 98.6K€
44

Table 1b CDASDDC (China)

CDASPFB (China) ADS3000+ (Japan)

VLBI2010 

Compliant Yes (VSI-H) Yes (VSI-H) Yes (VSI-H)

IF’s/Unit 4 2 4

Units/VLBI2010 4(half)/8(full) 4(half)/8(full) 4(half)/8(full)

Sampler 

resolution (bits) 8 8

10 at ADC/8 at FPGA/ 

4 for processing

Input Gain Set Internal External Inernal (see note)

Sampler BW 

(MHz) 50 -1024 50 -1024 0-2500(-3dB@1800)

Input BW (MHz) 512 512

4 x 512

2 x 1024

1 x 2048

PFB - Channel 

BW (MHz) - 32 /64 -

PFB – Max # of 

channels per IF - 15/7 -

PFB - Channel 

selection - All -

DDC - Channel 

BW (MHz) 1/2/4/8/16/32 - 4/8/16/32

DDC - # of 

channels per unit 16 - 16

DDC – Frequency 

resolution (Hz) 1 (10K) - 1

Requantization 

threshold 1-,2- or 4-bit 1- or 2-bit 2- or 4-bit

Real/Complex Yes/No Yes/No Yes/Yes

Pcal/Total Pwr yes/yes No/yes no/no

Data Rate/Unit 

(Gbps)

2 (VLBI2010 

mode) 4 2 (VLBI2010 mode)

Total Output Rate 

(Gbps) 8(half)/16(full) 16(half)/32(full) 8(half)/16(full)

Output Layer VSI-H

(10GE soon)

VSI-H

(10GE soon)

VSI-H

(10GE soon)

VDIF With converter With converter With converter

Availability Small number Small number Commercial

Availability Date Now Now Now

Upgradable Yes Yes Yes

Cost/Unit $50K $10K $40K

Cost

(Half VLBI2010) $200K $40K $150K

(Full VLBI2010) $400K $80K $285K
45

Table 1c BRAS

(Russia)

JPL DBE 

(USA)

XCube

(USA)

VLBI2010 

Compliant Half Half Half/Full

IF’s/Unit 8 2 4/8(2013)

Units/VLBI2010 1 4 1 or 2

Sampler resolution 

(bits) 8

10 (8 used)

(@1280 Gsps) 8 (10 planned)

Input Gain Set Internal Internal External

Sampler BW (MHz) 0-1600 0-2000 50-1600

Input BW (MHz) 512 500 512

PFB - Channel BW 

(MHz) 512 160 for internal use only 32/16(2013)

PFB - Max # of 

channels per IF 1

8 for internal use 

only 16/32(2013)

PFB - Channel 

selection

NA (only one 

512 MHz 

band/IF)

All - but for 

internal use only

All – selectable 

IF

DDC - Channel BW 

(MHz) -

32 or less, 

programmable (2013)

DDC - # of 

channels per unit -

16 complex or 

32 UL

DDC – Frequency 

resolution (Hz) - -

Requantization 

threshold 2- to 8-bits - 2-bit

Real/Complex Yes/No Yes/Yes Yes/No(?)

Pcal/Total Pwr Yes/no Yes/Yes Software 

Programmable

Data Rate/Unit 

(Gbps) 8 2 8/16(32)

Total Output Rate 

(Gbps) 8 8 8/(16)

Output Layer 10GE 10GE Disk/10GE

VDIF - - (2013, software)

Availability Not commercial Not commercial Commercial

Availability Date Mid-2013 Oct 2013 Now

Upgradable NA NA NA

Cost/Unit NA NA $50/70K

(incl. recorder)

Cost

(Half VLBI2010) NA NA $50/$70K 

(incl. recorder)

(Full VLBI2010) NA NA $100K/($140K)
46

Flexible Down Converter Comparison Table (Table 2)

In Table 2, two flexible down-converters are compared. These include:

 UpDown Converter (UDC): This flexible down-converter was designed by 

Alan Rogers at Haystack Observatory. It is a traditional analog design. 

More information can be obtained from:

o AEE Rogers, Haystack Observatory arogers@haystack.mit.edu

 See Mk5 Memo’s 59 and 70.

 DBBC3: This flexible down-converter was designed by Gino Tuccari. It is 

a fully digital design with a high speed input sampler. More information 

can be obtained from:

o Gino Tuccari, INAF/IRA, g.tuccari@ira.inaf.it

Heading descriptions:

 VLBI2010 compliant: VLBI2010 flexible down-converters need to handle 

a pair of 2-14 GHz RF inputs (assumed to be both polarizations of the 

same signal), down-converting, with sub-MHz resolution, four pairs of 

1024 MHz (or 512 MHz for Half compliant) bands to a Nyquist zone for 

sampling.

 Units/VLBI2010. This is the number of units required for a VLBI2010 

system, i.e. the number of units needed to down-convert four pairs of 

bands.

 Sampler Resolution (bits). This is the number of bits resolution per 

sample.

 Input range (GHz). The input range is assumed to be 2-14 GHz for 

VLBI2010.

 BW per Output Band(GHz). This is assumed to be 512 MHz for Half

VLBI2010 compliant and 1024 MHz for Full compliant.

 Total # of outputs per RF input. This needs to be at least 4 for 

VLBI2010.

 Band selection step size. This needs to be at least sub-MHz, but for full 

compatibility with the original Haystack UpDown Converter this needs to 

be a sub-multiple of 0.4 MHz.

 Channel formation. Analog or digital.

 Total output rate. This is only meaningful for digital systems.

 Output layer. This is only meaningful for digital systems.
47

Table 2

Up-Down 

Converter 

(UDC)

DBBC3

VLBI2010 

Compliant

nearly (input 

range and 

output BW need 

adjusting)

Full

RF Inputs/Unit 2 4

Units/VLBI2010 4 1

Sampler 

resolution (bits) Analog 8 @ 28 Gsps

Input Range 

(GHz)

1-12

(2-14 planned) 0-14

BW per Output 

Band(MHz)

512

(1024 planned) 512/1024

Total # outputs 

per RF input 4 8

Band selection 

step size (MHz) 0.4 0.01

Channel 

Formation Analog DDC

Total Output Rate 

(Gbps) Analog 224 per IF

Output Layer Analog 40/100 GE

Commercially 

Available Possible orders possible in 2013

Availability Date TBD about 8 months 

after order

Upgradable Yes Yes

Cost/Unit $20-25K USD 30-35K€

Cost

(Full VLBI2010) $80-100K USD 30-35K€
48

VLBI2010 Feed Comparison

Bill Petrachenko

February 14, 2013

Introduction.

VLBI2010 requires a feed that simultaneously has high efficiency over the full 2.2−14 GHz frequency 

range. The simultaneity requirement implies that the feed must operate at high efficiency over the full 

frequency range without the need to adjust its focal position to account for frequency dependent phase 

centre variations. Two feeds meet this specification:

 The Eleven Feed developed at Chalmers University. (For more information, contact Miroslav 

Pantaleev, miroslav.pantaleev@chalmers.se. The Eleven Feed, integrated with LNA’s in a 

cryogenic receiver, is available as a product from Omnisys Instruments, info@omnisys.se).

 The Quadruple Ridged Flared Horn (QRFH) developed at the California Institute of Technology.

(For more information please contact Ahmed Akgiray, aakgiray@ieee.org or Sander Weinreb, 

sweinreb@caltech.edu)

Although not VLBI2010 compliant, two triband S/X/Ka feeds are also being developed for the

commissioning of VLBI2010 antennas, for S/X observations during the VLBI2010 transition period, and to 

support X/Ka CRF observations. The two feeds are:

 The Twin Telescopes Wettzell (TTW) triband feed developed by Mirad Microwave. (For more 

information please contact Gerhard Kronschnabl, Gerhard.Kronschnabl@bkg.bund.de)

 The RAEGE (Spain) triband feed developed at Yebes Observatory. (For more information please 

contact Jose Antonio Lopez Perez, ja.lopezperez@oan.es)

Broadband Feed Comparison. 

The Eleven and QRFH broadband feeds are compared in Table 1. [See also appended notes describing

table parameters.] In addition one of the most important feed parameters, the aperture efficiency was 

compared via simulation in a Cassegrain reflector system. The results are shown in Figure 1. There are 

three notable differences between the feeds:

LNAs per Polarization. Due to the differential port configuration of the Eleven Feed, each polarization 

output requires a network to combine the output from four antenna ports. To avoid noise 

degradation from the combining network, LNA’s are required directly on each antenna port for a total 

of 4 LNA’s per polarization or 8 LNA’s per Eleven feed. Furthermore, since mismatches in the LNA’s

degrade feed performance, it is necessary that the LNA’s be matched within specified limits. In 

contrast, the QRFH requires no combining network, only one LNA per polarization, and no LNA 

matching. [Note: The total number of LNA’s for the Eleven Feed could be reduced to four through the 

use of broadband baluns. Although a broadband balun is under development at Onsala Observatory, 

it is not yet ready for use.]

Calibration Signal Injection. For both feeds it is possible to radiate the calibration signal directly into 

the feed or to couple it into the signal chain after the LNA. [See Table 1 notes for more details.]

However, due to the combining network and multiple LNAs needed for the Eleven Feed, it is not 

practical when using this feed to inject calibration signals between the feed and LNA.

Design adaptability. The QRFH design can be optimized to match a variety of antenna optics whereas 

the Eleven Feed has a fixed 10-dB half-beamwidth of about 65°. To be fair, the performance of the 

Eleven Feed does not degrade quickly as antenna optics change so it is in fact compatible with a fair 

range of antenna optics. However, for the case of legacy IVS antennas requiring 10-dB halfbeamwidths that are significantly different from 65°, the adaptability of the QRFH design will likely 

lead to improved performance.
49

Eleven QRFH

 VLBI2010 Compatibility Yes Yes

Frequency range (GHz) 1.2−14 2.2−14

Polarization Dual-Linear Dual-Linear

Port Configuration Differential Single-Ended

LNAs per Polarization 4 1

LNAs per Feed 8 2

LNA Balance Requirements 1.6 dB amp

14° phase None

Calibration Signal Injection Radiated or

post-LNA

Radiated,

pre-LNA, or

post-LNA

Aperture Efficiency

(F/D ~ 0.375) See Figure 1

Ground Noise Contribution

(F/D ~ 0.4)

Preliminary 10−20K, but more 

research is needed

< 20K (2.2−5 GHz)

< 10K (5−14 GHz)

F/D Range 0.35−0.5 Adaptable for nominal

0.3−2.5

Feed 10-dB half-beamwidth 65° Adaptable for nominal 

15°−70°

Size

(Half-beamwidth ~ 65°)

Diameter 210 mm 

height 65 mm

diameter 160 mm

height 150 mm

Cost (USD) 33K (TBC) 15K

Table 1. VLBI2010 Broadband Feed comparison. Although the QRFH design is adaptable, note that the 

QRFH table entries for aperture efficiency, ground noise contribution, and size assume its design has been 

optimized for a half-beamwidth of 65°.

Notes on table parameters:

Aperture Efficiency: This is the total aperture efficiency for each feed feeding reflector optics that are 

nominally 0.4 F/D (65° feed half-angle). In addition to the impact of return loss, all feed sub-efficiencies 

including those related to beamwidth and phase center variations with frequency are accounted for in 

this parameter. If the feed is to be considered for an antenna system having significantly different optics, 

the aperture efficiency needs to be recomputed. Note that phase center variations have not been broken 

out as a separate table entry since, due to the directional nature of VLBI antennas, they do not impact 

VLBI geometric products.

Figure 1 compares the feeds as they would perform in a 12m shaped reflector system like the one 

manufactured by Intertronics Solutions. The version of the QRFH used in the comparison was designed 

specifically for these optics assuming a frequency range of 2−12 GHz; hence no data were available for a 

comparison in the 12−14 GHz range. [Note however that the QRFH design can easily be scaled to cover 

the 2.2−14 GHz range with similar performance.] The efficiency plot for the QRFH was calculated using

Physical Optics software at JPL while the efficiency plot for the Eleven feed was calculated using GRASP 

software at Onsala Observatory. In both cases measured far field patterns were used as input. Real-world 
50

complications such as feed leg scattering have not been taken into account. From figure 1 it can be seen 

that the performance of the feeds is comparable with the Eleven feed having slightly higher efficiency 

over the 3−5 GHz band and the QRFH having slightly higher efficiency over the 9−11 GHz band.

2 4 6 8 10 12 14

0.4

0.5

0.6

0.7

0.8

0.9

1

Frequency [GHz]

Efficiency, [%]

QRFH and Eleven Feed in Intertronics antena based on measured feed beam patterns

Eleven feed

QRFH 

Figure 1: Comparison of the aperture efficiencies of the Eleven feed and the QRFH in a 12m Cassegrain 

shaped reflector antenna system. The result for the Eleven feed, red curve, is calculated with GRASP

software while the result for the QRFH, green curve, is calculated with Physical Optics software. In both 

cases measure far field patterns were used as input. Real-world complications such as feed leg scattering 

have not been taken into account.

Ground Noise Contribution: This is a computation of the expected ground noise pickup when a dualreflector antenna system is pointed at Zenith; this contribution will increase at lower elevation angles or 

for prime focus optics. This does not include LNA noise or thermal losses in the feed hardware.

Calibration Signal Injection: Mode of injecting calibration signals into the receiver.

 Radiated – signal is radiated into the feed via a small transmitting probe. This mode calibrates 

the entire signal chain but is susceptible to phase cal antenna-orientation-dependent 

multipath interference.

 Pre-LNA – signal is injected via microwave hardware preceding the LNA. This mode calibrates 

the entire signal chain and does not suffer from antenna-orientation-dependent multipath like 

the radiated technique but instead incurs a slight increase (~5K) in the receiver temperature.

 Post-LNA – signal is injected after the LNA so that multipath and receiver temperature 

increase need not be considered. However, the entire signal chain is not calibrated
51

Triband Feed Comparison

The Raege and Mirad feeds are compared in Table 2.

Raege Triband Mirad Triband

VLBI2010 Compatibility

No 

(for compatibility with S/X and 

X/Ka and for antenna 

commissioning)

No 

(for compatibility with S/X and 

X/Ka and for antenna 

commissioning)

Frequency range (GHz)

S: 2.2−2.7

X: 7.5−9

Ka: 28−33

S: 2.15−2.8

X: 7.0−9.5

Ka: 26.5−33

Polarization Dual-Circular Dual-Circular

Port Configuration Single-Ended

(use of hybrids to combine ports)

Single-Ended

(use of hybrids to combine ports)

LNAs per Polarization 1 1

LNAs per Feed 6 

(3 bands x 2 Pols)

6 

(3 bands x 2 Pols)

LNA Balance Requirements None None

Calibration Signal Injection

Radiated,

pre-LNA, or

post-LNA

Radiated,

pre-LNA, or

post-LNA

Aperture Efficiency > 70% > 70% (70-83%)

Ground Noise Contribution

< 20 K S-band

< 10 K X-band

< 5K Ka-band

< 20 K S-band (17K@60°)

< 10 K X-band (12K@60°)

< 5K Ka-band

F/D Range 0.4 0.29

Feed 10-dB Half- Beamwidth 65° 55°

Size (DxH – mm) 190x245

Feed alone: 190x400

Feed + Waveguide: 

(500-900)x1250

Operating Temp (°K) 20 room temp

Cost (USD) 25K (including hybrids and Kaband septum)

250K (including feed, waveguide 

and feed cone)

Table 2. Comparison of Triband Feeds.

IVS Coordination

NASA Goddard Space Flight Center IVS Coordinating Center

Coordinating Center Report

Dirk Behrend

Abstract

This report summarizes the activities of the IVS Coordinating Center during the year 2012 and

forecasts activities planned for the year 2013.

1. Coordinating Center Operation

The IVS Coordinating Center is based at the Goddard Space Flight Center and is operated by

NEOS (National Earth Orientation Service), a joint effort for VLBI by the U.S. Naval Observatory

and the NASA Goddard Space Flight Center.

The mission of the Coordinating Center is to provide communications and information for

the IVS community and the greater scientific community and to coordinate the day-to-day and

long-term activities of IVS.

The Web server for the Coordinating Center is provided by Goddard. The address is

http://ivscc.gsfc.nasa.gov

2. Activities during 2012

During the period from January through December 2012, the Coordinating Center supported

the following IVS activities:

• Directing Board support: Coordinated, with local committees, two IVS Directing Board

meetings, in Madrid, Spain (March 2012) and at the Haystack Observatory, MA, USA (October 2012). Notes from each meeting were published on the IVS Web site.

Figure 1. Attendees of the IVS Directing Board meeting held at MIT Haystack

Observatory in October 2012.

IVS 2012 Annual Report 55
IVS Coordinating Center NASA Goddard Space Flight Center

• Communications support: Maintained the general IVS Web pages and the session Web pages,

the e-mail lists, and the Web-based mail archive files.

• Publications: Published the 2011 Annual Report in summer/fall 2012. Published three

editions of the IVS Newsletter in April, August, and December 2012. All publications are

available electronically as well as in print form.

• Observing Program Committee (OPC): Coordinated meetings of the OPC to monitor the

observing program, review problems and issues, and discuss changes.

• 2012 Master Schedule: Generated and maintained the master observing schedule for 2012.

Coordinated VLBI resources for observing time, correlator usage, and disk modules. Coordinated the usage of Mark 5 systems at IVS stations and efficient deployment of disk modules.

• 2013 Master Schedule: Generated the proposed master schedule for 2013 and received approval from the Observing Program Committee.

• VLBI2010: Supported the activities of the VLBI2010 Committee (V2C) and the VLBI2010

Project Executive Group (V2PEG). Worked with the Local Committee and the Program

Committee to prepare the VLBI2010 Workshop on Technical Specifications (TecSpec) held

in Bad K ̈otzting, Germany in March 2012.

Figure 2. Participants of the VLBI2010 Workshop on Technical Specifications (TecSpec) held in Bad

K ̈otzting, Germany in March 2012. More information about the workshop can be found at the URL

http://www.fs.wettzell.de/veranstaltungen/vlbi/tecspec2012/index.html.

• Meetings: Coordinated, with the Local Committee, the seventh IVS General Meeting, held

in Madrid, Spain in March 2012. Chaired the Program Committee for the meeting.

3. Staff

The staff of the Coordinating Center is drawn from individuals who work at Goddard. The

staff and their responsibilities are listed in Table 1.

4. Plans for 2013

The Coordinating Center plans for 2013 include the following:

56 IVS 2012 Annual Report
NASA Goddard Space Flight Center IVS Coordinating Center

Table 1. IVS Coordinating Center staff.

Name Title Responsibilities

Dirk Behrend Director Web site and e-mail system maintenance, Directing Board support, meetings, publications, session Web page monitoring

Cynthia Thomas Operation Manager Master schedules (current year), resource management and monitoring, meeting and travel support, special sessions

Frank Gomez Web Manager Web server administration, mail system maintenance, Data Center support, session processing

scripts, mirror site liaison

Karen Baver General Programmer

and Editor

Publication processing programs, LaTeX support and editing, session Web page support and

scripts

Kyla Armstrong Data Technician Publications support and Web site support

• Maintain the IVS Web site and the e-mail system.

• Publish the 2012 Annual Report (this volume).

• Coordinate, with the local committee, the seventh IVS Technical Operations Workshop to

be held at the MIT Haystack Observatory, MA, USA in May 2013.

• Support Directing Board meetings in 2013.

• Coordinate the 2013 master observing schedules and IVS resources.

• Publish Newsletter issues in April, August, and December.

• Support the VLBI2010 activities of the V2C and V2PEG.

IVS 2012 Annual Report 57
IVS Analysis Coordinator Institut f ̈ur Geod ̈asie und Geoinformation der Universit ̈at Bonn

Analysis Coordinator Report

A. Nothnagel

Abstract

We present the IVS analysis coordination issues of 2012. The IVS Analysis Coordinator is responsible for generating and disseminating the official IVS products. This requires consistency of the input

data by strict adherence to models and conventions. The term of the current IVS Analysis Coordinator

will end on February 28, 2013.

1. General Issues

The “Thirteenth IVS Analysis Workshop” was held at the Royal Observatory of Madrid, Spain,

on March 8, 2012, in connection with the 7th IVS General Meeting. In this workshop, the coordination of IVS routine data analysis was discussed as well as a number of individual items concerning

geodetic and astrometric data analysis in the framework of the IVS. Due to personnel limitations

at some of the analysis centers, the progress in improving the analysis software packages was slow.

This is important for the necessary changes following the IERS Conventions 2010 in particular.

Concerning atmospheric gradient modeling, a decision was made by the attendees that the Chen

and Herring model [1] should be the conventional model of the IVS, using the constant C = 0.0031

for estimating the hydrostatic gradient. Since the hydrostatic contribution is the biggest one

and the coefficient for the total gradient contribution is only slightly different (C = 0.0032), no

noticeable effect on the estimates is expected. The MacMillan model [2] produces essentially the

same results, but for consistency with the analyses of the IGS, the Chen and Herring model [1]

was adopted.

An unsolved problem is the issue of the sidelobe ambiguities resulting from loss of channels,

e.g., due to radio frequency interference (RFI). For certain stations and sessions, this causes a

loss of many observations. The only way to overcome this problem is by re-fringing the correlator

output with a narrow search window (±10 ns). The author offers a little program which creates

fourfit run commands with suitable search windows for a refringe. As input, it needs the listing

of the post-fit residuals of the Solve program and the alist file of the aedit program. Because this

requires that an analyst taking care of these observations has to extract the post-fit residuals from

his solution, has to have access to the raw correlator output, and has to have some knowledge

of running fourfit, the number of possible candidates for taking care of this job singlehandedly is

small. It is, therefore, necessary that a suitable data flow is organized between the submitting

Analysis Center and the respective correlator group.

2. IVS Operational Data Analysis and Combination

Since October 1, 2009, the operational combination has been carried out by the IVS Combination Center at the German Bundesamt f ̈ur Kartographie und Geod ̈asie (BKG) in Frankfurt a.M.

(see separate report by BKG/DGFI). The input to these combinations is datum-free (constraintfree) normal equation systems in SINEX format (Solution INdependent EXchange format) containing elements for radio source positions, Earth orientation parameters, and radio telescope

coordinates.

58 IVS 2012 Annual Report
Institut f ̈ur Geod ̈asie und Geoinformation der Universit ̈at Bonn IVS Analysis Coordinator

3. Epilog

In September 2012, I gave notice to the IVS Directing Board that I will terminate my mandate

as IVS Analysis Coordinator on February 28, 2013. At that time I will have served as Analysis

Coordinator for more than 13 years. Thanks to the help and efforts of many individuals, it was a

period of constant progress in the field of analysis and also in the field of combination products. Of

course, expectations of how much progress should have been made have always been higher than

could be realized. In the field of VLBI data analysis, there have been too many improvements

to discuss or even mention. Concerning the combinations of the analysis results for the final

IVS products, I made the first proposal to use datum-free normal equations in 2002. Although

there are serious problems with filter-based solutions, I still defend my decision to go for normal

equations. In the process of generating combinations for the International Terrestrial Reference

Frame (e.g., ITRF2005 or ITRF2008), the IVS has always been the service that could prove and

guarantee that the solutions were unconstrained. In the near future, the source positions will be

handled in a consistent way together with the terrestrial reference frame and the Earth orientation

parameters. Combination on the basis of datum-free normal equations containing the elements

of all the parameters of the VLBI solutions will be a straightforward method without awkward

constructions of the functional model between the parameters and the setting up of additional

Helmert parameters as will be necessary for the solutions reported to the IERS with covariance

matrices.

At the time of writing, the new IVS Analysis Coordinator, John Gipson (who works for NVI,

Inc. at NASA GSFC), had already been elected by the IVS Directing Board. I am sure that John

will be a capable and diligent leader of the analysis community within the IVS. I wish him good

luck with all his new ideas and a good portion of persistence to motivate the IVS analysis groups

to produce even better solutions in a timely fashion.

References

[1] G. Chen, and T.A. Herring (1997) Effects of atmospheric azimuthal asymmetry on the analysis of space

geodetic data. J Geophys Res, Vol. 102, No. B9, pp. 20489-20502, doi: 10.1029/ 97JB01739.

[2] D. S. MacMillan (1995) Atmospheric gradients from very long baseline interferometry observations.

Geoph Res Letters, Vol. 22, No. 9, pp. 1041-1044, doi: 10.1029/95GL00887.

IVS 2012 Annual Report 59
Network Coordinator NVI, Inc.

Network Coordinator Report

Ed Himwich, Richard Strand

Abstract

This report includes an assessment of the network performance in terms of lost observing time

for the 2012 calendar year. Overall, the observing time loss was about 12.3%, which is in-line with

previous years. A table of relative incidence of problems with various subsystems is presented. The

most significant identified causes of loss were electronics rack problems (accounting for about 21.8%

of losses), antenna reliability (18.1%), RFI (11.8%), and receiver problems (11.7%). About 14.2% of

the losses occurred for unknown reasons. New antennas are under development in the USA, Germany,

and Spain. There are plans for new telescopes in Norway and Sweden. Other activities of the Network

Coordinator are summarized.

1. Network Performance

The overall network performance was for the most part good. This year we return to reporting

a detailed assessment, which was not provided for the two previous years.

This network performance report is based on correlator reports for experiments in calendar year

2012. This report includes results for the 148 24-hour experiments that had detailed correlator

reports available as of March 8, 2013. The data set examined includes approximately 500,000

dual frequency observations. Results for 16 experiments were omitted because either they were

correlated at the VLBA, they have not been correlated yet, or correlation reports were not available

on the IVS data centers. Experiments processed at the VLBA correlator were omitted because

the information provided for them is not as detailed as that from Mark IV correlators. The

experiments that have not been correlated or do not have correlator reports available yet include

some JADE, JAXA, OHIG, R&D, T2, and EUR experiments. In summary, roughly 90% of the

data from scheduled 24 hour experiments for 2012 are included in this report. That is similar to,

and actually a little more complete than, the coverage of reports for previous years.

An important point to understand is that in this report, the network performance is expressed

in terms of lost observing time. This is straightforward in cases where the loss occurred because

operations were interrupted or missed. However, in other cases, it is more complicated to calculate.

To handle this, a non-observing time loss is typically converted into an equivalent lost observing

time by expressing it as an approximate equivalent number of recorded bits lost. As an example,

a warm receiver will greatly reduce the sensitivity of a telescope. The resulting performance will

be in some sense equivalent to the station having a cold receiver but observing for (typically)

only one-third of the nominal time and therefore recording the equivalent of only one-third of

the expected bits. In a similar fashion, poor pointing can be converted into an equivalent lost

sensitivity and then equivalent fraction of lost bits. Poor recordings are simply expressed as the

fraction of total recorded bits lost.

Using correlator reports, an attempt was made to determine how much observing time was lost

at each station and why. This was not always straightforward to do. Sometimes the correlator

notes do not indicate that a station had a particular problem, while the quality code summary

indicates a significant loss. Reconstructing which station or stations had problems—and why—in

these circumstances does not always yield accurate results. Another problem was that it is hard

to determine how much RFI affected the data, unless one or more channels were removed and that

60 IVS 2012 Annual Report
NVI, Inc. Network Coordinator

eliminated the problem. It can also be difficult to distinguish between BBC and RFI problems.

For individual station days, the results should probably not be assumed to be accurate at better

than the 5% level.

The results here should not be viewed as an absolute evaluation of the quality of each station’s

performance. As mentioned above, the results themselves are only approximate. In addition, some

problems such as weather and power failures are beyond the control of the station. Instead the

results should be viewed in aggregate as an overall evaluation of what percentage of the observing

time the network is collecting data successfully. Development of the overall result is organized

around individual station performance, but the results for individual stations do not necessarily

reflect the quality of operations at that station.

Since stations typically observe with more than one other station at a time, the average lost

observing time per station is not equal to the overall average loss of VLBI data. Under some

simplifying assumptions, the average loss of VLBI data is roughly twice the average loss of station observing time. This approximation is described in the Network Coordinator’s section of

the IVS 2001 Annual Report. For 2012, this agrees reasonably well with the actual number of

(single frequency: S or X) single baseline observations on which the correlator reported failure,

approximately 21.1%, but other factors, particularly the dual frequency nature of useful geodetic

observations, complicate the picture. For 2012, the actual percentage of data (dual frequency) that

was not included by the analysts was approximately 28.1%. This is even larger (by approximately

34%) than the single baseline observations reported lost by the correlator. It is expected that this

number should be higher because the analysts use additional criteria beyond what is discussed

here to decide when to exclude observations. However, it means in effect that only about 72% of

the observations we attempted to collect were useful.

For the 148 experiments from 2012 examined here, there were 1,261 station days or approximately 8.5 stations per experiment on average. This compares to 135 experiments considered in

the report for 2009 (the most recent year with a detailed report), which included 1,051 station days

with 7.9 stations per experiment. The increase in the number of analyzed experiments essentially

just reflects that the results for more experiments were available for consideration at the time the

report was written. However the increase in the number of stations per experiment is probably

due to a concerted effort by the IVS Coordinating Center to make the networks in the experiments

larger. The onset of operations by the AuScope and Warkworth stations helped to make this

possible. Of the station days for 2012, approximately 12.3% (or approximately 155 days) of the

observing time was lost. For comparison to reports from earlier years, please see Table 1.

The lost observing time for 2012 is more in-line with results from years before 2009. The results

for 2009 may be artificially high due to a change in the way the results were tabulated for that

year. We believe this year’s calculations are more in-line with how they were made before 2009.

An assessment of each station’s performance is not provided in this report. While individual

station information was presented in some previous years, this practice seemed to be counterproductive. Although many caveats were provided to discourage people from assigning too much

significance to the results, there was feedback that suggested that the results were being overinterpreted. Additionally, some stations reported that their funding could be placed in jeopardy

if their performance appeared bad, even if it was for reasons beyond their control. Last and least,

there seemed to be some interest in attempting to “game” the analysis methods to improve station

results. Consequently, only summary results are presented here. Detailed results are presented to

the IVS Directing Board. Each station can receive the results for their station by contacting the

IVS 2012 Annual Report 61
Network Coordinator NVI, Inc.

Table 1. Lost observing time.

Year Percentage

1999-2000* 11.8

2001 11.6

2002 12.2

2003 14.4

2004 12.5

2005 14.4

2006 13.6

2007 11.4

2008 15.1

2009 21.5

2012 12.3

* The percentage applies to a subset

of the 1999-2000 experiments.

Percentages for 2010 and 2011 are

omitted, but should be 10-20%.

Network Coordinator (Ed.Himwich@nasa.gov).

For the purposes of this report, the stations were divided into two categories: large N: those

that were included in 20 or more network experiments among those analyzed here and small N:

those in 11 or fewer (no stations were in the 12-19 experiment range). The distinction between

these two groups was made on the assumption that the results would be more meaningful for the

stations with more experiments. The average observing time loss from the large N group was

much smaller than the average from the small N group, 10.6% versus 25.7%. There are many more

station days in the large N group than the small N group, 1,125 versus 136, so the large N group

is dominant in determining the overall performance.

There are 19 stations in the large N group. Nine stations observed in 50 or more experiments.

Of the 19, eight stations successfully collected data for approximately 90% or more of their expected

observing time. Nine more stations collected 80% or more of the time. The two remaining stations

collected data for more than about 60% of their observing time. These results are not significantly

different from previous years.

There are 24 stations in the small N group. The range of lost observing time for stations in

this category was 0%-100%. The median loss rate was approximately 11.3%, better than previous

years.

The losses were also analyzed by sub-system for each station. Individual stations can contact

the Network Coordinator (Ed.Himwich@nasa.gov) for the sub-system breakdown (and overall loss)

for their station. A summary of the losses by sub-system (category) for the entire network is

presented in Table 2. This table includes results since 2003 sorted by decreasing loss in 2012.

The categories in Table 2 are rather broad and require some explanation, which is given below.

Antenna This category includes all antenna problems, including mis-pointing, antenna control

computer failures, non-operation due to wind, and mechanical breakdowns of the antenna.

62 IVS 2012 Annual Report
NVI, Inc. Network Coordinator

Table 2. Percentage of observing time lost by sub-system.

Sub-System 2012 2009 2008 2007 2006 2005 2004 2003

Rack 21.8 6.6 8.7 11.4 16.3 5.1 6.8 5.0

Antenna 18.1 29.4 19.2 34.6 19.0 24.4 32.9 17.8

Unknown 14.2 14.2 17.7 14.9 4.0 3.3 10.1 12.6

RFI 11.8 5.9 14.8 10.4 11.6 6.2 5.0 9.3

Receiver 11.7 18.6 13.8 14.9 20.8 24.2 18.0 25.2

Miscellaneous 6.9 15.3 12.8 7.6 18.0 8.0 8.0 6.0

Recorder 5.7 2.9 4.1 4.6 3.3 8.9 11.1 10.9

Shipping 3.6 4.0 5.4 1.0 0.0 0.2 1.4 6.1

Power 2.1

Operations 2.0 1.2 2.3 0.0 2.0 4.7 6.1 3.6

Clock 1.8 1.9 0.5 0.3 4.9 14.5 0.5 3.4

Software 0.3 0.1 0.1 0.4 0.1 0.5 0.1 0.1

Percentages for 2010 and 2011 were not calculated.

Clock This category includes situations where correlation was impossible because the clock offset

either was not provided or was wrong, leading to the “no fringes” case. Maser problems and

coherence problems that could be attributed to the Maser were also included in this category.

Phase instabilities reported for Kokee were included in this category.

Miscellaneous This category includes several small problems that do not fit into other categories,

mostly problems beyond the control of the stations, such as power (only prior to 2012),

(non-wind) weather, cables, scheduling conflicts at the stations, and errors in the observing

schedule provided by the Operation Centers. For 2006 and 2007, this category also includes

errors due to tape operations at the stations that were forced to use tape because either they

did not have a disk recording system or they did not have enough media. All tape operations

have since ceased. This category is dominated by weather and scheduling conflict issues.

Operations This category includes all operational errors, such as DRUDG-ing the wrong schedule, starting late because of shift problems, operator (as opposed to equipment) problems

changing recording media, and other problems.

Power This category includes data lost due to power failures at the sites. Prior to 2012, losses

due to power failures were included in the Miscellaneous category.

Rack This category includes all failures that could be attributed to the rack (DAS) including the

formatter and BBCs. There is some difficulty in distinguishing BBC and RFI problems in

the correlator reports, so some losses are probably mis-assigned between the Rack category

and the RFI category.

Receiver This category includes all problems related to the receiver, including outright failure,

loss of sensitivity because the cryogenics failed, design problems that impact the sensitivity,

LO failure, and loss of coherence that was due to LO problems. In addition, for lack of a more

clearly accurate choice, loss of sensitivity due to upper X band Tsys and roll-off problems

were assigned to this category.

IVS 2012 Annual Report 63
Network Coordinator NVI, Inc.

Recorder This category includes problems associated with data recording systems. Starting with

2006, no problems associated with tape operations are included in this category.

RFI This category includes all losses directly attributable to interference, including all cases of

amplitude variations in individual channels, particularly at S-band. There is some difficulty

in distinguishing BBC and RFI problems in the correlator reports, so some losses are probably

mis-assigned between the Rack category and the RFI category.

Shipping This category includes all observing time lost because the media were lost in shipping

or held up in customs or because problems with electronic transfer prevented the data from

being correlated with the rest of the experiment’s data.

Software This category includes all instances of software problems causing observing time to be

lost. This includes crashes of the Field System, crashes of the local station software, and

errors in files generated by DRUDG.

Unknown This category is a special category for cases where the correlator did not state the

cause of the loss and it was not possible to determine the cause with a reasonable amount of

effort.

Interesting results for 2012 include the fact that the largest source of losses was due to “Rack”

problems, (21.8%). About half the loss in this category is associated with DBBCs, which were in

use at several stations in the Southern Hemisphere. The remaining rack problems were largely due

to problems at stations with aging racks for which replacement parts are hard to find. However,

significant improvements were made at two of the three stations with these problems by the end

of the year.

The next largest area of loss was “Antenna” problems (18.1%). This is down significantly

from previous years and reflects the fact that there were no lengthy outages due to catastrophic

antenna failures. Stations with significant antenna problems were Matera, Svetloe, Tsukuba, and

Yarragadee.

The “RFI” losses (11.8%) were more back in-line with years before 2009. The higher value in

2009 may be related to differences in how the losses were treated that year. The stations with the

most serious RFI problems were Fortaleza and Matera.

“Receiver” sub-system problems (11.7%) was lower than in previous years. For 2012 this is

probably due to fewer cryogenic problems, due partly to several new stations having uncooled

receivers.

The “Miscellaneous” category loss was smaller than previous years. This was to a small extent

due to the fact that “Power” was broken out as a separate category this year, but this does not

account for the majority of the change.

Overall, while the network operated well for the most part, there are a few notable issues (in

alphabetical order of station), while some situations improved from the previous year:

• Fortleza RFI for channel SR4U caused almost 15% data loss for that station over the year.

An attempt to fix this by bandpass filtering the RFI signal in the station’s S-band IF did

not work.

• Hobart26 is now observing without a phase calibration antenna unit.

• Hobart, Katherine, and Yarragadee have timing issues with the DBBC back-ends. These

cause occasional clock breaks and data gaps when they occur. The manufacturer is investigating this issue.

64 IVS 2012 Annual Report
NVI, Inc. Network Coordinator

• Kokee Park’s damaged gearbox was repaired and was re-installed. This improved the antenna’s pointing and its SEFDs but did not return them to their normal levels. There are still

problems with both azimuth gearboxes, which will need to be repaired. The station replaced

the AC wiring going to the telescope to prevent the cryogenic compressor from tripping off.

• The receiver at Medicina warmed up in November 2011. It is not clear when it will be

repaired.

• Matera’s Mark 5 samplers for S-band channels 5 and 6 have failed. Efforts are being made

to locate replacements. Matera had an antenna failure that was repaired.

• After completion of its bearing repair, the Noto antenna started observing again in May

2012. Noto also repaired its BBCs, so that it has at most one or two bad BBCs now. In any

event, it is expected that Noto will replace its aging VLBA4 rack with a DBBC in 2013.

• Ny- ̊Alesund’s receiver communications were repaired using the system that the TIGO station

developed for their receiver, which had the same original design.

• Svetloe had intermittent antenna problems that caused occasional data losses. Badary and

Zelenchukskaya’s antenna reliability has improved.

• TIGO has shown higher than normal SEFDs for several years. There has been no success in

resolving this issue.

• The Tskuba32 telescope had a major structural failure and was repaired.

• Warkworth lost most of the scans scheduled for 2012 because of a maser failure, now repaired.

• The Westford azimuth antenna drives continue to trip off sometimes when the site is unattended.

• Yarragadee solved its antenna problems by installing a bandpass filter in a diplexer to eliminate the need to stow the antenna when a satellite up-link is active.

2. New Stations

There are prospects for new stations on several fronts. These include (in approximate order of

how soon they will start regular observations):

• At GSFC in the USA, a new 12-m antenna has been erected and is undergoing testing. While

this antenna is primarily for use in the development of the VGOS systems, it is expected

that it will eventually join the network for regular observing.

• At Wettzell in Germany, construction of the new Twin Telescope Wettzell (TTW) for VGOS

is underway and is expected to be commissioned in April 2013.

• At Arecibo in Puerto Rico a new 12-m antenna has been erected and is expected to be used

for geodetic observing.

• In Spain/Portugal, the RAEGE (Atlantic Network of Geodynamical and Space Stations)

project aims to establish a network of four fundamental geodetic stations including radio

telescopes that will fulfill the VGOS specifications: Yebes (1), Canary Islands (1), and Azores

(2).

IVS 2012 Annual Report 65
Network Coordinator NVI, Inc.

• In Norway, the Norwegian Mapping Authority (NMA) has received initial funding for a

project to establish a fundamental station at Ny- ̊Alesund, which will include a twin telescope

of the Wettzell type.

• Onsala has applied for funds for a twin telescope system.

• In Russia, an effort is underway to get 12-m VGOS antennas at some of the QUASAR

network sites.

• Korea is planning to build one antenna primarily for geodesy (Korea VLBI system for

Geodesy, KVG) at Sejong. There is also interest in geodetic use of the Korean VLBI Network

(KVN), which will consist of three stations intended primarily for astronomy.

• There is interest in India in building a network of four telescopes that would be useful for

geodesy.

• Saudi Arabia is investigating having a combined geodetic observatory, which would presumably include a VLBI antenna.

• Colombia is investigating having a combined geodetic observatory, which would presumably

include a VLBI antenna.

Many of these antennas may become available for use in the next few years. Efforts are being

made to ensure that these antennas will be compatible with VGOS.

3. Network Coordination Activities

Network coordination involved dealing with various network and data issues. These included:

• Reviewing all experiment “ops” messages, correlator reports, and analysis reports for problems and working with stations to resolve them

• Responding to requests from stations for assistance

• Providing AuScope staff with a technical operations workshop (“Mini-TOW”) for training

• Making station visits to Hobart and Warkworth for software updates and training

• Identifying network station issues and working with the IVS Coordinating Center and the

stations to resolve them. This year these included:

– Dealing with Mark 5B/5B+ “,E” scan check errors

– Dealing with Mark 5B/5B+ time issues

– Preparing Mark 5 modules for use and correcting VSN problems

– Helping stations avoid the Linux “day 49” kernel problem

– Maintaining the FS PC kernel

• Reviewing RFI sources, selecting bandpass filters, and providing them to the sites

• Participating in development of the new VEX2 schedule file standard

66 IVS 2012 Annual Report
NVI, Inc. Network Coordinator

• Updating RDV experiment VEX files to allow proper operation with the VLBA correlator,

updating the notes file to reflect equipment set-up at different stations, and encouraging

timely shipping of data

• Recognizing and reporting DBBC issues to station observing staff

• Reviewing Mark 5 recording error checks for problems and informing correlator staff and

station staff

• Assisting in troubleshooting the Kokee X-band dewar failure

• Troubleshooting power supplies and identifying the correct parts for shipping

• Troubleshooting video converters and organizing shipments to stations

• Coordinating shipment of phase calibration sync trigger units to each station with a Mark

5B/5B+

• Troubleshooting phase calibration issues and coordinating parts shipments

• Providing telescope pointing analysis and advice.

4. Future Activities

Network coordination activities are expected to continue next year. The activities will largely

be a continuation of the previous year’s activities:

• Reviewing all experiment “ops” messages, correlator reports, and analysis reports for problems and working with stations to resolve them

• Responding to requests from stations for assistance

• Identifying network station issues and working with the IVS Coordinating Center and the

stations to resolve them

• Updating Network Station configuration files

• Planning for and teaching at TOW 2013

• Other activities as needed.

IVS 2012 Annual Report 67
IVS Technology Coordinator Report MIT Haystack Observatory

IVS Technology Coordinator Report

Alan Whitney

Abstract

This report of the Technology Coordinator includes the following: 1) continued work to implement

the new VLBI2010 system, 2) the 1st International VLBI Technology Workshop, 3) a VLBI DigitalBackend Intercomparison Workshop, 4) DiFX software correlator development for geodetic VLBI,

5) a review of progress towards global VLBI standards, and 6) a welcome to new IVS Technology

Coordinator Bill Petrachenko.

1. VLBI2010 Progress

Progress continues towards the goal of a next-generation VLBI2010 system. Much more detailed

information about VLBI2010 development is presented elsewhere in this volume; here we briefly

report some of the highlights.

1.1. Development of the VLBI2010 Broadband System

The VLBI2010 system continues to be developed at several locations:

1. The VLBI2010 13-m ‘twin-telescopes’ installed at Wettzell will be formally inaugurated in

April 2013. RMS surface accuracy is better than 60 micrometers, and the antenna and the

subreflector are aligned. A tri-band feed will be installed soon, followed by measurements

of G/T and pointing tests. A new broadband “Eleven” feed and accompanying receiver and

recording systems are currently being installed.

2. The broadband ‘QRFH’ 2-14 GHz broadband feed from Caltech has been successfully tested

on the VLBI2010 prototype antenna at NASA/GGAO and will soon also be installed on

the Westford antenna. Experimental results for beam patterns and efficiencies closely match

theoretical predictions. The QRFH feed can be easily re-designed to accommodate a wide

variety of antenna geometries.

3. Digital-backend development continues in China, Europe, Japan, Russia, and the United

States. A VLBI Digital-Backend Intercomparison Workshop was conducted at Haystack

Observatory in October 2012 to test inter-compatibility between independently developed

DBE units.

4. Mark 6 VLBI data system: The Mark 6 system is entering service at 8 Gbps. Several

successful experiments have already been conducted, and the system continues to be made

more robust. Routine service at 8 Gbps is expected in the first half of 2013, with expansion

to 16 Gbps by the end of 2013.

5. A number of VLBI2010 data-taking sessions between Westford and NASA/GSFC were conducted during 2012, including several operating at 8 Gbps/station. Many were recorded

onto four Mark 5C units at each station using RDBE backend units as data sources, at an

aggregate data rate of 8 Gbps/station, but a single Mark 6 is now able to replace the four

Mark 5C units. More of the processing of VLBI2010 data continues to be moved from the

68 IVS 2012 Annual Report
MIT Haystack Observatory IVS Technology Coordinator Report

Mark IV correlator to the DiFX correlator at Haystack Observatory as the DiFX correlator

becomes more capable of processing VLBI2010 data.

6. DiFX correlators at MPI, Haystack Observatory, and U.S. Naval Observatory continue to be

developed and used for processing geodetic VLBI data.

2. 1St International VLBI Technology Workshop at Haystack Observatory

The annual international e-VLBI workshop, the 10th of which was convened in 2011 in South

Africa, was expanded in 2012 to include a broader scope of technical VLBI developments and was

renamed 1

st International VLBI Technology Workshop. It was held at Haystack Observatory 22-24

October 2012 and attended by 68 participants from 17 countries.

Prior to the meeting, an intrepid group of ∼20 attendees braved cold and wind to climb

∼1000m-high Mt. Monadnock in nearby New Hampshire, which offered spectacular views of the

New England fall foliage display.

The three-day workshop included sessions on antennas, receivers, digital backends, phasecalibration, recording, and e-VLBI, as well as some recent VLBI science achievements, and it was

judged to be highly successful by all. The program and presentations from the workshop are

available on-line at http://www.haystack.mit.edu/workshop/ivtw/program.html.

The 2nd International VLBI Technology Workshop will be held in fall 2013 in South Korea.

Figure 1. Attendees of 1st International VLBI Technology Workshop held at MIT Haystack Observatory.

IVS 2012 Annual Report 69
IVS Technology Coordinator Report MIT Haystack Observatory

3. VLBI Digital-Backend Intercomparison Workshop

The 2nd International VLBI Digital-Backend Intercomparison Workshop was held at Haystack

Observatory immediately following the VLBI technical workshop reported above. (The first was

held in 2009.) Participants from China, Europe, Japan, and the U.S. spent two very busy days

preparing equipment, recording wide-bandwidth correlated noise, and processing through the

Haystack DiFX correlator to test the proper operation and intercompatibility of all the units

under test. A full report of this workshop is contained elsewhere in this IVS annual report.

4. DiFX Software Correlator for Geodetic VLBI

The so-called DiFX software correlator was originally developed at Swinburne University in

Australia by Adam Deller, primarily for astronomical VLBI use. The development of an economical

and powerful software correlator, a dream less than a decade ago, has been made possible by the

relentless march of Moore’s Law to provide powerful inexpensive clustered PCs with high-speed

data interconnections that can distribute and correlate VLBI data in an efficient manner. Several

institutions that support geodetic VLBI correlation processing now have DiFX correlators (MPIfR,

USNO, and Haystack Observatory) and have been working to augment the core DiFX software

to meet the needs of geodetic VLBI. This includes the integration of much of the Mark IV postcorrelation software involving data-management, output data formats, fringe finding and delay

estimates, and editing/quality-assurance software. In addition, a substantial amount of work has

been done to support the VDIF data-input format and to support correlation of mismatched sample

rates and recording bandwidths.

5. Review of Global VLBI Standards

One of the goals of the IVS Technology Coordinator over the past 15 years has been to promote

development and implementation of global standards for VLBI. During this time, the following

VLBI-related standards represent some of the progress that has been made.

5.1. VEX/VEX2

VEX (VLBI EXperiment), created in the late 1990s and updated in the early 2000s, is a pseudolanguage that describes the detailed configuration of each station in an experiment, as well as the

schedule of observations. The scheduling process creates a VEX observation file for each experiment

that describes that configuration and schedule for each station, as well as a corresponding stationspecific SNAP file (Standardized Notation for Antenna Procedures, created in the 1980s) that is

created to drive the Field System at each station. During an experiment, a VEX-format log file

is created that aids in post-experiment correlation and post-correlation processing. VEX is now

used to support a majority of geodetic VLBI observations and is also becoming quite prevalent for

astronomical VLBI as well.

Over the past few years, evolving VLBI technologies and capabilities have prompted the creation of a VEX2 Task Force to update and modernize VEX to accommodate these new capabilities,

particularly digital backends and VDIF data formats, in a natural way. The VEX2 specification

is nearing completion and is projected to be released in early spring 2013.

70 IVS 2012 Annual Report
MIT Haystack Observatory IVS Technology Coordinator Report

5.2. VSI

The original VSI (VLBI Standard Interface) specification was created in 1999 to specify a

standardized electrical data interface (dubbed VSI-H for ‘VSI-Hardware’) and software control interface (dubbed VSI-S for ‘VSI-Software’). As a result, many of the VLBI data-recording/playback

systems developed in the 2000s (Mark 5B, PC/EVN, K5, and LBA) support the VSI interface specification. In recent years, the VSI-H specification has been superseded by the industry-standard

10-Gigabit Ethernet interface that is now being widely adopted in new VLBI data systems (Mark

5C and Mark 6).

5.3. VDIF Data Format

The VLBI Data Interchange Format (VDIF) format was developed by the VDIF Task Force

and subsequently ratified by the VLBI community in 2009. Designed to be fully compatible with

10Gigabit Ethernet, as well as being very flexible in terms of channelization, sample depth, sample

rate, etc., it is being implemented in virtually all new VLBI data equipment. In addition, software

has been implemented on several software correlators to support at least some basic VDIF modes.

As more complex VDIF modes are put into use at stations, correlator software will need to develop

in parallel to support them.

A VDIF2 data format, including the accommodation of arbitrary sample rates (including those

that do not have an integral number of samples in a single second) is nearing completion but is not

quite ready for ratification; such ‘non-standard’ sample rates are being designed into some of the

new SKA-related systems that would like to participate in global VLBI over the next few years.

The new VDIF2 standard will also relax the constraint of an integral number of filled data packets

per second and will allow much more flexibility in the choice of packet lengths. Progress towards

completion and ratification of VDIF2 is expected in 2013.

5.4. VTP

VLBI Transport Prototype (VTP) has been developed to specify how VDIF data frames should

be streamed over standard networks such as Ethernet, and it is gaining acceptance for e-VLBI data

transport and transfers. One of the primary purposes of VTP is to allow the easy identification

of dropped and/or duplicated packets that might occur during the data-transmission process over

high-speed networks.

5.5. VLBI Standards Website

The Web site www.vlbi.org has been created to act as a common source for definitions and

information on VLBI standards, as well as a directory to VLBI on-line technical information located

at numerous VLBI institutions around the globe. These include VEX, VSI-H, VSI-S, VDIF, VTP,

and standardized VLBI file-naming conventions, as well as a VLBI technical resources page. As

new standards and technical VLBI resources emerge, they will be included at this Web site.

6. Welcome to New IVS Technology Coordinator

The author will be stepping down as IVS Technology Coordinator at the end of 2012, coincident

with retirement from MIT after 45 years of involvement with VLBI (although I plan to continue

IVS 2012 Annual Report 71
IVS Technology Coordinator Report MIT Haystack Observatory

part-time for at least a while). It has been my great privilege to serve in this capacity and to work

in this endeavor with so many wonderful and talented people over all the globe; without this great

community support, my job would have been made much harder and the results less satisfactory.

Thanks to you all.

Bill Petrachenko of Natural Resources Canada (NRCan) has been selected as the new IVS

Technology Coordinator, beginning in 2013, and will be serving in a permanent position on the

IVS Directing Board. Bill has long and deep experience in the theory and practice of VLBI and

will be a great addition to the IVS team. Many of you are already familiar with the key role that

Bill has played, and continues to play, in the development of VLBI2010. I have no doubt that

his vision, expertise, and steadfastness will be a major force in helping to successfully steer VLBI

technology development over the coming years.

72 IVS 2012 Annual Report
Network Stations

Institute of Applied Astronomy of Russian Academy of Sciences Badary Station

Badary Radio Astronomical Observatory

Sergey Smolentsev, Valery Olifirov

Abstract

This report provides information about the Badary network station: general information, facilities,

staff, present status, and outlook.

1. General Information

The Badary Radio Astronomical Observatory (Figure 1) was created by the Institute of Applied

Astronomy (IAA) as one of three stations of the Russian VLBI network QUASAR [1].

The sponsoring organization of the project is the Russian Academy of Sciences (RAS). The

Badary Radio Astronomical Observatory is situated in the Republic Buryatia (East Siberia) about

130 km east of Baikal Lake (see Table 1). The geographic location of the observatory is shown

on the IAA RAS Web site (http://www.ipa.nw.ru/PAGE/rusipa.htm). The main instruments of

the observatory are the 32-m radio telescope equipped with special technical systems for VLBI

observations, GPS/GLONASS/Galileo receivers, a DORIS antenna, and the SLR system.

Figure 1. Badary observatory.

IVS 2012 Annual Report 75
Badary Station Institute of Applied Astronomy of Russian Academy of Sciences

Table 1. The Badary observatory location and address.

Longitude 102◦14′

Latitude 51◦46′

Republic Buryatia

671021, Russia

oper@badary.ipa.stbur.ru

2. Technical Staff

Vladimir Shpilevsky — the head of the observatory,

Roman Sergeev — the chief engineer, FS, pointing system control specialist, and

Roman Kuptsov — the engineer.

3. Technical and Scientific Information

Characteristics of the radio telescope are presented in Table 2.

Table 2. Technical parameters of the radio telescope.

Year of construction 2005

Mount AZEL

Azimuth range ±270◦

(from south)

Elevation range from −5

◦

to 95◦

Maximum azimuth *

- velocity 0.83 ◦/s

- tracking velocity 2.5

′/s

- acceleration 12.0

′/s2

Maximum elevation *

- velocity 0.5

◦/s

- tracking velocity 0.8

′/s

- acceleration 12.0

′/s2

Pointing accuracy better than 10′′

Configuration Cassegrain (with asymmetrical subreflector)

Main reflector diameter 32 m

Subreflector diameter 4 m

Focal length 11.4 m

Main reflector shape quasi-paraboloid

Subreflector shape quasi-hyperboloid

Main reflector surface accuracy ± 0.5 mm

Frequency range 1.4–22 GHz

Axis offset * 3.7 ± 2.0 mm

* These values were changed to optimize the performance of the antenna system. The axis

offset was measured in summer 2012 by geodesist Andrey Shamov.

76 IVS 2012 Annual Report
Institute of Applied Astronomy of Russian Academy of Sciences Badary Station

4. Co-location of VLBI, GPS/GLONASS, DORIS, and SLR System

The Javad GPS/GLONASS/Galileo receiver with automatic meteorological station WXT-510

is in operation (Figure 2).

The SLR system “Sazhen-TM” (Figure 3) was mounted in July 2011. The “Sazhen-TM” SLR

system was manufactured by Open Joint-stock Research-and-Production Corporation “Precision

Systems and Instruments”. Technical characteristics of the system are presented in Table 3. The

SLR system at Badary joined ILRS in March 2012.

Figure 2. Javad GPS/GLONASS/Galileo receiver and DORIS beacon at the Badary observatory.Figure 3. “Sazhen-TM” SLR system at Badary observatory.

Table 3. Technical parameters of the SLR system “Sazhen-TM”.

Ranging distance, day 400-6000 km

Ranging distance, night 400-23000 km

Aperture 25 cm

Wavelength 532 nm

Beam divergence 12′′

Laser pulse frequency 300 Hz

Pulse energy 2.5 mJ

Mass 170 kg

Normal points precision 1 cm

Angular precision 1-2′′

5. Current Status and Activities

The Badary observatory participates in IVS and domestic VLBI observational programs. In

2012 Badary station participated in 27 diurnal IVS sessions — IVS-R4, IVS-T2, and EURO.

Badary participated in 47 diurnal sessions of the domestic Ru-E program to determine all Earth

IVS 2012 Annual Report 77
Badary Station Institute of Applied Astronomy of Russian Academy of Sciences

orientation parameters and in 191 one-hour Ru-U sessions for obtaining Universal Time using eVLBI data transfer. Since July 2012, observations for the Ru-U program have been performed

daily.

6. Outlook

We have the following plans for the coming year:

• To participate in IVS observations

• To carry out domestic observational programs with e-VLBI data transfer to daily obtain

Universal Time and to weekly obtain Earth orientation parameters

• To carry out SLR observations of geodetic and navigation satellites

• To participate in EVN and RADIOASTRON observational sessions

• To continue geodetic monitoring of the antenna parameters

• To build foundation and to conduct survey operations for VLBI2010 antenna installation in

2014 (Figures 4 and 5).

Figure 4. The foundation for RT-13 is planned to be built in

2013.

Figure 5. RT-13 is planned to be installed

in 2014.

References

[1] Finkelstein A., Ipatov A., Smolentsev S. The Network “Quasar”: 2008 — 2011 // “Measuring the

future”, Proceedings of the Fifth IVS General Meeting, A. Finkelstein, D. Behrend (eds.), St. Petersburg,

“Nauka”, 2008. pp. 39–46.

78 IVS 2012 Annual Report
CRAAM-INPE, R ́adio-observat ́orio Espacial do Nordeste Fortaleza

Fortaleza Station Report for 2012

Pierre Kaufmann, A. Mac ́ılio Pereira de Lucena, Adeildo Sombra da Silva

Abstract

This is a brief report about the activities carried out at the Fortaleza geodetic VLBI station (ROEN:

R ́adio Observat ́orio Espacial do Nordeste), located in Eus ́ebio, CE, Brazil, during the period from January until December 2012. The observing activities were resumed in May after the major maintenance

that comprised the azimuth bearing replacement. The total observational experiments consisted of 103

VLBI sessions and continuous GPS monitoring recordings.

1. General Information

The R ́adio Observat ́orio Espacial do Nordeste, ROEN, located at INPE facilities in Eus ́ebio,

nearly 30 km east of Fortaleza, Cear ́a State, Brazil, began operations in 1993. Geodetic VLBI

and GPS observations are carried out regularly, as contributions to international programs and

networks. ROEN is part of the Brazilian space geodesy program, which was initially conducted by

CRAAE (a consortium of the Brazilian institutions Mackenzie, INPE, USP, and UNICAMP) in

the early 1990s. The program began with antenna and instrumental facilities erected, with activities sponsored by the U.S. agency NOAA and the Brazilian Ministry of Science and Technology’s

FINEP agency. ROEN is currently coordinated by CRAAM (Center of Radio Astronomy and

Astrophysics), at the engineering school of the Mackenzie Presbyterian University in S ̃ao Paulo,

in agreement with the Brazilian National Space Research Institute, or INPE. The activities are

currently carried out under an Agreement of Cooperation signed between NASA—representing

research interests of NOAA and USNO—and the Brazilian Space Agency, or AEB, which was

extended until 2021. Under the auspices of the NASA-AEB Agreement, a contract was signed between NASA and CRAAM, MacKenzie Presbyterian Institute and University, to partially support

the activities at ROEN. The contract was extended until 2014. The counterpart of the operational

costs, staff, and support of infrastructure are provided by INPE and by Mackenzie.

Figure 1. Fortaleza’s 14.2-m radio telescope.

IVS 2012 Annual Report 79
Fortaleza CRAAM-INPE, R ́adio-observat ́orio Espacial do Nordeste

2. Main Instruments

The largest instrument at ROEN is the 14.2-m radio telescope, on an alt-azimuth positioner.

It is operated at S- and X-bands, using cryogenic radiometers. The system is controlled by the

Field System, Version 9.10.4. Observations are recorded with a Mark 5 system. One Sigma-Tau

hydrogen maser clock standard is operated at ROEN. GPS monitoring is performed within a

cooperative program with NOAA (USA). There is a Leica System 1200 installed at the station,

and it operates continuously. The collected data are provided to the NOAA/IGS center and to

the Brazilian IBGE center. ROEN has all basic infrastructures for mechanical, electrical, and

electronic maintenance of the facilities.

3. Staff

The Brazilian space geodesy program is coordinated by a Principal Investigator (PI), one of the

authors (PK), who is Brazil’s AEB representative in the NASA-AEB Agreement. The coordination receives support from the S ̃ao Paulo office at CRAAM/Instituto and Universidade Presbiteriana Mackenzie, with administrative participation from Valdomiro S. Pereira and Luc ́ıola Russo,

CRAAM administrative manager and executive secretary, respectively. The Fortaleza Station facilities and geodetic VLBI and GPS operations are managed on site by Dr. Antonio Macilio Pereira

de Lucena (CRAAE/INPE), assisted by Eng. Adeildo Sombra da Silva (CRAAE/Mackenzie),

and the technicians Avicena Filho (CRAAE/INPE) and Francisco Renato Holanda de Abreu

(CRAAE/Mackenzie).

4. Current Status and Activities

4.1. VLBI Observations

In the year 2012, Fortaleza carried out geodetic VLBI experiments as listed in Table 1.

Table 1. 2012 session participation.

Experiment Number of Sessions

IVS-R1 45

IVS-R4 37

IVS-T2 04

IVS-R&D 03

IVS-RDV 03

IVS-CRF 04

IVS-CRMS 02

IVS-OHIG 05

4.2. Operational and Maintenance Activities

The summary of activities performed in the period is listed below:

80 IVS 2012 Annual Report
CRAAM-INPE, R ́adio-observat ́orio Espacial do Nordeste Fortaleza

1. Repair of the elevation drive base;

2. Repair and maintenance of the following equipment: cryogenic system, Mark 5 recorder,

shaft encoder electronics, receiver box temperature controller, GPS time receiver, and IF

distributor;

3. Maintenance and adjustment of DC azimuth and elevation motors;

4. Calibration of receiver box telemetry;

5. Operation and maintenance of geodetic GPS (NOAA within the scope of NASA contract);

6. Operation and maintenance of power supply equipment at the observatory (main and diesel

driven standby); and

7. Maintenance of the Web site (http://www.roen.inpe.br) and the local server computer.

4.3. GPS Operations

The IGS network GPS receiver operated regularly at all times during 2012. Data were collected

and uploaded to an IGS/NOAA computer.

5. Future Plans

Plans for the immediate future consist of the continuation of geodetic VLBI regular observations and the support of GPS receiver operations. Further progress is expected to expand data

transmission via high speed national and international networks.

IVS 2012 Annual Report 81
Goddard Geophysical and Astronomical Observatory NASA Goddard Space Flight Center

Goddard Geophysical and Astronomical Observatory

Ricardo Figueroa

Abstract

This report summarizes the technical parameters and the technical staff of the VLBI system at

the fundamental station GGAO. It also gives an overview about the VLBI activities during the report

year. The outlook lists the outstanding tasks to improve the performance of GGAO.

Figure 1. Goddard Geophysical and Astronomical Observatory.

1. GGAO at Goddard

The Goddard Geophysical and Astronomical Observatory (GGAO) consists of a 5-meter radio

telescope for VLBI, a new 12-meter radio telescope for VLBI2010 development, a 1-meter reference

antenna for microwave holography development, an SLR site that includes MOBLAS-7, the NGSLR

development system, a 48′′ telescope for developmental two-color Satellite Laser Ranging, a GPS

timing and development lab, a DORIS system, meteorological sensors, and a hydrogen maser. In

addition, we are a fiducial IGS site with several IGS/IGSX receivers.

GGAO is located on the east coast of the United States in Maryland. It is approximately 15

miles NNE of Washington, D.C. in Greenbelt, Maryland (Table 1).

82 IVS 2012 Annual Report
NASA Goddard Space Flight Center Goddard Geophysical and Astronomical Observatory

Table 1. Location and addresses of GGAO at Goddard.

Longitude 76.4935◦ W

Latitude 39.0118◦ N

MV3

Code 299.0

Goddard Space Flight Center (GSFC)

Greenbelt, Maryland 20771

http://cddisa.gsfc.nasa.gov/ggao/vlbi.html

2. Technical Parameters of the VLBI Radio Telescopes at GGAO

The 5-m radio telescope for VLBI at MV3 was originally built as a transportable station;

however, it was moved to GGAO in 1991 and has been used as a fixed station. In the winter of

2002 the antenna was taken off its trailer and permanently installed at GGAO.

In October of 2010, construction of the new 12-meter VLBI2010 developmental antenna was

completed. This antenna features all-electric drives and a Cassegrain feed system. Integration of

the broadband receiver and the associated sub-systems is underway as a joint effort between Exelis

and the MIT Haystack Observatory.

The technical parameters of the radio telescopes are summarized in Table 2.

Table 2. Technical parameters of the radio telescopes at GGAO.

Parameter 5-m 12-m

Owner and operating agency NASA NASA

Year of construction 1982 2010

Diameter of main reflector d 5m 12m

Azimuth range +/ − 270◦ +/ − 270◦

Azimuth velocity 3

◦/s 5◦/s

Azimuth acceleration 1

◦/s2 1◦/s2

Elevation range +/ − 90◦ 5 − 88◦

Elevation velocity 3

◦/s 1.25◦/s(Avg.)

Elevation acceleration 1

◦/s2 1◦/s2

Receiver System

Focus Cassegrain Cassegrain

Receive Frequency 2 − 14GHz 2 − 14GHz

Tsys 100 K 50 K(T heoretical)

Bandwidth 512MHz, 4 bands 512MHz, 4 bands

G/T 26 dB/K 43 dB/K

VLBI terminal type CDP VLBI2010

Recording media Mark IV Mark 5C

IVS 2012 Annual Report 83
Goddard Geophysical and Astronomical Observatory NASA Goddard Space Flight Center

3. Technical Staff of the VLBI Facility at GGAO

GGAO is a NASA R&D and data collection facility. On April 9, 2011 the NENS contract

transitioned to the SCNS contract operated by Exelis Information Systems. The staff at GGAO

consists of four people under the contract. Exelis staff includes Jay Redmond and Katherine

Pazamickas conducting VLBI operations and maintenance at GGAO with the support of Ricardo

Figueroa and Charles Kodak.

4. Status of MV3 at GGAO

Having ceased VLBI operations in May 2007, MV3 continues on a full time basis to be a

major component in the program to demonstrate the feasibility of the VLBI2010 broadband delay

concept. Working under the guidance of the Exelis team, MV3’s S/X components are currently in

the process of being upgraded to provide additional support to the VLBI2010 System. The 2012

accomplishments for the 5-m antenna include:

• The ACU and Control Panel was completely rebuilt.

• The Cryogenic Dewar and the components required for restoration of the X-band have been

located, and the wiring of the 017 box was upgraded.

• The feed assembly was repaired and is ready to be placed back on the antenna. The FSS

has been recoated with a highly reflective surface.

Much of the 2012 activities at GGAO have been focused on performance testing and upgrading

of the VLBI2010 12-m antenna. However, there were some other activities worth noting:

• Wideband system testing and characterization of the 12-m antenna.

• Procurement of new test equipment for characterization of the wideband RF hardware.

• Broadband Phase Cal performance testing.

• Performance testing of the 16 Gbps VLBI recording, demonstrated using Mark 6.

• Installation of the high frequency optical fiber link system.

Activities to understand antenna deformations that could potentially dilute the accuracy of

the VLBI2010 system started in 2012. Initially, survey data collections were performed using

the 5-m dish as the antenna to be tested and a 1-m satellite receiving dish as the phase reference.

Preliminary results from 2010 data collection show that the imaging technique was able to faithfully

reconstruct deformations in the aperture of the primary reflector. These deformations included

GPS antennas mounted on the rim of the dish, an RF absorbing block, the offset feed Water Vapor

Radiometer (WVR) cover, and the subreflector in the center of the primary as shown in Figure 2.

5. Outlook

GGAO will continue to support VLBI2010, e-VLBI, and other developmental activities during

the upcoming year. Tentative plans for 2013 include:

84 IVS 2012 Annual Report
NASA Goddard Space Flight Center Goddard Geophysical and Astronomical Observatory

Figure 2. Holographic imaging of the 5-m antenna.

• Continue to upgrade the VLBI2010 broadband receiver system on the 12-m antenna and the

new self-retractable feed positioner.

• Conduct IVS observations using the Mark 5C and Mark 6 recorders to demonstrate the

VLBI2010 capabilities.

• Continue testing of the new broadband phase calibrator for the VLBI2010 system.

• Continue the upgrade of the 5-m antenna and initiate testing of the S/X band.

• Continue the use of the RDBEs, Mark 5Cs, and Mark 6s, replacing the DBE1s and

Mark 5B+s.

• Continue to measure the baseline between the 5-m and the 12-m antennas for position ties

to the reference frame.

• Try to understand the source of the elevation creep, which appears to have stopped.

• Try to understand why the antenna will not move in elevation under computer control when

first started up on cold mornings.

IVS 2012 Annual Report 85
Hartebeesthoek Radio Astronomy Observatory (HartRAO) HartRAO, NRF

Hartebeesthoek Radio Astronomy Observatory (HartRAO)

Marisa Nickola, Mike Gaylard, Jonathan Quick, Ludwig Combrinck

Abstract

HartRAO provides the only fiducial geodetic site in Africa, and it participates in global networks

for VLBI, GNSS, SLR, and DORIS. This report provides an overview of geodetic VLBI activities at

HartRAO during 2012, including the conversion of a 15-m alt-az radio telescope to an operational

geodetic VLBI antenna.

1. Geodetic VLBI at HartRAO

Hartebeesthoek is located 65 kilometers northwest of Johannesburg, just inside the provincial

boundary of Gauteng, South Africa. The nearest town, Krugersdorp, is 32 km away. The telescope

is situated in an isolated valley which affords protection from terrestrial radio frequency interference. HartRAO currently uses a 26-meter equatorially mounted Cassegrain radio telescope built

by Blaw Knox in 1961. The telescope was part of the NASA deep space tracking network until 1974

when the facility was converted to an astronomical observatory. The telescope is co-located with

an ILRS SLR station (MOBLAS-6), an IGS GNSS station (HRAO), and an IDS DORIS station

(HBMB) at the adjoining South African National Space Agency Earth Observation (SANSA EO)

site. HartRAO is a full member of the EVN.

Figure 1. The HartRAO 26-m observing a source during R1551 on September 11, 2012, with the 15-m

operating in tag-along mode as part of a commissioning test. (Credit: M. Gaylard)

86 IVS 2012 Annual Report
HartRAO, NRF Hartebeesthoek Radio Astronomy Observatory (HartRAO)

2. Technical Parameters of the 26-m and 15-m Telescopes of HartRAO

Table 1 contains the technical parameters of the HartRAO 26-m and 15-m radio telescopes,

while Table 2 contains technical parameters of the HartRAO 26-m and 15-m receivers. The current

data acquisition system consists of a Mark 5 terminal and a Mark 5B+ recorder. Another two Mark

5B+ recorders are used, one with the 15-m and one for e-transfer of data. Two DBBC terminals

have been acquired and will replace the Mark 5 terminal once FS support is available and recorders

have been upgraded to Mark 5C. Three hydrogen masers are available for use, namely the iMaser

72, which is currently employed during geodetic VLBI, as well as two spares - EFOS-28 and the

resuscitated EFOS-6.

Table 1. Antenna parameters.

Parameter HartRAO 26-m HartRAO 15-m

Owner and operating agency HartRAO HartRAO

Year of construction 1961 2007

Radio telescope mount Offset equatorial Az-El

Receiving feed Cassegrain Prime focus

Diameter of main reflector d 25.914 m 15 m

Focal length f 10.886 m 7.5 m

Focal ratio f /d 0.42 0.5

Surface error of reflector (RMS) 0.5 mm 1.6 mm

Short wavelength limit 1.3 cm 2 cm

Pointing resolution 0.001◦ 0.001◦

Pointing repeatability 0.004◦ 0.004◦

Slew rate on each axis HA: 0.5

◦

s

−1 Az: 2◦

s

−1

Dec: 0.5

◦

s

−1 El: 1◦

s

−1

Table 2. 26-m and 15-m receiver parameters. The degraded performance of the 26 m is due to the use of

the dichroic reflector for simultaneous S- and X-band VLBI.

26-m Dish 15-m Dish

Parameter X-band S-band X-band S-band

Feeds dual CP conical dual CP conical stepped horn wide-angle coaxial

corrugated horn

Amplifier type cryo HEMT cryo HEMT cryo HEMT cryo HEMT

Tsys (K) 52 40 40 42

SSEF D (Jy) 849 1190 1400 1050

PSS (Jy/K) 16.3 29.8 35 25

3 dB beamwidth (◦) 0.096 0.418 0.16 0.57

IVS 2012 Annual Report 87
Hartebeesthoek Radio Astronomy Observatory (HartRAO) HartRAO, NRF

3. Current Status

Conversion of the 15-m KAT prototype to an operational telescope for geodetic VLBI started

on March 30, 2012 with the installation of the S/X (2.3 and 8.4 GHz) prime-focus cryogenic

receiver. On June 6, 2012, during cooled operation, the 15-m co-observed the radio galaxy 3C123

in test mode, together with the 26-m. As part of its commissioning, the 15-m participated in four

R4 sessions during October and November 2012, and it produced data of acceptable quality. On

November 29, it joined in Ultra-Rapid sessions for the determination of EOP. The last of these

three sessions for 2012, UR1203 on December 17, was run remotely from home by Jonathan Quick.

The 26-m had already started participating in Ultra-Rapid sessions with Tsukuba, Japan, at the

end of August 2012, but the 15-m is capable of much faster slewing rates, making it ideally suited

for these types of observations. The 15-m can also observe down to horizon level in all directions,

whereas the equatorially-mounted 26-m has limited sky coverage to the south. Currently, geodetic

VLBI data from all sessions, barring the RDV sessions, are being e-transferred to the correlators.

Telescope time allocation for geodetic VLBI consisted of 59 24-hour experiments in 2012 (Table 3).

Table 4 lists the HartRAO station staff who are involved in geodetic VLBI. Jonathan Quick (VLBI

friend) provides technical support for the Field System as well as for hardware problems.

Table 3. Geodetic VLBI experiments in which

HartRAO participated during 2012.

Experiment Number of Sessions

R1 29

RD 8

CRDS 7

T2 6

CRF 3

OHIG 3

RDV 3

Total 59

Table 4. Staff supporting geodetic VLBI at

HartRAO.

Name Function Program

L. Combrinck Program Geodesy

Leader

J. Quick Hardware/ Astronomy

Software

R. Botha Operator Geodesy

J. Grobler Operator Technical

L. Masongwa Operator Technical

R. Myataza Operator Technical

M. Nickola Logistics/ Geodesy

Operations

P. Stronkhorst Operator Technical

C. Zondi Operator Technical

4. Future Plans

The idea is to lighten the 26-m antenna’s workload considerably, offloading as many of the

geodetic VLBI observations as possible onto the quick-slewing, all-sky seeing 15 m. We are actively

pursuing implementation of VLBI2010, for which extra funding will be needed. HartRAO will be

represented by radio astronomer Alet de Witt in the IAU’s working group aimed at creating the

next generation full-sky celestial reference frame (ICRF3). A tide gauge and seismometer will be

added to the 2012 installation of a new GNSS station at Gough Island. Lunar Laser Ranger (LLR)

refurbishment and design will proceed during 2013.

88 IVS 2012 Annual Report
HartRAO, NRF Hartebeesthoek Radio Astronomy Observatory (HartRAO)

Figure 2. 15-m XDM’s S/X receiver package being

hoisted into position for prime-focus installation.

(Credit M. Gaylard)

Figure 3. The 15-m, with cryogenically cooled receiver, co-observing radio galaxy 3C123 together

with the 26-m. (Credit M. Gaylard)

Figure 4. On August 7, these visitors enjoyed the

first snow at HartRAO since the NASA days in the

1960s. (Credit: F. Majola)

Figure 5. Ludwig Combrinck with the GNSS antenna installed on Gough Island in the South Atlantic Ocean.

Acknowledgements

The Space Geodesy Programme is an integrated program, combining VLBI, SLR, and GNSS,

and it is active in several collaborative projects with GSFC, JPL, and GFZ (Potsdam) as well as

numerous local institutes. Collaboration also includes CNES/GRGS/OCA and the ILRS community in a Lunar Laser Ranger (LLR) project with local support from the University of Pretoria

and the National Laser Centre (CSIR), among others. General information as well as news and

progress on geodesy and related activities can be found at http://geodesy.hartrao.ac.za/.

IVS 2012 Annual Report 89
Hobart 12 m and 26 m, Katherine, and Yarragadee University of Tasmania

AuScope VLBI Project and Hobart 26-m Antenna

Jim Lovell, John Dickey, Brett Reid, Jamie McCallum, Stas Shabala, Christopher Watson,

Simon Ellingsen, Anthony Memin

Abstract

This is a report on the activities carried out at the three AuScope VLBI observatories and the

Hobart 26-m antenna. In 2012 the three AuScope 12-m antennas at Hobart (Hb), Katherine (Ke), and

Yarragadee (Yg) completed their first full year of operations as an array. The Hobart 26-m antenna

(Ho) continued to make a contribution to IVS, providing overlap with the Hb time series. In total the

AuScope antennas and the Hobart 26 m observed for 146 antenna days in 2012.

In this report we also briefly highlight our research activities during 2012 and our plans for 2013.

1. VLBI Facilities

As part of AuScope (www.auscope.org.au), the University of Tasmania (UTAS) operates the

AuScope VLBI Array (Lovell et al., 2013), three radio telescopes on the Australian continent (Figure 1), located near Hobart (Tasmania), Yarragadee (Western Australia), and Katherine (Northern

Territory). Newly derived telescope coordinates are presented in Table 1. The AuScope telescopes

closely follow the International VLBI Service VLBI2010 specification for the next generation of

telescopes for geodesy (Petrachenko et al., 2009) or provide an upgrade path to meet the specification where it is not currently possible to do so.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Katherine

Yarragadee

Hobart

3211 km

2360 km

3432 km

Figure 1. The geographical distribution of VLBI and GNSS infrastructure for AuScope. The locations of

the new 12-m telescopes are labeled, and the new GNSS sites are indicated by filled dots.

90 IVS 2012 Annual Report
University of Tasmania Hobart 12 m and 26 m, Katherine, and Yarragadee

Table 1. Calculated positions for the three AuScope VLBI antennas at epoch 2012.0, ITRF2005 datum

(Lovell et al., 2013). The first uncertainty represents the average formal error in an individual measurement.

The second uncertainty corresponds to weighted scatter about the best estimate.

Hobart 12 m (Hb)

No. Sessions 82

Latitude (d m s) −42 48 20.0621 ± (0.0006, 0.0012)

Longitude (d m s) 147 26 17.3070 ± (0.0006, 0.0012)

Height (m) 40.967 ± (0.019, 0.036)

Katherine 12 m (Ke)

No. Sessions 24

Latitude (d m s) −14 22 31.6679 ± (0.0006, 0.0004)

Longitude (d m s) 132 09 08.5439 ± (0.0007, 0.0006)

Height (m) 189.262 ± (0.021, 0.017)

Yarragadee 12 m (Yg)

No. Sessions 14

Latitude (d m s) −29 02 49.7226 ± (0.0012, 0.0006)

Longitude (d m s) 115 20 44.2576 ± (0.0013, 0.0013)

Height (m) 248.236 ± (0.040, 0.029)

The new Hobart telescope (Hb) is co-located with the existing 26-m telescope (Ho) to preserve

the more than 20 year VLBI time series at the site. Midway between the 26-m and 12-m telescopes

is the HOB2 GNSS installation which has been a core site of the International GNSS Service (IGS)

since its conception. A hut capable of housing a mobile gravimeter is also co-located on the site.

The Yarragadee telescope (Yg) provides a far western point on the continent and is co-located with

multiple existing geodetic techniques including SLR, GNSS, DORIS, and gravity. The Katherine

site (Ke) is new and provides a central longitude, northern site. The telescope at Katherine is

co-located with a new GNSS site that forms part of the AuScope GNSS network.

Each AuScope VLBI observatory is equipped with a main reflector that is 12.1 m in diameter.

The telescope specifications include: 0.3 mm of surface precision (RMS), fast slewing rates (5

deg/s in azimuth and 1.25 deg/s in elevation), and acceleration (1.3 deg/s/s). All three sites are

equipped with dual polarization S- and X-band feeds with room temperature receivers covering 2.2

to 2.4 GHz at S-band and 8.1 to 9.1 GHz at X-band. System Equivalent Flux Densities (SEFDs)

are 3500 Jy in both bands. Data digitization and formatting is managed by the Digital Base

Band Converter (DBBC) system, and data are recorded using the Mark 5B+ system. Each site is

equipped with a Hydrogen maser time and frequency standard.

All three observatories were designed and constructed to be remotely controlled and monitored

to keep operating costs at a minimum. Operation of the AuScope VLBI array is being carried out

from a dedicated operations room on the Sandy Bay campus of the University of Tasmania.

2. Staff

Staff at UTAS consist of academics, Professor John Dickey (director), Dr. Simon Ellingsen,

Dr. Christopher Watson, and Professor Peter McCulloch. Dr. Jim Lovell is Project Manager for

IVS 2012 Annual Report 91
Hobart 12 m and 26 m, Katherine, and Yarragadee University of Tasmania

the AuScope VLBI project. Dr. Jamie McCallum, Dr. Stas Shabala, and Dr. Anthony Memin

are Australian Research Council Super-Science Fellows who are carrying out research aimed at

improving geodetic solutions in the southern hemisphere. Mr. Brett Reid is the Observatory

Manager whose position is funded by the university. In addition we have an electronics technical

officer, Mr. Eric Baynes. For operation of the observatories during geodetic observations we rely

heavily on support from astronomy PhD and postgraduate students. Logistical and maintenance

support at Katherine is provided by Mr. Martin Ephgrave and at Yarragadee by Mr. Randall

Carman and team at the MOBLAS5 SLR station.

3. AuScope VLBI Project Status

The Hobart telescope began IVS observations in October 2010 with Yarragadee and Katherine

joining in May and June 2011 respectively. 2012 was the first full year that all three telescopes

participated in IVS sessions.

The AuScope VLBI array is currently funded for operations at the level of 70 observing days

per year until the end of 2014. The Hobart 26-m antenna will continue to participate in IVS

sessions at the level of six days per year to assist in the maintenance and enhancement of the

Celestial Reference Frame in the southern hemisphere.

4. Geodetic VLBI Observations

In 2012 the AuScope and Hobart 26-m antennas participated in 72 IVS sessions for a total of

146 antenna days of observing. A summary of the sessions is presented in Table 2.

Table 2. AuScope and Hobart 26-m antenna participation (number of days) in IVS sessions in 2012.

Session Antenna

Ho Hb Ke Yg

APSG 1 1

AUSTRAL 4 4 4

CRDS 1 6 3 3

OHIG 3

R1 5 18 17 15

R4 5 16 18 19

T2 1 1 1

Total 11 49 44 42

5. Research Activities

5.1. Source Structure

A key area of research over the past year has involved investigating the effects of quasar

structure and evolution on geodetic solutions. In particular, we have begun using the IVS flux

density data to track quasar evolution. Some promising metrics have been obtained for assessing

92 IVS 2012 Annual Report
University of Tasmania Hobart 12 m and 26 m, Katherine, and Yarragadee

the effects of quasar evolution on source position stability as evaluated by geodetic software. We

plan to develop this work further in the coming year, with the ultimate goal of helping schedulers

decide which quasars should be included in a given IVS session. Other related projects include a

better calibration of the IVS flux density data, and simulation-based evaluation of the effects of

quasar evolution on geodetic measurements.

5.2. Non-tidal Deformation

Taking into account the deformation of the Earth due to a range of well-known geophysical

processes is required to accurately resolve VLBI solution parameters including EOPs and station

coordinates. Models describing the dominant tidal signals (solid Earth tides, pole tide, and ocean

tide loading) are routinely employed following the International Earth Rotation and Reference

Systems Service recommendations. However to achieve greater accuracy at the millimeter level,

non-tidal deformations must also be considered.

To this aim we investigated the effect induced by high-frequency non-tidal ocean loading at

18 Australian geodetic GPS sites. We found that correcting for this effect improved the daily

geodetic observation scatter by up to 15% in 61% of the studied vertical coordinate time series

(mean improvement about 6−8%). Another project has involved the investigation of hydrologically

induced deformation which has a highly spatially correlated regional signature. The temporal

variability in surface gravity, as deduced from the Gravity Recovery And Climate Experiment

(GRACE) data, will help to extract the seasonal signal that will be compared to the geodetic

time series. We aim to assess the improvement in station coordinates and the impact on other

parameter estimates when including these non-tidal deformations in VLBI solutions.

5.3. Antenna Structural Deformation Study

In order to realize the full potential of the telescopes and achieve positional accuracy at the

millimeter level, several sources of systematic error must be understood and mitigated. One such

error source is structural deformation of the telescopes themselves, particularly due to the effects

of thermal expansion. In 2013 we will embark on a high precision survey of the Hobart 12-m

telescope in order to provide an insight into the structural behavior of the telescope. We will use

the Australian Geophysical Observing System (AGOS) robotic telescope monitoring infrastructure,

including a Leica TDRA6000 total station and an array of temperature sensors deployed over the

telescope to study how the structure responds to the diurnal temperature cycle. We will compare

our observations with modelled estimates obtained through computer modelling of the telescope

with the final aim of establishing a corrective model for the AuScope telescopes to mitigate the

effect in our geodetic analysis.

References

[1] Petrachenko, B. et al., 2009, “Design Aspects of the VLBI2010 System. Progress Report of the IVS

VLBI2010 Committee”. NASA/TM-2009-214180, June 2009.

[2] Lovell, J. E. J. et al., 2013, “The AuScope Geodetic VLBI Array”, Journal of Geodesy, accepted.

IVS 2012 Annual Report 93
Kashima 34-m Radio Telescope Kashima Space Research Center, NICT

Kashima 34-m Radio Telescope

Mamoru Sekido, Eiji Kawai

Abstract

The Kashima 34-m radio telescope has been continuously operated and maintained by the National

Institute of Information and Communications Technology (NICT) as a facility of the Kashima Space

Technology Center (KSTC) in Japan. This brief report summarizes the status of this telescope, the

staff, and activities during 2012.

1. General Information

The Kashima 34-m radio telescope (Figure 1, left) was constructed as a main station of the

“Western Pacific VLBI Network Project” in 1988. The telescope has been used not only for geodetic

experiments but also for astronomical observations and spacecraft tracking under collaboration

with National Astronomical Observatory of Japan (NAOJ), Kagoshima University, Institute of

Space and Astronautical Science (ISAS), and other related institutes. The 34-m antenna was

damaged by the big earthquake that occurred in north east Japan on March 11, 2011, and its

operation was stopped for repair work until the end of March 2013.

The Kashima 34-m station is located about 100 km east of Tokyo in Japan. The Kashima 11-

m radio telescope and the International GNSS Service station (KSMV) (Figure 1, right) are also

co-located in the Kashima Space Technology Center. The station is maintained by the Space-Time

Measurement Project of the Space-Time Standards Group, NICT.

34-m radio

Kashima Station

11-m radio

telescope

telescope

GEONET Station

IGS Station

Figure 1. Left panel is a picture of the 34-m diameter radio telescope. Right panel indicates the location of

Kashima KSTC in Japan and locations of 34-m antenna, 11-m antenna, and the GNSS station (KSMV) at

the site.

2. Component Description

The receiver equipment of the Kashima 34-m radio telescope is summarized in Table 1 and

Table 2. For radio frequency interference (RFI) mitigation, a high temperature superconductor

94 IVS 2012 Annual Report
Kashima Space Research Center, NICT Kashima 34-m Radio Telescope

Table 1. Main specifications of the 34-m radio telescope.

Main reflector aperture 34 m

Latitude N 35◦ 57’ 21.27”

Longitude E 140◦ 39’ 36.33”

Height of AZ/EL intersection above sea level 43.7 m

Height of azimuth rail above sea level 26.9 m

Antenna design Modified Cassegrain

Mount type AZ-EL mount

Drive range azimuth ±270◦from the North

Drive range elevation 7◦-90◦

Maximum speed azimuth 0.8

◦/sec

Maximum speed elevation 0.64◦/sec

Maximum operation wind speed 13 m/s

Table 2. The receiver specifications of the 34-m radio telescope.

Band frequency (MHz) Trx (K) Tsys (K) Efficiency SEFD (Jy) Polarization

L 1405-1435 18 45 0.68 200 L/R

S 2193-2350 19 72 0.65 340 L/R

X-n (∗) 8180-9080 40 48 0.68 210 L/R

X-wL(#) 8180-9080 40 67 0.68 300 L/R

X-wH(#) 7860-8360 - 67 0.68 300 L/R

K 22000-24000 105 141 0.5 850 L

Ka 31700-33700 85 150 0.4 1100 R

Q 42300-44900 180 350 0.3 3500 – (†)

∗ : 8 GHz narrow band LNA . # : 8 GHz wide band LNA. † : No Polarizer

(HTS) band-pass filter (2193 - 2473 MHz) for S-band [1], and a conventional band-pass filter (1405

- 1435 MHz) for L-band have been used since 2008.

3. Staff

The engineering and technical staff of the Kashima Station are listed in Table 3.

4. Current Status and Activities

Recent status and activities related to the 34-m radio telescope in the NICT VLBI group are

as follows:

Repair of Azimuth Wheel and Rail Cracking damage to the azimuth wheel, which is due to

the big earthquake, was found in an inspection. Repair work to replace the azimuth wheels

and rails is in progress and will finish at the end of March 2013.

IVS 2012 Annual Report 95
Kashima 34-m Radio Telescope Kashima Space Research Center, NICT

Table 3. The engineering and technical staff of the Kashima station.

Name Responsibility

KAWAI Eiji Operations and maintenance.

SEKIDO Mamoru Operations, maintenance, and coordination of development.

ICHIKAWA Ryuichi Maintaining GNSS observation systems.

TAKEFUJI Kazuhiro Development and experiments of wideband VLBI system.

UJIHARA Hideki Designing of new wideband feed.

TSUTSUMI Masanori Computer network and computer systems.

HASEGAWA Shingo Computers for K5 system and supporting data conversion

for e-transfer of IVS VLBI sessions.

IVS sessions The 34-m antenna could not participate in IVS sessions since 2011 because of the

damages. In April 2013, the 34-m station will return to observing in the IVS sessions as it

used to do.

Data transport of international and domestic VLBI observations has been made via etransfer, rather than a physical shipping of recorded data disks. Depending on the request,

Mark 5 data or K5 data are prepared and provided to IVS correlators from our data server,

which is accessible from the Internet with a 1 Gbps connection.

Development of New Wideband Feed The main project of the VLBI group in NICT is a

VLBI application for frequency comparison between distant atomic frequency standards.

For pursuit of this project, a wideband observation system semi-compliant with a VLBI2010

system is under development. Due to some restriction, we decided to fix four observation

frequency bands (3.2-4.2 GHz, 4.8-5.8 GHz, 9.6-10.6 GHz, and 12.8-13.8 GHz) for the new

observation system. A new wideband feed system for this frequency selection is being designed. It will replace the original C-band receiver. The C-band receiver was already removed

in June 2012, and the new wideband feed system will be installed in 2013.

5. Future Plans

The 34-m station will come back to operation after the first quarter in 2013. As mentioned in the

former section, the new wideband feed is going to be installed, and a new optical wideband signal

transmission system is to be installed for that. A new direct sampling system, which converts an

analog RF signal to digital data without frequency conversion by taking advantages of the aliasing

effect of sampling, is going to be employed experimentally for wideband observing. More details

about technology development at NICT will be found in the NICT Technology Development Center

Report, this volume.

References

[1] Kawai, E., J. Nakajima, H. Takeuchi, H. Kuboki, T. Kondo, M. Suzuki, K. Saito, RFI mitigation at a

2 GHz band by using a wide-band high-temperature superconductor filter, J. Geod. Soc. Jpn., Vol. 54,

No. 1, pp. 31–37, 2008.

96 IVS 2012 Annual Report
Kashima Space Research Center, NICT Kashima 34-m Radio Telescope

[2] Takefuji, K, and H. Ujihara, Technology Development Center at NICT, International VLBI Service for

Geodesy and Astrometry 2012 Annual Report, edited by K. D. Baver and D. Behrend, this volume,

2013.

IVS 2012 Annual Report 97
Kashima and Koganei 11-m VLBI Stations Kashima Space Technology Center, NICT

Kashima and Koganei 11-m VLBI Stations

Mamoru Sekido, Eiji Kawai

Abstract

Two 11-m VLBI antennas at Kashima and Koganei are continuously operated and maintained by the

National Institute of Information and Communications Technology (NICT). This report summarizes

the status of these antennas, the staff, and the activities in 2012.

1. General Information

Figure 1. 11-m VLBI antennas at Kashima (left) and Koganei (right).

Two 11-m VLBI antennas at Kashima and Koganei (Figure 1) have been operating for the

monitoring of crustal deformation of the Tokyo metropolitan area (Key Stone Project) since 1995

[1]. After the regular VLBI sessions with the KSP VLBI Network terminated in 2001, the 11-

m VLBI stations at Kashima and Koganei have mainly been used for research and technical

developments.

2. Component Description

The antenna parameters of Kashima-11 and Koganei-11 are summarized in Table 1. The bandpass filters for S-band (2215-2375 MHz) have been installed since 2010 for RFI mitigation at both

stations. A phase calibration signal (P-cal) of 5 MHz interval has been used instead of a 1 MHz

interval at these KSP stations.

98 IVS 2012 Annual Report
Kashima Space Technology Center, NICT Kashima and Koganei 11-m VLBI Stations

Table 1. The antenna parameters of the 11-m antennas.

Kashima Koganei

Antenna Type Cassegrain type

Diameter of the Main Reflector 11 m

Mount Style Az El mount

Latitude N 35◦ 57’ 19.46” N 35◦ 42’ 37.89”

Longitude E 140◦ 39’ 26.86” E 139◦ 29’ 17.06”

Height of Az/El intersection above sea level 62.4 m 125.4 m

S band 2212 ∼ 2360 2212 ∼ 2360

Input Frequency [MHz] X Low band 7700 ∼ 8200 7700 ∼ 8200

X High band 8180 ∼ 8680 8100 ∼ 8600

S band 3000 3000

Local Frequency [MHz] X Low band 7200 7200

X High band 7680 7600

SEFD [Jy] X-band 5700 9500

S-band 3300 5500

2.1. Kashima-11

Figure 2. Precise temperature control box located at

Kashima 11-m Station.

The original design of these antennas was

identical. However, the frequency of the first

local oscillator of X-H band at the Kashima

11-m station was changed by 80 MHz in 2008,

so that the observation frequency range became

the same as that of the Kashima 34-m station.

A compact hydrogen maser atomic time standard was installed in November 2011. Since

then the reference signal of the Kashima 11-m

station has been provided from this frequency

standard. Also, a precise temperature control

box (PTCB: Figure 2) has been used since 2010

to keep the environmental temperature of the

reference signal distribution unit, which is sensitive to temperature variation, constant. The

PTCB can keep the air temperature variation

in the box within a few tenths of degrees, while

the room temperature around the PTCB varies in the range of a few degrees under the control of

a standard air conditioner.

2.2. Koganei-11

The reference signal (5 MHz) has been provided from an H-maser standard, which has been

synchronized to the UTC(NICT), through the optical loop-back controlled reference signal transIVS 2012 Annual Report 99
Kashima and Koganei 11-m VLBI Stations Kashima Space Technology Center, NICT

mission system since 2009 [2]. Therefore the clock of the Koganei 11-m station is highly stable,

and its rate is maintained to be close to zero with respect to the UTC.

3. Staff

The 11-m antenna stations at Kashima and Koganei are operated and maintained by the members of the Space-Time Standards Laboratory. The staff members contributing to the operation

and maintenance of the 11-m antennas are as follows:

• AMAGAI Jun (Okinawa): has supported Antenna System and Timing Systems at the Koganei 11-m station. He moved to Okinawa Electromagnetic Technology Center in July 2012.

• HASEGAWA Shingo (Kashima): Maintenance of computer system.

• ICHIKAWA Ryuichi (Koganei, Tokyo): Maintenance of meteorological sensors and IGS receivers.

• KAWAI Eiji (Kashima): Overall antenna system.

• SEKIDO Mamoru (Kashima): Operation and overall maintenance of the VLBI systems.

• TAKEFUJI Kazuhiro (Kashima): Operation and maintenance of data acquisition system.

The operation and maintenance of the 11-m VLBI station at Koganei have been also supported

by the Space Weather and Environment Informatics Laboratory and the Space Communication

Systems Laboratory at the Koganei Headquarters of NICT.

4. Current Status and Activities

The two 11-m antennas have been used for a variety of VLBI sessions and single dish sessions

as follows:

International and Domestic VLBI Observation for Geodesy: The Kashima region was

widely affected by the big earthquake that occurred on March 11, 2011 in the north east

area of Japan. Fortunately the Kashima 11-m and Koganei 11-m stations were not seriously

damaged. These two antennas have been participating in IVS-T2, APSG, and JADE sessions since 2011. These participations are important for monitoring the change of the global

positions of the Kashima and Koganei stations after the earthquake.

Data transport of international and domestic VLBI observations are made via e-transfer,

rather than via physical shipping of recorded data disks. Depending on the request, Mark 5

data or K5 data are stored and provided to the correlator from our data server, which is

accessible from the Internet with a 1 Gbps connection.

VLBI Experiments for Frequency Comparison: The Space-Time Standards Laboratory is

in charge of keeping the national standard time of Japan and is developing optical frequency

standards for the primary frequency standards of the next generation. The main mission

of the VLBI group of NICT is the development of a VLBI system that could be used for

frequency comparison between optical frequency standards at intercontinental distances. For

this purpose, a new VLBI system with small diameter antenna pairs and a wideband observation system are under development [3]. Before the new VLBI system becomes available,

100 IVS 2012 Annual Report
Kashima Space Technology Center, NICT Kashima and Koganei 11-m VLBI Stations

test experiments with the 11-m antenna pair will have been conducted several times for a

feasibility study of frequency comparison.

Astronomical Observation: A flare up of the galactic center Sgr-A* of our galaxy is predicted

to occur in the summer of 2013 by Glissen et al. [4]. Based on the proposal by Miyoshi

et al. [5] and Tsuboi et al. [5], monitoring observations of the flux variations of Sgr-A* in

S/X-band were conducted in June, October, and December in 2012. The observations will

be continued until the fall of 2013 at least.

Receiving the Down-link Signal from STEREO Spacecraft: The Koganei 11-m antenna

has been used to download data from the STEREO spacecrafts1in cooperation with the

Space Weather and Environment Informatics Laboratory of NICT. When VLBI sessions or

maintenance work were not scheduled, the Koganei 11-m antenna has been mostly used for

tracking the STEREO.

5. Future Plan

The antenna performance of the Koganei 11-m antenna is about 60% with respect to that of

the Kashima 11-m antenna. The reason for this degradation is not known yet. We are going to

investigate the reason and to recover the performance of the Koganei 11-m antenna to the same

level with that of Kashima 11-m.

References

[1] Special issue for the Key Stone Project, J. Commun. Res. Lab., Vol. 46, No. 1, March 1999.

[2] Fujieda, M., M. Kumagai, S. Nagano, and T. Gotoh, UTC(NICT) signal transfer system using optical

fibers, IVS NICT-TDC News, No. 31, 17-20, 2010.

[3] Takefuji, K. et al., Technology Development Center at NICT, International VLBI Service for Geodesy

and Astrometry 2012 Annual Report, edited by K. D. Baver and D. Behrend, 2013, this volume.

[4] Gillessen, S., et al., A gas cloud on its way towards the supermassive black hole at the Galactic Centre,

Nature, Volume 481, Issue 7379, pp. 51-54 (2012).

[5] Miyoshi, M., et al., private communication, 2012.

[6] Tsuboi, M., et al., Short baseline VLBI Observation of 2013 Event of Sagitarius A*, Astronomical

Society Japan Spring Meeting in 2013, B08a, 2012.

1Two STEREO spacecrafts were launched by NASA in October 2006 to investigate the solar terrestrial environment and to provide 3D images of the Sun and solar storms.

IVS 2012 Annual Report 101
Kokee Park Geophysical Observatory USNO and NASA GSFC

Kokee Park Geophysical Observatory

Ron Curtis

Abstract

This report summarizes the technical parameters of the VLBI system at the Kokee Park Geophysical

Observatory and provides an overview of the activities that occurred in 2012.

1. Location

The Kokee Park Geophysical Observatory (KPGO) is located in Kokee State Park on the island

of Kauai in Hawaii at an elevation of 1,100 meters near the Waimea Canyon, often referred to as

the Grand Canyon of the Pacific. KPGO is located on the map at longitude 159.665◦ W and

latitude 22.126◦ N.

2. Technical Parameters

The receiver is of NRAO (Green Bank) design (dual polarization feed using cooled 15 K HEMT

amplifiers). The antenna is of the same design and manufacture as those used at Green Bank and

Ny- ̊Alesund. A Mark 5B+ recorder is currently used for all data recording.

Timing and frequency is provided by a Sigma Tau Maser with a NASA NR Maser providing

backup. Monitoring of the station frequency standard performance is provided by a CNS (GPS)

Receiver/Computer system. The Sigma Tau performance is also monitored via the IGS Network.

3. Staff

The staff at Kokee Park consists of six full time people employed by ITT Exelis under the

SCNS contract to NASA for the operation and maintenance of the observatory. Chris Coughlin,

Lawrence Chang, Kiah Imai, and Ron Curtis conduct VLBI operations and maintenance. Ben

Domingo is responsible for antenna maintenance, with Amorita Apilado providing administrative,

logistical, and numerous other support functions. Kelly Kim also supports VLBI operations and

maintenance during 24-hour experiments and as backup support.

4. Mission Support

Kokee Park has participated in many VLBI experiments including IVS R4 and R1. KPGO also

participates in the RDV experiments. KPGO averaged two experiments of 24 hour duration each

week, with daily Intensive experiments in 2012. After the earthquake in Japan in March 2011,

KPGO began supporting the INT2 weekend Intensive experiments while data from the Tsukuba

VLBI station was being analyzed for weekend Intensive experiment support. The KPGO support

of the weekend Intensive experiments concluded in April 2012.

Kokee Park also hosts other systems, including a 7-m PEACESAT command and receive antenna, a Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS) beacon and

remote control, a Quasi-Zenith Satellite System (QZSS) monitoring station, a Two-Way Satellite

Time and Frequency Transfer (TWSTFT) relay station, and a Turbo-Rogue GPS receiver. Kokee

102 IVS 2012 Annual Report
USNO and NASA GSFC Kokee Park Geophysical Observatory

Park is an IGS station.

Table 1. Technical parameters of the radio telescope at KPGO.

Parameter Kokee Park

owner and operating agency USNO-NASA

year of construction 1993

radio telescope system Az-El

receiving feed primary focus

diameter of main reflector d 20m

focal length f 8.58m

f /d 0.43

surface contour of reflector 0.020inchesrms

azimuth range 0 . . . 540◦

azimuth velocity 2

◦/s

azimuth acceleration 1

◦/s2

elevation range 0 . . . 90◦

elevation velocity 2

◦/s

elevation acceleration 1

◦/s2

X-band

(reference ν = 8.4GHz, λ = 0.0357m)

8.1 − 8.9 GHz

Tsys 40 K

SSEF D(CASA) 900 Jy

G/T 45.05 dB/K

η 0.406

S-band

(reference ν = 2.3GHz, λ = 0.1304m)

2.2 − 2.4GHz

Tsys 40 K

SSEF D(CASA) 665 Jy

G/T 35.15 dB/K

η 0.539

VLBI terminal type VLBA/VLBA4-Mark 5

Field System version 9.11.1

5. Recent Activities

In January 2012, ITT Exelis support personnel from the Goddard Space Flight Center made a

trip to KPGO and, working with local KPGO staff, were successful in repairing the failed NASA

NR-1 Maser. The NASA NR-1 Maser remains in its backup role to the Sigma Tau Maser for

timing and frequency at KPGO.

The PEACESAT mission came to an end near the end of 2011. In March 2012, KPGO staff

and NOAA personnel performed the de-orbit maneuvers of the GOES-7 spacecraft to formally end

the PEACESAT support at KPGO.

IVS 2012 Annual Report 103
Kokee Park Geophysical Observatory USNO and NASA GSFC

The KPGO 20-m antenna has been in service for 20 years and is starting to show signs of its age

and obsolescence. In March 2012, the KPGO 20-m antenna construction contractor, GD Satcom,

made a site visit to assess some observed anomalies in the 20 m’s mechanical operation. There

is noticeable axial play in the 20 m’s azimuth bearing, and it is outside of design specifications

but still capable of supporting the VLBI mission. The most significant impact of the axial play is

increased wear on the azimuth bull gear teeth caused by the azimuth drive pinions as a result of

the degraded tooth mesh with the axial play of the bearing. The GD Satcom engineers indicated

that the wear on the azimuth bull gear teeth will eventually result in the 20-m antenna falling

out of mission support capability. Actions are being planned to extend the 20 m mission support

life-cycle given the current degraded condition of the azimuth bearing and its impacts.

On June 18, 2012, we started our scheduled experiments while our receiver was in the process

of re-cooling. As the receiver re-cooled, we noticed that the X-band was not present in our

local monitoring systems. We verified the missing X-band with the USNO correlator and began

troubleshooting. We reached out to NRAO and NVI for their insights and quickly narrowed the

issue down to a failed LNA in the dewar of the receiver. The normal process would be to pull the

receiver box and work on removing the dewar with the receiver box in the workshop. With the

current rusted state of the receiver box focus rails, bringing the receiver box to the ground and

then having to re-focus after re-installation presented substantially increased complexity to the

repair efforts. After assessing the side panel access to the receiver box, we were able to partially

disassemble some components from the dewar and carefully remove the dewar itself to examine it

on an operations building workbench. The practice in previous years was to send the dewar back

to NRAO for servicing, which probably would have resulted in an extended period of downtime.

After discussing the process with NRAO, we felt comfortable in working on the dewar ourselves.

We opened the dewar and verified a failed XR LNA with a short to ground on Stage 1. NRAO

had an identical custom built spare on their shelf that they shipped overnight to us to replace the

failed LNA. While waiting for the arrival of the replacement LNA, we used our time to clean other

components in the cryogenic system and replace worn components as necessary in preparation

for re-installation in the receiver box. Some of this work was previously planned including the

running of a new 30A circuit up to the helium compressor on the elevation platform, replacing old

transducers, replacing a damaged refrigerator, and replacing an aging vac-ion pump. We received

the replacement LNA late on June 26 and began work on the dewar first thing in the morning

on June 27. We installed the replacement LNA in the dewar and it tested nominal. We worked

through some Kokee weather issues and completed the dewar reinstallation into the receiver box

and verified nominal status for all components. We re-cooled the receiver into nominal 15K and

50K stage ranges and reached temperature levels we had never previously seen. We discussed this

with NRAO and NVI, and we came to the conclusion that we fixed what might have been a bad

thermistor connection when we installed the replacement LNA. The readings we are seeing now

are very good and nominal. On the morning of June 28 we verified the new LNA readings after it

had been cooled for 24 hours, and all were in nominal ranges. We started observing session R4539

at scan 180-2202 upon our return to operational status. After session I12181, we adjusted the bias

on the XR LNA per NRAO direction to optimize the X-band performance. The extended team

effort by KPGO staff, NRAO, NVI, and remote ITT Exelis support personnel made it possible to

identify the problem and get the issue resolved in a little over a week.

The e-transfer of the INT1 sessions from KPGO to USNO were performed over microwave

infrastructure provided by the Pacific Missile Range Facility (PMRF) and connecting KPGO to

104 IVS 2012 Annual Report
USNO and NASA GSFC Kokee Park Geophysical Observatory

DREN. Plans to migrate to a dedicated fiber connection to DREN at PMRF have been delayed due

to damage to the fibers by a wild fire. MIT is working with the Hawaii Intranet Consortium (HIC)

and DREN to improve the KPGO e-transfer rate. Long term plans are still to make real-time

VLBI data transfers from KPGO a reality.

Figure 1. 20-m S/X dewar. Figure 2. LNA repair.

6. Outlook

GD Satcom is scheduled to make a site visit to KPGO to implement some changes to the

KPGO 20-m antenna configuration in an effort to reduce the wear on the azimuth bull gear teeth

due to the axial play in the azimuth bearing. Those changes include re-alignment of the azimuth

drives to improve teeth mesh between the azimuth pinions and the bull gear. They will also tune

the servo system to decrease the acceleration and deceleration of both the azimuth and elevation

drive systems.

KPGO is making progress in efforts to upgrade the 20-m antenna signal path to VLBI2010

specifications. The RDBE and up-down converter components of a new digital backend system

have been delivered to KPGO from MIT. There have been some discussions on implementing the

digital backend components with the existing 20-m antenna S/X feed, and progress on that is

currently limited by Mark 5C recorder capabilities at both KPGO and correlators. KPGO staff,

ITT Exelis personnel at GSFC, USNO personnel, and MIT have begun planning the final design

and installation of a new broadband front end for the KPGO 20-m antenna.

PMRF is working on repairs to the fiber runs that were damaged by a wild fire. Those repairs

are expected to be completed in the first half of 2013, and progress on establishing a dedicated

fiber path to HIC/DREN for KPGO e-transfers can continue next year.

In September 2012, USNO personnel made a site visit to KPGO to assess possible locations

and local environmental impacts of constructing a next generation VLBI antenna. KPGO will

continue to assist USNO in an effort to establish a next generation VLBI telescope at KPGO.

IVS 2012 Annual Report 105
Matera CGS VLBI Station Agenzia Spaziale Italiana

Matera CGS VLBI Station

Giuseppe Bianco, Giuseppe Colucci, Francesco Schiavone

Abstract

This report describes the status of the Matera VLBI station. Also, in an overview of the station,

some technical characteristics of the system, and staff addresses are given.

1. General

Figure 1. The Matera “Centro di Geodesia Spaziale” (CGS).

The Matera VLBI station is located at the Italian Space Agency’s ‘Centro di Geodesia Spaziale

G. Colombo’ (CGS) near Matera, a small town in the south of Italy. The CGS came into operation

in 1983 when the Satellite Laser Ranging SAO-1 System was installed at CGS. Fully integrated into

the worldwide network, SAO-1 was in continuous operation from 1983 up to 2000, providing high

precision ranging observations of several satellites. The new Matera Laser Ranging Observatory

(MLRO), one of the most advanced Satellite and Lunar Laser Ranging facilities in the world, was

installed in 2002 and replaced the old SLR system. CGS also hosted mobile SLR systems MTLRS

(Holland/Germany) and TLRS-1 (NASA).

106 IVS 2012 Annual Report
Agenzia Spaziale Italiana Matera CGS VLBI Station

In May 1990, the CGS extended its capabilities to Very Long Baseline Interferometry (VLBI),

installing a 20-m radio telescope. Since then, Matera has observed in 876 sessions up through

December 2012.

In 1991 we started GPS activities, participating in the GIG 91 experiment and installing

at Matera a permanent GPS Rogue receiver. In 1994 six TurboRogue SNR 8100 receivers were

purchased in order to create the Italian Space Agency GPS fiducial network (IGFN). At the moment

12 stations are part of the IGFN, and all data from these stations, together with 24 other stations in

Italy, are archived and made available by the CGS Web server GeoDAF (http://geodaf.mt.asi.it).

In 2000 we started activities with an Absolute Gravimeter (FG5 Micro-G Solutions). The

gravimeter operates routinely at CGS, and it is available for external campaigns on request.

Thanks to the co-location of all precise positioning space based techniques (VLBI, SLR, LLR,

and GPS) and the Absolute Gravimeter, CGS is one of the few “fundamental” stations in the world.

With the objective of exploiting the maximum integration in the field of Earth observations, in

the late 1980s ASI extended CGS’ involvement also to remote sensing activities for present and

future missions (ERS-1, ERS-2, X-SAR/SIR-C, SRTM, ENVISAT, and COSMO-SkyMed).

Figure 2. MLRO in action.

IVS 2012 Annual Report 107
Matera CGS VLBI Station Agenzia Spaziale Italiana

2. Technical/Scientific Overview

The Matera VLBI antenna is a 20-meter dish with a Cassegrain configuration and an AZ-EL

mount. The AZ axis has ±270 degrees of available motion. The slewing velocity is 2 deg/sec for

both the AZ and the EL axes.

The technical parameters of the Matera VLBI antenna are summarized in Table 1.

The Matera time and frequency system consists of three frequency sources (two Cesium beam

and one H-maser standard) and three independent clock chains. The EFOS-8 H-maser from

Oscilloquartz is used as a frequency source for VLBI.

Table 1. Matera VLBI Antenna Technical Specifications.

Input frequencies S/X 2210−2450 MHz / 8180−8980 MHz

Noise temperature at dewar flange S/X <20 K

IF output frequencies S/X 190−430 MHz / 100−900 MHz

IF Output Power (300 K at inp. flange) S/X 0.0 dBm to +8.0 dBm

Gain compression S/X <1 dB at +8 dBm output level

Image rejection S/X >45 dB within the IF passband

Inter modulation products S/X At least 30 dB below each of two carriers

at an IF output level of 0 dBm per carrier

Tsys S/X 55/65 K

SEFD S/X 800/900 Jy

3. Staff

The list of the VLBI staff members of the Matera VLBI station is provided in Table 2.

Table 2. Matera VLBI staff members.

Name Agency Activity E-Mail

Dr. Giuseppe Bianco ASI Space Geodesy Manager giuseppe.bianco@asi.it

Francesco Schiavone e-geos Operations Manager francesco.schiavone@e-geos.it

Giuseppe Colucci e-geos VLBI contact giuseppe.colucci@e-geos.it

4. Status

In 2012, 52 sessions were observed. Figure 3 shows a summary of the total acquisitions per

year, starting in 1990.

In 2004, in order to fix the existing rail problems, a complete rail replacement had been planned.

In 2005, due to financial difficulties, it was instead decided that only the concrete pedestal under

the existing rail would be repaired. From then on, no rail movements have been noted [1]-[3].

108 IVS 2012 Annual Report
Agenzia Spaziale Italiana Matera CGS VLBI Station

Figure 3. Acquisitions per year.

5. Outlook

In order to plan the eventual building of a VLBI2010 system, the fund raising investigation

process has been started. At this moment it is not clear when the budget for starting the project

will be ready.

In May 2012, the remaining two azimuth wheels were replaced. The other two were replaced

in 2008 and 2009 respectively.

The process of purchasing a new H-Maser has been already started. The delivery of the new

unit is planned for 2013.

References

[1] M. Mannarella “Relazione sulle misure effettuate sulla rotaia dell’antenna VLBI”, Telespazio doc. OTSPA-SM REL 180010 1140 0222, 21/01/2004.

[2] M. Mannarella “Misure sugli spostamenti indotti sulle piastre e sulla rotaia dell’antenna VLBI”,

Telespazio doc. OT-SPA-SM REL 180010 1320 0661, 06/04/2005.

[3] M. Mannarella “Relazione sull’esito dei lavori di ripristino delle parti ammalorate della fondazione

dell’antenna VLBI”, Telespazio Doc. OT-SPA-SM REL 180010 1320 0732, 27/06/2005.

IVS 2012 Annual Report 109
Medicina Network Station Istituto di Radioastronomia, Medicina

The Medicina Station Status Report

Alessandro Orfei, Andrea Orlati, Giuseppe Maccaferri

Abstract

General information about the Medicina Radio Astronomy Station, the 32-m antenna status, and

the staff in charge of the VLBI observations is provided. In 2012, the data from geodetic VLBI

observations were acquired using the Mark 5A recording system with good results. Updates of the

hardware were performed and are briefly described.

1. The Medicina 32-m Antenna: General Information

The Medicina 32-m antenna is located at the Medicina Radio Astronomy Station. The station

is run by the Istituto di Radioastronomia and is located approximately 33 km east of Bologna.

The Consiglio Nazionale delle Ricerche was the funding agency of the Istituto di Radioastronomia

until the end of 2004. Since January 1, 2005, the funding agency has been the Istituto Nazionale

di Astrofisica (INAF).

The antenna, which was inaugurated in 1983, has regularly taken part in IVS observations

since 1985 and is an element of the European VLBI network. A permanent GPS station (MEDI),

which is a part of the IGS network, is installed in the vicinity. Another GPS system (MSEL) is

installed near the VLBI telescope and is part of the EUREF network.

2. Antenna Description

The Medicina antenna has Cassegrain optics, consisting of a primary mirror that is 32 m in

diameter and a secondary mirror, called the subreflector, of convex shape and approximately 3 m

in diameter. The subreflector, mounted on a quadrupod, is placed opposite the primary mirror

and focuses the radio waves at its center, where the receiver system is located. For some observing

frequencies, a simplified optical system is enough. The subreflector is therefore shifted from its

normal position, and the receiving system is placed at the primary focus. This is the case for the

S-X observations. The antenna can operate in the range between 327 MHz and 22 GHz.

The receivers are cooled with cryogenic techniques to improve the system sensitivity. The antenna’s operative receiver is easily changed; only a few minutes are needed to change the observing

frequency. A recent picture of the antenna is shown in Figure 1.

3. The Staff

Many scientists and technicians take care of the observations. However, a limited number

are dedicated to maintaining and improving the reliability of the antenna during the observations:

Alessandro Orfei is the Chief Engineer, expert in microwave receivers, and Andrea Orlati, Software

Engineer, takes care of the observing schedules and regularly implements SKED, DRUDG, and

the Field System. In 2012, Giuseppe Maccaferri took a half-time contract. Marco Bartolini and

Simona Righini have been temporary included in the staff, helping Andrea Orlati for the VLBI

preparation and observation.

110 IVS 2012 Annual Report
Istituto di Radioastronomia, Medicina Medicina Network Station

Figure 1. View of the Medicina 32-m dish taken during geodetic VLBI observations. Note that the subreflector is shifted to allow the use of the S/X receiver located in the primary focus of the radio telescope.

4. Current Status and Activities

The Mark 5C board and the DBBC have been delivered. At the time of this report they are

on the way to be integrated in the observing system.

A new Helium pipeline and new cryogenic compressors have been installed on the antenna.

The new H-maser has been successfully tested at the factory. It will be delivered before the

end of February.

The driving system of the subreflector is going to be re-engineered; installation, tests, and

commissioning are expected to occur during autumn 2013.

The upgrade of the fiber optic link to 10 Gb/s is complete. A full bandwidth (without data

drop) e-VLBI observation has been carried out. IVS data correlated in Bonn are regularly transferred off-line through optical fiber.

5. Geodetic VLBI Observations

In 2012, Medicina took part in 22 24-hour routine geodetic sessions (namely two IVS-T2, 17

IVS-R4, one R&D, and two EUROPE experiments).

IVS 2012 Annual Report 111
Mets ̈ahovi Radio Observatory Aalto University Mets ̈ahovi Radio Observatory

Mets ̈ahovi Radio Observatory - IVS Network Station

Minttu Uunila, Nataliya Zubko, Markku Poutanen, Juha Kallunki, Ulla Kallio

Abstract

In 2012, Mets ̈ahovi Radio Observatory together with Finnish Geodetic Institute officially became

an IVS Network Station. Eight IVS sessions were observed during the year. Two spacecraft tracking

and one EVN X-band experiment were also performed. In 2012, the Mets ̈ahovi VLBI equipment was

upgraded with a Digital Base Band Converter, a Mark 5B+, a FILA10G, and a FlexBuff.

1. General Information

Aalto University Mets ̈ahovi Radio Observatory and Finnish Geodetic Institute (FGI) are two

separate institutes which together form the Mets ̈ahovi IVS Network Station. Mets ̈ahovi Radio

Observatory operates a 13.7 meter radio telescope at the premises of Aalto University at Mets ̈ahovi,

Kylm ̈al ̈a, Finland about 35 km from the university campus. In the same area, near Mets ̈ahovi

Radio Observatory, there is the Mets ̈ahovi Research Station of FGI.

Figure 1. Mets ̈ahovi Radio Observatory.

2. Component Description

The Mets ̈ahovi Radio Observatory has been operational since 1974. The telescope was upgraded in 1992-1994. The radome was replaced with a new one, and new surface panels were

installed. Mets ̈ahovi together with FGI started observing IVS T2 and EUROPE sessions in 2004.

Approximately six to eight sessions are observed per year. The antenna speed of the Mets ̈ahovi

antenna is 1.2 degrees per second. The surface accuracy of the present telescope is 0.1 mm (rms).

The geodetic VLBI receiver of Mets ̈ahovi uses right circular polarization and 8.15-8.65 and 2.21-

2.35 GHz frequency bands. Astronomical orbservations are also carried out. Mets ̈ahovi is known

for its long-term quasar monitoring. Astronomical VLBI observations are carried out with the 22

GHz receiver.

2.1. Mets ̈ahovi Fundamental Station

Finnish Geodetic Institute (FGI) is running the Mets ̈ahovi Fundamental Station. It is a part

of the IAG GGOS Core station network. The instrumentation includes geodetic VLBI (in cooperation with Aalto University), Satellite Laser Ranging (SLR), DORIS, GNSS, and absolute

112 IVS 2012 Annual Report
Aalto University Mets ̈ahovi Radio Observatory Mets ̈ahovi Radio Observatory

and superconducting gravimeters. Currently, instrumentation is being renewed based on special

funding from the Ministry of Agriculture and Forestry. During the next five years, the plan

includes e.g. a new VLBI2010 compatible radio telescope. FGI is committed to maintain and

develop Mets ̈ahovi as a geodetic fundamental station.

3. Staff

FGI is responsible for the geodetic VLBI observations and is the owner of the S/X receiver.

The radio telescope is owned and operated by the Aalto University, and an annual agreement is

made on its use for geodetic VLBI sessions. It is not possible to increase the number of annual

sessions (currently six to eight), because the telescope is mainly used for astronomical observations.

Operation during the geo-VLBI sessions and technical questions are handled jointly; all other

technical work, telescope maintenance, and maintenance of instrumentation and data connections

are done by the personnel of the radio telescope.

Mets ̈ahovi personnel working with geodetic VLBI observations in 2012 are listed in Table 1.

Dr. Elizaveta Rastorgueva-Foi is in charge of all VLBI observations at Mets ̈ahovi. The theses are

listed in the sub-section: Data analysis. The preparation, operation of GeoVLBI observations, and

submission of data are provided by staff from FGI. The personnel engaged in the work are listed

in Table 2.

Table 1. Mets ̈ahovi Radio Observatory personnel involved in geodetic VLBI observations during 2012.

Name Title Responsibility

Lic.(tech.) Juha Kallunki Laboratory manager VLBI equipment, NEXPReS

M.Sc.(tech.) Ari Mujunen Laboratory manager NEXPReS

Dr. Elizaveta Rastorgueva-Foi VLBI friend VLBI observations

M.Sc. Minttu Uunila Doctoral candidate VLBI equipment

M.Sc.(tech.) Petri Kirves Operating engineer Receivers

Tomi Salminen Research assistant NEXPReS

Table 2. FGI personnel involved in geodetic VLBI observations during 2012.

Name Title Responsibility

Prof. Markku Poutanen Head of the Department of Mets ̈ahovi research station

Geodesy and Geodynamics

Dr. Nataliya Zubko Senior research scientist preparation of GeoVLBI sessions,

operation of GeoVLBI observations,

e-transfer of data

M.Sc. Veikko Saaranen Special research scientist operation of GeoVLBI observations

M.Sc. Ulla Kallio Senior research scientist Local ties measurements

M.Sc. Simo Marila Research scientist operation of GeoVLBI observations

IVS 2012 Annual Report 113
Mets ̈ahovi Radio Observatory Aalto University Mets ̈ahovi Radio Observatory

4. Current Status and Activities

4.1. Geodetic VLBI Experiments

Mets ̈ahovi together with FGI observed eight IVS sessions in 2012. Also two spacecraft tracking

experiments were performed. Mets ̈ahovi radio antenna contributed to the following EURO and T2

IVS sessions: EUR115, EUR116, EUR117, EUR118, T2082, T2083, T2084, and T2086. Most of

the observations were achieved properly. However, some technical problems also occurred during

the observations. In particular, within the EUR115 session, the problems with antenna slewing

appeared a few times, so most of the scans were not recorded. Besides, time differences between the

Field System and the formatter clocks were found during some sessions. Troubles with the Mark 5

recording system happened, but because the observations are simultaneously recorded with two

independent systems, namely Mark 5 and PC-EVN, all the observations were successfully recorded.

For the period of 2012, most of the sessions were observed without antenna cable calibration, due to

technical reasons. Therefore, the possible changes in the cable’s length were not monitored. Most

of the sessions were correlated at the Bonn correlator. The data were sent there via e-transfer

using the Tsunami protocol. In accordance with the correlation reports, the amounts of correlated

observations varied from 60% to 80%.

4.2. Technical Activities and Issues

In December 2012, Mets ̈ahovi successfully tested the new equipment consisting of DBBC and

Mark 5B+ during a Venus Express spacecraft tracking experiment. Also the new standalone

FILA10G together with the new FlexBuff data storage computer developed in the EU NEXPReS

project were successfully deployed.

4.2.1. BBC/DBBC Status

The status of the old VLBI hardware is not as good as it could be: some rack BBCs are

broken. Two of the broken BBCs were repaired, and now a total of 12 BBCs are being used in the

experiments. The repair was done by replacing the BBC’s oscillator chain with a $300 synthesizer.

The DBBC ordered from Hat-Lab arrived in September with the standalone FILA10G. Also, a

new Mark 5B+ arrived in spring of 2012. We successfully tested the new equipment in parallel

with the old equipment in December 2012.

4.2.2. Recording Systems

We have developed a new DAQ system, the FlexBuff, using COTS components. Local UDP

streaming performance tests were performed with wirespeed 10GE. Long (30 minute) tests demonstrated the ability to write at maximum wire speed with zero packet loss. Writing to 34 disks

without a network (using local machines), the architecture can handle 40 Gbps, and it can always

handle > 30 Gbps. We have fixed our Mark 5A 1 Gbps recording problems by changing an R25

resistor to a 27-ohm resistor in the Mark 5A I/O board. We also purchased a Mark 5B+ system,

which is now ready to be used.

114 IVS 2012 Annual Report
Aalto University Mets ̈ahovi Radio Observatory Mets ̈ahovi Radio Observatory

4.2.3. Other Technical Issues at Mets ̈ahovi

Mets ̈ahovi has been suffering from the old formatter being out of sync during various sessions.

After deploying the Mark 5B+ and the DBBC these problems will vanish. Because the phase cal

box is temperature dependent, and because there has been a lot of drifting and phase jumps, the

box will be temperature stabilized. A phase coherence problem due to the 5 MHz reference signal

was found and corrected with a new 5 MHz distribution unit. The 1PPS distributor destroyed the

Mets ̈ahovi 1PPS going to the old VLBI equipment. A new distributor has been purchased.

4.3. Data Analysis

In 2010 FGI and Mets ̈ahovi Radio Observatory received four-year funding from Academy of

Finland to start geodetic VLBI data analysis. During 2012 one doctoral dissertation (Guifr ́e

Molera Calv ́es: “Radio spectroscopy and space science with VLBI radio telescopes for Solar System

research”) and one master’s thesis (N. Kareinen: “Geodetic Very Long Baseline Interferometry

and the effects of Tohoku Earthquake — Case analysis of Tsukuba station”) were finished. In

addition one doctoral dissertation (M. Uunila: “Improving geodetic VLBI: UT1 accuracy, latency

of results and data quality monitoring”) was sent to the pre-examination process in late 2012.

Data analysis at FGI is performed by N. Zubko. The research of stochastic model selection for

GeoVLBI data analysis has been done. Also, the project of source structure study and its influence

on estimated geodetic VLBI parameters has been started with E. Rastorgueva-Foi from Mets ̈ahovi

Radio Observatory. Diego Meschini is responsible for correlation.

4.3.1. Local Ties between VLBI and GPS at Mets ̈ahovi

The local ties measurements between the co-located instruments at Mets ̈ahovi are provided by

Ulla Kallio. A local tie between IGS station METS and the VLBI antenna reference point was

regularly performed with kinematic GPS measurements during the geo-VLBI campaigns starting

in 2008. Testing shows that a millimeter level accuracy can be achieved in local tie vector determination with the kinematic GPS method. In July 2012, the local tie vector between the new Doris

and Regina (GPS) antennas was determined by Thomas Donal and Jean-Claude Poyard (IGN) in

June 2012. The local tie between Regina and VLBI was measured in July with kinematic GPS

during the EUROPE-118 geo-VLBI session. The SINEX file of the tie vector is available.

5. Outlook

In the upcoming years Mets ̈ahovi will continue spacecraft tracking experiments and participating in IVS sessions together with FGI. Five T2 and two EUROPE sessions have been scheduled

for Mets ̈ahovi in 2013. The FlexBuff development and geodetic VLBI data analysis will continue

in 2013.

Acknowledgements

Both the FGI and Mets ̈ahovi teams acknowledge support from the Academy of Finland (grant

number 135101).

IVS 2012 Annual Report 115
National Astronomical Observatory of Japan Mizusawa VLBI Observatory, NAOJ

VERA Geodetic Activities

Takaaki Jike, Yoshiaki Tamura, Makoto Shizugami, VERA group

Abstract

This report briefly describes the geodetic activities of VERA in the year 2012. The regular geodetic

observations are carried out both in K- and S/X-bands. The frequency of regular observations is three

times a month—twice for the VERA internal observations in K-band. The networks of the S/X sessions

are JADE of GSI and IVS-T2. The raw data of the T2 and JADE sessions are electronically transferred

to the Bonn, Haystack, and GSI correlators via Internet.

Gravimetric observations are carried out at the VERA stations. An SG was installed at Mizusawa

and placed in the vicinity of the VERA antenna in order to monitor vertical displacement at the end

of 2008, and the observations continued throughout the year. Also at the VERA-Ishigakijima station,

continuous operation of the SG started in 2012.

The crustal movements generated by the 2011 earthquake off the Pacific coast of Tohoku continued

during 2012, and displacement of the VERA-Mizusawa position by post-seismic creeping continued.

1. General Information

VERA is a Japanese domestic VLBI network consisting of the Mizusawa, Iriki, Ogasawara, and

Ishigakijima stations. Each station is equipped with a 20-m radio telescope and a VLBI backend.

The VERA-Ishigakijima antenna is shown in Figure 1. The VERA array is controlled from the

Array Operation Center (AOC) at Mizusawa via Internet.

The primary scientific goal of VERA is to reveal the structure and the dynamics of our galaxy

by determining three-dimensional force field and mass distribution. Galactic maser sources are

used as dynamical probes, the positions and velocities of which can be precisely determined by

phase referenced VLBI relative to extragalactic radio sources. The distance is measured as a

classical annual trigonometric parallax. The observing frequency bands of VERA are S and X,

K (22 GHz), and Q (43 GHz). Geodetic observations are made in S/X- and K-bands. Q-band is

currently not used for geodesy. Only a single beam is used in K-band in geodetic observations,

although VERA can observe two closely separated (0.2

◦ < separation angle < 2.2◦

) radio sources

simultaneously by using the dual beam platforms.

General information about the VERA stations is summarized in Table 1, and the geographic

locations are shown in Figure 2. Lengths of baselines range from 1000 km to 2272 km. The skyline

at Ogasawara station ranges from 7◦to 18◦ because it is located at the bottom of an old volcanic

crater. The northeast sky at Ishigakijima station is blocked by a nearby high mountain. However,

the majority of the skyline is below 9◦. The skylines at Mizusawa and Iriki are low enough to

observe sources with low elevation. Since Ogasawara and Ishigakijima are small islands in the

open sea and their climate is subtropical, the humidity in the summer is very high. This brings

about high system temperatures in the summer, in particular in K and Q bands. These stations,

as well as Iriki station, are frequently hit by strong typhoons. The wind speed sometimes reaches

up to 60–70 m/s.

2. Component Description

Parameters of the antennas and the front- and back-ends are summarized in Tables 2 and 3,

respectively. Two observing modes are used in geodetic observations. One is the VERA internal

116 IVS 2012 Annual Report
Mizusawa VLBI Observatory, NAOJ National Astronomical Observatory of Japan

Figure 1. VERA-Ishigakijima 20-m antenna. Figure 2. Locations of the VERA stations.

Table 1. General information.

Sponsoring agency Mizusawa VLBI Observatory,

National Astronomical Observatory of Japan

Contributing type Network observing station

Location

Mizusawa 141◦ 07’ 57”.199 E, 39◦ 08’ 00”.726 N, 75.7 m(sea level)

Iriki 130◦ 26’ 23”.593 E, 31◦ 44’ 52”.437 N, 541.6 m(sea level)

Ogasawara 142◦ 12’ 59”.809 E, 27◦ 05’ 30”.487 N, 223.0 m(sea level)

Ishigakijima 124◦ 10’ 15”.578 E, 24◦ 24’ 43”.834 N, 38.5 m(sea level)

mode in K-band with the recording rate of 1 Gbps. The other is the conventional S/X-band mode

with K5-VSSP. JADE, which is GSI’s domestic observation project, and IVS-T2 sessions belong

to this class. Only Mizusawa and Ishigakijima participated in these sessions.

Table 2. Antenna parameters.

Diameter 20-m Slew Azimuth Elevation

Mount Az-El range -90◦ – 450◦ 5

◦ – 85◦

Surface accuracy 0.2mm(rms) speed 2.1◦/sec 2.1◦/sec

Pointing accuracy <12”(rms) acceleration 2.1◦/sec2 2.1◦/sec2

S X K

HPBW 1550” 400” 150”

Aperture efficiency 0.25 0.4 0.47

3. Staff

Noriyuki Kawaguchi is the director of Mizusawa VLBI Observatory. The geodesy group consists of Seiji Manabe (scientist, retired in March 2012), Yoshiaki Tamura (scientist), Takaaki Jike

(scientist), and Makoto Shizugami (engineer).

IVS 2012 Annual Report 117
National Astronomical Observatory of Japan Mizusawa VLBI Observatory, NAOJ

Table 3. Front-end and back-end parameters.

Front-end

Frequency Frequency Receiver Polarization Receiver Feed

band range (GHz) temperature type

S 2.18–2.36 100◦ K RHC HEMT Helical array

X 8.18–8.60 100◦ K RHC HEMT Helical array

K 21.5–24.5 39±8

◦ K LHC HEMT (cooled) Horn

Back-end

Type Channels BW/channel Filter Recorder Deployed

station

VERA 16 16 MHz Digital DIR2000 four VERA

K5-VSSP 16 4 MHz Analog BBC HDD Mizusawa

Ishigakijima

4. Current Status and Activities

4.1. VLBI

VERA observes seven days per week. The 24-hour geodetic sessions are allocated twice or

three times in a month. Among these geodetic sessions, VERA internal geodetic observations in

K-band are performed once or twice in a month, and Mizusawa and Ishigakijima participate in

JADE by GSI or IVS-T2 sessions in S/X-band on a once-a-month basis. The main purpose of

the VERA internal geodetic observations is to determine relative positions of the VERA antennas

accurate enough for astrometric requirements. The purpose of the S/X sessions is to link the VERA

coordinates into the IVS reference frame. The reason for the shift of the observing frequency band

from S/X-band to K-band is to avoid the strong radio interference by cellular phone in S-band,

particularly at Mizusawa. The interfering signal which has line spectra is filtered out. However,

this filtering considerably degrades the system noise temperature. It is likely that the S-band

observing will become impossible in the near future. On the other hand, VERA has the highest

sensitivity in K-band as shown in Table 3. Thanks to the high sensitivity in this band the maximum

number of scans in K-band is 800/station/24-hours, while that in S/X-band is 500 at most. It has

been confirmed that the K-band observations are far more precise, although no correction is made

for ionospheric delay. In fact, standard deviations of the individual determinations of the antenna

positions in K-band are less than half of those in S/X-band.

In order to link the VERA network to the international reference frame, VERA continues

participation in the IVS-T2 sessions by using the Mizusawa and Ishigakijima stations. In 2012, a

long maintenance period during October to December was allocated, during which the azimuth,

elevation, and feed rotator motors were overhauled. Therefore, the period when VERA carried out

regular VLBI observations was from January to September. We participated in six T2 sessions and

in four JADE sessions. VERA internal geodetic observations were carried out 18 times. The final

estimation of the geodetic parameters are derived by using the software developed by the VERA

team.

118 IVS 2012 Annual Report
Mizusawa VLBI Observatory, NAOJ National Astronomical Observatory of Japan

4.2. Other Activities

Continuous GPS observations were carried out at each VERA station throughout the year. The

superconducting gravimeter (SG) installed within the enclosure of the Mizusawa VLBI observatory,

in order to accurately monitor gravity change for the purpose of monitoring height change at

the VERA Mizusawa station, continued acquisition of gravity data. Four water level gauges

surrounding the SG were used for monitoring the groundwater level. The preliminary results show

that gravity variation due to the variation of the water table can be corrected as accurately as the

1μgal level. The SG was newly installed also in the VERA Ishigakijima station, and observing

was started in January 2012. This observing aims at solving the cause of the slow slip event which

occurs frequently around the Ishigaki island.

5. State of the Crustal Movement after the March 11, 2011 Earthquake at Mizusawa

After the 2011 earthquake off the Pacific coast of Tohoku (Mw=9.0) [Epoch=11 March 2011,

14:16:18 JST], VERA-Mizusawa was displaced by co-seismic crustal movement and post-seismic

creeping. Also, during 2012, the creeping continued, although the speed declined (Figure 3).

According to the newest analysis, the co-seismic steps are North=-1.274 m, East=2.337 m, and

Up=-0.128 m in the horizontal coordinate system, and the displacement by creeping amounts to

North=-0.258 m, East=0.756 m, and Up=0.067 m.

Figure 3. Movements of VERA-Mizusawa after 2011.

6. Future Plans

Now, the examination which increases the recording rate to 4 Gbps from 1 Gbps is being carried

out. Furthermore, the examination for changing the recording system from tape recorder to HDD

is also being implemented. With these changes, regular operation of a new software correlator is

due to begin.

IVS 2012 Annual Report 119
Noto VLBI Station Istituto di Radioastronomia INAF, Stazione VLBI di Noto

Noto Station Status Report

G. Tuccari, S. Buttaccio, P. Cassaro, C. Contavalle, G. Nicotra, L. Nicotra, C. Nocita,

L. Papaleo, M. Patern ́o, P.R. Platania, F. Schillir ́o

Abstract

The Noto VLBI station was fully operational in 2012, and the upgrade projects could be restarted,

involving mainly the receiver area. Another important improvement was the activation of the 1 Gbps

network.

1. Frequency Agility

A frequency agility system is in the design phase. The system will install a set of receivers

in the antenna secondary focus so that the receivers will automatically become operative within

a few minutes. The primary focus will receive a revised version of the SXLP receiver that was

developed some years ago but was never used due to the difficult mechanical operations required to

implement it. This frequency agility project has been funded, and the activities started in summer

2012. The C, K, Q, and W receivers will be placed in the secondary focus in fixed position to make

it possible to switch between them in a very short time. The W band will be covered by a revised

version of a receiver acquired from IRAM. This solution is particularly convenient because it can

be implemented as part of the vertex room reconstruction. The receiver will require specialized

installation because it is filled with liquid helium in order to cool it down to the 4K stage, and

the helium must remain in its tank while the antenna moves through a 0 to 90 degree range of

elevation. Noto could join the millimeter VLBI network as soon as it becomes operational.

2. Fiber Optics Connection

A fiber optics link for e-VLBI activities has been activated by the GARR (Italian Academic

and Research Network), and it is now operating at a 1 Gbps data rate since March 2012. An

upgrade increasing the connection rate up to 10 Gbps is planned to become available in the next

few months. The new connection permitted Noto to participate in the e-VLBI EVN observations

and greatly reduced the need to send disk packs to the correlators for the IVS sessions.

3. VLBI2010 at the Station

The Noto station will participate in VLBI sessions with the legacy antenna until it is possible to

install a VLBI2010 12-m antenna. Operations in this technology require adoption of a broadband

receiver and a dedicated backend. The first is under construction with a prototype feed. This

receiver covers the range 2-14 GHz and, apart from the first amplification stages, is fully digital.

Indeed no analog down-conversion is included for the entire band covered up to 14 GHz. In order to

adapt the feed to the 32-m antenna optics, an additional tertiary mirror is planned, to be installed

on the antenna surface during the observation periods. The final destination for this receiver is a

12-m fast slewing VLBI2010 compliant antenna.

The DBBC2 backend in Noto was partly upgraded to DBBC2010. This requires the installation

of a total number of eight 1 GHz bandwidth IFs to provide a total number of boards able to support

120 IVS 2012 Annual Report
Istituto di Radioastronomia INAF, Stazione VLBI di Noto Noto VLBI Station

eight wideband PFB (Polyphase Filter Bank) elements, for a minimum total aggregate output

data rate of 32 Gbps. A FILA10G Ethernet interface, which is already operational at several EVN

stations, is required to produce 32 Gbps output; producing more than 32 Gbps output requires

additional interfaces. Such a board will be installed in Noto in 2013, with the completion of the

DBBC2010 upgrade.

The DBBC3 project financed by Radionet started in July 2012. This project will produce the

newest front-backend system compliant with EVN32Gbps and VLBI2010. The new system will

provide the entire dual polarization VLBI2010 14 GHz broadband coverage in full digital fashion,

including the support for data processing and multiple 40G network capability. It will also include

burst modes and a buffer/recording system, which is an alternative to other VLBI high data rate

recorders and which is able to support external disk-packs at 32-64-128 Gbps. A DBBC3 schematic

block view is shown in Figure 1.

Figure 1. DBBC3 schematic block view.

4. Observations

Noto was scheduled for one 24-hour session per month, starting from February 2012, when the

antenna was again operational after the azimuth track replacement. The scheduled experiments

have been: EUROPE-116, CRF67, EUR117, EUR118, T2084, EUR119, T2085, CRF70, T2086,

IVS 2012 Annual Report 121
Noto VLBI Station Istituto di Radioastronomia INAF, Stazione VLBI di Noto

EUR120, and CRF71. Due to the high number of inoperative, old analog baseband converters, the

efficiency was not as desired. A great effort was made to reactivate the maximum possible number

of such units, but the actual solution to the problem will come with the operational introduction

of the upgraded DBBC backend, in the first half of 2013.

122 IVS 2012 Annual Report
Geodetic Institute, Norwegian Mapping Authority Ny- ̊Alesund Geodetic Observatory

Ny- ̊Alesund Geodetic Observatory

Moritz Sieber

Abstract

In 2012 the 20-m telescope at Ny- ̊Alesund, Svalbard, operated by the Norwegian Mapping Authority

(NMA), took part in 163 out of 168 scheduled sessions of the IVS program. Since spring, all data was

transferred by network, and the receiver monitoring computer was replaced by a bus-coupler. In

autumn, the NMA received building permission for a new observatory from the Governor of Svalbard.

The bidding process and first construction work for the infrastructure will start in 2013.

1. General Information

The Geodetic Observatory of the Norwegian Mapping Authority (NMA) is situated at 78.9◦ N

and 11.9◦ E in Ny- ̊Alesund, in Kings Bay, at the west side of the island of Spitsbergen. This is the

biggest island in the Svalbard archipelago. In 2012, Ny- ̊Alesund was scheduled for 122 24-hour

VLBI sessions, including R1, R4, EURO, RD, T2, and RDV sessions, and 46 one-hour Intensives

within the Int3 program.

In addition to the 20-meter VLBI antenna, the Geodetic Observatory has two GPS antennas in

the IGS system and a Super Conducting Gravimeter in the Global Geodynamics Project (GGP)

installed at the site. The French-German AWIPEV research base in Ny- ̊Alesund operates a DORIS

station. In October 2004, a GISTM (GPS Ionospheric Scintillation and TEC Monitor) receiver was

installed at the Mapping Authority’s structure in the frame of ISACCO, an Italian research project

on ionospheric scintillation observations, led by Giorgiana De Franceschi of the Italian Institute of

Volcanology and Geophysics (INGV). Another Real-Time Ionospheric Scintillation (RTIS) Monitor

was set up by the NMA in November 2012.

2. Component Description

The antenna, which has a 20 m diameter, is intended for geodetic use and receives data in Sand X-band. Its design and construction are similar to those at Green Bank and Kokee Park.

A rack with 14 video-converters, a Mark IV decoder, and a Mark 5 sampler streams the data to

a Mark 5B+ recorder. A Mark 5A unit is used to transfer data via network to the correlators.

Timing and frequency is provided by a NASA NR maser, which is monitored by a CNS system.

3. Staff

The staff at Ny- ̊Alesund consists of four people employed at 75%, which means that three

full-time positions are covered. Each position goes with a two-year contract that can be extended

up to 12 years, but on average people stay three to four years. The observatory is part of the

Geodetic Division of the Mapping Authority with the main office at Hønefoss (near Oslo).

In summer 2012, Carl Petter married and moved with his wife Carina to the mainland –

Congratulations! By end of 2012, Kent Roskifte had been recruited as a new operator, and Moritz

will take over the role of station manager after Carl Petter. See Table 1 for an overview.

IVS 2012 Annual Report 123
Ny- ̊Alesund Geodetic Observatory Geodetic Institute, Norwegian Mapping Authority

Figure 1. Wedding scene in Kongsfjorden (Photo: Linda Bakken).

Table 1. Staff related to VLBI operations at Ny- ̊Alesund.

Hønefoss Section Manager Reidun Kittelsrud

Technical Manager Leif Morten Tangen

Ny- ̊Alesund Station Manager Carl Petter Nielsen (until 2012.12.31)

Engineer Geir Mathiassen

Engineer Kent Roskifte (from 2013.01.01)

Engineer Moritz Sieber

Engineer  ̊Asmund Skjæveland

4. Current Status and Activities

Monitoring After the former receiver monitoring system (based on a 386-board) stopped working

after 16 years, we were looking for alternatives. TIGO ran into similar problems with their

hardware in 2009 and had good experiences with a solution based on a Beckhoff BK9000

bus-coupler. We kindly were provided with their bits of software (which saved us a great

deal of trouble and headache, so thanks a lot!) which fit into our environment.

For the documentation-wiki, at the station some scripts do a good job of generating graphs

of the sessions’ midob-data and thus provide both current data and their recent development

not just for the FS-computer.

Session Performance After spurious phase-cal signals of unknown origin, the phase-cal unit

was replaced during the maintenance-week in October. No bigger problems were observed

afterwards, but the cable is probably beginning to wear out, also.

Four Int3 sessions were not observed due to a crack in one of the support pillars for the sub124 IVS 2012 Annual Report
Geodetic Institute, Norwegian Mapping Authority Ny- ̊Alesund Geodetic Observatory

reflector at Tsukuba-32m. Seshan, which participated instead, was not available for those

four dates.

An overview of sessions with trouble and their explanations can be found in Table 2. All

other sessions were observed according to schedule.

Table 2. Sessions with trouble.

EUR115 general problem with schedule, updated on late notice

R1525 not ready after scheduled maintenance period (installing receiver monitor). The Int3-Intensive on the same day was

replaced by a J-schedule on late notice

R1530 fieldsystem PC hard disk trouble slowing down the RAID

and everything else

R4534 receiver warming up during last six hours

R1539 last six hours warm

RDV93 late start due to cooling down receiver

R4553 FS crashed due to bug in rxcom (the station’s program doing the communication via TCP/Modbus with the receiver

monitor). Restarted, but lost 15 minutes or so

R1559 late start, too late getting schedule

R4560 no data for two hours

R1564 warm receiver during the whole session

E-Transfer All measurement data is transferred by network to the correlators now, to Socorro

with the great help of Haystack, which buffers the data. This is a great improvement since

the ground handling of outbound freight from SAS Cargo and FedEx in Oslo recently became

less and less reliable.

New Instrumentation At the end of April, NavSys AS started broadcasting RTCM3.x-data for

customers of the CPOS-service in the Kings Bay area. Now the positioning accuracy has

increased to a few centimeters, without the need to establish a reference station for each

measurement.

The Norwegian Mapping Authority established two of its own instruments: another RealTime Ionospheric Scintillation (RTIS) monitor at the end of November and an absolute

gravimeter co-located to the existing superconducting gravimeter at the end of December.

New Observatory After the budget was granted in 2011, the Governor of Svalbard approved the

impact analysis of the new observatory project. Construction work for the road will start in

2013, in parallel with the tendering process.

5. Future Plans

After the iron-values for one of the two azimuth gears showed high and increasing values in the

past, it was decided to replace the gearbox with a spare, which will take place during the scheduled

maintenance week in March. Later in 2013 the road construction work to the new observatory’s

location will start. Due to the arctic climate and environmental protection plans, this has to wait

until summer.

IVS 2012 Annual Report 125
German Antarctic Receiving Station (GARS) O’Higgins Bundesamt f ̈ur Kartographie und Geod ̈asie (BKG)

German Antarctic Receiving Station (GARS) O’Higgins

Alexander Neidhardt, Christian Pl ̈otz, Thomas Kl ̈ugel

Abstract

In 2012, the German Antarctic Receiving Station (GARS) O’Higgins contributed to the IVS observing program with four observation sessions. Maintenance and upgrades were made, and a new

replacement dewar is under construction in the observatory at Yebes, Spain.

1. General Information

The German Antarctic Receiving Station (GARS) is jointly operated by the German Aerospace

Center (DLR) and the Federal Agency for Cartography and Geodesy (BKG, under the duties of

the Geodetic Observatory Wettzell (GOW)). The Institute for Antarctic Research Chile (INACH)

coordinates the activities and logistics. The 9-m radio telescope at O’Higgins is mainly used for

the downloading of remote sensing data from satellites ERS-2 (mission ended in September 2012)

and TanDEM-X, for the control and monitoring of spacecraft telemetry, and for geodetic VLBI. In

2012, the station was manned by DLR staff the entire year and by BKG staff only in January and

the beginning of March for the VLBI observations. The VLBI campaign in November-December

2012 had to be canceled due to the reduced staffing situation. Besides engineers and operators

from DLR and BKG, a team for maintaining the infrastructure (e.g. power and generation of fresh

water) was present all year.

Over the last years, special flights using “Hercules C-130”-aircrafts and small “Twin Otter

DHC-6”-aircrafts as well as transportation by ship were organized by INACH in close collaboration

with the Chilean Army, Navy, and Airforce and with the Brazilian and Uruguayan Airforce in order

to transport staff, technical material, and food for the entire campaign from Punta Arenas via Base

Frei on King George Island to O’Higgins on the Antarctic Peninsula. Due to the fact that the

conditions for landing on the glacier are strongly weather dependent and involve an increasing

risk, transport of personnel and cargo is always a challenging task. Arrival and departure times

strongly depend on the climate conditions and on the logistic circumstances.

After the long Antarctic winter the VLBI equipment at the station has to be initialized. Damages resulting from the winter conditions or strong storms have to be identified and repaired.

Shipments of each kind of material, such as spare parts or upgrade kits, have to be carefully prepared in advance.

On location at the site the following instruments are operated:

• An H-Maser, an atomic Cs-clock, a GPS time receiver, and a Total Accurate Clock (TAC)

to offer time and frequency.

• Two GNSS receivers, both operating in the frame of the IGS network, while one receiver is

additionally part of the Galileo CONGO network. The receivers worked without failure in

2012.

• A meteorological station providing pressure, temperature, humidity, and wind information,

as long as the extreme conditions did not disturb the sensors.

126 IVS 2012 Annual Report
Bundesamt f ̈ur Kartographie und Geod ̈asie (BKG) German Antarctic Receiving Station (GARS) O’Higgins

• A radar tide gauge which was installed in 2012. The radar sensor itself is referenced to space

by a GPS antenna mounted on top and referenced to the Earth via the local survey network.

The radar gauge is operated only during the Antarctic summer.

• An underwater sea level gauge for permanent monitoring of water pressure, temperature,

and salinity, which was replaced in 2012.

The 9-m radio telescope is designed for a dual purpose:

• Performing geodetic VLBI, and

• Receiving data from and sending commands to remote sensing satellites, mainly ERS-2 and

TanDEM-X.

Figure 1. The 9-m radio telescope of GARS O’Higgins.

2. Technical Staff

The members of staff for the operation, maintenance, and upgrade of the VLBI system and

other geodetic devices are summarized in Table 1.

Table 1. Staff – members.

Name Affiliation Function Working for

Johannes Ihde BKG interim head of the GOW (till February 2012) GOW

Ulrich Schreiber BKG head of the GOW (since March 2012) GOW

Christian Pl ̈otz BKG electronic engineer O’Higgins (responsible), RTW

Christian Schade BKG geodesist O’Higgins operator, SLR

Reiner Wojdziak BKG software engineer O’Higgins, IVS Data Center

Leipzig

Andreas Reinhold BKG geodesist partly O’Higgins operator

Thomas Kl ̈ugel BKG geologist administration for O’Higgins,

laser gyro and local systems

Wettzell

Rudolf Stoeger BKG geodesist logistics for O’Higgins

Alexander Neidhardt FESG head of the RTW group and VLBI station chief RTW, TTW (partly O’Higgins,

laser ranging)

Gerhard Kronschnabl BKG electronic engineer RTW, TTW (partly TIGO

and O’Higgins)

IVS 2012 Annual Report 127
German Antarctic Receiving Station (GARS) O’Higgins Bundesamt f ̈ur Kartographie und Geod ̈asie (BKG)

3. Observations in 2012

GARS participated in the following sessions of the IVS observing program during the Antarctic

summer campaign (January-March 2012):

• IVS-T2081 February 14 - 15, 2012.

• IVS-OHIG76 February 15 - 16, 2012.

• IVS-OHIG77 February 28 - 29, 2012.

• IVS-OHIG78 February 29 - March 1, 2012,

The observations were recorded with Mark 5A. The related data modules were carried from

O’Higgins to Punta Arenas by the staff on their way back. From Punta Arenas, the disk units

were shipped by regular air freight back to Wettzell and then to the correlator in Bonn, Germany.

4. Maintenance

The extreme environmental conditions in the Antarctic require special attention to the GARS

telescope and the infrastructure. Corrosion frequently results in problems with connectors and

capacitors. Defective equipment needs to be detected and replaced. The antenna, the S-X-band receiver, the cooling system, and the data acquisition system have to be activated properly. A COMserver was replaced by a RS232 converter. The existing GNSS receiver Leica GRX1200GGPRO

was replaced by another Leica GRX1200+GNSS. A problem is the low transfer rates (often with

only 50 kbps) on the communication connection, so that Internet and phone access was reduced.

The Web cams are also regularly maintained.

The defective tide gauge was dismounted. A new system was tested in the workshop and

installed in cooperation with the Chilean military base and the service team of the DLR. The radar

tide gauge was installed for the duration of the campaign and dismounted before the Antarctic

winter.

The construction of the new dewar is in progress in order to replace the original O’Higgins

dewar. This one has to be evacuated permanently by a turbo molecular pump to maintain the

required vacuum due to a leakage.

5. Technical Improvements

The new Symmetricon NTP-server was installed and put into operation. A new meteorological

mast was raised and populated with the required sensors. A new data logger for the meteorological

data was put in operation. The new meteorological station was also integrated into the automated

data acquisition, graphical interfacing, and NASA Field System.

The remote control of complete VLBI-sessions could be extended. Using the newly developed

Wettzell software, the O’Higgins Field System can be controlled over a secure Internet connection

from Wettzell. This is a key feature to extend the operation periods in GARS O’Higgins.

A new NAS server was installed and activated.

128 IVS 2012 Annual Report
Bundesamt f ̈ur Kartographie und Geod ̈asie (BKG) German Antarctic Receiving Station (GARS) O’Higgins

6. Upgrade Plans for 2013

The replacement dewar will be completed. A dedicated plan should offer a shared, interleaved

observation of satellites (DLR) and VLBI sources (BKG) during the whole year. Some antenna

motors must be replaced, and a gear needs to be inspected. There are further plans to replace the

receiver with a more suitable, smaller, and more easily maintained system, similar to the TWIN

tri-band-receiver. This needs to be planned and designed.

IVS 2012 Annual Report 129
Onsala Space Observatory (OSO) Onsala Space Observatory (OSO)

Onsala Space Observatory – IVS Network Station

R ̈udiger Haas, Gunnar Elgered, Johan L ̈ofgren, Tong Ning, Hans-Georg Scherneck

Abstract

During 2012 we participated in 40 IVS sessions. As in the previous four years, we used the majority

of the sessions that involved both Onsala and Tsukuba to do ultra-rapid dUT1 observations together

with our colleagues in Tsukuba. We observed one four-station ultra-rapid EOP session together with

Tsukuba, Hobart, and HartRAO. We also observed the RadioAstron satellite and several GLONASS

satellites using the Onsala 25-m telescope.

The highlight in 2012 was that our proposal to the Knut and Alice Wallenberg Foundation to

establish a twin-telescope system at Onsala in accordance with the VLBI2010 recommendations was

accepted.

1. General Information

The Onsala Space Observatory is the National Facility for Radioastronomy in Sweden with the

mission to support high-quality research in radio astronomy and geosciences. The geoscience instrumentation at Onsala includes equipment for geodetic VLBI, GNSS, a superconducting gravimeter,

several radiometers for atmospheric measurements, both GNSS-based and pressure sensor based

tide gauges, and a seismometer. The Onsala Space Observatory can thus be regarded as a fundamental geodetic station. Figure 1 shows an aerial photo with the location of all of its observational

infrastructure. The area planned for the future Onsala Twin Telescope is highlighted, too.

The staff associated with the IVS Network Station at Onsala remained the same as reported

in last year’s report. Contact information is found on www.chalmers.se/rss/oso-en/.

Figure 1. Aerial photo of the Onsala Space Observatory with the location of all observational infrastructure.

The area planned for the future Onsala Twin Telescope is highlighted as well. The distance between the

20-m telescope and the 25-m telescope is approximately 600 m.

130 IVS 2012 Annual Report
Onsala Space Observatory (OSO) Onsala Space Observatory (OSO)

2. VLBI Observations for Geodesy and Space Navigation

During 2012 Onsala was involved in five IVS observing series, EUROPE, R1, T2, RD, and

RDV, see Table 1. Observations were acquired during 40 IVS sessions. The success rate of our

observations was very high, and in all but two of the sessions that have been correlated so far, the

percentage of scheduled Onsala observations that could be used in the IVS analysis of a session

exceeded the average percentage for the stations in that session. All experiments were recorded

with our Mark IV VLBI rack and recorded on the Mark 5A unit. For all experiments except one,

the data were recorded in parallel on the PCEVN-computer that is daisy-chained to the Mark 5A

unit. This made it possible to e-transfer the data offline to the respective correlators at Bonn and

Haystack. The only experiment where a Mark 5-module needed to be shipped was RDV94, which

is supposed to be correlated at Soccoro.

We used the majority of the R1- and RD-sessions involving both Onsala and Tsukuba to

perform ultra-rapid dUT1 observations. In these cases the Onsala data were e-transferred in

real-time to the Tsukuba correlator using the Tsunami protocol. The data were correlated with

the corresponding data from the Tsukuba station in near real-time, followed by a near real-time

analysis to determine dUT1. Using this automated strategy, dUT1 results were determined already

during the ongoing VLBI observations using a “sliding window” approach.

On December 17-18 we observed the first four-station ultra-rapid EOP experiment, together

with Tsukuba, HartRAO, and Hobart. The experiment was successful, and polar motion and

dUT1 were determined in ultra-rapid mode, i.e. during the ongoing session.

We continued to test our digital VLBI system which consists of a DBBC and a Mark 5B+

recorder. For several experiments the observational data were recorded in parallel with the analog

system and the digital system. The Bonn correlator supported these tests and correlated the data.

Based on these tests we could improve our IF-distribution and optimize the performance of the

digital system. Fringes with the digital system were found for several experiments, and the Bonn

correlator prepared several databases including Onsala both as an analog and as a digital station.

We again participated in observations for space craft navigation. In January we observed a

session to determine the orbit of the RadioAstron satellite. In April we performed an experiment

to observe GLONASS satellites.

Radio interference due to UMTS mobile telephone signals continued to be a disturbing factor for

the S-band observations. We started to systematically map the RFI environment at the observatory

between 2 and 26 GHz.

3. Monitoring Activities in 2012

We continued with the monitoring activities as described in previous annual reports:

Vertical height changes of the telescope tower.

We continued to monitor the vertical height changes of the telescope tower using the invar rod

system at the 20-m telescope. The measurements are available at wx.oso.chalmers.se/pisa/.

IVS 2012 Annual Report 131
Onsala Space Observatory (OSO) Onsala Space Observatory (OSO)

Table 1. VLBI observations for geodesy and space navigation at Onsala during 2012. Information is given

on whether the data were e-transferred in real-time (RT) and/or off-line (OL) and to which correlator,

whether modules were shipped to a correlator, and whether ultra-rapid dUT1 (UR-dUT1) results were

produced. The final column gives general remarks and/or information on the percentage of the scheduled

Onsala observations that were used in analysis (as reported in the IVS session Web pages’ analysis reports),

compared to the station average percentage per experiment.

Exper. Date E-transfer Mod. UR- General remarks, % of scheduled observations

RT OL ship. dUT1 used in analysis (according to IVS analysis reports).

R1-514 01.03 – Bonn – – Onsala: 96.1% (station average: 95.2%)

R1-515 01.09 – Bonn – – Onsala: 94.5% (station average: 92.1%)

RA-01-14 01.14 – JIVE – – OK, RadioAstron observations, 2 h

EUR-115 01.16 – Bonn – – Onsala: 27.9% (station average: 17.8%)

R1-517 01.23 – Bonn – – Onsala 72.9% (station average: 61.9%)

RD-12-01 01.24 – Hays – – Onsala: 96.8% (station average: 95.2%)

R1-518 01.30 – Bonn – – Onsala: 81.7% (station average: 71.8%)

R1-520 02.13 Tsuk Bonn – yes Onsala: 94.0% (station average: 89.5%)

T2-081 02.14 Tsuk Bonn – yes Onsala: 78.8% (station average: 63.2%)

R1-526 03.26 – Bonn – – Onsala: 96.5% (station average: 85.0%)

EUR-116 03.28 – Bonn – – Onsala: 68.8% (station average: 50.1%)

G-0402 04.02 – JIVE – – OK, Glonass observations, 6 h

R1-527 04.02 – Bonn – – Onsala: 84.7% (station average: 69.8%)

RD-12-02 04.03 – Hays – – Onsala: 90.0% (station average: 85.2%)

R1-528 04.10 Tsuk Bonn – yes Onsala: 63.1% (station average: 68.0%)

R1-532 05.07 Tsuk Bonn – yes Onsala: 94.2% (station average: 92.0%)

T2-083 05.08 Tsuk Bonn – yes Onsala: 80.9% (station average: 61.8%)

EUR-117 05.09 – Bonn – – Onsala: 73.8% (station average: 54.8%)

R1-539 06.25 Tsuk Bonn – – Onsala: 64.0% (station average: 43.9%)

R1-540 07.02 – Bonn – – Onsala: 76.6% (station average: 58.8%)

EUR-118 07.03 – Bonn – – Onsala: 73.0% (station average: 53.3%)

R1-545 08.06 Tsuk Bonn – yes Onsala: 92.4% (station average: 88.2%)

R1-546 08.13 Tsuk Bonn – yes Onsala: 96.1% (station average: 90.9%)

RDV-94 08.22 – – Socc – Onsala: 88.1% (station average: 69.0%)

R1-548 08.27 Tsuk Bonn – yes Onsala: 92.8% (station average: 91.4%)

RD-12-06 08.28 Tsuk Hays – yes Onsala: 81.1% (station average: 82.9%)

EUR-119 09.03 – Bonn – – Onsala: 78.7% (station average: 63.9%)

R1-549 09.04 Tsuk Bonn – yes Onsala: 92.6% (station average: 86.4%)

R1-550 09.10 Tsuk Bonn – yes Onsala: 94.5% (station average: 92.5%)

T2-085 09.11 Tsuk Bonn – yes not correlated yet in Bonn

R1-552 09.24 – Bonn – – Onsala: 81.3% (station average: 76.7%)

RD-12-07 09.25 – Hays – – Onsala: 96.6% (station average: 95.4%)

R1-553 10.01 Tsuk Bonn – yes Onsala: 91.7% (station average: 87.4%)

RD-12-08 10.02 Tsuk Hays – yes Onsala: 93.4% (station average: 92.0%)

R1-554 10.10 Tsuk Bonn – yes Onsala: 91.5% (station average: 85.4%)

R1-555 10.15 Tsuk Bonn – yes Onsala: 92.3% (station average: 87.1%)

EUR-120 11.22 – Bonn – – not correlated yet

R1-561 11.26 Tsuk Bonn – yes Onsala: 91.3% (station average: 82.2%)

RD-12-09 11.27 – Hays – – not correlated yet

R1-563 12.10 Tsuk Bonn – yes Onsala: 92.5% (station average: 82.3%)

RD-12-10 12.11 Tsuk Hays – yes not correlated yet

UR-12-03 12.17 Tsuk – – yes ultra-rapid EOP with four stations

R1-564 12.18 Tsuk Bonn – yes Onsala: 94.0% (station average: 90.1%)

132 IVS 2012 Annual Report
Onsala Space Observatory (OSO) Onsala Space Observatory (OSO)

Microwave radiometry.

One water vapor radiometer, Konrad, was in operation continuously during 2012 observing

in a so-called sky-mapping mode. The second water vapor radiometer, Astrid, was operated for

shorter periods in the winter and spring but then had to be upgraded and repaired. The mechanical pointing and the switches for the calibration of the 31 GHz channel were repaired, and since

November 2012 Astrid has been operational again.

Calibration of pressure sensor.

We continued to calibrate the Onsala pressure sensor using a Vaisala barometer borrowed from

the Swedish Meteorological and Hydrological Institute (SMHI). This instrument was installed at

Onsala in late 2002 and has been calibrated at the SMHI main facility in Norrk ̈oping every 1–2

years since then. The latest calibration was on October 11, 2011. Since the installation of a new

VLBI pressure sensor in 2008, the agreement between the Onsala pressure sensor and the SMHI

pressure sensor has been on the level of ±0.1 hPa.

Sea-level monitoring.

The GNSS-based tide gauge was operated continuously at its new location. A tide gauge based

on pressure sensors was operated next to it throughout the year. However, the pressure based tide

gauge was damaged by lightning in the summer and was out of operation for about two months.

Superconducting gravimetry.

The superconducting gravimeter operated continuously during 2012 and produced a highly

precise record of gravity variations. Further information on the superconducting gravimeter can

be found on http://holt.oso.chalmers.se/hgs/SCG/monitor-plot.html.

Absolute gravimetry.

We supported visiting absolute gravity measurement campaigns by the University of Hannover

(Germany) and Lantm ̈ateriet, the Swedish mapping, cadastral, and land registration authority.

Seismological observations.

The seismometer owned by Uppsala University and the Swedish National Seismic Network

(SNSN) was moved from the gravimeter laboratory to a new dedicated underground site on the

observatory premises. The new location has the advantage of being less disturbed by man-made

seismic noise.

4. Outlook

The Onsala Space Observatory will continue to operate as an IVS Network Station and to

participate in the IVS observation series. For 2013, we plan to participate in 40 IVS sessions,

and we envisage completing the transition from our analog to our digital VLBI system. We also

will continue our efforts concerning the ultra-rapid EOP project, together with our colleagues in

Japan, South Africa, and Australia.

A major part of our activities in 2013 will be the Onsala Twin Telescope project that starts

officially in January 2013. The plan is to build two new 12-m diameter radio telescopes following

the VLBI2010 recommendations. In parallel to these efforts, we will operate the 20-m telescope

for geodesy during an overlapping period together with the twin telescope.

IVS 2012 Annual Report 133
Parkes Network Station CSIRO Astronomy and Space Science

Parkes 2012 IVS Report

John Reynolds

Abstract

This report presents the status of the Parkes Observatory in 2012, as well as our future plans.

1. Status

The Parkes Observatory participated in three 24-hour IVS sessions during 2012, compared to six

in the previous year. All three sessions were recorded using the station’s Mark 5b system and were

generally successful, including one recorded using a relatively new “IF3” observing configuration.

A significant development was that data for two of these sessions were transferred electronically

to the correlator at USNO. The intention is that such transfers become more routine during 2013.

Parkes also continues to support a program led by Leonid Petrov (ADNET Systems/GSFC)

of hybrid astronomy/geodesy observations, refining the locations of several Southern Hemisphere

radio stations that are equipped with neither dual S/X receiving systems nor IVS-compatible

recording systems. This program also aims to identify additional calibrator sources in the Southern

Hemisphere for “densification” of the ICRF in the South.

2. Future Plans

The outlook for 2013 and beyond continues to be a little uncertain owing to scheduling constraints arising from changes to the Parkes Operations model that could impact the availability

of the dual S/X receiver. See http://www.atnf.csiro.au/management/atuc/2012feb/docs/carretti

ATUC 1202.pdf for details. This is currently constraining the number of IVS sessions in which

Parkes can participate. We are continuing to work with our Australian colleagues to ensure that

the S/X receiver and recording systems remain available and that the active participation of Parkes

in IVS observing programs continues to be both valued and supported.

134 IVS 2012 Annual Report
National Geographic Information Institute Sejong Station

Korea Geodetic VLBI Station, Sejong

Baek Donghyun, Yi Sangoh, Oh Hongjong, Han Sangchul

Abstract

The Sejong VLBI station officially joined the IVS as a new Network Station in 2012. This report

summarizes the activities of the Sejong station during 2012. The following are the activities at the

station. 1) VLBI test observations were carried out with the Tsukuba 34-m antenna of the GSI in

Japan. As a result, the Sejong antenna needs to improve its efficiency, which is currently in progress.

2) A survey to connect the VLBI reference point to GNSS and ground marks was conducted. 3) To see

the indirect effects of RFI (Radio Frequency Interference) at this place, we checked the omni-direction

(AZ 0◦to 360◦, EL fixed at 7◦) for RFI influence.

1. General Information

The Sejong station is the first geodetic VLBI station in the Republic of Korea which is dedicated

to geodetic purposes only. The station is located about 120 km south of Seoul, in the middle of

Sejong City, which serves as a new administrative capital. The Sejong antenna is 22 meters in

diameter, and its slew speed is 5◦/sec in both azimuth and elevation; its specifications have been

designed for the possible addition of other small antennas in the future.

The observatory was constructed on the top of a small mountain in Sejong City, which was

officially approved as a new town in July 2012. The city is a newly designated administrative

capital city planned by the government, and it will be developed in phases over the next 20 years.

The Sejong VLBI station was previously called “KVG” (Korea VLBI system for Geodesy) which

was named after the project purpose in its initial stage. However, now “Sejong Station” is the

official title to prevent possible confusion in addressing the station.

National Geographic Information Institute (NGII, http://ngii.go.kr) manages the observatory,

and Table 1 shows the staff members of the Sejong station. A newly appointed site director, Mr.

Baek Dong Hyun, started work in November 2012, and Mr. Joo Hyun Hee, who showed outstanding

work in Sejong VLBI construction, was transferred to another group. Staff at the observatory carry

out the VLBI observation, baseline analysis, international cooperation including the IVS, antenna

maintenance, and management of the observatory.

Table 1. Staff members of the Sejong station.

Name Function e-mail

Baek Donghyun Site Director baekdh@korea.kr

Yi Sangoh S/W engineer sangoh.yi@korea.kr

Oh Hongjong H/W engineer stockoh11@korea.kr

Han Sangchul Antenna system hsc4907@korea.kr

2. Sejong VLBI System

The Sejong VLBI configuration is listed in Table 2. The IVS letter codes and the CDP and

DOMES numbers have been newly registered during this year. The antenna has the Cassegrain

IVS 2012 Annual Report 135
Sejong Station National Geographic Information Institute

Figure 1. VLBI 22-m antenna, monument pillars 1 - 4, GNSS, and UCP (Unified Control Point) layout.

shape, and the 22-m main reflector consists of 200 rectangular aluminium panels. Each panel has

four elevation adjustments at the edge of the panel, so that the antenna main reflector surface can

be properly arranged.

Technical parameters of the receiver are presented in Table 3. However, some items are omitted

due to the antenna efficiency improvement work. The Sejong station uses the Field System (version

FS-9.10.4) and a K5 data recorder.

3. Activities in 2012

3.1. VLBI Observation

The Sejong antenna carried out several fringe tests with the Tsukuba 34-m antenna in Japan.

A few observations failed to get fringes due to a wrong setting for time synchronization. After

that we successfully got fringes from all channels in the S and X bands. As a result, the Sejong

antenna needs to improve its antenna efficiency, which is currently in progress.

3.2. Co-location

We performed a ground survey that used four pillars to tie the cross point of the axes of the

VLBI antenna to the Sejong GNSS monument. Figure 2 shows the local tie layout in the site.

The antenna reference position was calculated by a 3D circle fitting method, with measurement of

the distances from the pillars to the reflection sheet on the antenna surface. Therefore, a ground

network consisting of VLBI, GNSS, and the pillars was established. Monitoring for the antenna

reference position and ground subsidence of the new site will regularly be done by local tie survey.

136 IVS 2012 Annual Report
National Geographic Information Institute Sejong Station

Table 2. Sejong Antenna parameters.

Parameters Sejong VLBI

IVS letter codes Sejong (Kv)

CDP number 7368

DOMES number 23907S001

Location 127◦18’E, 36◦31’N Elevation 177 m

Diameter of main reflector 22 m

Antenna type Shaped Cassegrain

Aperture efficiency about 60%

Pointing accuracy 0.0131◦

Reflector surface accuracy 86μm

Operation range AZ: ±270◦ EL: 0 ∼ 90◦

Slew speed 5

◦/sec (AZ and EL)

FS Version 9.10.4

Data acquisition Rack/Recorder K4/K5

Table 3. Receiving system of the Sejong VLBI system.

Bands S X K Q

Freq. [GHz] 2.1-2.6 8.0-9.0 21-23 42-44

Receiver noise temp. < 20K < 30K < 50K < 80K

Polarization R,L R,L R,L R,L

First LO Freq. NONE NONE 13.5 GHz 33.9 GHz

First IF Freq. NONE NONE 8-10 GHz 8-10 GHz

IF Pout/BW -50 dbm/500 MHz

Phase noise@1KHz -120 dBc/Hz

Reference Freq. 100 MHz

3.3. RFI Monitoring

Even at the Sejong site, RFI is unavoidable. We scanned all directions (AZ 0◦to 360◦) at a fixed

elevation of 7◦to see the maximum values in S band (2.2 ∼ 2.4GHz). Figure 3 shows the change

of signal power. It shows that most RFI is detected over 2.3 GHz. It is also direction-dependent.

In other words, there was more RFI coming from the north direction.

4. Future Plans

We will take on the following activities in 2013: 1) The Sejong station, as a new IVS Network

Station in 2012, will participate in regular IVS sessions. 2) Antenna efficiency improvement is

currently in progress. 3) After that, we will proceed to join IVS observing as soon as possible by

contacting the IVS Coordinating Center. 4) A local tie survey is also planned.

IVS 2012 Annual Report 137
Sejong Station National Geographic Information Institute

Figure 2. Facilities for local ties at the Sejong station.

Figure 3. RFI measurement results using a spectrum analyzer.

138 IVS 2012 Annual Report
Shanghai Astronomical Observatory, CAS Sheshan VLBI Station

Sheshan VLBI Station Report for 2012

Bo Xia, Zhiqiang Shen, Xiaoyu Hong, Qingyuan Fan

Abstract

This report summarizes the observing activities at the Sheshan station (SESHAN25) in 2012. It

includes international VLBI observations for astrometry, geodesy, and astrophysics and domestic observations for satellite tracking. We also report on updates and on development of the facilities at the

station.

1. General Information

The Sheshan VLBI station (SESHAN25) is located at Sheshan, 30 km west of downtown

Shanghai. It is hosted by the Shanghai Astronomical Observatory (SHAO), Chinese Academy

of Sciences (CAS). A 25-meter radio telescope is in operation at 1.3, 3.6/13, 5, 6, and 18 cm

wavelengths. The Sheshan VLBI station is a full member of the IVS and EVN. The SESHAN25

telescope takes part in international VLBI sessions in astrometric, geodetic, and astrophysics

research. Apart from its international VLBI activities, the telescope spent a large amount of

time on the Chinese Lunar Project, including the test observations and the tracking campaign of

Chang’E-2.

Figure 1. SESHAN25 Radio Telescope.

2. VLBI Observations in 2012

In 2012, SESHAN25 participated in 19 IVS sessions (including six INT3 Intensive sessions).

SESHAN25 also participated in the EVN sessions in February and October. Because of a VSI-C

IVS 2012 Annual Report 139
Sheshan VLBI Station Shanghai Astronomical Observatory, CAS

card problem, there were no fringes found in R1539 and R1540. In the Chinese Chang’E-2 Lunar

Exploration Project, SESHAN25 observed the Chang’E-2 satellite for two or three sessions per

week.

3. Development and Maintenance of Sheshan Telescope in 2012

A new pcal unit for S/X band was installed in December 2012. The pcal was injected before

the LNA and after the feed. The pcal unit’s input is 10 MHz from the H Maser. The pulse intervals

can be adjusted by FS to 500 KHz, 1 MHz, 2 MHz, 5 MHz, or 10 MHz. Most of the time it works

in 1 MHz mode.

We performed routine maintenance of our antenna from May to June. It included changing

the gear box, painting, and control room decoration.

4. The Staff of the Sheshan VLBI Station

Table 1 lists the group members of the Sheshan VLBI Station. The staff are involved in the

VLBI program at the station with various responsibilities.

Table 1. The staff of the Sheshan VLBI Station.

Name Background Position & Duty Contact

Xiaoyu HONG Astrophysics Director, Astrophysics xhong@shao.ac.cn

Qingyuan FAN Ant. control Chief Engineer, Antenna qyfan@shao.ac.cn

Zhiqiang SHEN Astrophysics Head of VLBI Division zshen@shao.ac.cn

Zhuhe XUE Software Professor, FS zhxue@shao.ac.cn

Quanbao LING Electronics Senior Engineer, VLBI terminal qling@shao.ac.cn

Bin LI Microwave Technical friend, Receiver bing@shao.ac.cn

Tao AN Astrophysics Astrophysics antao@shao.ac.cn

Bo XIA Electronics VLBI friend, VLBI terminal bxia@shao.ac.cn

Hong YU Ant. control Associated Professor, Antenna yuhong@shao.ac.cn

Li FU Ant. mechanics Engineer, Antenna fuli@shao.ac.cn

Jinqing WANG Electronics Engineer, Antenna jqwang@shao.ac.cn

Lingling WANG Software Engineer, VLBI terminal llwang@shao.ac.cn

Rongbing ZHAO Software Engineer, VLBI terminal rbzhao@shao.ac.cn

Weiye ZHONG Microwave Engineer, Receiver wyzhong@shao.ac.cn

Wei GOU Electronics Engineer gouwei@shao.ac.cn

Linfeng YU Electronics Engineer lfyu@shao.ac.cn

Yongbin JIANG Electronics Engineer jyb@shao.ac.cn

Yunxia Sun HVAC Engineer, Refrigeration sunyunxia@shao.ac.cn

Xiaocong Wu Electronics Engineer wuxc@shao.ac.cn

Wen Guo Electronics Engineer gw@shao.ac.cn

Jian Dong Ant. Control Engineer dongjian@shao.ac.cn

140 IVS 2012 Annual Report
Shanghai Astronomical Observatory, CAS Sheshan VLBI Station

5. Outlook

In 2013, the Sheshan radio telescope will take part in 14 24-hour IVS sessions and 12 INT-3

sessions.

IVS 2012 Annual Report 141
Simeiz station Radio Astronomy Lab of Crimean Astrophysical Observatory

Simeiz VLBI Station - Geodetic and Astrophysical Study

A.E. Volvach

Abstract

This report gives an overview about the geodetic VLBI activities at the Simeiz station. It also

summarizes the seasonal and long-term variability of the Black Sea level near Yalta, Odessa, Ochakov,

and Katsively.

1. General Information

The Simeiz VLBI Station (also known as CRIMEA in the geodetic community), operated by

Radio Astronomy Laboratory of Crimean Astrophysical Observatory, is situated on the coast of

the Black Sea near the village Simeiz, 20 km west of the city Yalta in the Ukraine (Figure 1).

Figure 1. Simeiz VLBI station.

The fundamental geodynamics area “Simeiz-Katsively” is also situated on the coast of the

Black Sea near the village Simeiz. It consists of two satellite laser ranging stations, a permanent

GPS receiver, a sea level gauge, and the radio telescope RT-22. All of these components are located

within 3 km (Figure 2).

142 IVS 2012 Annual Report
Radio Astronomy Lab of Crimean Astrophysical Observatory Simeiz station

KATS-PIL

KATS-SLR

RT

22

SIMI-SLR

GPS-CRAO

Figure 2. The geodynamics area “Simeiz-Katsively”.

RT-22, the 22-meter radio telescope which was set in operation in 1966, is among the five

most efficient telescopes in the world. Various observations in the centimeter and millimeter wave

ranges are being performed with this telescope now and will be performed in the near future. First

VLBI observations were performed in 1969 on the Simeiz (RT-22) — Green Bank (RT-43, USA)

intercontinental baseline. RT-22 is equipped with radiometers at the 92 cm, 18 cm, 13 cm, 6 cm,

3.5 cm, 2.8 cm, 2.3 cm, 2.0 cm, 13.5 mm, and 8 mm wavelengths.

2. The Black Sea Level

The 22-m radio telescope RT-22 is located 80 m from the edge of the Black Sea. The geodynamics area “Simeiz-Katsively” consists of two satellite laser ranging stations, a permanent GPS

receiver, a sea level gauge, and the radio telescope RT-22 (Nesterov and Volvach, 2002). All these

components are located within 3 km. The Yalta level gauge is located near Yalta, 20 km east of

RT-22.

A temporal spectrum of the Black Sea level variations and a possible relation between this

spectrum and dynamics of changes in the position of the CRAO RT-22 as an element of the

European geodynamic VLBI network are discussed in [1].

Using some results of the international geodynamic VLBI program for 1994 — 2011, the coordinates of the station Simeiz have been determined. The measurement results for the Simeiz

RT-22 coordinates are compared with long-term monthly-averaged measurements for the Black

IVS 2012 Annual Report 143
Simeiz station Radio Astronomy Lab of Crimean Astrophysical Observatory

Sea level which are performed at the stations located in Odessa, Ochakov, Sevastopol, Yalta, and

Katsively. All the stations of the sea level measurements have a different water flow, which gives

the opportunity to explore global geodynamic processes and a relationship between them and a

solar activity cycle. A spectrum of sea level variations at various points shows the presence of

periods from one to 11 and 22 years. Results are presented in Table 1.

Table 1. The main periods of the Black Sea level variations.

Station Period (month) Value of periodogram

Ochakov 6 376

(1986-2005) 12 5000

14 624

17 675

20 698

40 743

Odessa 6 146

(1945-2010) 12 12839

20 1799

28 1346

44 2851

53 1777

99 1761

132 2806

396 3173

Yalta 6 225

(1992-2003) 10 282

12 1420

14 586

21 358

29 643

Katsively 6 363

(1992-2009) 12 1986

17 594

40 754

The periods for each station’s level are estimated separately with the use of wavelet analysis

(Figure 3).

3. Current Status and Activities

During last year the Space Geodesy and Geodynamics stations regularly participated in the

International Network programs — IVS, the International GPS Service (IGS), and the International

Laser Ranging Service (ILRS).

During the period of January 1 – December 31, 2012, the Simeiz VLBI station participated

in 12 24-hour geodetic sessions. Simeiz regularly participated in the EUROPE and T2 series of

144 IVS 2012 Annual Report
Radio Astronomy Lab of Crimean Astrophysical Observatory Simeiz station

Figure 3. Wavelet analysis of the sea level in Odessa.

geodetic sessions.

Use of the Simeiz antenna is shared with the “Radioastron” program: the testing of the groundbased segment of the Radioastron mission at wavelengths of 1.35 cm.

In accordance with the scientific cooperation between Ukraine and Russia, the Simeiz (radio

astronomy laboratory) team held a series of studies for the preparation of the operation of the

ground segment of the “RadioAstron” mission. Using the 22-m radio telescope RT-22, the team

prepared the scientific program of measurements, a substantial part of which is the study of the

compact structures in the extragalactic sources. For testing of the model of the ground segment

of “Radioastron”, RT-22 of Crimean Astrophysical Observatory in Simeiz and RT-70 (P-2500) in

Evpatoria jointly conducted ground-based VLBI test experiments at 1.35 cm [2].

4. Future Plans

Our plans for the coming year are the following: to put into operation the VLBI Data Acquisition System DBBC, to upgrade the laser of the SLR Simeiz-1873 station, and to set up a new

GPS station near the Simeiz VLBI station.

References

[1] M.I. Ryabov, A. E. Volvach, et al., // Space Science and Technology. 2012. T.18. N.1. P.13 — 20.

[2] Volvach A.E., Kostenko V.I., Larionov M.G., Volvach L.N., et al. // Bulletin of the Crimean Astrophysical Observatory. 2012. T.108. N.1. P.1 — 7.

IVS 2012 Annual Report 145
Svetloe Station Institute of Applied Astronomy of Russian Academy of Sciences

Svetloe Radio Astronomical Observatory

Sergey Smolentsev, Ismail Rahimov

Abstract

This report summarizes information about the Svetloe Radio Astronomical Observatory activities

in 2012. Last year, a number of changes took place in the observatory to improve some technical

characteristics and to upgrade some units to their required status. The report provides an overview of

current geodetic VLBI activities and gives an outlook for the future.

1. General Information

The Svetloe Radio Astronomical Observatory (Figure 1) was created by the Institute of Applied

Astronomy (IAA) as the first station of the Russian VLBI network QUASAR [1].

The sponsoring organization of the project is the Russian Academy of Sciences (RAS). The

Svetloe Radio Astronomical Observatory is situated near the village Svetloe, in the Priozersky

district, Leningrad Region (Table 1). The geographic location of the observatory is shown on the

IAA RAS Website: http://www.ipa.nw.ru/PAGE/rusipa.htm. The main instruments of the observatory are the 32-m radio telescope equipped with special technical systems for VLBI observations,

GPS/GLONASS/Galileo receivers, and the SLR system.

Figure 1. Svetloe observatory.

146 IVS 2012 Annual Report
Institute of Applied Astronomy of Russian Academy of Sciences Svetloe Station

Table 1. Svetloe Observatory location and address.

Longitude 29◦47′

Latitude 60◦32′

Leningrad region, Priozerski district

188833 Russia

rahimov@osvtl.spb.ru

2. Technical Staff

Prof. Ismail Rahimov — the head of the observatory,

Vladimir Tarasov — the chief engineer,

Tatiana Andreeva — the engineer, and

Andrey Mikhailov — FS, pointing system control specialist.

3. Technical and Scientific Information

Table 2. Technical parameters of the radio telescope.

Year of construction 2000

Mount AZEL

Azimuth range ±270◦

(from south)

Elevation range from −5

◦

to 95◦

Maximum azimuth *

- velocity 0.83 ◦/s

- tracking velocity 2.5

′/s

- acceleration 12.0

′/s2

Maximum elevation *

- velocity 0.5

◦/s

- tracking velocity 0.8

′/s

- acceleration 12.0

′/s2

Pointing accuracy better than 10′′

Configuration Cassegrain (with asymmetrical subreflector)

Main reflector diameter 32 m

Subreflector diameter 4 m

Focal length 11.4 m

Main reflector shape quasi-paraboloid

Subreflector shape quasi-hyperboloid

Main reflector surface accuracy ± 0.5 mm

Frequency range 1.4–22 GHz

Axis offset * 5.5 ± 2.0 mm

* These values were changed to optimize the performance of the antenna system. The axis

offset was measured in summer 2011 by geodesist Andrey Shamov.

IVS 2012 Annual Report 147
Svetloe Station Institute of Applied Astronomy of Russian Academy of Sciences

4. Co-location of VLBI, GPS/GLONASS, and SLR System

The Topcon GPS/GLONASS/Galileo receiver with meteo station WXT-510 is in operation

(Figure 2).

Figure 2. Topcon GPS/GLONASS/Galileo receiver at Svetloe observatory.

The SLR system “Sazhen-TM” (Figure 3) was mounted in October 2011 and joined ILRS in

March 2012.

The technical characteristics of the system are presented in Table 3.

Figure 3. “Sazhen-TM” SLR system at Svetloe observatory.

5. Current Status and Activities

The Svetloe observatory participates in IVS and domestic VLBI observing programs. In 2012,

Svetloe station participated in 28 diurnal IVS-R4, IVS-T2, and EURO sessions and in 18 IVS

Intensive sessions.

148 IVS 2012 Annual Report
Institute of Applied Astronomy of Russian Academy of Sciences Svetloe Station

Table 3. Technical parameters of the SLR system “Sazhen-TM”.

Ranging distance, day 400-6000 km

Ranging distance, night 400-23000 km

Aperture 25 cm

Wavelength 532 nm

Beam divergence 12′′

Laser pulse frequency 300 Hz

Pulse energy 2.5 mJ

Mass 170 kg

Normal points precision 1 cm

Angular precision 1-2′′

Svetloe participated in 47 diurnal sessions of the domestic Ru-E program for determining all

Earth orientation parameters, and in 36 one-hour Ru-U sessions to obtain Universal Time using

e-VLBI data transfer.

6. Outlook

We have the following plans for the coming year:

• To participate in IVS observations

• To carry out domestic observing programs to obtain Universal Time with e-VLBI data transfer and Earth orientation parameters once a week

• To carry out SLR observations of geodetic and navigation satellites

• To participate in EVN and RADIOASTRON observing sessions

• To continue geodetic monitoring of the antenna parameters.

References

[1] Finkelstein A., Ipatov A., Smolentsev S. The Network “Quasar”: 2008-2011 // “Measuring the future”, Proceedings of the Fifth IVS General Meeting, A. Finkelstein, D. Behrend (eds.), St. Petersburg,

“Nauka”, 2008. pp. 39–46.

IVS 2012 Annual Report 149
JARE Syowa Station 11-m Antenna National Institute of Polar Research

JARE Syowa Station 11-m Antenna, Antarctica

Yuichi Aoyama, Koichiro Doi, Kazuo Shibuya

Abstract

In 2012, the 52nd and the 53rd Japanese Antarctic Research Expeditions (hereinafter, referred to

as JARE–52 and JARE–53, respectively) participated in five OHIG sessions — OHIG76, 78, 79, 80,

and 81. These data were recorded on hard disks through the K5 terminal. Only the hard disks for the

OHIG76 session have been brought back from Syowa Station to Japan, in April 2012, by the icebreaker,

Shirase, while those of the other four sessions are scheduled to arrive in April 2013. The data obtained

from the OHIG73, 74, 75, and 76 sessions by JARE–52 and JARE–53 have been transferred to the

Bonn Correlator via the servers of National Institute of Information and Communications Technology

(NICT). At Syowa Station, JARE–53 and JARE–54 will participate in six OHIG sessions in 2013.

1. General Information

To investigate polar science, the National Institute of Polar Research (NIPR) is managing

Japanese Antarctic Research Expeditions (JAREs). The 31 members of JARE–53 overwintered at

Syowa Station, East Ongul Island, East Antarctica in 2012.

Syowa Station has become one of the key observation sites in the Southern Hemisphere’s

geodetic and geophysical networks (shown in Figure 1), as reported in [1]. As part of these

geodetic measurements, the JAREs have been operating the 11-m S/X–band antenna at Syowa

Station (69.0◦S, 39.6◦E) for geodetic VLBI experiments since February 1998. A total of 102 quasiregular geodetic VLBI experiments were performed by the end of 2012.

Figure 1. Syowa VLBI antenna. Figure 2. Syowa VLBI staff of JARE–53, H.

Hayakawa (right) and T. Yoshioka (left).

150 IVS 2012 Annual Report
National Institute of Polar Research JARE Syowa Station 11-m Antenna

2. Component Description

For VLBI, the Syowa antenna is registered as IERS Domes Number 66006S004 and as CDP

Number 7342. The basic configuration of the Syowa VLBI front-end system has not changed from

the description in [2]. Syowa’s K4 recording terminal had been fully replaced by K5 simultaneously

with the termination of the SYW session at the end of 2004. Syowa has participated in the OHIG

sessions in the austral summer season since 1999. Data transfer through an Intelsat satellite link

from Syowa Station to NIPR has been available since 2004. However, its recent bandwidth is about

2 MB, and its effective speed of FTP transfer is about 100kB/sec which is too slow to transfer the

huge VLBI data practically.

3. Staff of the JARE Syowa Station 11-m Antenna

The Syowa Station 11–m antenna is operated and maintained by JARE and NIPR. The staff

members are listed in Table 1. OHIG sessions in 2012 were performed primarily by the staff of

JARE–53 as shown in Figure 2. The staff of JARE–52 supported them in the OHIG76 session,

in order to hand the operation and maintenance of the 11–m antenna over to JARE–53 as their

successor.

Table 1. Staff members.

Name Affiliation Function

Kazuo SHIBUYA NIPR Project coordinator

Koichiro DOI NIPR Liaison officer

Yuichi AOYAMA NIPR Liaison officer

Syunsuke IWANAMI Tomakomai Nationl Chief operator of JARE–52

College of Technology

Shinobu TAKAHIRA NEC Antenna engineer for JARE–52

Hideaki HAYAKAWA NIPR Chief operator of JARE–53

Takeshi YOSHIOKA NEC Antenna engineer for JARE–53

JARE–52: February 2011 – January 2012 JARE–53: February 2012 – January 2013

4. Current Status and Activities

4.1. Notes on System Maintenance

There used to be two hydrogen masers, Anritsu RH401A HM–1001C and HM–1002C at Syowa

Station. Since a failure had occurred in the HM–1002C, it had been repaired and overhauled

at Anritsu Co., Ltd. in Japan between April and October 2011. We attempted to return the

HM–1002C to Syowa Station immediately. However, it was impossible to transport it, because the

icebreaker, Shirase, could not approach Syowa Station in the 2011/2012 austral summer season due

to dense and thick sea ice. Then the HM–1002C was turned back to Japan in April 2012 and was

maintained at Anritsu Co., Ltd. until October 2012. Although we planned to re-install the HM–

1002C at the Syowa Station again in the 2012/2013 austral summer season, we had to abandon its

re-installation, because Shirase could not approach Syowa Station for a second consecutive year.

The other hydrogen maser, HM–1001C, has operated for VLBI observations since January

IVS 2012 Annual Report 151
JARE Syowa Station 11-m Antenna National Institute of Polar Research

2011. On March 11, 2011, its ion pump was interrupted, and an uninterruptible power supply

(UPS) for the HM–1002C was broken down by instability in both the voltage and the frequency of

the generator for power supplies at Syowa Station. Since then, the ion pump has been interrupted

occasionally. In 2012, such interruptions, which caused a low vacuum inside the HM–1001C and

attenuated the hydrogen maser oscillator, occurred on February 25, August 15, September 2, and

November 20. The JARE–53 staff had to form a high vacuum and to check the hydrogen maser

generation at all such times. They also checked that there was no apparent difference in 1 PPS and

10 MHz between HM–1001C and GPS whenever they restarted the HM–1001C. For the purpose

of lightening these work loads, we have purchased a new hydrogen maser, which is miniaturized

to be carried on the helicopter. We will install the new one in Syowa Station in the next austral

summer.

Write errors sometimes occurred during data recording to HDD of the K5 system, so that the

K5 system froze. These were caused by inadequate setting for the ATA transfer mode. Starting

with OHIG81, we configured the ATA transfer mode with UDMA66; therefore such problems were

solved.

A system for delay calibration (D–Cal) recording is independent of the K5 system. D–Cal

signals used to be recorded at the start and the end of each Syowa scan onto the floppy disk (FD)

by using a Basic program based on the old NEC PC. However, timing to record D–Cal came to be

unsynchronized with each Syowa scan since the updating of SKED in 2010. We have not modified

this program yet. In addition, the FD drive broke down in November 2012, so that we could not

record D–Cal during OHIG79-81. The broken FD drive was replaced by a spare in January 2013,

and D–Cal signals resumed being stored on FD.

4.2. Session Status

Table 2 summarizes the status of processing as of December 2012 for the sessions after 2011.

The OHIG sessions involved Fortaleza (Ft), O’Higgins (Oh), Kokee Park (Kk), TIGO Concepci ́on

(Tc), Hobart 26-m antenna (Ho), Hobart 12-m antenna (Hb), HartRAO (Hh), Warkworth (Ww),

and Syowa (Sy). In 2005, Syowa joined the CRD sessions, but after 2006, Syowa participated only

in OHIG sessions. Syowa took part in five OHIG sessions in 2012.

K5 HDD data brought back from Syowa Station were transferred to NICT servers and converted

to the Mark 5 format data there. The converted data were transferred from the NICT servers to

the Bonn Correlator by FTP.

4.3. Analysis Results

As of December 2012, Syowa had contributed 93 sessions starting in May 1999. According to

the results analyzed by the BKG IVS Analysis Center, the length of the Syowa–Hobart baseline is

increasing with a rate of 55.5 ± 1.1 mm/yr. The Syowa–HartRAO baseline shows a slight increase

in its length with a rate of 12.3 ± 1.1 mm/yr. The Syowa–O’Higgins baseline also shows a slight

increase, although its rate is only 2.4 ± 1.1 mm/yr. Detailed results from the data until the end

of 2003 as well as comparisons with those from other space geodetic techniques were reported in

[3].

152 IVS 2012 Annual Report
National Institute of Polar Research JARE Syowa Station 11-m Antenna

Table 2. Status of OHIG sessions as of December 2012.

Code Date Station Hour Correlation Solution Notes

OHIG70 2011/Feb/02 Sy, Hb, Hh, Ho, Kk, Oh, Tc 24 h Yes Yes J52 †1

OHIG71 2011/Feb/08 Sy, Hb, Hh, Kk, Oh, Tc 24 h Yes Yes †1

OHIG72 2011/Feb/09 Sy, Hh, Kk, Oh, Tc 24 h No No †1

OHIG73 2011/Nov/01 Sy, Ft, Kk, Ww 24 h Yes Yes †1

OHIG74 2011/Nov/08 Sy, Ft, Kk, Tc, Ww 24 h Yes Yes

OHIG75 2011/Nov/09 Sy, Ft, Kk, Tc, Ww 24 h Yes Yes

OHIG76 2012/Feb/15 Sy, Ft, Hh, Kk, Oh, Tc 24 h Yes Yes J53

OHIG77 2012/Feb/28 Ft, Kk, Oh, Tc 24 h – – †2

OHIG78 2012/Feb/29 Sy, Ft, Hh, Kk, Oh, Tc 24 h – –

OHIG79 2012/Nov/06 Sy, Ft, Hb, Kk, Tc 24 h – –

OHIG80 2012/Nov/07 Sy, Ft, Hb, Kk, Tc 24 h – –

OHIG81 2012/Nov/14 Sy, Hb, Hh, Kk, Tc 24 h – –

J52: JARE–52, op S. Iwanami eng S. Takahira

J53: JARE–53, op H. Hayakawa eng T. Yoshioka

†1 : Large clock offset occurred.

†2 : Syowa canceled participation in OHIG77 experiment because of malfunction of HM–1001C.

5. Future Plans

Dismantling the current Syowa VLBI antenna is scheduled for the 2015/2016 austral summer

season. Because Shirase could not approach Syowa Station for two consecutive years, this schedule will possibly be postponed. We presented a proposal to budget for new VLBI2010 antenna

construction in 2018. We will make every effort until this proposal is approved.

References

[1] Shibuya, K., Doi, K., and Aoki, S. (2003): Ten years’ progress of Syowa Station, Antarctica, as a

global geodesy network site. Polar Geoscience, 16, 29-52.

[2] Shibuya, K., Doi, K., and Aoki, S. (2002): JARE Syowa Station 11-m Antenna, Antarctica, in

International VLBI Service for Geodesy and Astrometry 2002 Annual Report, 149-152, NASA/TP2003-211619, ed. by N. R. Vandenberg and K. D. Baver.

[3] Fukuzaki, Y., Shibuya, K. Doi, K., Ozawa, T., Nothnagel, A., Jike, T., Iwano, S., Jauncey, D.L.,

Nicolson, G.D., and McCulloch, P.M. (2005): Results of the VLBI experiments conducted with

Syowa Station, Antarctica. J. Geod., 79, 379-388.

IVS 2012 Annual Report 153
TIGO Network Station Bundesamt f ̈ur Kartographie und Geod ̈asie - TIGO

Status of the TIGO VLBI Station in Concepci ́on

Hayo Hase, Cristian Herrera, Felipe Pedreros, Octavio Zapata, Pedro Pino

Abstract

The main activities at the TIGO VLBI station during 2012 have been 120 successful VLBI sessions

and the investigation of an alternate site for TIGO for future operation.

1. General Information

Since 2002, TIGO has been located in the terrain of the Universidad de Concepci ́on (longitude

73.025 degrees West, latitude 36.843 degrees South), in Concepci ́on, Chile.

The TIGO project is carried out on the basis of governmental decree 489, which considers

four Chilean institutions as project partners for the German Federal Agency of Cartography and

Geodesy (BKG). Two Chilean partners had left in 2004 and 2007, and by the end of 2011 the

Universidad de Concepci ́on, as the main partner, had to recall its commitment to the TIGO

project. Hence with the beginning of 2012 only one Chilean partner remained for the German

BKG: the Instituto Geogr ́afico Militar. The TIGO project lacks management to achieve financial

support by the Chilean government. A temporary financial aid from BKG allowed for continuous

operation in 2012 and 2013. Without full Chilean support, Germany is obliged to find new partners

elsewhere and to look for an alternate site for its future operation. The candidate site is the

Instituto Argentino de Radioastronom ́ıa (IAR) near La Plata in Argentina.

2. Component Description

The IVS Network Station TIGOCONC constitutes the VLBI part of the Geodetic Observatory

TIGO, which was designed to be a fundamental station for geodesy. Hence, the VLBI radio

telescope is co-located to an SLR telescope (ILRS site), a GPS/Glonass permanent receiver (IGS

site), and other instruments such as a seismometer, a superconducting gravimeter, and an absolute

gravity meter.

The atomic clock ensemble of TIGO consists of three hydrogen masers, three cesium clocks, and

four GPS time receivers realizing the Chilean contribution to the Universal Time scale (Circular

T, BIPM).

The technical parameters of the TIGO radio telescope as published in [1] have not been changed.

3. Staff

The 2012 VLBI staff consisted of four persons, as listed in Table 1. Felipe Pedreros left TIGO

in July to work for one year at the South Pole station. He was replaced by Pedro Pino. Octavio

Zapata reduced his obligations from full-time to half-time for the second part of the year.

154 IVS 2012 Annual Report
Bundesamt f ̈ur Kartographie und Geod ̈asie - TIGO TIGO Network Station

Figure 1. 2012 VLBI Staff: Herrera, Zapata (until December), Pedreros (until July), and Hase. Not shown

in the photo is Pedro Pino, who replaced Felipe Pedreros.

Table 1. TIGO-VLBI support staff in 2012.

Staff Function Email Remark

Hayo Hase Head hayo.hase@tigo.cl

Cristian Herrera Informatic Engineer cristian.herrera@tigo.cl

Felipe Pedreros Telecommunications Engineer felipe.pedreros@tigo.cl until July 2012

Octavio Zapata Telecommunications Engineer octavio.zapata@tigo.cl until December 2012

Pedro Pino Electronic Engineer pedro.pino@tigo.cl since August 2012

all VLBI operators vlbistaff@tigo.cl

4. Current Status and Activities

4.1. IVS Operation

During 2012, TIGO was scheduled to participate in 120 regular IVS sessions. Three 24-hour

additional participations had been carried out within the TANAMI-project [2]. Table 2 gives an

overview about the participation of TIGOCONC in 2012. Out of 123 requested observation days,

120 could be observed successfully, reaching an efficiency of 97%. The main reasons for data

loss have been related to technical problems in the refrigerating system of the receiver, recording

problems on bad data carriers, and unexpected delays in the customs clearance procedure of data

carriers.

Table 2. TIGO’s IVS observation statistics for 2012.

Name R1xxx R4xxx OHIGxx T2 RD TANAMI Total IVS

# of Exp. 52 52 6 2 8 3 123

Correlated 50 52 5 2 8 3 120

No result 2 0 1 0 0 0 3

IVS 2012 Annual Report 155
TIGO Network Station Bundesamt f ̈ur Kartographie und Geod ̈asie - TIGO

4.2. Search for New Site for TIGO

Some conversations between Germany and Argentina concerning a future cooperation for the

operation of a Geodetic Observatory have been fruitful. A potential site for TIGO was identified

at the Instituto Argentino de Radioastronom ́ıa (IAR) near La Plata in Argentina. From July to

October 2012 investigations into the radio frequency situation at IAR were carried out. From the

data of one month of continuous monitoring, it was concluded that the proposed site is suitable

for future VLBI observations [3]. During November 2012 three engineers from IAR visited TIGO

in order to become familiar with the necessities of this observatory (Figure 2).

Figure 2. Visit of technical staff from IAR in November 2012: Guillermo Gancio, Augusto Cassino, and

Daniel Perilli.

5. Future Plans

The VLBI activities in 2013 will be focused on:

• Execution of the IVS observing program for 2013, and

• Preparation and disassembling of TIGO for its transportation to a new site.

References

[1] Vandenberg, N.R.: International VLBI Service for Geodesy and Astrometry 1999 Annual Report,

NASA/TP–1999-209243, 1999.

[2] M. Kadler, R. Ojha, S. Tingay, and J. Lovell, The TANAMI Program: Southern-Hemisphere VLBI

Monitoring of Relativistic Jets in Active Galaxies, American Astronomical Society, AAS Meeting #211,

#04.13; Bulletin of the American Astronomical Society, Vol. 39, p.732.

[3] Gancio, G., Perilli, D., Hase, H., Larrarte, J.J.: BKG RFI Month Report, OBS-RFI-00126-RP, Instituto

Argentino de Radioastronom ́ıa, 2012 (internal report).

156 IVS 2012 Annual Report
Geospatial Information Authority of Japan Tsukuba 32-m VLBI Station

Tsukuba 32-m VLBI Station

Ryoji Kawabata, Shinobu Kurihara, Yoshihiro Fukuzaki, Jiro Kuroda, Tadashi Tanabe,

Yasuko Mukai, Takashi Nishikawa

Abstract

The Tsukuba 32-m VLBI station is operated by the Geospatial Information Authority of Japan.

This report summarizes activities of the Tsukuba 32-m VLBI station in 2012. More than 200 sessions

were observed with the Tsukuba 32-m and other GSI antennas in accordance with the IVS Master

Schedule of 2012. We have started installing the observing facilities that will be fully compliant with

VLBI2010 for the first time in Japan.

1. General Information

The Tsukuba 32-m VLBI station (TSUKUB32, Figure 1) is located at the Geospatial Information Authority of Japan (hereafter GSI) in Tsukuba Science City, which is about 50 km to the

northeast of the capital of Japan, Tokyo. GSI has three regional stations besides TSUKUB32:

SINTOTU3, CHICHI10, and AIRA, which form a geodetic VLBI network in Japan covering the

whole country (Figure 2).

GSI carried out the domestic VLBI session series called “JADE (JApanese Dynamic Earth

observation by VLBI)”. The main purposes of the JADE series are to maintain the reference frame

of Japan and to monitor the plate motions for the advanced study of crustal deformations around

Japan. Additionally, Mizusawa (VERAMZSW) and Ishigakijima (VERAISGK), which are part

of the VERA network of the National Astronomical Observatory of Japan (NAOJ), and Kashima

(KASHIM11) and Koganei (KOGANEI) 11-m stations, which belong to the National Institute

of Information and Communications Technology (NICT), have also participated in some JADE

sessions.

Figure 1. Tsukuba 32-m VLBI station.

120 ̊

120 ̊

130 ̊

130 ̊

140 ̊

140 ̊

150 ̊

150 ̊

20 ̊ 20 ̊

30 ̊

30 ̊

40 ̊

40 ̊

50 ̊

50 ̊

CHICHI10

TSUKUB32

VERAISGK

VERAMZSW

AIRA

SINTOTU3

Figure 2. Geodetic VLBI network in Japan.

IVS 2012 Annual Report 157
Tsukuba 32-m VLBI Station Geospatial Information Authority of Japan

2. Component Description

The specifications of the Tsukuba 32-m antenna are summarized in Table 1.

Table 1. Tsukuba 32-m antenna specifications.

Owner and operating agency Geospatial Information Authority of Japan

Year of construction 1998

Radio telescope mount type Az-El

Antenna optics Cassegrain

Diameter of main reflector 32 m

Azimuth range 10 – 710◦

Elevation range 5 – 88◦

Az/El drive velocity 3

◦/sec

Tsys at zenith (X/S) 50 K / 65 K

SEFD (X/S) 320 Jy / 360 Jy

RF range (X1) 7780 – 8280 MHz

RF range (X2) 8180 – 8680 MHz

RF range (X3) 8580 – 8980 MHz

RF range (S with BPF) 2215 – 2369 MHz

Recording terminal K5/VSSP32, ADS3000+ with DDC

3. Members

Table 2 lists the regular members belonging to the GSI VLBI observation group. Misao Ishihara

and Kensuke Kokado moved to another division at the beginning of April. Therefore, Tadashi

Tanabe has become the director of our division. Routine operations were mainly performed under

contract with Advanced Engineering Service Co., Ltd. (AES).

Table 2. Member list of the GSI VLBI group.

Name Main Function

Tadashi TANABE Supervisor

Jiro KURODA Management, Co-location

Yoshihiro FUKUZAKI Installation of VLBI2010 system

Shinobu KURIHARA Correlation, Analysis, IVS Directing Board member

Ryoji KAWABATA Observation, Co-location

Kazuhiro TAKASHIMA Research

Yasuko MUKAI Operation (AES, Co., Ltd)

Takashi NISHIKAWA Operation (AES, Co., Ltd)

Toshio NAKAJIMA System engineer (I-JUSE)

158 IVS 2012 Annual Report
Geospatial Information Authority of Japan Tsukuba 32-m VLBI Station

4. Current Status and Activities

4.1. Geodetic VLBI Observations

The regular sessions in the IVS Master Schedule which were observed by using GSI antennas

are shown in Table 3. TSUKUB32 participated in 87 domestic and international 24-hr VLBI

sessions, and in 131 Intensive 1-hr sessions for dUT1 measurement in 2012. TSUKUB32 could

not participate in the IVS sessions from the end of February to March due to the repair of some

cracks in the supporting structures of the subreflector as mentioned in Section 4.2. Some IVS-CRF

sessions were observed by TSUKUB32 this year. The other GSI antennas, SINTOTU3, CHICHI10,

and AIRA, participated not only in domestic sessions but also in some international sessions.

Table 3. The number of regular sessions observed by using GSI antennas in 2012. The numbers in parentheses show those of canceled sessions listed in the IVS Master Schedule.

Sessions TSUKUB32 SINTOTU3 CHICHI10 AIRA

IVS-R1 44(4) – – –

IVS-R4 9(3) – – –

IVS-T2 6(1) – 7 7

APSG 2 2 2 2

VLBA 5 – – –

IVS-R&D 9(1) – – –

IVS-CRF 3 – – –

JADE 8 7 4 4

JAXA 1 – 1 1

IVS-INT2 88 – – –

IVS-INT3 43 – – –

Total 218 9 14 14

4.2. Repair of Tsukuba 32-m Antenna

At the end of February, we investigated the TSUKUB32 antenna in order to find the cause of a

reduction of main beam efficiency in K-band especially at low elevation angles, which was reported

by our research collaborator, Tsukuba University. After the investigation, some cracks were found

on the joint parts of the subreflector supporting structure, which could cause the change of the

subreflector position depending on the elevation angle. TSUKUB32 could not participate in the

IVS sessions for just over one month, until we repaired these cracks and reinforced the joint parts

by using iron covers at the end of March.

4.3. Fringe Tests with Sejong 22-m Antenna

The Sejong 22-m antenna, which is the first geodetic VLBI antenna in Korea, was constructed

and became an IVS network station in 2012. TSUKUB32 had some fringe tests with the Sejong

antenna in order to check the Sejong antenna system before participating in the IVS sessions.

After some tests, we managed to detect fringes in both S and X-band (Figure 3).

IVS 2012 Annual Report 159
Tsukuba 32-m VLBI Station Geospatial Information Authority of Japan

Figure 3. Fringes in X-band (blue) and S-band (red) found in the experiment on October 31.

5. VLBI2010 Project in GSI

We have entered into contracts with some manufacturers for a new antenna and necessary

components for GSI VLBI2010 observing facilities. The GSI VLBI2010 station is now planned

to be installed at a candidate site in Ishioka city located about 17 km northeast from Tsukuba

(Figure 4), and it will be compliant with all requirements for VLBI2010 specification. The site

has stable foundation ground and is in a relatively RFI-quiet environment. We considered special

features of the antenna structure and the location of the survey pillars so that we can efficiently

perform a local-tie survey with a GNSS observation point, which is also planned to be installed at

the same site.

Figure 4. Location of the candidate site for the GSI VLBI2010 station.

160 IVS 2012 Annual Report
Institute for Radio Astronomy and Space Research, Auckland University of Technology Warkworth Observatory

Warkworth 12-m VLBI Station: WARK12M

Stuart Weston, Hiroshi Takiguchi, Tim Natusch, Lewis Woodburn, Sergei Gulyaev

Abstract

The Warkworth 12-m radio telescope is operated by the Institute for Radio Astronomy and Space

Research (IRASR) at AUT University, Auckland, New Zealand. Here we review the characteristics of

the 12-m VLBI station and report on a number of activities and technical developments in 2012.

1. General Information

Table 1: Specifications of the Warkworth 12-m antenna.

Antenna type Dual-shaped Cassegrain

Manufacturer Cobham/Patriot, USA

Main dish Diam. 12.1 m

Secondary refl. Diam. 1.8 m

Focal length 4.538 m

Surface accuracy 0.35 mm

Pointing accuracy 18′′

Mount alt-azimuth

Azimuth axis range 90◦ ± 270◦

Elevation axis range 4.5

◦

to 88◦

Azimuth axis max speed 5◦/s

Elevation axis max speed 1◦/s

The WARK12M VLBI station is located some 60 km north of the city of Auckland, near the

township of Warkworth. Specifications of the Warkworth 12-m antenna are provided in Table

1. The radio telescope is equipped with an S/X dual-band dual-circular polarization feed at the

secondary focus and an L-band feed at the prime focus. Backend data digitizing is handled by a

digital baseband converter (DBBC) developed by the Italian Institute of Radio Astronomy. The

station frequency standard is a Symmetricom Active Hydrogen Maser MHM-2010 (75001-114).

Mark 5B+ and Mark 5C data recorders are used for data storage and streaming of recorded data

off site through the network. The observatory network is directly connected to the national network

KAREN (Kiwi Advanced Research and Education Network) via a 1 Gbps fiber link to the site [1].

2. Component Description

2.1. 12-m Antenna: Progress and Issues

The new L-Band feed was designed by Cobham, USA and installed in May 2012 (Figure 1). It is

located behind the secondary mirror at the prime focus, so for L-band observations the secondary

mirror has to be removed.

IVS 2012 Annual Report 161
Warkworth Observatory Institute for Radio Astronomy and Space Research, Auckland University of Technology

Figure 1: The new L-Band feed installed at prime

focus on the 12 m. Credit: S. Weston.

In late 2012, the Hydrogen maser developed a fault,

and it had to be returned to Symmetricom. It is expected to be back and operational in February-March

2013. This has severely impacted our station’s participation in IVS and LBA observations from late 2012

to date. Another problem was connected with the

jack screw elevation bearing; this was finally repaired

in early February 2013. This would appear to have

been caused by poor initial assembly, with the grease

passage way blocked by the protective plastic membrane not having been removed prior to assembly. The

DBBC has had new filters installed to the input IF’s

for the L-band; this will allow the RF to be received

directly with no mixing. We are working on finishing

the L-band backend for LBA sessions in 2013. We have

undertaken a big tidy up of the racks to try to make the systems more manageable; all systems

not required in the 12-m system racks have been moved to the 30 m computer room across the

road to help reduce the heat sources within the 12-m control room because the maser resides here.

2.2. 30-m Antenna: Progress and Issues

The 30-m Cassegrain beam-waveguide NEC antenna was used by Telecom NZ after construction

in 1984. It was handed over to AUT in 2010. Renovation of the 30 m started in 2011. Old azimuth

and elevation motors have been removed and replaced with new ones (see Figure 2). A new

control system from Control Techniques, UK, very similar to the system used on the 12 m, was

installed. A new cable wrap system was installed, and new cables have been pulled through. In

mid-February 2013 Mark Godwin will be on-site to commission the new control system. A bolt

replacement program by a local rigging contractor has started. We are in the process of negotiating

a maintenance contract with them for both the 30 m and the 12 m. Additional DBBC and Mark

5C equipment have been ordered for the 30 m. Work continues on using the existing satellite

receiver in C-Band, but we are also talking with other parties about receiver systems. Obviously

we would like to have L, S, C, and X but are unsure of the waveguide optics.

2.3. Warkworth Network

We continue to e-transfer data to the correlators. We have installed a new 10Gbit switch in the

30 m computer room. This provides fiber point to point connectivity between the DBBC and Mark

5C via the Fila10G interface and gives us a 10Gbit backbone at the observatory. The network

topography was changed so that the 12 m is now a spur from the 30 m KAREN POP. Warkworth

now has a direct IP presence on KAREN, so data transfers should no longer go through the

University Campus (of mutual benefit to us and campus LAN users). It is hoped with the upgrades

taking place with the KAREN network that we will have 10Gbps international connectivity to/from

the observatory in the near future. The 30 m building has been wired with cat6 and fiber has been

installed from the computer room to the pedestal room beneath the dish where the wave guide

terminates. In addition, equipment has been installed for distribution of 1PPS and 10 MHz from

162 IVS 2012 Annual Report
Institute for Radio Astronomy and Space Research, Auckland University of Technology Warkworth Observatory

Figure 2: The 30 m: Top left, one of the old azimuth motors being replaced. Top right, Tim and Takiguchi having

finished replacing one of the elevation motors. Bottom left, an example of the corrosion we have to get on top of.

Bottom right, with the new motors and control system we are now able to move the dish once again. Image Credit:

S. Weston.

the maser at the 12 m over to the 30 m pedestal room using a Symmetricom RF via fiber system.

3. Current Status and Activities

In March 2012 we had a visit by Gino Tuccari with Jim Lovell and Jamie McCallum from

Hobart for a mini workshop about the DBBC, looking at diagnoses and issue resolution. Later

in the year during September Ed Himwich also paid a visit, during which he installed the new

Field System DBBC support components. Now when we run Drudg, the generated schedule .prc

file contains the appropriate commands to program and setup the DBBC. We have successfully

installed SDK 9.2 on our Mark 5B to support disk packs larger than 8 TB. We now have a station

pool of five 16 TB disk packs which we will be using for LBA and the AUSTRAL experiments with

AuScope antennas in Australia. In addition to the IVS and LBA observations, the WARK12M is

now also a tracking station for SpaceX on their supply missions to the International Space Station.

IVS 2012 Annual Report 163
Warkworth Observatory Institute for Radio Astronomy and Space Research, Auckland University of Technology

3.1. Co-operative Observation

Co-operative observation for geodetic purposes with NICT (Japan) and University of Tasmania

(Australia) started. The baseline of WARK12M and KASHIM11 is a long north-south baseline of

over 8,000 km. The first observation of the WARK12M-KASHIM11 baseline was carried out in

April 2012 and the baseline length has been determined as 8,075,003,545±150 mm. By repeating

the observation, we expect to obtain information about the relative tectonic motion of Japan and

New Zealand. Also, we are working to establish the ability to derive EOP ultra-rapidly by utilizing

this baseline, existing UT1 products (such as from the IVS INT2 sessions), and data transfers by

high-speed network. The University of Tasmania operates three 12-m radio telescopes located in

Hobart (HOBART12), Yarragadee (YARRA12M), and Katherine (KATH12M) under the AuScope

project [2]. These three telescopes and WARK12M are located on the Australian tectonic plate

and consequently are ideally placed for measurements of intra-plate deformation. WARK12MAuScope observations started in July 2012. Monthly 24-h observations and a series of multi-day

observations together with AuScope antennas will be scheduled from early 2013.

Figure 3 shows the baseline length changes of the Warkworth-Hobart baseline derived from

both GNSS and VLBI data sources for the epoch 2011-2013. We checked all of the baselines

of AuScope and WARK12M. GNSS results indicate a small intra-plate deformation. On some

baselines current VLBI results appear to be in disagreement with the GNSS data. At this stage

it is not possible to comment further on this discrepancy due to the statistically small number of

VLBI observations. Our proposed co-operative observations will add vital data points, reduce the

noise, and compensate for this current VLBI weakness.

-60

-40

-20

0

20

40

60

55600 55700 55800 55900 56000 56100 56200 56300

Hb-Ww: 2.8 mm/yr 

-60

-40

-20

0

20

40

60

55600 55700 55800 55900 56000 56100 56200 56300

HOB2-WARK: -5.3 mm/yr 

!!"!!"

#$%&'()&"*&)+,-".-$)+&/"""""""""0$12341,-"5"647$1,"

!"# %&'(

Figure 3: The baseline length changes of the Warkworth-Hobart baseline derived from both GNSS and VLBI data

sources for the epoch 2011-2013. GNSS results were produced by analysis of the GNSS data (IGS: alic, auck, hob2,

karr, kat1, yarr + PositioNZ: wark) using the GAMIT/GLOBK software package. VLBI baseline behavior was

determined from results produced by the IVS analysis center. The difference of color indicates whether these data

were used (red) for the calculation of the change rate or excluded (blue).

References

[1] Weston, S., Natusch, T., Gulyaev, S., Radio Astronomy and e-VLBI using KAREN. In Proceedings of

the 17th Electronics New Zealand Conference, 2010. Preprint arXiv:1011.0227.

[2] Lovell, J. E. J., McCallum, J. N., Reid, P. B., McCulloch, P. M., Baynes, B. E., Dickey, J. M., Shabala,

S. S., Watson, C. S., Titov, O., Ruddick, R., Twilley, R., Reynolds, C., Tingay, S. J., Shield, P.,

Adada, R., Ellingsen, S. P., Morgan, J. S., Bignall, H. E., The AuScope geodetic VLBI array, Journal

of Geodesy, 1-12. doi:10.1007/s00190-013-0626-3, 2013.

164 IVS 2012 Annual Report
MIT Haystack Observatory Westford Antenna

Westford Antenna

Mike Poirier

Abstract

Technical information is provided about the antenna and the VLBI equipment at the Westford site

of the Haystack Observatory and about changes to the systems since the IVS 2011 Annual Report.

1. Westford Antenna at Haystack Observatory

Since 1981, the Westford antenna has been one of the primary geodetic VLBI sites in the world.

Located ∼70 km northwest of Boston, Massachusetts, the antenna is part of the MIT Haystack

Observatory complex.

Figure 1. The radome of the Westford antenna.

Table 1. Location and addresses of the Westford antenna.

Longitude 71.49◦ W

Latitude 42.61◦ N

Height above m.s.l. 116 m

MIT Haystack Observatory

Off Route 40

Westford, MA 01886-1299 U.S.A.

http://www.haystack.mit.edu

The Westford antenna was constructed in 1961 as part of the Lincoln Laboratory Project West

Ford that demonstrated the feasibility of long-distance communication by bouncing radio signals

off a spacecraft-deployed belt of copper dipoles at an altitude of 3600 km. In 1981 the antenna was

converted to geodetic use as one of the first two VLBI stations of the National Geodetic Survey

Project POLARIS. Westford has continued to perform geodetic VLBI observations on a regular

IVS 2012 Annual Report 165
Westford Antenna MIT Haystack Observatory

basis since 1981. Westford has also served as a test bed in the development of new equipment and

techniques now employed in geodetic VLBI worldwide. Funding for geodetic VLBI at Westford is

provided by the NASA Space Geodesy Program.

2. Technical Parameters of the Westford Antenna and Equipment

The technical parameters of the Westford antenna, which is shown in Figure 2, are summarized

in Table 2.

Figure 2. Wide-angle view of the Westford antenna inside the radome. The VLBI S/X receiver is located at

the prime focus. The subreflector in front of the receiver is installed when observing with the TAL receiver

(see Section 4), which is located at the Cassegrain focus.

The antenna is enclosed in a 28-meter diameter air-inflated radome made of 1.2 mm thick

Teflon-coated fiberglass—see Figure 1. When the radome is wet, system temperatures increase by

10–20 K at X-band and by a smaller amount at S-band. The major components of the VLBI data

acquisition system are a Mark IV electronics rack, a Mark 5B recording system, and a Pentiumclass PC running PC Field System version 9.10.2. The primary frequency and time standard is

the NR-4 hydrogen maser. A CNS Clock GPS receiver system provides a 1 pps reference clock to

which the maser 1 pps is compared.

Westford also hosts the WES2 GPS site of the IGS network. A Dorne-Margolin chokering

antenna is located on top of a tower ∼60 meters from the VLBI antenna, and a LEICA GRX1200

Reference Station receiver acquires the GPS data.

166 IVS 2012 Annual Report
MIT Haystack Observatory Westford Antenna

Table 2. Technical parameters of the Westford antenna for geodetic VLBI.

Parameter Westford

primary reflector shape symmetric paraboloid

primary reflector diameter 18.3 meters

primary reflector material aluminum honeycomb

S/X feed location primary focus

focal length 5.5 meters

antenna mount elevation over azimuth

antenna drives electric (DC) motors

azimuth range 90◦ − 470◦

elevation range 4

◦ − 87◦

azimuth slew speed 3

◦

s

−1

elevation slew speed 2

◦

s

−1

X-band system S-band system

frequency range 8180-8980 MHz 2210-2450 MHz

Tsys at zenith 50–55 K 70–75 K

aperture efficiency 0.40 0.55

SEFD at zenith 1400 Jy 1400 Jy

3. Westford Staff

The personnel associated with the geodetic VLBI program at Westford and their primary

responsibilities are:

Chris Beaudoin broadband development

Joe Carter antenna servo support

Brian Corey VLBI technical support

Kevin Dudevoir pointing system software

Dave Fields technician, observer

Alex Burns technician, observer

Glenn Millson observer

Arthur Niell principal investigator

Michael Poirier site manager

Colin Lonsdale site director

4. Standard Operations

From January 1, 2012, through December 31, 2012, Westford participated in 46 standard 24-

hour sessions. Westford regularly participated in IVS-R1, IVS-R&D, and RD-VLBA observations.

Use of the Westford antenna is shared with the Terrestrial Air Link (TAL) Program operated

by the MIT Lincoln Laboratory. In this project Westford serves as the receiving end on a 42-km

long terrestrial air link designed to study atmospheric effects on the propagation of wideband

communications signals at 20 GHz.

IVS 2012 Annual Report 167
Westford Antenna MIT Haystack Observatory

5. Research and Development

In its role as a test bed for VLBI development, the Westford antenna was implemented several

times during the year with the VGOS broadband feed assembly and used successfully as the second

element of the interferometer with the GGAO 12-m VGOS system.

The first VGOS geodetic observations were scheduled and observed in October. Two six-hour

sessions were run on successive days. The initial results agree at the few millimeter level, consistent

with the expected performance of the two systems [1].

The antenna was also equipped with the Mark 6 prototype data recorder for a demonstration

of 16 Gbps recording capability [2]. The equipment has been left in place for additional Mark 6

testing and development.

6. Outlook

Westford is expected to participate in seventy-three 24-hour sessions in 2012. We also plan to

support five 24-hour VGOS sessions along with the occasional fringe test, e-VLBI experiments,

and the continuing VGOS broadband development program.

Westford is planning to upgrade the PC Field System and to complete the pointing system

upgrade which will facilitate compatibility with the VGOS/MCI system to be installed on the

Westford antenna.

The Westford broadband system will see several upgrades in 2013, including improvements to

the dewar, implementation of noise diode calibration, and separation of the RF signal path into

two bands to reduce sensitivity to S-band RFI.

Acknowledgements

I would like to thank Arthur Niell, Christopher Beaudoin, and Chester Ruszczyk for their

contributions to this report.

References

[1] Niell et al, Haystack Analysis Center Report, this volume.

[2] Beaudoin et al, Haystack Technology Center Report, this volume.

168 IVS 2012 Annual Report
Forschungseinrichtung Satellitengeod ̈asie (FESG) Geodetic Observatory Wettzell: 20-m radio and Twin telescopes

Geodetic Observatory Wettzell - 20-m Radio Telescope and Twin

Telescope

Alexander Neidhardt, Gerhard Kronschnabl, Raimund Schatz

Abstract

In the year 2012, the 20-m radio telescope at the Geodetic Observatory Wettzell, Germany again

contributed very successfully to the IVS observing program. Technical changes, developments, improvements, and upgrades were made to increase the reliability of the entire VLBI observing system.

In parallel, the new Twin radio telescope Wettzell (TTW) got the first feedhorn, while the construction

of the HF-receiving and the controlling system was continued.

1. General Information

The 20-m Radio telescope in Wettzell (RTW) is an essential component of the Geodetic Observatory Wettzell (GOW) and is jointly operated by Bundesamt f ̈ur Kartographie und

Geod ̈asie (BKG) and Forschungseinrichtung Satellitengeod ̈asie (FESG) of the Technische Universit ̈at M ̈unchen (Technical University Munich). In addition to the RTW, an ILRS laser ranging

system, several IGS GPS permanent stations, a large laser gyroscope G (ringlaser), as well as the

associated local techniques such as time and frequency, meteorology, and super conducting gravity

meter are also operated. Also, the building of the first fully VLBI2012 compliant Twin telescope

at the location of the GOW is currently in the final phases. It should extend the observation

possibilities according to the new technical suggestions of the IVS Working Group 3 (WG3).

Within the responsibility of the GOW are also the TIGO system in Concepci ́on, Chile, operated

mainly together with the Universidad de Concepci ́on (see the separate report about TIGO), and

the German Antarctic Receiving Station (GARS) O’Higgins at Antarctica, operated together with

the German Space Center (DLR) and the Institute for Antarctic Research Chile (INACH) (see the

separate report about O’Higgins).

2. Staff

The staff of the GOW consists of 34 members (excluding students) for operations, maintenance,

repair issues, and improvement and development of the systems. The staff operating RTW is

summarized in Table 1. One additional engineer is in a position which is funded by the “Novel

EXploration Pushing Robust e-VLBI Services” (NEXPReS) project in cooperation with the MaxPlanck-Institute for Radioastronomy (MPIfR), Bonn. It was also possible to support the student

operators to work within development projects and internships.

3. Observations in 2012

The 20-m RTW has been supporting the geodetic VLBI activities of the IVS, and partly other

partners, such as the EVN, for almost 30 years. All successfully observed sessions in the year 2012

are summarized in Table 2. After the repair of the bearings in 2010 the RTW is again completely

in all schedules as before, and except for some problems with the gears and the servo system, which

are also overaged, the telescope is in a very good and stable state. The main priority in operations

IVS 2012 Annual Report 169
Geodetic Observatory Wettzell: 20-m radio and Twin telescopes Forschungseinrichtung Satellitengeod ̈asie (FESG)

Table 1. Staff members of RTW.

Name Affiliation Function Mainly working for

Ulrich Schreiber BKG head of the GOW (until March 2012) GOW

Reiner Dassing BKG interim head of the GOW (from April 2012) GOW

together with

Johannes Ihde BKG interim head of the GOW (from April 2012) GOW

Alexander Neidhardt FESG head of the RTW group and VLBI station chief RTW, TTW

(partly O’Higgins,

laser ranging development)

Erhard Bauernfeind FESG mechanical engineer RTW

Ewald Bielmeier FESG technician RTW

Gerhard Kronschnabl BKG electronic engineer RTW, TTW (partly TIGO

and O’Higgins)

Christian Pl ̈otz BKG electronic engineer O’Higgins, RTW

Raimund Schatz FESG software engineer RTW

Walter Schwarz BKG electronic engineer RTW (partly O’Higgins

and WVR)

Reinhard Zeitlh ̈ofler FESG electronic engineer RTW

Martin Ettl FESG/MPIfR IT and computer scientist NEXPReS (EU FP7)

Jan Kodet FESG applied physical engineer Reference systems (DFG)

Yvonne Klingl FESG/BKG student Operator WLRS/RTW

Gerhard M ̈uhlbauer FESG/BKG student (April to December 2012) Operator WLRS/RTW

Daniel Prexler FESG/BKG student Operator WLRS/RTW

Johannes Vogl FESG/BKG student (April to September 2012) Operator RTW/WLRS,

VLBI project work

was participation in all daily one-hour INTENSIVE-sessions (INT) in order to determine UT1-

UTC. For these sessions the complete data transfer is done with e-VLBI techniques. RTW now

also routinely uses the increased Internet connection capacities of 1 Gbit/sec for the e-transfers to

Bonn, Tsukuba, and Haystack for the 24h sessions. Following the implementation of a Field System

extension for remote control, weekend INTENSIVEs were partly done in the new observation

modes by remote attendance, remote control from students at the laser ranging system (WLRS),

or completely unattended.

In addition to the standard sessions RTW was also active for other special observations such as

the tracking of the ESA Venus Express spacecraft and RadioAstron satellite for the EVN. Another

participation in the EVN network was made with the monitoring of the supernova SN2011dh in

M51. These sessions were coordinated by the Joint Institute for VLBI Europe (JIVE).

Table 2. RTW observations in 2012.

program number of special program number of

24h-sessions 1h-sessions

IVS R1 52 1h-INT1(Kokee-RTW) 229

IVS R4 51 1h-INT2/K(Tsukuba-RTW) 153

IVS T2 7 1h-INT3/K(Tsukuba-RTW-NyAl) 40

IVS R&D 10 ESA VENUS Express 6

RDV/VLBA 6 EVN RadioAstron 62

EUROPE 6 EVN sopernova monitoring 10

total 132 total (in hours) 454

total (in hours) 3168

170 IVS 2012 Annual Report
Forschungseinrichtung Satellitengeod ̈asie (FESG) Geodetic Observatory Wettzell: 20-m radio and Twin telescopes

4. Technical Improvements and Maintenance

Regularly, tasks and maintenance days (obtaining replacements for the hardware, 8-pack repairs, gear maintenance, exchange of motors after they reach their lifetime, NASA Field System

updates, cryo-system maintenance, servo replacements, and improvements for e-VLBI issues) were

scheduled for the usual maintenance work. The components of the servo system are overage and

not available on the market anymore. Therefore it was possible to commission a replacement of the

whole system and to upgrade to a similar, modern technique such as is installed in the Twin telescopes. The upgrade will be done in the middle of 2013. Upgrades and repairs were also necessary

for the Mark IV data acquisition rack. The revision of the replacement dewar systems for Wettzell

and O’Higgins were commissioned to be done by the cooperation partners at the observatory at

Yebes in Spain, where specialists update the systems to the state-of-the-art.

The usage of the EVN-PC for e-Transfer was continuously extended. In addition e-Transfer

for the 24h sessions to Bonn, Haystack, and Washington was installed and tested at rates up to

600 Mbit per second. A combination of the Mark 5 software “fuseMk5” and the communication

protocol “Tsunami” was used on a regular Mark 5B system. Meanwhile all R1 sessions were

regularly sent to the Bonn correlator using e-VLBI techniques, which reduced the shipping costs

tremendously. In parallel with that, all Mark 5 systems were updated or upgraded.

Figure 1. Example of the transfer volume with e-VLBI from the 20-m radio telescope.

The usage of the new Digital Baseband Converters (DBBC) progressed. They were tested,

calibrated, and adjusted again. Several test data were correlated at the Bonn correlator to check the

functionality and quality. Additionally new CoMo boards were ordered to upgrade to a standard

version of the equipment. The development is still in progress.

The remote control software “e-RemoteCtrl” was also extended, mainly by the TUM. In close

cooperation with the developers of the NASA Field System and with other test sites at Australia

(e.g. Hobart, Katherine, and Yarragadee), new features were established. The deliveries were

on time, so the newly implemented authentication and authorization with user roles could be

successfully tested. The AuScope network and the Wettzell site already use the software routinely.

During the days off around the new year the Wettzell radio telescope was completely remotely

controlled including the preparation of the data transfer. Students at the laser ranging system

regularly used the software to control the radio telescope in parallel with the laser observation

to optimize shift times. The software development is funded in task 3 of work package 5 of the

NEXPReS project and is performed in cooperation with the MPIfR.

IVS 2012 Annual Report 171
Geodetic Observatory Wettzell: 20-m radio and Twin telescopes Forschungseinrichtung Satellitengeod ̈asie (FESG)

As a pilot study, ideas for a permanent survey of the telescopes were realized to enable reference

movements, which are surveyed with a total station and 20 to 30 reflectors in the back-structure.

First software models for the calculation of the positions and the surveying were implemented.

The broadband RFI- and data acquisition for the RFI surveys for a possible new location for

the TIGO system in La Plata, Argentina was prepared in Wettzell. Therefore an RFI measuring

system was implemented and developed to allow a broadband analysis of dual-polarized RFI signals

with an omnidirectional antenna.

Another new field is the preparation of the tracking of global navigation satellites. Therefore

new amplifier and receiver boards were implemented, which can be used after the waveguides for

S- and X-band to receive the L-band of the satellite. Additionally the software from the laser

ranging system was changed to create schedules for the NASA Field System, which can be used

to track the satellites with the 20-m radio telescope, using one-second orbit sampling points.

5. The TWIN Radio Telescope Wettzell (TTW)

The Twin Telescope Wettzell project is Wettzell’s realization of complete VLBI2010 conformity.

While the construction of the buildings and telescopes was the main focus in recent years, the year

2012 was used to install parts of the interior and to commission the final elements for the receiving

system. Therefore at the beginning of 2012, the final review of the telescopes was completely

possible without any critical issues. Both telescopes are now completely controllable and movable.

After that the first installations, such as air conditioning, helium flex-lines, and communication

cable to the operator building, were made by the Wettzell team. In the operator building all

server racks are now mounted and partly populated with hardware and computers. The network

was installed and configured to build up a separate network enclave for VLBI.

A big milestone was the final review of the first three-band feedhorn (triband horn from the

company Mirad, Switzerland for S/X/Ka-band). The first test results offered an excellent receiving

performance in combination with the ring-focus antennas of Twin. There were some delays with

the final review of the dewar, as amplifiers for the S-band, provided by the BKG, became defective

during the tests. They had to be shipped back to the vendor.

A final design review for the second horn of the broadband feedhorn was held in June 2012.

The second horn is an “Elevenfeed” from Omnisys, Sweden, which allows tunable frequency bands

between 2 and 14 GHz. The reviewers were able to decide on the constructive parameters, and

construction of the feedhorn started.

A special task was the organization of the IVS VLBI2010 workshop for technical specifications

for March 2012. Local organizers were the BKG and the FESG/TUM. Several new technical issues

were discussed and presented during this meeting. More than 80 participants from geodetic fields,

industry, and science attended the very successful meeting.

6. Plans for 2013

During 2013, dedicated plans are:

• Upgrading the gear, servo, and control system of the 20-m radio telescope,

• Inaugurating the first Twin telescope in April, and

• Finalizing the NEXPReS developments.

172 IVS 2012 Annual Report
Instituto Geogr ́afico Nacional Instituto Geogr ́afico Nacional – Yebes

Instituto Geogr ́afico Nacional of Spain

Francisco Colomer, Susana Garc ́ıa–Espada, Jes ́us G ́omez–Gonz ́alez,

Jos ́e Antonio L ́opez–Fern ́andez, Alvaro Santamar ́ıa–G ́omez, Pablo de Vicente  ́

Abstract

This report updates the description of the space geodesy facilities of the Spanish National Geographic Institute (IGN). The current 40-m radio telescope at Yebes, a network station for IVS, has

performed geodetic VLBI observations regularly since September 2008. In addition to this, the project

to establish an Atlantic Network of Geodynamical and Space Stations (RAEGE) is progressing with

the construction of the first antenna, which is being erected at Yebes.

1. General Information: the IGN Facilities at Yebes

The National Geographic Institute of Spain (Instituto Geogr ́afico Nacional, Ministerio de Fomento), has run geodetic VLBI programs at Yebes Observatory since 1995 and now operates a

40-m radio telescope which is a network station for IVS. Yebes Observatory is also the reference station for the Spanish GNSS network and holds permanent facilities for gravimetry. A new

VLBI2010-type antenna is being built at Yebes as part of the RAEGE project.

2. IGN Staff Working on VLBI Projects

Table 1 lists the IGN staff who are involved in space geodesy studies and operations. The

VLBI activities are also supported by other staff such as receiver engineers, computer managers,

telescope operators, secretaries, and students.

Table 1. Staff in the IGN VLBI group (e-mail: vlbitech@oan.es).

Name Background Role Address∗

Francisco Colomer Astronomer VLBI Project coordinator IGN

Susana Garc ́ıa–Espada Engineer geoVLBI expert CAY

Jes ́us G ́omez–Gonz ́alez Astronomer Deputy Director for IGN

Astronomy, Geophysics,

and Space Applications

Jos ́e Antonio L ́opez–Fdez Engineer Yebes and RAEGE Director CAY

Javier L ́opez–Ramasco Geodesist Geodesist CAY

Alvaro Santamar ́ıa  ́ Geodesist Geodesist CAY

Pablo de Vicente Astronomer VLBI technical coordinator CAY

Addresses:

IGN: Instituto Geogr ́afico Nacional. Calle General Iba ̃nez de Ibero 3, E–28003 Madrid, Spain.

CAY: Centro Astron ́omico de Yebes. Apartado 148, E–19080 Guadalajara, Spain.

IVS 2012 Annual Report 173
Instituto Geogr ́afico Nacional – Yebes Instituto Geogr ́afico Nacional

3. Status of Geodetic VLBI Activities at IGN

The 40-m radio telescope has participated in 37 sessions (five EURO, 12 R4, 19 R1, and one

T2). Data to be correlated in Bonn (R1 experiments) and in WACO (R4) are transferred by

Internet using the tsunami protocol.

The relative position of the reference points of the different space geodetic instruments is a

key issue in the realization of the International Terrestrial Reference Frame. Following the works

started in 2011 to realize such local ties at Yebes, simulations were carried out to estimate the

Invariant Reference Point (IRP) coordinates of the 40-m radio telescope at the Yebes Observatory.

From those simulations the authors showed the extent to which the precision of the estimated IRP

coordinates depends on the number, the quality, and the geometry of the survey observations.

Based on these results, an automated system will be set up at the Yebes Observatory in the future

in order to determine the IRP of the 40-m radio telescope with a precision better than 1 mm

(Santamar ́ıa-G ́omez et al., 2012).

Using the estimated coordinates in a common terrestrial frame, we have obtained the relative

vector between the reference points of the GPS station and the 14-m and 40-m VLBI radio telescopes. As a preliminary assessment of the local tie survey, the estimation of the position and

the velocity in the ITRF2008 is used to derive the relative vector between these three instruments

at the Yebes Observatory. In the absence of systematic errors in the VLBI, the GPS, and the

terrestrial survey observations, local tie surveys, and ITRF-derived relative vectors should agree.

Figure 1. Residuals of the VLBI radio telescope positions at Yebes Observatory. Left: 14-m. Right: 40-m.

174 IVS 2012 Annual Report
Instituto Geogr ́afico Nacional Instituto Geogr ́afico Nacional – Yebes

The subreflector of the 40-m radio telescope has been kept fixed to its optimum position for an

elevation of 45ofor sessions since July 12, 2011. A position offset was therefore discovered in the

time series, and the radio telescope coordinates were estimated before and after the discontinuity.

The radio telescope velocity was constrained between both segments. After the change of the focus,

a significant offset of approximately 4.6 cm was found in the vertical coordinate (see Figure 1).

4. Project RAEGE

IGN, together with its Portuguese colleagues in DSCIG (Azores Islands), continues the construction of a network of four new Fundamental Geodynamical and Space Stations. The RAEGE

project has been described in previous IVS Annual Reports. The first antenna is being erected in

Yebes (see Figure 2), and the construction of a tri-band (S/X/Ka) receiver and optics, developed

at Yebes Labs, is also progressing. It is expected to be completed and to start operation in 2013.

Activities have also started at RAEGE’s Santa Mar ́ıa site with the construction of the concrete

tower and the infrastructure facilities. The assembly of the steel backstructure is anticipated for

June 2013. On September 17, 2012, an official inauguration ceremony kicked off the start of construction. The event took place in the presence of local authorities as well as regional government

representatives. The infrastructure project includes the construction of the main control building,

a building for power distribution, a social facilities building (to be built in a second phase), and

access roads. The Santa Mar ́ıa site will include a completely isolated gravimetry pavilion, buried

in a small hill, on top of which a permanent GNSS station will be installed.

Figure 2. Left: RAEGE telescope under construction at Yebes. Lifting of the azimuth cabin. Right: Work

for the RAEGE telescope in Santa Mar ́ıa (Azores Islands).

5. Meetings

IGN hosted the 7th IVS General Meeting “Launching the Next-Generation IVS Network” on

March 4-9 2012, at the premises of the Royal Observatory of Madrid. A total of 150 participants

(see Figure 3) from 25 countries representing 65 institutions submitted 120 abstracts, delivering

60 oral presentations and 50 poster presentations, available at:

http://www.oan.es/gm2012/show-presentations-pdf.php.

IVS 2012 Annual Report 175
Instituto Geogr ́afico Nacional – Yebes Instituto Geogr ́afico Nacional

Figure 3. Participants in the 7th IVS General Meeting are photographed in front of the IGN 40-m radio

telescope at Yebes Observatory.

References

[1] Colomer F., G ́omez–Gonz ́alez J., L ́opez–Fern ́andez J. A., Assis M., Santos L., “An Atlantic Network

of Geodynamical and Space Stations (Project RAEGE)”, 2012. Proceedings of the 10th International

e-VLBI Workshop “Towards Global Real-Time e-VLBI”, Amanzingwe Conference Centre, Broederstroom, South Africa. (See http://www.hartrao.ac.za/e-vlbi2011/e-vlbi2011.html).

[2] Garc ́ıa–Espada S., Santamar ́ıa–G ́omez A., “Tying VLBI and GPS terrestrial frames: case study at

Yebes Observatory”. 2012. IVS 2012 General Meeting Proceedings. CP-2012-217504. In press.

[3] L ́opez–P ́erez J. A., L ́opez–Fern ́andez J. A., “Radio-frequency interference measurements in Tenerife island for the selection of the RAEGE antenna site”. Informe T ́ecnico OAN 2012-4 (see

http://www1.oan.es/informes/archivos/IT-OAN-2012-4.pdf).

[4] Santamar ́ıa–G ́omez A., “Very Short Baseline Interferometry with GPS at the Yebes Observatory”. Informe T ́ecnico OAN 2012-13 (see http://www1.oan.es/informes/archivos/IT-OAN-2012-13.pdf).

[5] Santamar ́ıa–G ́omez A., Garc ́ıa–Espada S., Haas R., L ́opez–Ramasco J., “Estimation of the invariant

reference point: first steps at Yebes”. 2012. IVS 2012 General Meeting Proceedings. CP-2012-217504.

In press.

176 IVS 2012 Annual Report
Institute of Applied Astronomy of Russian Academy of Sciences Zelenchukskaya Station

Zelenchukskaya Radio Astronomical Observatory

Sergey Smolentsev, Andrei Dyakov

Abstract

This report summarizes information about Zelenchukskaya Radio Astronomical Observatory activities in 2012. Last year a number of changes took place in the observatory to improve some technical

characteristics and to upgrade some units to the required status. The report provides an overview of

current geodetic VLBI activities and gives an outlook for the future.

1. General Information

The Zelenchukskaya Radio Astronomical Observatory (Figure 1) was created by the Institute

of Applied Astronomy (IAA) as one of three stations of the Russian VLBI network QUASAR [1].

The sponsoring organization of the project is the Russian Academy of Sciences (RAS).

The Zelenchukskaya Radio Astronomical Observatory is situated in Karachaevo-Cherkesskaya

Republic (the North Caucasus) about 70 km south of Cherkessk, near Zelenchukskaya village

(Table 1). The geographic location of the observatory is shown on the IAA RAS Website:

http://www.ipa.nw.ru/PAGE/rusipa.htm. The main instruments of the observatory are the 32-

m radio telescope equipped with special technical systems for VLBI observations, the SLR system,

and the GPS/GLONASS/Galileo receivers.

Figure 1. Zelenchukskaya observatory.

IVS 2012 Annual Report 177
Zelenchukskaya Station Institute of Applied Astronomy of Russian Academy of Sciences

Table 1. The Zelenchukskaya Observatory location and address.

Longitude 41◦34′

Latitude 43◦47′

Karachaevo-Cherkesskaya Republic

369140, Russia

ipazel@mail.svkchr.ru

2. Technical Staff

Andrei Dyakov — the head of the observatory,

Dmitry Dzuba — FS, pointing system control specialist, and

Anatoly Mishurinsky — front end and receiver support specialist.

3. Technical and Scientific Information

Table 2. Technical parameters of the radio telescope.

Year of construction 2003

Mount AZEL

Azimuth range ±270◦(from south)

Elevation range from −5

◦

to 95◦

Maximum azimuth *

- velocity 0.83 ◦/s

- tracking velocity 2.5

′/s

- acceleration 12.0

′/s2

Maximum elevation *

- velocity 0.5

◦/s

- tracking velocity 0.8

′/s

- acceleration 12.0

′/s2

Pointing accuracy better than 10′′

Configuration Cassegrain (with asymmetrical subreflector)

Main reflector diameter 32 m

Subreflector diameter 4 m

Focal length 11.4 m

Main reflector shape quasi-paraboloid

Subreflector shape quasi-hyperboloid

Main reflector surface accuracy ± 0.5 mm

Frequency range 1.4–22 GHz

Axis offset * 3.6 ± 2.0 mm

* These values were changed to optimize the performance of the antenna system. The axis

offset was measured in summer 2012 by geodesist Andrey Shamov.

178 IVS 2012 Annual Report
Institute of Applied Astronomy of Russian Academy of Sciences Zelenchukskaya Station

4. Co-location of VLBI, GPS/GLONASS, and SLR System

The Javad GPS/GLONASS/Galileo receiver with meteo station WXT-510 is in operation (Figure 2). The SLR system “Sazhen-TM” (Figure 3) of the Zelenchukskaya observatory joined ILRS

in March 2012. The technical characteristics of the system are presented in Table 3.

Figure 2. Javad GPS/GLONASS/Galileo receiver at

the Zelenchukskaya observatory.

Figure 3. “Sazhen-TM” SLR system at the Zelenchukskaya observatory.

Table 3. Technical parameters of the SLR system “Sazhen-TM”.

Ranging distance, day 400-6000 km

Ranging distance, night 400-23000 km

Aperture 25 cm

Wavelength 532 nm

Beam divergence 12′′

Laser pulse frequency 300 Hz

Pulse energy 2.5 mJ

Mass 170 kg

Normal points precision 1 cm

Angular precision 1-2′′

5. Current Status and Activities

The Zelenchukskaya observatory participates in IVS and domestic VLBI observational programs. In 2012, Zelenchukskaya station observed in 27 diurnal IVS sessions — IVS-R4, IVS-T2,

and EURO.

Zelenchukskaya participated in 47 diurnal sessions of the Ru-E program and in 171 one-hour

Ru-U sessions using e-VLBI data transfer. Since July 2012, observations for the Ru-U program

have been performed daily.

IVS 2012 Annual Report 179
Zelenchukskaya Station Institute of Applied Astronomy of Russian Academy of Sciences

6. Outlook

We have the following plans for the coming year:

• To participate in IVS observations

• To carry out domestic Ru-U and Ru-E observational programs with e-VLBI data transfer

• To carry out SLR observations of geodetic and navigation satellites

• To participate in EVN and RADIOASTRON observational sessions

• To continue geodetic monitoring of the antenna parameters

• To build a foundation and to conduct survey operations for VLBI2010 antenna installation

in 2014 (Figures 4 and 5).

Figure 4. Foundation for RT-13, planned to be built in 2013. Figure 5. RT-13 is planned to be installed

in 2014.

References

[1] Finkelstein A., Ipatov A., Smolentsev S. The Network “Quasar” : 2008-2011 // “Measuring the future”, Proceedings of the Fifth IVS General Meeting, A. Finkelstein, D. Behrend (eds.), St. Petersburg,

“Nauka”, 2008. pp. 39–46.

180 IVS 2012 Annual Report
Operation Centers

Institut f ̈ur Geod ̈asie und Geoinformation der Universit ̈at Bonn Bonn Operation Center

The Bonn Geodetic VLBI Operation Center

A. Nothnagel, A. M ̈uskens

Abstract

In 2012, the IGGB Operation Center has continued to carry out tasks for organizing and scheduling

the observing sessions of the IVS-T2, IVS-OHIG, IVS-INT3, and EUROPE series.

1. Center Activities

The IGGB VLBI Operation Center is located at the Institute of Geodesy and Geoinformation

of the University of Bonn, Nussallee 17, D-53115 Bonn, Germany. It has been organizing and

scheduling VLBI observing sessions for more than twenty years. The observing series organized

and scheduled in 2012 are very similar to those in 2011.

• Measurement of Vertical Crustal Motion in Europe by VLBI (EUROPE)

In Europe, a series of special sessions has been scheduled for the determination of precise

station coordinates and for long term stability tests. This year, six sessions with Ny- ̊Alesund,

Onsala, Metsahovi, Svetloe, Zelenchukskaya, Badary, Effelsberg, Wettzell, Simeiz, Medicina,

Matera, Noto, and Yebes (YEBES40M) were scheduled employing the frequency setup of

16 channels and 4 MHz bandwidth in fan-out mode (identical to the setup of the IVS-T2

sessions).

• IVS-T2 Series

This series has been observed roughly every second month (seven sessions in 2012) primarily

for maintenance and stabilization of the VLBI terrestrial reference frame as well as for Earth

rotation monitoring as a by-product. Each station of the global geodetic VLBI network is

scheduled to participate at least once per year in the T2 sessions. In view of the limitations

in station days, priority was given to stronger and more robust networks with many sites over

more observing sessions. Therefore, generally 15 to 20 stations have been scheduled in each

session. The processing is carried out with the DiFX software correlator. The scheduling

of these sessions has to take into account that a sufficient number of observations should

be planned for each baseline of these global networks. The recording frequency setup is 16

channels and 4 MHz channel bandwidth.

• Southern Hemisphere and Antarctica Series (OHIG):

In February 2012, three sessions of the Southern Hemisphere and Antarctica Series with

the Antarctic stations Syowa (Japanese) and O’Higgins (German) plus Fortaleza, Hobart,

HartRAO, and Kokee have been organized. Furthermore, OHIGGINS was also included

successfully in the T2081 session. The (southern) winter O’Higgins burst was scheduled and

observed but without the stations of O’Higgins and Warkworth for various reasons. The

purpose of these sessions is the maintenance of the VLBI TRF and the monitoring of Earth

rotation as a by-product. The recording frequency setup is 16 channels and 4 MHz channel

bandwidth. Due to the fact that Syowa is not able to deliver the recorded data for nearly one

year after the observations, the correlation and the generation of the databases is delayed

considerably.

IVS 2012 Annual Report 183
Bonn Operation Center Institut f ̈ur Geod ̈asie und Geoinformation der Universit ̈at Bonn

• UT1 Determination with Near-real-time e-VLBI (INT3):

The so-called INT3 sessions included the telescopes of Ny- ̊Alesund, Tsukuba and Wettzell for

weekly UT1 determinations with rapid processing time. Since August 2007, these sessions

have been scheduled to start every Monday morning at 7:00 a.m. UT.

The operations of the INT3 series are directly linked to data transmission and correlation

since the raw VLBI observation data of the three sites is directly transferred to the Bonn

Correlator by Internet connections to speed up delivery of the results. The transmission rate

is about 100 Mb/s for Ny- ̊Alesund (limited due to the use of a radio link for the first part

of the distance) and 400-600 Mb/s from Tsukuba and Wettzell. The correlation is solely

carried out with the DiFX software correlator.

In 2012, 45 sessions were observed and transmitted successfully. 90% of the sessions were

correlated and the databases were delivered within the first five hours after the end of the

observations. A further 5% were completed within 10 hours. The rest took between 10 and

48 hours due to difficulties with networking hardware and/or station and processor problems.

In March and April, Seshan participated in some INT3 sessions replacing Tsukuba, which

could not observe due to maintenance activities. Since then Seshan has taken part in INT3

sessions periodically.

2. Staff

Table 1. Personnel at IGGB Operation Center.

Arno M ̈uskens +49-228-525264 mueskens@mpifr.de

Axel Nothnagel +49-228-733574 nothnagel@uni-bonn.de

184 IVS 2012 Annual Report
NVI, Inc. CORE Operation Center

CORE Operation Center Report

Cynthia C. Thomas, Daniel MacMillan

Abstract

This report gives a synopsis of the activities of the CORE Operation Center from January 2012 to

December 2012. The report forecasts activities planned for the year 2013.

1. Changes to the CORE Operation Center’s Program

The Earth orientation parameter goal of the IVS program is to attain precision of at least

3.5 μs for UT1 and 100 μas for pole position.

The IVS program, which started in 2002, used the Mark IV recording mode for each session.

The IVS program began using the Mark 5 recording mode in mid-2003. By the end of 2007,

all stations had been upgraded to Mark 5. Due to the efficient Mark 5 correlator, the program

continues to be dependent on station time and media. The following are the network configurations

for the sessions for which the CORE Operation Center was responsible in 2012:

• IVS-R1: 52 sessions, scheduled weekly and mainly on Mondays, five to eleven station networks

• RDV: Six sessions, scheduled evenly throughout the year, 15 to 16 station networks

• IVS-R&D: Ten sessions, scheduled monthly, seven to eight station networks

2. IVS Sessions from January 2012 to December 2012

This section displays the purpose of the IVS sessions for which the CORE Operation Center is

responsible.

• IVS-R1: In 2012, the IVS-R1s were scheduled weekly with five to eleven station networks.

During the year, 18 different stations participated in the IVS-R1 network, but there were

only eight stations that participated in at least half of the scheduled sessions—Wettzell (52),

Tigo (50), Ny- ̊Alesund (46), Tsukuba (44), Fortaleza (44), Westford (36), HartRAO (29),

and Kokee (28). Urumqi was tagged along to one IVS-R1 session for testing in preparation

for joining the IVS-R1 network during 2013.

The purpose of the IVS-R1 sessions is to provide weekly EOP results on a timely basis.

These sessions provide continuity with the previous CORE series. The “R” stands for rapid

turnaround because the stations, correlators, and analysts have a commitment to make the

time delay from the end of recording to the results as short as possible. The time delay goal

is a maximum of 15 days. Participating stations are requested to ship disks to the correlator

as rapidly as possible or to transfer the data electronically to the correlator using e-VLBI.

The “1” indicates that the sessions are mainly on Mondays.

• RDV: There are six bi-monthly coordinated astrometric/geodetic experiments each year that

use the full 10-station VLBA plus up to six geodetic stations.

These sessions are being coordinated by the geodetic VLBI programs of three agencies: 1)

USNO performs repeated imaging and correction for source structure; 2) NASA analyzes

IVS 2012 Annual Report 185
CORE Operation Center NVI, Inc.

this data to determine a high accuracy terrestrial reference frame; and 3) NRAO uses these

sessions to provide a service to users who require high quality positions for a small number of

sources. NASA (the CORE Operation Center) prepares the schedules for the RDV sessions.

• R&D: The purpose of the ten R&D sessions in 2012, as decided by the IVS Observing

Program Committee, was to support observations close to the Sun.

3. Current Analysis of the CORE Operation Center’s IVS Sessions

Table 1 gives the average formal errors for the R1, R4, RDV, and T2 sessions from 2012. The

R1 session formal uncertainties are not significantly different from the 2010-2011 errors. The R4

uncertainties for 2012 sessions are much better than for 2011 or 2010. This improvement is due in

part to the better performance of stations in 2012; in 2012, 22 sessions lost one or more stations

from the original scheduled network, while there were 37 such sessions in 2011. R1 uncertainties

for 2012 (as well as for 2011) are worse than for 2010. This is most likely due to the contribution

of TSUKUB32 to the EOP solution estimates. Since the Japanese earthquake in March 2011,

we have been estimating the position of TSUKUB32 for each observing session. This weakens its

contribution to EOP. If we use a GPS a priori model to obtain the post-earthquake behavior at

Tsukuba, then the formal uncertainties are reduced by 10-20%. We will be applying this model in

the next GSFC operational quarterly solution.

RDV uncertainties are not significantly different among the three years from 2010 to 2012. The

RDV formal errors are significantly better than the formal errors from any of the other experiment

series. This is due to the larger number of RDV stations as well as better global geometry. T2 EOP

uncertainties are markedly better in 2012 than for 2010-2011. For comparison, we also included the

formal uncertainties for the CONT11, which are much better than any of the networks discussed

above that observed in 2012.

Table 2 shows EOP differences with respect to the IGS series for the R1, R4, RDV, T2, and

CONT11 series. The WRMS differences were computed after removing a bias, but estimating

rates does not affect the residual WRMS significantly. The R1 and R4 series show approximately

the same WRMS agreement in x-pole and y-pole for 2012 as for these series since 2000. The

R1s are worse for x-pole, which is most likely due to the treatment of TSUKUB32 in solutions as

discussed above. Adopting the improved GPS a priori model strategy mentioned above improves

the agreement with IGS by 20%. The polar motion biases of the R1 and R4 sessions relative to

IGS differ by 10-20 μas, which is at the level of the uncertainty (1-2 sigma) of the bias estimates.

The biases for the six RDV sessions are significantly smaller. Perhaps there is a network bias

between the RDV and the R1/R4 networks, but this would require further investigation. Of all

the series, the RDV series has the best WRMS agreement of x-pole and y-pole with IGS estimates

in 2012 as well as for all sessions since 2000. There are really too few RDV and T2 sessions to give

significance to the WRMS differences for 2012 compared with the difference for full series from

2000-2012. For comparison with the 2012 sessions discussed here, we included the statistics for

the 15 CONT11 sessions. The WRMS agreement with IGS is much better because 1) the network

has better geometry; 2) short-term scatter is always smaller than long-term scatter, and 3) the

performance of stations was most likely better because of the increased station checkout that is

done for the R&D continuous session experiments.

186 IVS 2012 Annual Report
NVI, Inc. CORE Operation Center

Table 1. Average EOP Formal Uncertainties for 2012.

Session Number X-pole Y-pole UT1 DPSI DEPS

Type (μas) (μas) (μs) (μas) (μas)

R1 51 (52) 73(67,62) 63(65,58) 3.4(3.1,2.4) 110(113,116) 44(46,46)

R4 5l (52) 70(84,96) 67(75,85) 2.8(3.2,3.3) 124(161,172) 49(65,70)

RDV 3 (6) 48(49,44) 48(46,44) 2.5(2.6,2.1) 68(75,67) 28(30,28)

T2 4 (7) 91(100,93) 69(107,101) 4.5(5.0,5.2) 166(216,192) 63(79,75)

CONT11 15 (15) 39 38 1.7 42 17

For the number of sessions in 2012, the number of sessions processed at this time is given,

with the number of observed sessions in parentheses. For the other columns, the values

in parentheses are for 2011, followed by the values for 2010.

Table 2. Offset and WRMS Differences (2012) Relative to the IGS Combined Series.

X-pole Y-pole LOD

Session Type Number Offset WRMS Offset WRMS Offset WRMS

(μas) (μas) (μas) (μas) (μs/d) (μs/d)

R1 52(562) -64(9) 107(95) 42(13) 88(88) 1.5(0.3) 14(16)

R4 52(560) -42(-23) 109(113) 32(15) 113(111) 3.4(1.8) 17(18)

RDV 6(78) 15(59) 97(82) 24(5) 55(66) 0.3(-0.5) 10(14)

T2 4(81) -80(3) 234(145) 152(2) 61(122) 13.8(1.7) 11(20)

CONT11 15 42 36 9 29 7.0 7

Values in parentheses are for the entire series (since 2000) for each session type.

4. The CORE Operations Staff

Table 3 lists the key technical personnel and their responsibilities so that readers will know

whom to contact about their particular question.

5. Planned Activities during 2013

The CORE Operation Center will continue to be responsible for the following IVS sessions

during 2013.

• The IVS-R1 sessions will be observed weekly and recorded in a Mark 5 mode.

• The IVS-R&D sessions will be observed ten times during the year.

• The RDV sessions will be observed six times during the year.

IVS 2012 Annual Report 187
CORE Operation Center NVI, Inc.

Table 3. Key Technical Staff of the CORE Operations Center.

Name Responsibility Agency

Dirk Behrend Organizer of CORE program NVI, Inc./GSFC

Brian Corey Analysis Haystack

Ricky Figueroa Receiver maintenance ITT Exelis

John Gipson SKED program support and development NVI, Inc./GSFC

Frank Gomez Software engineer for the Web site Raytheon/GSFC

David Gordon Analysis NVI, Inc./GSFC

Ed Himwich Network Coordinator NVI, Inc./GSFC

Dan MacMillan Analysis NVI, Inc./GSFC

Katie Pazamickas Maser maintenance ITT Exelis

David Rubincam Procurement of materials necessary for CORE

operations

GSFC/NASA

Braulio Sanchez Procurement of materials necessary for CORE

operations

GSFC/NASA

Dan Smythe Tape recorder maintenance Haystack

Cynthia Thomas Coordination of master observing schedule

and preparation of observing schedules

NVI, Inc./GSFC

188 IVS 2012 Annual Report
U.S. Naval Observatory NEOS Operation Center at USNO

NEOS Operation Center

David Hall, M.S. Carter

Abstract

This report covers the activities of the NEOS Operation Center at USNO for 2012. The Operation

Center schedules the IVS-R4 and the INT1 Intensive experiments.

1. VLBI Operations

NEOS operations in the period covered consisted, each week, of one 24-hour duration IVS-R4

observing session, on Thursday-Friday, for Earth Orientation, together with five daily one-hour

duration “Intensives” for UT1 determination, Monday through Friday. In 2012, the operational

IVS-R4 network included VLBI stations at Kokee Park (Hawaii), Wettzell (Germany), Ny- ̊Alesund

(Norway), TIGO (Chile), Fortaleza (Brazil), Tsukuba (Japan), Svetloe, Badary and Zelenchukskaya (Russia), Hobart, Katherine and Yarragadee (Australia), Yebes (Spain), and Matera and

Medicina (Italy). A typical R4 consisted of eight to twelve stations.

The regular stations for the weekday IVS Intensives were Kokee Park and Wettzell. Intensives

including Kokee Park, Wettzell, and Svetloe were occasionally scheduled in order to characterize

the Kokee Park — Svetloe baseline so that Svetloe can be used as an alternate for Wettzell should

it be needed. Odd-day Intensives were scheduled with the scheduling technique used since 2000;

even-day Intensives were scheduled with a new, experimental scheduling technique.

The Operation Center updated its version of SKED as updates became available.

All sessions are correlated at the Washington Correlator, which is located at USNO and is run

by NEOS.

Table 1. Experiments Scheduled during 2012.

Number Session Type

52 IVS-R4 experiments

230 Intensives

2. Staff

K. A. Kingham, D. M. Hall, and M. S. Carter are the only staff members of the NEOS Operation

Center. Dr. Kerry Kingham retired at the beginning of June, and Mr. Hall assumed his duties.

Hall is responsible for the overall management, and Carter makes the schedules. M. S. Carter is

located at the USNO Flagstaff Station (NOFS).

IVS 2012 Annual Report 189

Correlators

Institut f ̈ur Geod ̈asie und Geoinformation der Universit ̈at Bonn Bonn MPIfR/BKG Correlator

The Bonn Astro/Geo Correlator

Simone Bernhart, Walter Alef, Alessandra Bertarini, Laura La Porta, Arno M ̈uskens,

Helge Rottmann, Alan Roy

Abstract

The Bonn Distributed FX (DiFX) correlator is a software correlator operated jointly by the MaxPlanck-Institut f ̈ur Radioastronomie (MPIfR), the Institut f ̈ur Geod ̈asie und Geoinformation der Universit ̈at Bonn (IGG), and the Bundesamt f ̈ur Kartographie und Geod ̈asie (BKG) in Frankfurt.

1. Introduction

The Bonn correlator is hosted at the MPIfR1in Bonn, Germany. It is operated jointly by the

MPIfR and the BKG2

in cooperation with the IGG3. It is a major correlator for geodetic observations and astronomical projects, for instance those involving pulsar gating, millimeter wavelengths,

and astrometry.

2. Present Correlator Capabilities

The Distributed FX correlator4 was developed at Swinburne University in Melbourne, Australia by Adam Deller (and other collaborators). It has been adapted to the VLBA operational

environment by Walter Brisken and the NRAO staff, and it has been developed for a number of

years by the worldwide DiFX developers group. DiFX in Bonn is installed and running on a High

Performance Compute Cluster (HPC cluster).

Features of the software correlator cluster are:

• 60 nodes (eight compute cores each)

• four TFlops in the Linpack benchmark test

• 20 Gbps Infiniband interconnection

• 11 RAIDs (about 480 TB storage capacity)

• one control node for correlation (fxmanager)

• one computer (frontend) for executing parallelized jobs on the cluster, e.g., post-correlation

applications

• one control computer (appliance) for installing and monitoring the cluster

• closed loop rack cooling

The correlator cluster is connected via 20 Gbps Infiniband to 14 Mark 5 units5 used for playing

back the data. If more than 14 playback units are required, and in the case of e-VLBI, data are

copied to the raid systems prior to correlation. All Mark 5 units can play back all types of Mark 5

data (A/B/C). The disk-modules in the Mark 5 are controlled via NRAO’s mk5daemon program.

The available functionality includes all necessary functions such as recording the directories of the

modules, resetting and rebooting the units, and module conditioning.

1

http://www3.mpifr-bonn.mpg.de/div/vlbicor/index_e.html

2

http://www.bkg.bund.de/

3

http://www.gib.uni-bonn.de/

4DiFX: A Software Correlator for Very Long Baseline Interferometry using Multiprocessor Computing Environments, 2007, PASP, 119, 318

5

http://www.haystack.mit.edu/tech/vlbi/mark5/

IVS 2012 Annual Report 193
Bonn MPIfR/BKG Correlator Institut f ̈ur Geod ̈asie und Geoinformation der Universit ̈at Bonn

A summary of the capabilities of the DiFX software correlator is presented in Table 1.

Table 1. Correlator capabilities.

Playback Units

Number available 14 Mark 5 (four Mark 5A, two Mark 5B, and eight Mark 5C)

Playback speed 1.5 Gbps

Formats Mark 5A, Mark 5B, and VDIF

Sampling 1 bit and 2 bits

Fan-out (Mark 5A) 1:1, 1:2, and 1:4

No. channels ≤ 16 USB and/or LSB

Bandwidth/channel (2, 4, 6, 8, and 32) MHz

Signal Single- and dual-frequency; all four Stokes parameters for circular

and linear polarization

Correlation

Geometric model CALC 9

Phase cal Phase-cal extraction of all tones in a sub-band simultaneously

Pre-average time Milliseconds to seconds

Spectral channels Maximum number of FFT tested 218

Export FITS export. Interface to Mk IV data format which enables the use of

geodetic analysis software and the Haystack fringe fitting program.

Pulsar Pulsar with incoherent dedipersion

3. Staff

The people in the Geodesy VLBI group6 at the Bonn correlator are:

Arno M ̈uskens - group leader and scheduling of T2, OHIG, EURO, and INT3 sessions.

Simone Bernhart - e-transfer supervision and operations, experiment setup and evaluation of

correlated data, and media shipping.

Alessandra Bertarini - experiment setup and evaluation of correlated data for both astronomy

and geodesy, digital baseband converter (DBBC) testing, APEX fringe testing, Friend of the correlator.

Laura La Porta - experiment setup and evaluation of correlated data, DBBC testing, and programming for automated preparation of correlation reports.

The people in the astronomical group at the Bonn correlator are:

Walter Alef - head of the VLBI technical department, computer systems and cluster administration.

Alan Roy - deputy group leader, support scientist (water vapor radiometer, technical assistance,

development of FPGA firmware for linear to circular polarization conversion, and project manager

for equipping APEX for millimeter VLBI).

Helge Rottmann - software engineer for correlator development and operation, cluster administration, DBBC and RDBE control software, and Field System.

6

http://www3.mpifr-bonn.mpg.de/div/vlbicor/geodesy/index.html

194 IVS 2012 Annual Report
Institut f ̈ur Geod ̈asie und Geoinformation der Universit ̈at Bonn Bonn MPIfR/BKG Correlator

Heinz Fuchs - correlator operator, responsible for the correlator operator schedule, daily operations, and media shipping.

Hermann Sturm - correlator operator, correlator support software, media shipping, and Web

page development.

Rolf M ̈artens - technician maintaining cluster hardware and Mark 5 playbacks.

Michael Wunderlich - engineer, development, and testing of DBBC components.

Jan Wagner - PhD student, support scientist for APEX, DBBC development, and DiFX developer.

Armin Felke - FPGA programming for DBBC.

Gino Tuccari - guest scientist from INAF, DBBC development, and DBBC project leader.

David Graham - consultant (technical development, DBBC development, and testing).

4. Status

Experiments: In 2012, the Bonn group correlated 51 R1, six EURO, five T2, five OHIG, 43

INT3, and 16 astronomical experiments.

e-VLBI: On average ≥ 60% of the stations do e-transfer, and the number still increases. E.g.,

in the T2086 session, 16 stations participated in the observations, and 11 of them sent their data

via high-speed network connection. The average amount of e-transferred data per week ranges

from 4 to 6 TB considering only the regular INT3 and R1 experiments. Most transfers are done

using the UDP-based Tsunami protocol.

The total disk space available for e-VLBI data storage at the correlator is currently about

125 TB. The Web page that shows current active e-transfers and helps to coordinate transfer times

and rates on a first come-first served basis7, has been extended by information about the storage

capacity at the three correlators in Washington, Haystack, and Bonn. The envisaged upgrade of

the existing 1 Gbps Internet connection in order to meet the requirements of the higher observing

rate foreseen within VLBI2010 has not yet been realized due to still existing issues concering

funding. However, the transfer Web page currently seems well adopted by the community and

even though meanwhile more than 60% of the stations nowadays transfer their observational data

via Internet, we have merely been facing minor problems - if any - due to bandwidth limitations.

DiFX software correlator: A graphical user interface was installed on the DiFX control

computer, which simplifies the use of the software correlator.

A branch version of the DiFX software correlator for RFI mitigation has been developed as

part of a PhD project. DiFX RFI suppression via filtering fast off-source fringe rates is complete8.

While it reduces ringing by RFI along UV plane tracks, it has proven ineffective at removing a

residual constant RFI power in the affected channels, and it is not as powerful as the method for

Focal Plane Array RFI excision also included in the DiFX library.

DBBC: The Bonn group is involved in the development of the DBBC for the European VLBI

Network (EVN) and geodesy. The DBBC is designed as a full replacement for the existing analog

BBCs. The following stations have already bought one or more DBBCs: APEX, AuScope (Australia), Effelsberg, Onsala, Pico Veleta, Yebes, Wettzell, and Warkworth. Most of those DBBCs

are already in regular use. High data rate modes with 2 and 4 Gbps are being tested. First test observations at 2 Gbps and 4 Gbps were performed in June 2012 (at Yebes, Effelsberg, and Onsala).

7

http://www3.mpifr-bonn.mpg.de/cgi-bin/showtransfers.cgi

8

http://www.radionet-eu.org/fp7wiki/lib/exe/fetch.php?media=jra:albius:rfifringefilter_pub.pdf

IVS 2012 Annual Report 195
Bonn MPIfR/BKG Correlator Institut f ̈ur Geod ̈asie und Geoinformation der Universit ̈at Bonn

Regular testing with geodetic observations is performed for DBBCs at Onsala and Wettzell.

In the summer of 2012, a project to develop the next generation DBBC called DBBC3 was

started. In the first stage, a system which can handle 4 GHz bandwidth will be developed (DBBC3-

L). In the second stage, the DBBC3-H will be able to sample the full frequency range of 1 to 14 Ghz

without any downconversion required.

APEX: The Bonn VLBI group has equipped the APEX telescope for VLBI observations at

1 mm. The first successful fringe test took place in May 2012 on 3C 279 at 229 GHz with SMA

(Hawaii) and SMTO (Arizona). The fringe spacing achieved was 29 microarcseconds, adequate to

resolve the expected diameter of the shadow of the event horizon of 47 microarcseconds in Sgr A*.

A fringe plot of these observations is shown in Figure 1.

Figure 1. Successful 1 mm fringe tests performed in March 2012, baseline APEX- Submillimeter Telescope

Observatory (SMTO, Arizona), on 3C 279. The fringe spacing was 29 microarcseconds, the finest yet

achieved.

5. Outlook for 2013

DiFX Correlator: The planning to replace the now five-year-old cluster with a more modern

system will begin.

e-VLBI: e-transfer tests with other antennas are planned or ongoing.

DBBC: DBBC testing in the EVN stations that recently acquired DBBCs will continue. Wide

bandwidth modes are also under test. Development of the DBBC3 will take place.

APEX First real observations will take place at APEX in March 2013.

Phasing up ALMA The group is involved in an international project to add array phasing

capability to ALMA. This will enable its use as an extremely sensitive station in 1 mm VLBI

experiments.

196 IVS 2012 Annual Report
MIT Haystack Observatory Haystack Correlator

Haystack Observatory VLBI Correlator

Mike Titus, Roger Cappallo, Brian Corey, Kevin Dudevoir, Arthur Niell, Alan Whitney

Abstract

This report summarizes the activities of the Haystack Correlator during 2012. Highlights include

finding a solution to the DiFX InfiniBand timeout problem and other DiFX software development,

conducting a DBE comparison test following the First International VLBI Technology Workshop,

conducting a Mark IV and DiFX correlator comparison, more broadband delay experiments, more uVLBI Galactic Center observations, and conversion of RDV session processing to the Mark IV/HOPS

path. Non-real-time e-VLBI transfers and engineering support of other correlators continued.

1. Introduction

The Mark IV and DiFX VLBI correlators of the MIT Haystack Observatory, located in Westford, Massachusetts, are supported by the NASA Space Geodesy Program and the National Science

Foundation. They are dedicated mainly to the pursuits of the IVS, with a smaller fraction of time

allocated to processing radio astronomy observations for the Ultra High Sensitivity VLBI (u-VLBI)

project. The Haystack correlators serve as development systems for testing new correlation modes,

for hardware improvements such as the Mark 6 system, and in the case of the Mark IV, for diagnosing correlator problems encountered at Haystack and at the identical correlator at the U.S. Naval

Observatory. This flexibility is made possible by the presence on-site of the team that designed

the Mark IV correlator hardware and software. Some software support is provided to the Max

Planck Institute for Radioastronomy in Bonn, Germany, for DiFX processing of IVS sessions.

2. Summary of Activities

2.1. DiFX Cluster Developments

Efforts to diagnose InfiniBand fabric timeout errors which manifested themselves at high record

rates (1 Gb/sec and above) have come to fruition through an understanding that the particular

model of InfiniBand cards installed in the Mark 5 playback units were the cause. New cards were

procured and tested, and they appear to mitigate the problem. Cards were ordered and installed

in all the capable Mark 5 units. Various other DiFX related debugging projects were conducted,

and problems were corrected.

2.2. DiFX Software Support

Initially mysterious problems with multiband delay (mbd) scatter in many DiFX correlated

sessions from Bonn led to an investigation at Haystack. Data for session R1543 were transferred

from Bonn to Haystack and correlated on the Haystack Mark IV for comparison. This revealed a

problem with time registration of delay polynomials in the difx2mark4 conversion software. The

problem was corrected but not before ∼ 120 sessions were affected. Fortunately, the delays can

be corrected in the databases; as of the end of 2012, NASA Goddard and BKG had corrected

approximately half of the databases.

IVS 2012 Annual Report 197
Haystack Correlator MIT Haystack Observatory

2.3. DiFX-Mark IV Correlator Comparison of Experiment R1543

As a by-product of the diagnosis of the difx2mark4 problem, a comparison between DiFX

and the Mark IV correlator was conducted. Results show that mbd differences compare favorably between all combinations of crossings. The full analysis of this comparison be found at

http://cira.ivec.org/dokuwiki/doku.php/difx/difx2mark4

2.4. Broadband Delay

Major broadband delay tests were conducted in January, May, and October 2012. January had

a plethora of tests, and May and October featured six-hour “geodetic quality” schedules being run

at the GGAO 12-m and Westford antennas to fully test the VLBI2010 system. Various other tests

were conducted over the year, including overlapping bands, zoom mode (Mark IV vs. broadband),

a source transit experiment, a DBE1/Mark 5B+ vs. RDBE/Mark 5C comparison, and others.

2.5. DBE Comparison Test

Following the First International VLBI Technology Workshop held at Haystack in October, a DBE Compatibility Testing Workshop was hosted by Haystack staff. DBEs from

Haystack, China, Japan, and Europe were compared to test interoperability. All units participating in the workshop were successfully compared. A report of the results can be found at

http://www.haystack.mit.edu/workshop/ivtw/index.html. As a by-product of this test Haystack

provided the DiFX correlation setup to Seshan in order for them to duplicate the Haystack results.

This can be used for future debugging of their DBE on their DiFX installation.

2.6. Galactic Center Observations

Further u-VLBI observations of the Galactic Center with dual polarization at all sites were

recorded and correlated in 2012. Also, results were published for the ground-breaking observations

made in 2011 of the center of the galaxy M87 that spatially resolved the base of the jet in that

source. Fringe searching to the MPI/Onsala/ESO sponsored APEX antenna in Atacama, Chile,

was successful. These searches were conducted in Bonn, but searches for the participating U.S.

stations were done at Haystack. In the near future other new antennas will be tested and added

to the u-VLBI array, which will greatly increase its resolution.

2.7. RDV Fringe-fitting

Test fringe-fitting of the RDV sessions correlated on the NRAO DiFX correlator described last

year showed favorable results compared to the traditional NRAO AIPS package. Thus, processing

them through the Mark IV/HOPS path has become the routine production process. A summary

of this work can be found at http://www.oan.es/gm2012/pdf/poster id 117.pdf

2.8. e-VLBI

Non-real-time transfers have continued. Data from nineteen experiments were transferred to

Haystack this year from seventeen stations (seven in Japan, four in Western Europe, two in Australia, two in South America, one in Crimea, and one in South Africa): Kashima11, Koganei,

198 IVS 2012 Annual Report
MIT Haystack Observatory Haystack Correlator

Tsukuba, Chichijima, Ishigaki, Aira, Mizusawa, Onsala, Ny- ̊Alesund, Wetzell, Noto, Hobart, Yaragadee, Fortaleza, Tigo (via Bonn), Crimea (via Bonn) and HartRAO. e-VLBI transfers have significantly increased this year due to an upgrade of Haystack’s connectivity to the Internet which

has enabled data transfer rates up to 1.4 Gb/sec.

2.9. Experiments Correlated

Production processing on the Mark IV correlator continues amidst all the DiFX development.

In 2012, thirty-four geodetic VLBI experiments were processed, at least in part, on the Haystack

Mark IV correlator, including ten R&Ds, six T2s, one AUST, and the aforementioned R1543 experiment. The remaining 16 were various tests. The other test experiments included the broadband

experiments and fringe tests and an assortment of other projects, some of which were mentioned

in the summary above. As usual, smaller tests were not included in the above count because they

were too small to warrant individual experiment numbers.

2.10. Current/Future Hardware and Capabilities

As of the end of 2012 the Mark IV correlator was comprised of seven Mark 5A units, seven

station units, seven Mark 5B units (DOMs) with their associated correlator interface boards (CIBs),

16 operational correlator boards, two crates, and miscellaneous other support hardware. We have

the capacity to simultaneously process all baselines for 11 stations in the standard geodetic modes,

provided the aggregate recordings match the above hardware matrix. Note that all experiments

up to 15 stations have been done in one pass due to the ability to share playback units between

stations which do not co-observe. Six of the playback units are accessible to the six-server (12

cores each) DiFX cluster.

In 2013 we hope to transition to the software correlator, only keeping the hardware correlator

alive in support of USNO until their transition to a software correlator, which is expected in late

2013.

3. Staff

Staff who participated in aspects of Mark IV, DiFX, Mark 5/6, and e-VLBI development and

operations include:

3.1. Software Development Team

• John Ball - Mark 5A/5B; e-VLBI.

• Roger Cappallo - real-time correlator software and troubleshooting; system integration; post

processing; Mark 5B/5C/6; Linux conversion; e-VLBI; DiFX correlator development.

• Geoff Crew - DiFX correlator development, post processing software; Mark 6.

• Kevin Dudevoir - correlation; maintenance/support; Mark 5A/5B/5C; e-VLBI; Linux

conversion; correlator software and build system development; computer system support/development; DiFX correlator development.

• Jason SooHoo - e-VLBI; Mark 5A/5B/5C/6; computer system support.

IVS 2012 Annual Report 199
Haystack Correlator MIT Haystack Observatory

• Chester Ruszczyk - e-VLBI; Mark 5A/5B/5C.

• Alan Whitney - system architecture; Mark 5A/5B/5C/6; e-VLBI .

3.2. Operations Team:

• Peter Bolis - correlator maintenance.

• Alex Burns - playback drive maintenance; Mark 5 installation and maintenance; general

technical support; replacement for Dave Fields (see below).

• Brian Corey - experiment correlation oversight; station evaluation; technique development.

• Dave Fields - playback drive maintenance; Mark 5 installation and maintenance; general

technical support; retired in December 2012.

• Glenn Millson - correlator operator.

• Arthur Niell - technique development.

• Don Sousa - correlator operator; experiment setup; tape library and shipping.

• Mike Titus - correlator operations oversight; experiment setup; computer services; software

and hardware testing.

• Ken Wilson - correlator maintenance; playback drive maintenance; general technical support.

4. Conclusion/Outlook

A full transition to the DiFX software correlator is expected in early 2013. Operational testing

of the complete VLBI2010 system is expected to start in early 2013. Testing and implementation

of new digital back ends and recording systems will continue.

200 IVS 2012 Annual Report
IAA RAS IAA Correlator Center

IAA Correlator Center

Igor Surkis, Voitsekh Ken, Alexey Melnikov, Vladimir Mishin, Nadezda Sokolova,

Violet Shantyr, Vladimir Zimovsky

Abstract

The activities of the six-station IAA RAS correlator include regular processing of national geodetic

VLBI programs Ru-E, Ru-U, and Ru-F. The Ru-U sessions have been transferred in e-VLBI mode and

correlated in the IAA Correlator Center automatically since 2011.

The DiFX software correlator is used at the IAA in some astrophysical experiments.

1. Introduction

The IAA Correlator Center is located at and staffed by the Institute of Applied Astronomy in

St. Petersburg, Russia.

The IAA Correlator Center is devoted to processing geodetic, astrometric, and astrophysical

observations made with the Russian national VLBI network Quasar.

Figure 1. View of the six-station ARC correlator, showing four racks containing (left to right) signal

distribution and synchronization system (SDSS) and three Mark 5B playback units, two correlator crates

and KVM, three correlator crates, and one more cabinet with SDSS and three Mark 5B playback units.

IVS 2012 Annual Report 201
IAA Correlator Center IAA RAS

2. Component Description

The ARC (Astrometric Radiointerferometric Correlator) (Figure 1) was the main data processing device in the IAA Correlator Center in 2012. The ARC was designed and built in the IAA

RAS in 2007 - 2009. The correlator has an XF design and is based on FPGA technology.

The ARC is a six-station, 15-baseline correlator. It is able to process up to 16 frequency

channels on each baseline, for a total of 240 channels. The correlator accesses two-bit VLBI

signals with 32 MHz maximal clock frequency. The maximal data range from each station is

1 Gbit per second. The correlator requires VSI-H input VLBI signals, and it is equipped with

Mark 5B playback terminals.

Since 2011 the DiFX software correlator has been used in some astrophysical experiments. The

DiFX is installed at the IAA on a Sun Fire X4450 Server as a virtual machine under the VMware.

3. Staff

• Voitsekh Ken — GPU software developer;

• Alexey Melnikov — software developer, DiFX processing, scheduler of the Ru-sessions;

• Vladimir Mishin — software developer, data processing;

• Nadezda Sokolova — software developer;

• Violet Shantyr — software developer, post processing;

• Igor Surkis — leading investigator, software developer;

• Vladimir Zimovsky — leading data processing;

• Ekaterina Medvedeva — data processing;

• Alexander Salnikov — leading e-VLBI data transfer;

• Ilya Bezrukov — e-VLBI data transfer;

4. Current Status and Activities

The ARC correlator was used for processing all of the national geodetic VLBI observations in

the IAA Correlator Center in 2012. The RUE and RUU geodetic VLBI sessions were observed in

IAA RAS.

The three-station 24-hour RUE sessions for EOP determination were observed one time per

week, as in 2011.

The two-station one-hour sessions for UT1-UTC determination in e-VLBI mode were carried

out one time per week up to June 2012 and one time per day starting in July 2012. The RUU

sessions were executed on cold station receivers, with a frequency channel bandwidth of 8 MHz

and a total bitrate of 256 Mbps, and on warm receivers, with a frequency channel bandwidth of

16 MHz and a total bitrate of 512 Mbps. The data transfer speed from station to correlator was

improved in 2012, and near to realtime correlation processing with a data bitrate of 256 Mbps was

achieved.

In 2012, the DiFX software correlator became the main tool for a spectral radio source observation processing routine. We have started regular observing program Ru-P in 1.35 cm band and

202 IVS 2012 Annual Report
IAA RAS IAA Correlator Center

18 cm band. Target sources are Orion KL, W49N, W3OH, and W75, and the experiment bitrate

is 32 Mbps. The processing time for one second of real data is about eight seconds with DiFX

using current facilities on a Sun Fire X4450 Server and its virtual machines under the VMware.

The output data has a resolution from 1024 to 4096 spectral channels. Several experiments were

observed with station Simeiz: RU0069, RU0083, RU0084, RU0087, and RU0088. These were 1.35

cm band sessions. Data from the Simeiz station were transferred via Internet directly to IAA’s

server, then processed with DiFX. We also used DiFX in test experiments of a new wideband DAS:

a single IF channel of 512 MHz width with 2 Gbps total bitrate was successfully processed using

DiFX.

5. Future Plans

The design of a new FX software correlator intended for the new small antenna VLBI network

in comformance with VLBI2010 was started in 2012 at IAA RAS. The correlator design is supposed

to process up to 16 Gb/s data stream from each of up to six observatories. VLBI data are recorded

from four frequency bands with bandwidth up to 1024 MHz in one circular polarization or up to

512 MHz in two linear polarizations using 2-bit sampling. The input data format is VDIF. The

correlator computes cross-spectra with a resolution up to 4096 spectral channels, and it extracts

up to 16 phase calibration tones in each frequency band of each station. The correlator’s hardware

is based on hybrid blade server technology. Blade server contains two Intel CPU and two Nvidia

Tesla GPUs. All critical computing such as Fourier transform, spectra multiplication and addition,

and phase cal extraction will be perfomed using GPU; other tasks (data stream synchronization

and distribution) will be provided by CPU. By a preliminary estimate, the hardware will contain

up to 20 blade servers.

IVS 2012 Annual Report 203
VLBI Correlators in Kashima National Institute of Information and Communications Technology

VLBI Correlators in Kashima

Mamoru Sekido, Kazuhiro Takefuji

Abstract

Kashima Space Technology Center (KSTC) is making use of two kinds of software correlators, the

multi-channel K5/VSSP software correlator and the fast wide-band correlator ‘GICO3,’ for geodetic

and R&D VLBI experiments. Overview of the activity and future plans are described in this paper.

1. General Information

Figure 1. Locations of NICT Headquarters and KSTC.

The Kashima Space Technology Center (KSTC) of the National Institute of Information and Communications Technology has developed two types of VLBI systems. The multi-channel VLBI system

called ‘K5/VSSP’[1, 2] and the wide band

data acquisition system ‘K5/VSI’ [3, 4]

were developed for applications of geodesy

and astronomy, respectively. Software correlators for each of the systems have been

developed and used for geodetic observing

and R&D VLBI experiments.

The current main mission of our group

is the development of transportable VLBI

systems for frequency comparison over intercontinental distances. To gain better

sensitivity with small diameter antennas,

a wide-band observation system is employed in the system. Linear and dual polarization observing for the frequency range of 3-15 GHz almost meet the VLBI2010 specifications.

The computation load of correlation is estimated to increase about two orders of magnitude over

the conventional VLBI system; thus a new software correlator with a distributed computation

design named KFC is planned.

2. Component Description

The KSTC correlator is mainly used for processing geodetic and R&D VLBI experiments

organized by NICT. Two types of software correlators have been used.

2.1. K5/VSSP Software Correlator

Correlation Type: Both FX-type and XF-type software correlators are available in the

K5/VSSP software suite [2]. The FFT algorithm used in the FX-type correlator has advantages in correlation with a large lag (delay) window, so it is mainly used for the clock

204 IVS 2012 Annual Report
National Institute of Information and Communications Technology VLBI Correlators in Kashima

parameter search in the beginning of routine processing. The XF-type correlator is relatively

faster than FX-type in the processing of 1-bit quantization data with a small lag number.

Because a small lag number is sufficient for geodetic applications, the XF-type correlator is

mainly used in routine 1-bit quantization data processing for geodesy. Except for the case

above, the XF-type software is used.

Processing unit: The K5/VSSP32 DAS is designed with one or four channel inputs per unit,

so four channels is designed to be the maximum number of data streams to be fed to a

single correlation task. This is a benefit for distributed processing with this software correlator, because correlation tasks are divided by the unit of channels and can be processed

independently with multiple CPUs.

Processing speed: The single four-channel processing rate is three to six times slower than the

data acquisition rate, when a single task is run on an Intel(R) Core2 Duo 3GHz processor,

for example. The total processing rate is compensated by multiple run of the tasks on a

cluster of computers in routine operation. This software correlator code is compiled with the

GNU gcc compiler and can work on any CPU.

Other functions: The correlation product includes all the necessary information such as phase

calibration information for further reduction of geodetic VLBI. In the next step, the correlator

output files are synthesized by the bandwidth synthesis ‘komb’ software [5] to extract precise

group delays from the data.

2.2. GICO3 Software Correlator

Correlation Type: FX-type correlator that uses an FFT algorithm. The optimum lag window

is around 1024 lags, which is determined by the overhead of the function calls and the size

of the fast access cache memory [6].

Processing unit: Processing with an arbitrary number of channels is made possible by the initial

configuration.

Processing speed: The processing rate of 2 Gbps is a few times slower than the real-time data

acquisition rate in the case of processing with an Intel(R) Xeon(R) CPU with a 2.33GHz

clock, for example.

Other functions: Cross correlation and auto-correlation results are obtained at the same time, so

that it is suitable for astronomical applications. The extraction of precise delay observables

and the creation of Mark III databases is available through using Mk3Tools [7].

3. Staff

The names of the staff members who contribute to the correlator at NICT/Kashima and their

tasks are listed below in alphabetical order.

• HASEGAWA Shingo (Kashima): in charge of maintenance and troubleshooting of K5 system

computers, tasks of the data conversion from K5/VSSP format to Mark 5 format in IVS

sessions.

IVS 2012 Annual Report 205
VLBI Correlators in Kashima National Institute of Information and Communications Technology

• HOBIGER Thomas (Koganei, Tokyo): development of a new VLBI database system based

on NetCDF, research on atmospheric delay calibration with the ray tracing technique, and

development of the new software correlator KFC for the wide-band VLBI systems.

• KONDO Tetsuro (Bangkok, Thailand): maintenance of the software correlator package and

documentation of the K5/VSSP32 system.

• KOYAMA Yasuhiro (Koganei, Tokyo): the Leader of the International Cooperation Office

of NICT. Conductor of VLBI experiments for frequency comparison.

• SEKIDO Mamoru (Kashima): Coordination of VLBI experiments and development of the

new VLBI system for frequency comparison.

• TAKEFUJI Kazuhiro (Kashima): Development of the new wide-band VLBI system with

the small diameter antenna MARBLE and processing of experiment data with the GICO3

software correlator.

• TSUTSUMI Masanori (Kashima): maintenance of K5 system computers and the network.

4. Current Status and Activities

Table 1 shows a list of the experiments processed by the K5 software correlator. Because

Time and Frequency comparison is the main project, some experiments for feasibility testing were

made with the 11-m antennas. These data were processed with the K5/VSSP software correlator

running on multi-core PCs (e.g., CPU Intel Core i7 920 2.67 GHz cache 8192 KB, Processor 4

(Hyper Threading Total Core8), Memory 12 GB).

Table 1. Correlation tasks processed with the K5/VSSP correlator in 2012.

Project Exp code Date Stations baseline x scans Data rate

x days (Mbps)

Freq. Comp. K1203x 2-6 Feb. K1,Kg 1 x 4723 (4 days) 512

Freq. Comp. K12050 19-21 Feb. K1,Kg 1 x 2295 (2 days) 512

Freq. Comp. K12052 21-22 Feb. K1,Kg 1 x 1349 (1 day ) 512

Freq. Comp. K122nx 28-31 Jul. K1,Kg 1 x 4723 (3 days) 512

Freq. Comp. K122wx 31 Jul.-4 Aug. K1,Kg 1 x 3593 (3 days) 512

Sgr-A* sg1218x 28 Jun.-8 Jul. K1,Kg 1 x 35 x 10 days 512

Sgr-A* sg1228x 11-15 Oct. K1,Kg 1 x 35 x 6 days 512

Sgr-A* sg12362 27 Dec. K1,Kg 1 x 35 x 1 day 512

K1:Kashima-11m, Kg:Koganei-11m

Except for the frequency comparison, monitoring of Sgr-A* with S/X-band was organized with

K5/VSSP32. Since it is predicted that a bunch of material will fall into the massive black-hole

at the center of our galaxy by the summer in 2013, huge energy is expected to be emitted in the

form of electromagnetic radiation in a wide frequency range. This monitoring observation will be

continued in 2013 under collaboration with Keiou University, Ibaraki University, and the National

Astronomy Observatory of Japan.

206 IVS 2012 Annual Report
National Institute of Information and Communications Technology VLBI Correlators in Kashima

In addition to these experiments, fringe test and performance test experiments for a small

diameter antenna with the K5/VSI (ADS3000+) data acquisition system were conducted. The

GICO3 software correlator was used for this processing.

5. Future Plans

The project mission of the VLBI group in NICT is to establish a VLBI system for Time and

Frequency comparison. For this purpose, we are developing the transportable wide-band VLBI

system, which is semi-compliant with the VLBI2010 specifications. A new software correlator with

distributed computation design is planned for this project [8].

References

[1] T. Kondo, et al.: Development of a New VLBI Sampler Unit (K5/VSSP32) Equipped with a USB

2.0 Interface, IVS 2006 General Meeting Proceedings, edited by Dirk Behrend and Karen Baver,

NASA/CP-2006-214140, pp.195-199, 2006.

[2] Kondo, T., http://www2.nict.go.jp/aeri/sts/stmg/K5/VSSP/index-e.html

[3] Kimura, M., J. Nakajima, H. Takeuchi, T. Kondo: High Performance PC Based Gigabit VLBI System,

IVS NICT-TDC News No.25, pp. 64-.66, 2005.

[4] Kimura, M., http://www2.nict.go.jp/aeri/sts/stmg/K5/VSI/K5VSI/index-e.html

[5] Kondo, T., M. Sekido, H. Kiuchi, KSP Bandwidth Synthesizing Software, J. Comm Res. Lab., Vol. 46,

No. 1, pp.67-76, 1999.

[6] M. Kimura:, Development of the software correlator for the VERA system II, Technical Development

Center News NICT, No.26, pp.22-25, 2007.

[7] Hobiger, T., R. Ichikawa, and Y. Koyama, MK3TOOLS - seamless interfaces for the creation of VLBI

databases from post-correlation output, Proceedings of the Fifth IVS General Meeting, pp. 153 - 156,

2008.

[8] Takefuji, K., et al., Technology Development Center at NICT, International VLBI Service for Geodesy

and Astrometry 2012 Annual Report, edited by K. D. Baver and D. Behrend, this volume, 2013.

IVS 2012 Annual Report 207
Shanghai Correlator Shanghai Astronomical Observatory

Shanghai VLBI Correlator

Fengchun Shu, Weimin Zheng, Zhong Chen

Abstract

This report summarizes the activities of the Shanghai VLBI Correlator during 2012.

1. Introduction

The Shanghai VLBI Correlator is hosted and operated by the Shanghai Astronomical Observatory, Chinese Academy of Sciences. It is dedicated to the data processing of the Chinese

domestic VLBI observing programs, inclusive of the CMONOC project for monitoring the Chinese

regional crustal movement and the Chinese deep space exploration project for tracking spacecraft.

As shown in Figure 1, the VLBI stations near Shanghai, Kunming, and Urumqi participate in

some domestic geodetic sessions on an annual basis, while the Beijing station is mainly used for

spacecraft data downlinks and VLBI tracking.

 75oE 90oE 105oE 120oE 135oE 

 16oN 

 24oN 

 32oN 

 40oN 

 48oN 

 56oN 

SHANGHAI

BEIJING

KUNMING

URUMQI

Figure 1. Distribution of the VLBI stations in China.

2. Component Description

Based on the FX type VLBA correlator, we began to design two correlators in 2003. One is the

hardware correlator using the FPGA technology. The other one is the software correlator. The first

version of our software correlator has been operational since 2006, and it was installed on an AMD

Opteron 2200 CPU and later on an Intel X5400 CPU. The software correlator worked much better

than the hardware correlator in the VLBI spacecraft tracking sessions. Because it was much easier

to be modified, we adopted the second version of software correlator for geodetic applications. By

using Message Passing Interface (MPI) and the POSIX thread APIs, the software correlator has

208 IVS 2012 Annual Report
Shanghai Astronomical Observatory Shanghai Correlator

been migrated to a computer cluster based on blade servers to get better performance since 2010

(see Figure 2). It has been formally accepted as an IVS correlator in March 2012.

Features of the software correlator cluster are listed below.

• IBM HS22 Blade Server, six computing nodes

• Each computing node: two socket Intel X5570 CPU (2.93 GHz), 12 GB Memory

• Two I/O nodes, with 48 TB raw storage capacity

• One management node with Rocks cluster software

• 10G Ethernet for blade internal network connection.

Figure 2. Shanghai VLBI Correlator.

A summary of the capabilities of the software correlator is presented in Table 1.

Table 1. Correlator capabilities.

Number available five Mark 5B

Playback speed 1.8 Gbps

Input data formats Mark 5B

Sampling 1 bit, 2 bits

IF channels ≤ 16

Bandwidth/channel (2, 4, 6, 8, 32) MHz

Spectral points/channel ≤ 65536

Geometric model supports plane wave front and curved wave front

online averaging time 0.1s∼4s

Phase cal extraction yes

Output CVN matrix format. NGS card file.

IVS 2012 Annual Report 209
Shanghai Correlator Shanghai Astronomical Observatory

3. Staff

The people involved in the development and operation of the Shanghai Correlator are listed

below.

• Weimin Zheng: group head, software correlator development

• Xiuzhong Zhang: CDAS and other technique development

• Fengchun Shu: scheduler, experiment oversight, CDAS evaluation

• Zhong Chen: e-VLBI, cluster administration

• Weihua Wang: lead correlator operator, automatic correlation process development

• Juan Zhang: correlator software development and maintenance

• Yun Yu: operator, experiment support

• Wu Jiang: operator, experiment support

• Wenbin Wang: media library, computer services

• Renjie Zhu: CDAS development

• Zhijun Xu: FPGA programming, hardware correlator development

• Yajun Wu: FPGA programming.

4. Summary of Activities

4.1. Correlator Software

The correlator model calculations for Quasars or spacecraft, driven by VEX file, have been

implemented in the software in 2006. In order to improve the accuracy of differential VLBI

observations to the level of better than 0.1 ns, we have incorporated more corrections such as tidal

station motion and gravitational delay.

A great effort has been made to shorten the data latency for the navigation of spacecraft. After

adjustment of the software structure in the whole chain of data processing, we aim to produce the

final delay observables within one minute after data acquisition.

4.2. CDAS

The Chinese VLBI Data Acquisition System (CDAS) is a type of digital backend designed to

replace the traditional analog BBCs. In order to solve the irregular integer bit jumps when CDAS

is working at 1 Gbps or higher output data rate, we upgraded the VSI interface cards of CDAS

which had been deployed at the four stations since 2010. A three-hour fringe test showed that the

delay residuals had become stable on all baselines. In addition to the currently used DDC version,

we also developed a PFB version of CDAS with much more compact design.

210 IVS 2012 Annual Report
Shanghai Astronomical Observatory Shanghai Correlator

4.3. e-VLBI

The data link between the Shanghai VLBI center and Seshan25 has been upgraded to 10 Gbps.

The data link to other stations is reduced to 20 Mbps data rate for now and can be up to 155

Mbps for domestic e-VLBI observations.

Supported by Chinese Next Generation Network Scientific Research Information Demonstration Project, we established an experimental IPv6-based network connection from the Shanghai

VLBI center to Seshan25, Kunming, and Urumqi. e-VLBI application will be demonstrated as an

example to push forward the extensive usage of the next generation network.

4.4. Experiments Correlated

In 2012, five domestic geodetic VLBI experiments were carried out at 256 Mbps data rate

using 16 channels. The data correlations were done after the Mark 5 modules were shipped to the

Shanghai VLBI center. The differential VLBI observations continued to support the navigation of

the Chang’E-2 spacecraft from the probe orbiting around the Earth-Sun L2 Lagrangian point to

flying by the asteroid Toutatis. Data processing were performed largely in e-tranfer mode.

5. Future Plans

We will continue to support the data correlation of Chinese domestic VLBI observations. As

many efforts have been devoted to the development of the realtime correlation technique for differential VLBI observations of spacecraft, we plan to install a DiFX software correlator to meet

the requirements of more astronomical VLBI experiments and VLBI2010 technique development

in China.

IVS 2012 Annual Report 211
Tsukuba VLBI Correlator Geospatial Information Authority of Japan

Tsukuba VLBI Correlator

Shinobu Kurihara, Kentaro Nozawa

Abstract

The Tsukuba VLBI Correlator is invested by the Geospatial Information Authority of Japan (GSI).

The K5/VSSP correlation software is regularly used, and the IVS-INT2, JADE, and other various

sessions are correlated.

1. Introduction

The K5/VSSP software correlator (Figure 1), located in Tsukuba, Japan, is operated by the

Geospatial Information Authority of Japan (GSI). It is fully dedicated to processing the geodetic

VLBI sessions of the International VLBI Service for Geodesy and Astrometry. All of the weekend IVS Intensives (INT2) and the Japanese domestic VLBI observations organized by GSI were

processed at the Tsukuba VLBI Correlator.

Figure 1. Tsukuba VLBI correlator.

2. Component Description

2.1. e-VLBI

Nowadays when the Internet is spread throughout the world, it seems that the physical transportation of the magnetic media on which the observed VLBI data is recorded is a bit outdated.

212 IVS 2012 Annual Report
Geospatial Information Authority of Japan Tsukuba VLBI Correlator

Most of the observed VLBI data processed at the Tsukuba VLBI Correlator is delivered via networks. The Tsukuba VLBI Correlator has a 10 Gbps dedicated link to the SINET4 operated by

the National Institute of Informatics (NII), which is connected to some research networks such as

Internet2 in the U.S., GEANT2 in Europe, and TEIN4 at Singapore. It enabled us to tran  ́ sfer

massive amounts of data between the Tsukuba VLBI Correlator and the IVS Components overseas.

The ultra-rapid EOP experiment (see section 4.3) is also brought about by this network.

2.2. K5/VSSP Correlation Software

The K5/VSSP correlation software consists of several programs for the calculation of a-priori

values of delay and delay rate (apri calc), for the correlation processing for all baselines (fx cor or

cor), and for monitoring the results of the correlation processing by performing a so-called “coarse

search”, following several utilities [1]. Komb is a bandwidth synthesis software that was developed

on an HP-1000 series minicomputer using the FORTRAN program language when the K-3 VLBI

system was being developed. It has now been ported to a Linux operating system using the C

language. All these programs were developed and have been maintained by the National Institute

of Information and Communications Technology (NICT), which are available not only for the K5

data processing but also for the Mark 5 data processing by using the data format conversion

program (m5tok5).

The following are processes of the K5 correlation and programs used in each process.

1. Transferring data from network stations to correlator (tsunami and tsunamid).

2. Data format conversion from Mark 5 to K5 (m5tok5 or m5btok5).

3. Preparation of a-priori parameter files (apri calc).

4. Fringe search to find a clock offset at each station (fx cor or cor).

5. Running correlation processing for all baseline (fx cor or cor).

6. Coarse search for residual delay and delay rate and plotting a 3-D diagram to indicate the

delay and fringe-rate axis (sdelay).

7. Bandwidth synthesis to derive a multi-band delay (komb) and generation of a Mark III

database to be submitted to the IVS Data Center (MK3TOOLS).

We developed various management programs to run the above processes consecutively and

ultra-rapidly. A program for the management of data transfer, rapid transfer, accesses the hosts

in observing stations, executes tsunamid there, and then at the correlator side, executes tsunami

to transfer data automatically when an observation starts. The data is converted from Mark 5

to K5 format by a program rapid conv as necessary. Rapid cor is a program to search for fringes

of each baseline according to the clock information of each station written in the FS log. Once

the fringe is detected, the main correlation processing is run sequentially with the clock offset

and rate found in the fringe search until the last observation. The solution, a triad of the Earth

Orientation Parameter (EOP), is derived from a set of the bandwidth synthesis outputs generated

by rapid komb that executes komb one after another. The fully automated VLBI analysis software

c5++ developed by NICT estimates EOPs, clock parameters with respect to a reference station,

and atmospheric delays for each station according to the configuration of parameterizations defined

in advance [2]. The 3-D diagrams of the fringes of each baseline and the graphs of the time series

IVS 2012 Annual Report 213
Tsukuba VLBI Correlator Geospatial Information Authority of Japan

of EOP are available on the GSI Web page and updated by the minute during an ultra-rapid

experiment.

2.3. Correlator Hardware Capabilities

The hardware supporting the activities of the Tsukuba VLBI Correlator is summarized in Table

1. All these pieces of equipment are general-purpose and commercially available. It means that no

dedicated hardware is required in the K5 correlation processing. In a correlator, mass data storage

is required. Moreover, since some executed correlation processes access a file simultaneously, the

capability of the correlator depends on the Read I/O of the data storage. The Lustre File System

enables us to use numerous HDDs mounted on a lot of servers like one partition as if it were a

large virtual disk. Thus, the I/O performance is dramatically improved compared with NFS.

In 2012, some aging servers crashed and were removed from the correlation system. It has had

little impact on the overall capability of the correlator.

Table 1. Correlator Hardware Capabilities.

Number of servers 49

- 16 for correlation processing

- 2 for controlling correlation processing

- 31 for data storage

Operating System CentOS version 5.4 or 5.5

CPU Intel Pentium4 3.0 GHz / Intel Xeon 3.4 GHz dual CPU /

Xeon 3.06 GHz dual CPU / Intel Xeon 3.07 GHz quad CPU

Total storage capacity Lustre File System: 27.9 Tbytes

individual RAIDs: 102 Tbytes in total

Network 10 Gbps dedicated line connected to SINET4 by NII

3. Staff

The technical staff members at the Tsukuba VLBI Correlator are

• Shinobu Kurihara: correlator/analysis chief, software design and development.

• Kentaro Nozawa (AES): correlator/analysis operator, software development.

• Takashi Nishikawa (AES): correlator/analysis operator.

• Toshio Nakajima (I-JUSE): system engineer.

Kensuke Kokado, who had been the correlator/analysis chief until the end of May 2012, moved

to another division on April 1.

214 IVS 2012 Annual Report
Geospatial Information Authority of Japan Tsukuba VLBI Correlator

4. Correlator Operations

4.1. IVS-INT2 and IVS-INT3

In 2012, 107 IVS-INT2 sessions were correlated. 83 of them observed the Tsukuba-Wettzell

baseline, and the other 24 observed the Kokee-Wettzell baseline. The observed data at Wettzell

is transferred to the correlator in real-time with the VDIF/SUDP protocol and is recorded on

data storage in the K5 format directly. Since the whole processes from correlation to analysis are

implemented by the rapid programs (see section 2.2), a dUT1 solution can be derived within two

minutes after the end of the last scan of the session. In case of Kokee-Wettzell baseline, since the

observed data at Kokee was transferred via the U.S. Naval Observatory (USNO), it took a few

hours to derive a solution.

Besides, one IVS-INT3 observed on February 20 (k12051) was correlated instead of the Bonn

correlator.

4.2. JADE and JAXA

JADE is the domestic geodetic VLBI series involving four GSI stations (Tsukuba, Aira, Chichijima, and Shintotsukawa), two 11-m stations at Koganei and Kashima owned by NICT, and two

VERA stations of the National Astronomical Observatory of Japan (NAOJ) located in Mizusawa

and Ishigakijima. Eight JADE sessions were correlated in 2012. A JAXA session involving Usuda

64-m to provide precise geodetic coordinates required in the tracking of the deep space probes was

processed as well.

4.3. Ultra-Rapid EOP Experiment

This experiment is the joint project with Sweden, Australia, and South Africa, having been

continued since 2007. The HartRAO 26-m and 15-m antennas newly joined in the experiments, and

the automated ultra-rapid processing was implemented with a four-station/six-baseline network.

For details refer to the report “Tsukuba VLBI Analysis Center”, this volume.

5. Outlook

For more stable operation, we will make some improvements to rapid programs.

References

[1] Kondo, T., et al.: Development of hte K5/VSSP System, Journal of the Geodetic Society of Japan,

54(4), 233-248, 2008.

[2] Hobiger, T., et al.: Fully automated VLBI analysis with c5++ for ultra-rapid determination of UT1,

Earth Planets Space, 62, 933-937, 2010.

IVS 2012 Annual Report 215
Washington Correlator U. S. Naval Observatory

Washington Correlator

David M. Hall, David Boboltz

Abstract

This report summarizes the activities of the Washington Correlator for 2012. The Washington

Correlator provides up to 80 hours of attended processing per week plus up to 40 hours of unattended

operation, primarily supporting Earth Orientation and astrometric observations. In 2012, the major

programs supported include the IVS-R4, IVS-INT, APSG, and CRF observing sessions.

1. Introduction

The Washington Correlator (WACO) is located at and staffed by the U.S. Naval Observatory (USNO) in Washington, DC, USA. The correlator is sponsored and funded by the National

Earth Orientation Service (NEOS), which is a joint effort of the USNO and NASA. Dedicated to

processing geodetic and astrometric VLBI observations, the facility spent 100 percent of its time

on these sessions. The weekly IVS-R4 sessions, the IVS-INT01 Intensives, the Asian-Pacific space

geodynamics (APSG), the Australian AuScope (AUST), and the Celestial Reference Frame (CRF)

sessions were processed at WACO. The facility houses a Mark IV correlator and the new DiFX

correlator.

2. Correlator Operations

- The Washington Correlator continues to operate 80 hours per week with an operator on

duty. The correlator has continued to function well unattended, allowing another 40 hours

per week, on average, of extra processing. This has also decreased the time it takes to process

an R4 or other 24-hour session by one day, hence the latency in the data being fully processed

and available by one day.

- The correlator staff continues the testing and repair of Mark 5 modules. Not only were failed

disks replaced, but some modules were upgraded by the replacement of lower capacity disks

with higher capacity disks.

- Intensive observations from Kokee Park and Wettzell were routinely transferred via high

speed data networks (e-VLBI) during 2012. 24-hour sessions from both Hobart antennas, Katherine, Yarragadee, Warkworth, Ny- ̊Alesund, Fortaleza, Yebes, Noto, HartRAO,

Tsukuba, Aira, Kashima, Chichijima, and Sintotu were also transferred by high-speed data

networks.

- Table 1 lists the experiments processed during 2012.

3. Software Correlator

In September 2012, Phase I of the new DiFX software correlator was delivered by the National

Radio Astronomy Observatory (NRAO) to the USNO. This Phase I implementation consists of 33

compute nodes with 16 processor cores per node for a total of 528 cores. The compute nodes are

216 IVS 2012 Annual Report
U. S. Naval Observatory Washington Correlator

Table 1. Experiments processed during 2012.

52 IVS-R4

16 CRF

3 APSG

3 AUST

230 Intensives

connected via 10 Gbps Ethernet over fiber. Cluster management is performed via two infrastruture

servers that are connected to the diskless compute nodes. The new implementation runs the DiFX

software package along with the USNO implementation of the graphical user interface (GUI).

Since delivery, USNO personnel have been involved in the configuration and testing of the new

correlator. Successful processing of VLBI data from the VLBA and the IVS has been performed.

Data have been streamed from the two connected Mark 5C units, as well as directly from the

connected storage area network (SAN). Correlated data have been successfully passed through the

entire geodetic reduction path from correlation to fringing via the Haystack Observatory Postprocessing System (HOPS) package to database generation and analysis via Calc/Solve.

4. Staff

The Washington Correlator is under the management and scientific direction of the Earth

Orientation Department of the U.S. Naval Observatory. Due to a change in policy by the U.S.

Navy, the NVI support contract was ended. At the beginning of 2012 the VLBI division had

filled only three positions, Dr. Kerry Kingham, Mr. David Hall, and Ms. Roxanne Innis. Bruce

Thornton was hired in February, and in May Mr. Daniel Veillette joined the VLBI division. Dr.

Kerry Kingham retired at the beginning of June, and Ms. Maria Davis was hired later that month.

Table 2 lists staff and their duties.

Table 2. Staff.

USNO Staff Duties

Dr. Kerry Kingham Chief VLBI Operations Division and Correlator Project Scientist

David Hall VLBI Correlator Project Manager

Daniel Veillette Astronomer

Bruce Thornton Lead Physical Science Technician

Roxanne Inniss Media Librarian

Maria Davis Physical Science Technician

IVS 2012 Annual Report 217
Washington Correlator U. S. Naval Observatory

5. Outlook

During 2013, the processing load should be transferred from the present Mark IV hardware

correlator to a DiFX software correlator.

218 IVS 2012 Annual Report
Data Centers

Bundesamt f ̈ur Kartographie und Geod ̈asie BKG Data Center

BKG Data Center

Volkmar Thorandt, Reiner Wojdziak

Abstract

This report summarizes the activities and background information of the IVS Data Center for the

year 2012. Included is information about functions, structure, technical equipment, and staff members

of the BKG Data Center.

1. BKG Data Center Functions

The BKG (Federal Agency for Cartography and Geodesy) Data Center is one of the three

IVS Primary Data Centers. It archives all VLBI related data of IVS components and provides

public access for the community. The BKG Data Center is connected to the OPAR and GSFC

CDDIS Data Centers by mirroring the OPAR and the CDDIS file stocks several times per day.

The following sketch shows the principle of mirroring:

Figure 1. Principle of mirroring.

IVS components can choose one of these Data Centers through which to put their data into

the IVS network by using its incoming area, which each of them has at its disposal. The BKG

incoming area is protected, and users need to obtain the username and the password to get access.

An incoming script watches the incoming area and checks the syntax of the files sent by IVS

components. If it is okay, the script moves the files into the Data Center directories. Otherwise

the files will be sent to a badfile area. Furthermore, the incoming script informs the responsible

staff at the Data Center by sending e-mails about its activities. The incoming script is part of

the technological unit which is responsible for managing the IVS and the Operational Data Center

and for carrying out the first analysis steps in an automatic manner. All activities are monitored

to guarantee data consistency and to control all analysis steps from data arrival to delivery of

analysis products to IVS.

IVS 2012 Annual Report 221
BKG Data Center Bundesamt f ̈ur Kartographie und Geod ̈asie

Public access to the BKG Data Center is available through FTP and HTTP at the following

Web sites:

FTP: ftp://ivs.bkg.bund.de/pub/vlbi/

HTTP: http://ivs.bkg.bund.de/vlbi/

Structure of the BKG IVS Data Center:

vlbi/ : root directory

ivs-special/ : special CRF investigations

ivscontrol/ : controlfiles for the data center

ivsdata/ : VLBI observation files

ivsdocuments/ : IVS documents

ivs-iers/ : old IERS solutions

ivsproducts/ : analysis products

crf/ : celestial frames

trf/ : terrestrial frames

eops/ : earth orientation (24h sessions)

eopi/ : earth orientation (Intensive sessions)

daily_sinex/ : daily sinex files (24h sessions)

int_sinex/ : daily sinex files (Intensive sessions)

trop/ : troposphere

2. Technical Equipment

• DELL Server (SUSE Linux operating system)

• disk space: 500 GBytes (Raid system)

• backup: automatic tape library

3. Staff Members

1. Volkmar Thorandt (coordination, data analysis, data center; volkmar.thorandt@bkg.bund.de)

2. Reiner Wojdziak (data center, Web design; reiner.wojdziak@bkg.bund.de)

3. Dieter Ullrich (data analysis, data center; dieter.ullrich@bkg.bund.de)

4. Gerald Engelhardt (data analysis; gerald.engelhardt@bkg.bund.de)

222 IVS 2012 Annual Report
NASA Goddard Space Flight Center CDDIS Data Center

CDDIS Data Center Summary for the IVS 2012 Annual Report

Carey Noll

Abstract

This report summarizes activities during 2012 and future plans of the Crustal Dynamics Data

Information System (CDDIS) with respect to the International VLBI Service for Geodesy and Astrometry (IVS). Included in this report are background information about the CDDIS, the computer

architecture, staff supporting the system, archive contents, and future plans for the CDDIS within the

IVS.

1. Introduction

The Crustal Dynamics Data Information System (CDDIS) has supported the archiving and

distribution of Very Long Baseline Interferometry (VLBI) data since its inception in 1982. The

CDDIS is a central facility providing users access to data and derived products to facilitate scientific

investigation. The CDDIS archive of GNSS (GPS, GLONASS, etc.), laser ranging, VLBI, and

DORIS data are stored on-line for remote access. Information about the system is available via

the Web at the URL http://cddis.gsfc.nasa.gov. In addition to the IVS, the CDDIS actively

supports other IAG services including the International GNSS Service (IGS), the International

Laser Ranging Service (ILRS), the International DORIS Service (IDS), the International Earth

Rotation and Reference Frame Service (IERS), and the Global Geodetic Observing System (GGOS)

of the IAG. The current and future plans for the system’s support of the IVS are discussed below.

2. System Description

The CDDIS archive of VLBI data and products is accessible to the public through anonymous

ftp.

2.1. Computer Architecture

The CDDIS is operational on a dedicated server, cddis.gsfc.nasa.gov. The system has over 32

Tbytes of on-line disk storage; at this time, over 150 Gbytes are devoted to VLBI activities. The

CDDIS is located at NASA GSFC and is accessible to users 24 hours per day, seven days per week.

In 2011, the CDDIS staff procured new server hardware to further enhance the capabilities of

the system and ensure a robust archive environment. The new configuration is fully redundant with

the primary and secondary/failover systems located in different buildings on the GSFC campus.

Each system utilizes a distributed functionality (incoming, outgoing, processing, database, and

map servers) and is configured with a local backup system as well as a full backup system located

in a third building at GSFC. The archive is equipped with a 32 Tbyte RAID storage system and

is scaled to accommodate future growth. Users and suppliers of data and product files did not

need to update their software or procedures to access the new systems. The structure of the VLBI

data and product archive remained unchanged in this new system configuration. The new server

configuration became operational in May 2012.

IVS 2012 Annual Report 223
CDDIS Data Center NASA Goddard Space Flight Center

2.2. Staffing

Currently, a staff consisting of one NASA civil service employee and four (one full-time, three

part-time) contractor employees supports all CDDIS activities (see Table 1 below).

Table 1. CDDIS Staff.

Name Position

Ms. Carey Noll CDDIS Manager

Dr. Patrick Michael System Engineer (part-time)

Dr. Maurice Dube Senior programmer

Mr. Nathan Pollack Programmer (part-time)

Ms. Lori Tyahla Programmer (part-time)

3. Archive Content

The CDDIS has supported GSFC VLBI coordination and analysis activities for the past several

years through an on-line archive of schedule files, experiment logs, and data bases in several formats.

This archive has been expanded for the IVS archiving requirements.

The IVS Data Center content and structure is shown in Table 2. (A figure illustrating the

flow of information, data, and products between the various IVS components was presented in the

CDDIS submission to the IVS 2000 Annual Report.) In brief, dedicated ftp-only accounts have been

established on the CDDIS incoming computer, cddisin.gsfc.nasa.gov. Using specified file names,

operation and analysis centers deposit data files and analyzed results to appropriate directories

within their ftp-only accounts. Automated archiving routines, developed by GSFC VLBI staff,

peruse the directories and move any new data to the appropriate public disk area. These routines

migrate the data based on the file name to the appropriate directory as described in Table 2.

Index files in the main sub-directories under ftp://cddis.gsfc.nasa.gov/pub/vlbi are updated to

reflect data archived in the filesystem. Furthermore, mirroring software has been installed on the

CDDIS host computer, as well as all other IVS data centers, to facilitate equalization of data and

product holdings among these data centers. At this time, mirroring is performed between the IVS

data centers located at the CDDIS, the Bundesamt f ̈ur Kartographie und Geod ̈asie in Leipzig, and

the Observatoire de Paris.

The public filesystem in Table 2 on the CDDIS computer, accessible via anonymous ftp, consists

of a data area, which includes auxiliary files (e.g., experiment schedule information, session logs,

etc.) and VLBI data (in both database and NGS card image formats). A products disk area has

also been established to house analysis products from the individual IVS analysis centers as well

as the official combined IVS products. A documents disk area contains format, software, and other

descriptive files.

4. Data Access

During 2012, over 1,300 distinct hosts accessed the CDDIS on a regular basis to retrieve VLBI

related files. These users, which include other IVS data centers, successfully downloaded over 2.3

224 IVS 2012 Annual Report
NASA Goddard Space Flight Center CDDIS Data Center

Table 2. IVS Data and Product Directory Structure.

Directory Description

Data Directories

vlbi/ivsdata/db/yyyy VLBI database files for year yyyy

vlbi/ivsdata/ngs/yyyy VLBI data files in NGS card image format for year

yyyy

vlbi/ivsdata/aux/yyyy/ssssss Auxiliary files for year yyyy and session ssssss; these

files include: log files, wx files, cable files, schedule

files, correlator notes

vlbi/raw Raw VLBI data

Product Directories

vlbi/ivsproducts/crf CRF solutions

vlbi/ivsproducts/eopi EOP-I solutions

vlbi/ivsproducts/eops EOP-S solutions

vlbi/ivsproducts/daily sinex Daily SINEX solutions

vlbi/ivsproducts/int sinex Intensive SINEX solutions

vlbi/ivsproducts/trf TRF solutions

vlbi/ivsproducts/trop Troposphere solutions

Project Directories

vlbi/ivs-iers IVS contributions to the IERS

vlbi/ivs-pilotbl IVS Analysis Center pilot project (baseline)

Other Directories

vlbi/ivscontrol IVS control files (master schedule, etc.)

vlbi/ivsdocuments IVS document files (solution descriptions, etc.)

vlbi/dserver Dserver software and incoming files

Tbytes of data and products (2.5M files) from the CDDIS VLBI archive last year.

5. Future Plans

The CDDIS staff will continue to work closely with the IVS Coordinating Center staff to ensure

that our system is an active and successful participant in the IVS archiving effort.

IVS 2012 Annual Report 225
Italy INAF Data Center Istituto di Radioastronomia–Bologna

Italy INAF Data Center Report

M. Negusini, P. Sarti

Abstract

This report summarizes the activities of the Italian INAF VLBI Data Center. Our Data Center is

located in Bologna, Italy and belongs to the Institute of Radioastronomy, which is part of the National

Institute of Astrophysics.

1. Introduction

The main analysis activity and storage is concentrated in Bologna, where we store and analyze

single databases, using CALC/SOLVE software.

The IRA started to store geodetic VLBI databases in 1989, but the databases archived in

Bologna mostly contain data including European antennas from 1987 onward. In particular, most

of the databases available here have VLBI data with at least three European stations. However

we also store all the databases with the Ny- ̊Alesund antenna observations. In 2002, we decided to

store the complete set of databases available on the IVS data centers, although we limited the time

span to the observations performed from 1999 onwards. All the databases have been processed

and saved with the best selection of parameters for the final arc solutions. In order to perform

global solutions, we have computed and stored the superfiles for all the databases.

In some cases we have introduced GPS-derived wet delays into the European databases (1998

and 1999 EUROPE experiments, for the time being), as if they were produced by a WVR. These

databases are available and stored with a different code from the original databases. In order to

produce these databases, we have modified DBCAL, and this new version is available to external

users.

2. Computer Availability and Routing Access

To date, the main computer is a Linux workstation, on which Mark 5 Calc/Solve version 10

was installed and to which all VLBI data analysis was migrated. The Internet address of this

computer is sarip.ira.inaf.it. Since 2011 a new server with a storage capacity of 5 TB has been

available, and, therefore, all experiments performed in the previous years were downloaded and

archived, thus completing the catalog. The older experiments will be analyzed in order to perform

global long term analysis. At present, the databases are stored in the following directories:

1 = /data2/dbase2

2 = /geo1/dbase1

3 = /geo1/dbase

4 = /geo1/dbase3

The superfiles are stored in:

/data1/super1

The list of superfiles is stored in the file /data2/mk5/save files/SUPCAT. The username for

accessing the databases is geo. The password may be requested by sending an e-mail to

negusini@ira.inaf.it.

226 IVS 2012 Annual Report
National Institute of Information and Communications Technology Data Center at NICT

Data Center at NICT

Ryuichi Ichikawa, Mamoru Sekido

Abstract

The Data Center at the National Institute of Information and Communications Technology (NICT)

archives and releases the databases and analysis results processed at the Correlator and the Analysis

Center at NICT. Regular VLBI sessions of the Key Stone Project VLBI Network were the primary

objective of the Data Center. These regular sessions continued until the end of November 2001. In

addition to the Key Stone Project VLBI sessions, NICT has been conducting geodetic VLBI sessions

for various purposes, and these data are also archived and released by the Data Center.

1. Introduction

The IVS Data Center at National Institute of Information and Communications Technology

(NICT) archives and releases the databases and analysis results processed by the Correlator and

the Analysis Center at NICT. Major parts of the data are from the Key Stone Project (KSP)

VLBI sessions [1], but other regional and international VLBI sessions conducted by NICT are also

archived and released. Because routine observations of the KSP network terminated at the end of

November 2001, there have been no additional data from the KSP regular sessions since 2002.

On March 11, 2011, the devastating megaquake (Mw 9.0) hit our antennas. The azimuth track

and one azimuth wheel of the Kashima 34-m were damaged as a consequence of the megaquake.

Since the antenna is still under repair, there are no VLBI databases containing baselines with

the 34-m antenna in 2012. On the other hand, the 11-m antennas at Kashima and Koganei

were not damaged by the earthquake. We have carried out 39 VLBI experiments using the 11-m

antennas including time and frequency transfer experiments, international and domestic geodetic

experiments, and astrophysical experiments.

The analysis results in SINEX (Solution INdependent EXchange) format, as well as in other

formats, are available on the WWW server. Database files of non-KSP sessions, i.e. other domestic

and international geodetic VLBI sessions, are also available on the WWW server. Table 1 lists the

WWW server locations maintained by the NICT Data Center. In the past, an FTP server was

used to provide data files, but it was decided to terminate the FTP service because of the security

risks of maintaining an anonymous FTP server. Instead, the www3.nict.go.jp WWW server was

prepared to provide large size data files.

Table 1. URL of the WWW server systems.

Service URL

KSP WWW pages http://ksp.nict.go.jp/

IVS WWW mirroring http://ivs.nict.go.jp/mirror/

Database files http://www3.nict.go.jp/aeri/sts/stmg/database/

e-VLBI Sessions http://www2.nict.go.jp/aeri/sts/stmg/research/e-VLBI/UT1/

Hayabusa Sessions http://www2.nict.go.jp/aeri/sts/stmg/research/Navi/HAYABUSA/

IVS 2012 Annual Report 227
Data Center at NICT National Institute of Information and Communications Technology

The responsibility for the maintenance of these server machines was moved from the VLBI

research group in 2001 to a common division which handles all institutional network service for

the laboratory in order to improve the network security of these systems.

2. Data Products

2.1. KSP VLBI Sessions

The KSP VLBI sessions were performed with four KSP IVS Network Stations at Kashima,

Koganei, Miura, and Tateyama on a daily or bi-daily basis until May 1999. The high-speed ATM

(Asynchronous Transfer Mode) network line to the Miura station became unavailable in May

1999, and real-time VLBI observations with the Miura station became impossible. Thereafter,

the real-time VLBI sessions were performed with the three other stations. Once every six days

(every third session), the observed data were recorded to the K4 data recorders at three stations,

and the Miura station participated in the sessions with the tape-based VLBI technique. In this

case, the observed data at the three stations other than the Miura station were processed in realtime, and the analysis results were released promptly after the observations completed. A day

later, the observed tapes were transported from the Kashima, Miura, and Tateyama stations to

the Koganei station for tape-based correlation processing with all six baselines. After the tapebased correlation processing was completed, the data set produced with the real-time VLBI data

processing was replaced by the new data set.

In July 2000, unusual site motion of the Tateyama station was detected from the KSP VLBI

data series, and the frequency of the sessions was increased from bi-daily to daily on July 22, 2000.

The daily sessions were continued until November 11, 2000, and the site motions of the Tateyama

and Miura stations were monitored in detail. During the period, it was found that Tateyama

station moved about 5 cm in the northeast direction. The Miura station also moved about 3 cm

to the north. The unusual site motions of these two stations gradually settled, and the current

site velocities seem to be almost the same as the site velocities before June 2000. By investigating

the time series of the site positions, the unusual site motion started sometime between the end

of June 2000 and the beginning of July 2000. At the same time, volcanic and seismic activities

near the Miyakejima and Kozushima Islands began. These activities are believed to have caused

the regional crustal deformation in the area, explaining the unusual site motions at Tateyama and

Miura.

2.2. Other VLBI Sessions

In recent years, we have carried out time and frequency transfer experiments using VLBI. In

addition, domestic and international geodetic and astronomical VLBI sessions were conducted by

NICT in cooperation with the Geospatial Information Authority of Japan (GSI), the National

Astronomical Observatory of Japan (NAO), and other organizations. These sessions are listed in

Table 2. The recently observed data from these sessions were mainly processed by the K5 software

correlator at NICT either at Koganei or at Kashima or by using a real-time hardware correlator

developed by NAO.

In 2012, we have no data using the 34-m antenna since the antenna has been under repair to

recover from the damages due to the earthquake. The repair will be finished at the end of March

2013.

228 IVS 2012 Annual Report
National Institute of Information and Communications Technology Data Center at NICT

Table 2. VLBI sessions conducted by NICT (since 2005). ∗In 2012, all experiments were observed using the

11-m antennas at Kashima and Koganei because the 34-m antenna was under repair to recover from the

earthquake damage.

Year exp. names sessions

2005 Geodetic c0505 (CONT05, partial participation),

Hayabusa GEX13, 14 sessions

2006 Geodetic GEX14, viepr2, CARAVAN (3 sessions)

Spacecraft Geotail : 1 session

Pulsar 1 session

2007 Ultra Rapid e-VLBI 15 times, 29 sessions

Time Transfer 4 sessions, 12 days in total

Cs-Gas-Cell 1 session

Spacecraft Hayabusa : 1 session

2008 Ultra Rapid e-VLBI 8 times, 33 sessions

Time Transfer 26 sessions

Variable Star e-VLBI 31 sessions

2009 e-VLBI 15 sessions, 90.5 hours in total

IVS 12 sessions, 332 hours in total

Time Transfer 9 sessions, 72 hours in total

VERA 16 sessions, 149 hours in total

Survey 26 sessions, 276 hours in total

2010 IVS 38 sessions, 442 hours in total

Radio astronomy 34 sessions, 324 hours in total

Spacecraft (IKAROS, UNITEC-1, QZSS) 33 sessions, 259 hours in total

Domestic geodetic 13 sessions, 94 hours in total

Time Transfer 9 sessions, 86 hours in total

e-VLBI 9 sessions, 27 hours in total

2011 IVS two sessions, 48 hours in total

Radio astronomy 100 hours in total

earthquake damage investigation 216 hours in total

2012∗IVS 9 sessions, 216 hours in total

Radio astronomy (Sgr-A⋆) 13 sessions, 28 hours in total

Domestic geodetic 3 sessions, 72 hours in total

International fringe test 2 sessions, 16 hours in total

(New Zealand and Korea)

International geodetic (New Zealand) 1 session, 24 hours in total

Time transfer 11 sessions, 264 hours in total

3. Staff Members

The Data Center at NICT is operated and maintained by the Space-Time Standards Group at

the Kashima Space Research Center, NICT. The staff members are listed in Table 3.

IVS 2012 Annual Report 229
Data Center at NICT National Institute of Information and Communications Technology

Table 3. Staff members of the Space-Time Measurements Group, NICT. †Ichikawa moved to the Koganei

division of the NICT on May 1, 2012.

Name Main Responsibilities

ICHIKAWA Ryuichi† Frequency and Time Transfer using compact VLBI system

SEKIDO Mamoru Responsible for e-VLBI sessions

HASEGAWA Shingo System Engineer

4. Future Plans

The IVS Data Center at NICT will continue its service and will archive and release the analysis

results accumulated by the Correlator and the Analysis Center at NICT. In addition, a number of

VLBI sessions will be conducted for the purposes of various technology developments.

References

[1] Special issue for the Key Stone Project, J. Commun. Res. Lab., Vol. 46, No. 1, March 1999.

230 IVS 2012 Annual Report
Observatoire de Paris, SYRTE/UMR 8630 Paris Observatory (OPAR) Data Center

Paris Observatory (OPAR) Data Center

Christophe Barache, Sebastien Lambert

Abstract

This report summarizes the OPAR Data Center activities in 2012. Included is information about

functions, architecture, status, future plans, and staff members of OPAR Data Center.

1. OPAR Data Center Functions

The Paris Observatory (OPAR) has provided a Data Center for the International VLBI Service

for Geodesy and Astrometry (IVS) since 1999. The OPAR, as well as CDDIS and BKG, is one of

the three IVS Primary Data Centers. Their activities are done in close collaboration for collecting

files (data and analysis files) and making them available to the community as soon as they are

submitted.

The three Data Centers have a common protocol and each of them:

• has the same directory structure (with the same control file),

• has the same script,

• is able to receive all IVS files (auxiliary, database, products, and documents),

• mirrors the other ones every three hours, and

• gives free FTP access to the files.

Figure 1. Mirroring among the primary IVS Data Centers.

IVS 2012 Annual Report 231
Paris Observatory (OPAR) Data Center Observatoire de Paris, SYRTE/UMR 8630

This protocol gives the IVS community transparent access to a Data Center through the same

directory and permanent access to files in case of a Data Center breakdown.

2. Architecture

To be able to put a file in a Data Center, Operational and Analysis Centers have to be registered by the IVS Coordinating Center. The file names have to conform to the name conventions.

A script checks the file and puts it in the right directory. The script undergoes permanent improvement and takes into account the IVS components’ requests.

The structure of IVS Data Centers is:

RECENT/ : used for the new mirror method

ivscontrol/ : provides the control files needed by the data center

(session code, station code, solution code...)

ivsdocuments/ : provides documents and descriptions about IVS products

ivsdata/ : provides files related to the observations:

aux/ : auxiliary files (schedule, log...)

db/ : observation files in database CALC format

ngs/ : observation files in NGS format

sinex/ : observation files in SINEX format

ivsproducts/ : provides results from Analysis Center:

eopi/ : Earth Orientation Parameters, Intensive sessions

eops/ : Earth Orientation Parameters, sessions of 24h

crf/ : Celestial Reference Frame

trf/ : Terrestrial Reference Frame

daily_sinex/ : Time series solutions in SINEX format of Earth

orientation and site positions

int_sinex/ : Daily Intensive solution in SINEX format, mainly

designed for combination

trop/ : Tropospheric time series (starting July 2003)

3. Current Status

The OPAR Data Center is operated actually on a PC Server (PowerEdge 2800 - Xeron 3.0

GHz) located at Paris Observatory and running the Fedora Linux operating system.

To make all IVS products available on-line, the disk storage capacity was significantly increased,

and the server is equipped now with a RAID 3 TB disk extensible up to 4.7 TB.

The OPAR server is accessible 24 hours per day, seven days per week through Internet connections with 2 Mbit/s rate. Users can get the IVS products by using the FTP protocol. Access

to this server is free for users.

232 IVS 2012 Annual Report
Observatoire de Paris, SYRTE/UMR 8630 Paris Observatory (OPAR) Data Center

Figure 2. Monthly access of the OPAR Data Center during 2012. For each month listed in column 1,

columns 2 through 6 show the number of different visitors, the total number of visits, the number of pages

viewed, the number of hits, and the downloaded bandwidth in Megabytes (Mo) or Gigabytes (Go).

FTP access:

ivsopar.obspm.fr

username: anonymous

password: your e-mail

cd vlbi (IVS directory)

This year, from July to September, the OPAR was disconnected from the CDDIS Data Center

because of the new mirror method installation using lftp.

4. Future Plans

The OPAR staff will continue to work with the IVS community and in close collaboration with

the two other Primary Data Centers in order to provide public access to all VLBI related data.

To obtain information about the OPAR Data Center please contact: ivs.opa@obspm.fr

IVS 2012 Annual Report 233

Analysis Centers

Sobolev Astronomical Institute of Saint Petersburg University Analysis Center of Saint Petersburg University

Analysis Center of Saint Petersburg University

Dmitriy Trofimov, Veniamin Vityazev

Abstract

This report briefly summarizes the activities of the Analysis Center of Saint Petersburg University

during 2012. The current status, as well as our future plans, are described.

1. Introduction

The Analysis Center of Saint Petersburg University (SPU AC) was established in the Sobolev

Astronomical Institute of the SPb University in 1998. The main activity of the SPU AC for the

International VLBI Service before 2007 consisted of routine processing of 24-hour and one-hour

observational sessions for obtaining Earth Orientation Parameters (EOP) and rapid UT1-UTC

values, respectively. In 2008 we began submitting results of 24-hour session processing.

2. Staff

The assistant professor of Saint Petersburg University, Dmitriy Trofimov, was in charge of the

routine processing of the VLBI observations. General coordination and support for the activities

of the SPU AC at the Astronomical Institute was performed by Professor Veniamin Vityazev.

3. Activities in 2012

• In 2012, the routine estimation of the five Earth Orientation Parameters was performed. The

OCCAM software package (version 6 2) was used for current processing of VLBI data [1].

The time series is named spu00004.eops. It includes data obtained by the IRIS-A, NEOS-A,

R1, R4, RDV, and R&D observing programs, and it covers 25 years of observations (from

January 2, 1989 until the end of 2012). The total number of experiments processed at the

SPU AC is about 1870, of which about 100 VLBI sessions were processed in 2012. We also

complemented our series for 2011 by 118 sessions not processed before. Our experience and

the equipment of the Analysis Center was used for giving lectures and practical work on the

basics of radio interferometry for university students. We use our original manual on the

training in modern astrometry, in particular, VLBI [2].

In 2012, the work of the SPU AC was performed within the projects “Acquisition and analysis

of time-series in astronomy and study of astronomical catalogs” and “GLONASS, GPS and

VLBI observations as the basis of astronomical, gravimetric, and geodynamic studies” (the

SPU grants for fundamental research).

• All parameters were adjusted using the Kalman filter technique. For all stations (except the

reference station), the wet delay, clock offsets, clock rates, and troposphere gradients were

estimated. Troposphere wet delay and clock offsets were modeled as a stochastic process

such as a random walk. The clock rates and the troposphere gradients were considered to

be the constant parameters.

IVS 2012 Annual Report 237
Analysis Center of Saint Petersburg University Sobolev Astronomical Institute of Saint Petersburg University

• The main details of the preparation of the EOP time series spu00004.eops are summarized

below:

– Data span: 1989.01–2012.12

– CRF: fixed to ICRF-Ext.2

– TRF: VTRF2005 was used as an a priori TRF

– Estimated parameters:

1. EOP: x, y, UT1 − UT C, dψ, dε;

2. Troposphere: troposphere gradients were estimated as constant parameters, and

wet troposphere delays were modeled as a random walk process;

3. Station clocks were treated as follows: offset as a random walk process, rate as a

constant.

– nutation model: IAU 1980

– mapping function: VMF1

– technique: Kalman filter

– software: OCCAM v.6 2

4. Future Plans

In 2013, we are going to continue our regular processing of the VLBI sessions as well as giving

lectures and practical training for students in a special course on radio astrometry. This course is

a part of the systematic curriculum of astronomical education at SPb University.

References

[1] O. Titov, V. Tesmer, J. Boehm, OCCAM v. 6. 0 Software for VLBI Data Analysis, In International

VLBI Service for Geodesy and Astrometry 2004 General Meeting Proceedings, N. R. Vandenberg and

K. D. Baver (eds.), NASA/CP-2004-212255, pp. 267-271, 2004.

[2] V. Vityazev, I. Guseva, V. Kiyaev, M. Mishchenko, O. Titov, A. Tsvetkov. Celestial and Terrestrial

Coordinates (In Russian), Manual on Astrometry, 301 p., SPb University, 2011.

238 IVS 2012 Annual Report
Geoscience Australia Geoscience Australia Analysis Center

Geoscience Australia Analysis Center

Oleg Titov, Laura Stanford

Abstract

This report gives an overview of the activities of the Geoscience Australia IVS Analysis Center

during 2012.

1. General Information

The Geoscience Australia (GA) IVS Analysis Center is located in Canberra. The National

Geospatial Reference System Section operates as a part of the Mineral and Natural Hazard Division

(MNHD).

2. Component Description

Currently, the GA IVS Analysis Center contributes estimates of nutation offsets, EOP, and

EOP rates on a regular basis for the IVS-R1 and IVS-R4 networks and their predecessors (IRIS-A

and NEOS-A). The EOP time series are available from 1983 to 2012. The CRF catalogs, using a

global set of VLBI data since 1979, are regularly submitted to the IVS database.

3. Staff

• Dr. Oleg Titov - senior scientist

• Dr. Laura Stanford - VLBI scientist

4. Current Status and Activities

Several CRF solutions have been prepared using the OCCAM 6.2 software. The latest solution

was uploaded in September 2012. VLBI data comprising 4,109 daily sessions from 25 November

1979 to 31 May 2012 have been used to compute several global solutions with different sets of

reference radio sources. This includes 5,537,065 observational delays from 2,895 radio sources

having four or more observations.

Station coordinates were also estimated using No-Net-Rotation and No-Net-Tranlation constraints. The long-term time series of the station coordinates have been used to estimate the

corresponding velocities for each station. The tectonic motion for the Gilcreek VLBI site after the

Denali earthquake was modeled using an exponential function typical of post-seismic deformation

[1]. The tectonic motion of Tigoconc (2010) and Tsukub32 (2011) VLBI sites after the strong

earthquakes is currently under study.

The adjustment was made by least squares collocation [2], which considers the clock offsets, wet

troposphere delays, and tropospheric gradients as stochastic parameters with a priori covariance

functions. The gradient covariance functions were estimated from GPS hourly values [3].

Our first CRF solution, aus2012a.crf, did not impose the NNR constraints. The second CRF

solution, aus2012b.crf, imposed NNR constraints. This second solution is consistent with the CRF

solutions submitted by other Analysis Centers.

IVS 2012 Annual Report 239
Geoscience Australia Analysis Center Geoscience Australia

A progress report on the secular aberration drift was presented at the IAU General Assembly

in Beijing on August 28, 2012. This work was done in collaboration with colleagues from the

IVS Analysis Center of Paris Observatory. The new estimate of the dipole systematic effect,

5.3 ± 1.5 μas/yr, was found using the individual proper motion of the 643 reference radio sources

with the CALC/SOLVE software. New coordinates of the acceleration vector are α = 268 ± 12

degrees and δ = −30 ± 13 degrees [4].

5. Geodetic Activity of the Australian Radio Telescopes

In 2012, all three new AuScope 12-meter radio telescopes moved to full operational mode. Two

other Australian radio telescopes – Hobart26, operated by the University of Tasmania (UTAS),

and Parkes, operated by the Australia Telescope National Facility (ATNF) – participated in the

geodetic VLBI programs occasionally.

The Parkes 64-meter telescope participated in six geodetic VLBI sessions in 2012 for improvement of the ITRF and the ICRF in the Southern Hemisphere. This program was undertaken in

cooperation with ATNF and UTAS.

6. Optical Spectroscopic Observations of the Reference Radio Sources

A program for optical identification and spectroscopy of the reference radio sources is continued

in collaboration with the Australian Telescope National Facility, University of Sydney and Nordic

Optical Telescope. A new paper that includes redshifts of 126 reference radio sources was submitted

[5].

Acknowledgements

This report has been published with the permission of the CEO, Geoscience Australia.

References

[1] Titov, O., P. Tregoning, Post-seismic motion of Gilcreek geodetic sites following the November, 2002

Denali Earthquake, In: International VLBI Service for Geodesy and Astrometry 2004 General Meeting

Proceedings, NASA/CP–2004-212255, N. R. Vandenberg and K. D. Baver (eds.), 496–500, 2004.

[2] Titov, O., Estimation of subdiurnal tidal terms in UT1-UTC from VLBI data analysis, In: IERS

Technical Notes 28, B. Kolaczek, H. Schuh, and D. Gambis (eds.), 11–14, 2000.

[3] Haas, R., private communication.

[4] Titov, O, S. Lambert, Dipole systematics in the reference radio source proper motion. Presentation at

the IAU General Assembly, Joint Discussion 7, Beijing, 2012.

[5] Titov, O., L. Stanford, H. Johnston, R. Hunstead, D. Jauncey, K. Maslennikov, and A. Boldycheva,

Optical Spectra of Candidate International Celestial Reference Frame (ICRF) Flat-Spectrum Radio

Sources, submitted to AJ, 2013.

240 IVS 2012 Annual Report
Laboratoire d’Astrophysique de Bordeaux Bordeaux IVS Analysis Center

Report for 2012 from the Bordeaux IVS Analysis Center

Patrick Charlot, Antoine Bellanger, Romuald Bouffet, G ́eraldine Bourda, Arnaud Collioud,

Alain Baudry

Abstract

This report summarizes the activities of the Bordeaux IVS Analysis Center during the year 2012.

The work focused on (i) regular analysis of the IVS-R1 and IVS-R4 sessions with the GINS software

package; (ii) systematic VLBI imaging of the RDV sessions and calculation of the corresponding source

structure index and compactness values; (iii) investigation of the correlation between astrometric position instabilities and source structure variations; and (iv) continuation of our VLBI observational

program to identify optically-bright radio sources suitable for the link with the future Gaia frame.

Also of importance is the 11th European VLBI Network Symposium, which we organized last October

in Bordeaux and which drew much attention from the European and International VLBI communities.

1. General Information

The “Laboratoire d’Astrophysique de Bordeaux” (LAB), formerly Bordeaux Observatory, is

located in Floirac, near Bordeaux, in the southwest of France. It is funded by the University of Bordeaux and the CNRS (“Centre National de la Recherche Scientifique”). VLBI activities are primarily developed within the M2A team (“M ́etrologie de l’espace, Astrodynamique, Astrophysique”).

The contribution of the Bordeaux group to the IVS has been mostly concerned with the maintenance, extension, and improvement of the International Celestial Reference Frame (ICRF). This

includes regular imaging of the ICRF sources and evaluation of their astrometric suitability, as

well as developing specific VLBI observing programs for enhancing the celestial reference frame.

In addition, the group is in charge of the VLBI component in the multi-technique GINS software

package [1] as part of a collaborative effort within the French “Groupe de Recherches de G ́eod ́esie

Spatiale” (GRGS) to combine VLBI and space geodetic data (SLR, GPS, and DORIS) at the

observation level. This effort also involves space geodesy groups in Toulouse, Grasse, and Paris.

2. Description of the Analysis Center

The Bordeaux IVS group routinely analyzes the weekly IVS-R1 and IVS-R4 sessions with the

GINS software package. During the past year, weekly normal equations for all such sessions in

2012 (with six-hour EOP resolution) have been produced and integrated into the multi-technique

solutions derived by the GRGS within the framework of the “Combination at the Observation

Level” (COL) Working Group. The CONT08 and CONT11 sessions were also analyzed in the

same way.

The group is also focused on imaging the ICRF sources on a regular basis by systematic

analysis of the data from the RDV sessions, which are conducted six times a year. This analysis

is carried out with the AIPS and DIFMAP software packages. The aim of such regular imaging is

to characterize the astrometric suitability of the sources based on the so-called “structure index”,

and to compare source structural evolution and positional instabilities. Such studies are essential

for identifying sources of high astrometric quality, which is required, for example, for the future

Gaia link.

IVS 2012 Annual Report 241
Bordeaux IVS Analysis Center Laboratoire d’Astrophysique de Bordeaux

3. Scientific Staff

During the past year, the group was strengthened by the arrival of a Ph. D. student, Romuald

Bouffet. In all, six individuals contributed to IVS analysis and research activities during 2012. A

description of what each person worked on, along with the time spent on it, is given below.

• Patrick Charlot (20%): overall responsibility for Analysis Center work and data processing.

His research interests include the ICRF densification, extension, and link to the Gaia frame,

studies of source structure effects in astrometric VLBI data, and astrophysical interpretation.

• Antoine Bellanger (80%): engineer with background in statistics and computer science. His

tasks are to process VLBI data with GINS and to develop procedures and analysis tools to

automate such processing. He is also the Web master for the M2A group.

• Romuald Bouffet (30%): Ph. D. student from University of Bordeaux whose thesis is focused

on the study of the relationship between radio source structure and position instabilities. To

this end, he uses astrometric data and VLBI images produced from IVS sessions.

• G ́eraldine Bourda (50%): astronomer in charge of developing the VLBI part of GINS and

responsible for the analysis results derived from GINS. She also leads a VLBI observational

program for linking the ICRF and the future Gaia frame.

• Arnaud Collioud (100%): engineer with background in astronomy and interferometry. His

tasks are to image the sources in the RDV sessions using AIPS and DIFMAP, to develop

the Bordeaux VLBI Image Database and the IVS Live tool, and to conduct VLBI2010

simulations.

• Alain Baudry (10%): radioastronomy expert with specific interest in radio source imaging

and astrometric VLBI. Professor Emeritus and under a part-time ESO contract.

4. Analysis and Research Activities during 2012

As noted above, a major activity of the Bordeaux group consists of imaging the sources observed

during the RDV sessions on a systematic basis. During 2012, two such sessions were processed

(RDV86 and RDV88), resulting in 333 VLBI images at either X or S band for 159 different sources.

The imaging work load has been shared with USNO since 2007 (starting with RDV61): the USNO

group processes the odd-numbered RDV sessions while the Bordeaux group processes the evennumbered ones. The VLBI images are used in a second stage to derive structure correction maps

and visibility maps along with values for structure indices and source compactness (see [2, 3] for

a definition of these quantities) in order to assess astrometric source quality. All such information

is made available through the Bordeaux VLBI Image Database (BVID)1. At present, the BVID

comprises a total of 3517 VLBI images for 1110 different sources (with links to an additional

7851 VLBI images from the Radio Reference Frame Image Database of USNO at either S, X, K,

or Q band) along with 11,368 structure correction maps and as many visibility maps.

In the past year, a collaboration was established with the Paris Observatory Analysis Center in

order to look for correlation between astrometric instabilities and source structural variations. The

study is focused on a sample of 68 sources with VLBI images available at 20 epochs or more over the

1The BVID may be accessed at http://www.obs.u-bordeaux1.fr/BVID

242 IVS 2012 Annual Report
Laboratoire d’Astrophysique de Bordeaux Bordeaux IVS Analysis Center

period 1994–2003. The astrometric data consists of all IVS sessions conducted over the same period,

analyzed in a way that provides source positions on a monthly basis. A comparison of the time series

of source positions with the relative motion of the brightness centroid (as derived from the available

VLBI images) indicates similar trends in the evolution of the astrometric and brightness centroid

positions. Based on this initial comparison, and awaiting quantitative assessment, an explanation

of VLBI source position instabilities in terms of structural variations is thus favored [4].

Additionally, the work to identify and characterize appropriate radio sources to align the ICRF

and the future Gaia optical frame was pursued. On the observational side, a total of 119 opticallybright radio sources with high astrometric quality was observed with the combined Very Long

Baseline Array (VLBA) and European VLBI Network (EVN) during a dedicated 72-hour astrometric VLBI session conducted in May 2012. These sources were selected from an initial sample of

395 optically-bright weak radio sources, further reduced to 119 sources after assessing their VLBI

detectability and astrometric suitability (see [5] for details of the project). Data from this session

are being correlated. In parallel to this observational work, all ICRF2 sources (excluding those

observed only as part of the VLBA Calibrator Survey) were assessed in terms of optical magnitude

and astrometric suitability. This led to the identification of an additional 195 transfer sources,

making altogether a total of 314 such sources available for the Gaia link. As a further step, a

proposal was submitted to IVS to monitor the position stability and structure of the 195 ICRF2

transfer sources, some of which also require improvement in position accuracy.

5. Dissemination and Outreach

The highlight from the past year was the organization of the 11th EVN symposium by the

Bordeaux VLBI group. The purpose of the symposium was to share and publicize the latest

scientific results and technical developments from VLBI, space VLBI, and e-VLBI. The symposium

took place in Bordeaux from the 9th to the 12th of October and was attended by a total of

122 participants from 47 institutes in 19 countries worldwide. The program of the meeting consisted

of 71 oral presentations and 43 posters. Of particular interest to the IVS community was the session

entitled “Astrometry and planetary science”. The program also comprised an EVN Users Meeting

to foster interaction between the EVN users and the EVN organization. Further details may be

found at the symposium Web page available at http://evn2012.obs.u-bordeaux1.fr/.

The IVS Live Web site [6], dedicated to monitoring IVS sessions and viewing VLBI images

of the observed sources, was updated on a regular basis during 2012. It now includes 5302 IVS

sessions and more than 1600 sources. The Web site was also enhanced with a few features, including

the addition of a “webcams” page. Monitoring of the connections indicates that there were more

than 800 visits from around the world (47 countries) during 2012, 70% of which originate from

different individuals. On the other hand, the Bordeaux VLBI Image Database was accessed from

39 countries, with more than 900 connections, half of which are from different individuals.

6. Outlook

Our plans for the coming year are focused on moving towards operational analysis of the

IVS-R1 and IVS-R4 sessions with the GINS software package. Imaging of the RDV sessions and

evaluation of the astrometric suitability of the sources will continue along the same lines. On the

observational side, the immediate plan will be to analyze the astrometric data that we acquired

IVS 2012 Annual Report 243
Bordeaux IVS Analysis Center Laboratoire d’Astrophysique de Bordeaux

about the 119 Gaia transfer sources identified from our program (see Section 4), after correlation.

Following our proposal, we also expect the IVS to strengthen observations for the 195 ICRF2

transfer sources identified so far, especially after the launch of the Gaia satellite in Fall 2013. To

complete such identification, we would like to characterize the optical magnitude and astrometric

suitability of the VLBA Calibrator Survey sources as well. Finally, we expect to contribute to the

work towards the next realization of the ICRF because two of us were appointed to the Working

Group in charge of this task at the last IAU General Assembly in August 2012.

Acknowledgements

We would like to thank the “Observatoire Aquitain des Sciences de l’Univers” (OASU) for

supporting IVS activities in Bordeaux.

References

[1] Bourda, G., Charlot, P., Biancale, R.: 2007, GINS: A New Tool for VLBI Geodesy and Astrometry,

18th EVGA Working Meeting, Eds. J. B ̈ohm, A. Pany, and H. Schuh, IGG Vienna, p. 59–63.

[2] Fey, A. L., Charlot, P.: 1997, VLBA Observations of Radio Reference Frame Sources. II. Astrometric

Suitability Based on Observed Structure, ApJS, 111, pp.95–142.

[3] Charlot, P.: 2008, Astrophysical Stability of Radio Sources and Implication for the Realization of the

Next ICRF, 5th IVS General Meeting, St Petersburg, Eds. A. Finkelstein and D. Behrend, p. 345–354.

[4] Bouffet, R., Charlot, P., Lambert, S.: 2012, Radio Source Structure and VLBI Position Instabilities,

11th European VLBI Network Symposium (in press).

[5] Bourda, G., Collioud, A., Charlot, P., Porcas, R., Garrington, S.: 2012, Towards an Accurate Alignment

of the VLBI Frame and the Future Gaia Optical Frame: Global VLBI Imaging Observations of a Sample

of Candidate Sources for this Alignment, IVS 2012 General Meeting Proceedings, Eds. Dirk Behrend

and Karen D. Baver, NASA/CP-2012-217504, p. 334–338.

[6] Collioud, A.: 2011, IVS Live: All IVS on your deskstop, Proceedings of the 20th Meeting of the

European VLBI Group for Geodesy and Astronomy, Eds. W. Alef, S. Bernhart, and A. Nothnagel,

Universit ̈at Bonn, Institut f ̈ur Geod ̈asie und Geoinformation, Schriftenreihe 22, p. 14–18.

244 IVS 2012 Annual Report
BKG and DGFI BKG/DGFI Combination Center

BKG/DGFI Combination Center Annual Report 2012

Sabine Bachmann, Michael L ̈osler, Robert Heinkelmann, Michael Gerstl

Abstract

This report summarizes the activities of the BKG/DGFI Combination Center in 2012 and outlines

the planned activities for the year 2013. The main focus was the stabilization of outlier detection and

the update of the Web presentation of the combined products.

1. General Information

The BKG/DGFI Combination Center was established in October 2008 as a joint effort of the

Federal Agency for Cartography and Geodesy (Bundesamt f ̈ur Kartographie und Geod ̈asie, BKG)

and the German Geodetic Research Institute (Deutsches Geod ̈atisches Forschungsinstitut, DGFI).

The participating institutions, as well as the tasks and the structure of the IVS Combination

Center, have been described in [5]. The tasks comprise quality control and a timely combination of

the session-based intermediate results of the IVS Analysis Centers into a final combination product

(e.g., Earth Orientation Parameters (EOP)). In coordination with the IVS Analysis Coordinator,

the combination results are released as official IVS products. The Combination Center is also

expected to contribute to the generation of the official IVS input to any ITRF activities. These

tasks are performed on an operational basis.

2. Component Description

The BKG/DGFI Combination Center performs a combination of session-based results of the

IVS Analysis Centers on an operational basis. The strategy for the combination is based on the

combination of normal equations and has been adopted from the combination process developed

and performed by the IVS Analysis Coordinator (cf. [3], [4]).

At BKG the following tasks are performed:

• Ensuring quality control of the Analysis Center results: checking the format of the results

and their suitability for combination, performing identification and reduction of outliers,

comparing the Analysis Centers’ results with each other, and comparing the results w.r.t.

external time series, e.g. from IERS or IGS.

• Providing feedback to the Analysis Centers: quality control results are available at the BKG

IVS Combination Center Web page [7].

• Creating high quality combination products and performing timely archiving and distribution: combination products will be created by using the combination part DOGS-CS of

DGFI’s software package DOGS [6].

• Submitting official IVS combination products to the IERS: the products are submitted to

the responsible IERS components to be used for IERS product generation (e.g., EOP rapid

products and the EOP series IERS C04). Additionally, IVS product series are provided for

ITRF computation (see next item). This work is also supported by the staff of the IERS

Central Bureau hosted by BKG.

IVS 2012 Annual Report 245
BKG/DGFI Combination Center BKG and DGFI

• Generating official IVS input to the ITRF: the time series of the combined session products

(from 1984 to present) is submitted for ITRF computation in the form of normal equations

in SINEX format.

• Archiving Results: Final results are archived in the BKG Data Center and mirrored to the

IVS Data Centers at OPAR and CDDIS. This work is assisted by the staff of the BKG Data

Center in Leipzig.

DGFI is in charge of the following Combination Center functions:

• DGFI is developing state-of-the-art combination procedures. This work, as well as the following item, is also related to the ITRS Combination Center at DGFI and DGFI’s efforts

within the IERS WG on the Combination on Observation Level (COL).

• The software DOGS-CS is updated by implementing and documenting the developed stateof-the-art combination procedures.

• The DGFI DOGS software package is continuously updated to be in accordance with the

IERS Conventions.

• DGFI generates the operational IVS troposphere combination products, analyzes the individual AC contributions and gives feedback to the IVS AC, and publishes the results on

the Web page http://www.dgfi.badw.de/index.php?id=395. DGFI provides rapid as well as

long-term series of combined tropospheric products.

3. Staff

The list of the staff members of the BKG/DGFI Combination Center in 2012 is given in Table 1.

Table 1. Staff members of the BKG/DGFI Combination Center.

Name Affiliation Function E-Mail

Michael Gerstl DGFI Software gerstl@dgfi.badw.de

maintenance

Robert Heinkelmann* DGFI Combination heinkelmann@dgfi.badw.de

strategies

Sabine Bachmann BKG Combination sabine.bachmann@bkg.bund.de

Michael L ̈osler BKG Hardware/Web site michael.loesler@bkg.bund.de

maintenance

* Robert Heinkelmann left DGFI at the end of October 2012 and moved to GFZ Potsdam, Germany.

4. Current Status and Activities

The combination of the IVS Rapid EOP series (R1 and R4 sessions), which started in 2009

at BKG, has been continued routinely in 2012. In 2012, six IVS Analysis Centers (BKG, DGFI,

GSFC, IAA, OPA, and USNO) contributed to the IVS combined product (see [4]). Potential new

246 IVS 2012 Annual Report
BKG and DGFI BKG/DGFI Combination Center

ACs are AUS, CGS, NMA, and TUW (see also Section 5). The rapid solutions contain only R1 and

R4 sessions, and new data points are added twice a week as soon as the SINEX files of at least four

IVS Analysis Centers are available. Long-term series are generated quarterly and include every

24-hour session since 1984. The quarterly series include long-term EOP series, station positions,

and velocities. Furthermore, a VLBI TRF is generated and published. The preprocessing to read

and write source positions has been implemented, and the software has been extended to process

source parameters. The results of the combination process are archived by the BKG Data Center

in Leipzig. The combined rapid EOP series, as well as the results of the quality control of the

Analysis Center results, are also available directly at the BKG/DGFI Combination Center Web

page [7] or via the IVS Analysis Coordinator Web site. The inclusion of new Analysis Centers has

continued, a newly designed Web page has been brought on line and the Web-based analysis tools

have been enhanced.

5. Plans for 2013

In 2013 the work of the BKG/DGFI Combination Center will focus on the following:

• Including new Analysis Center solutions: one based on the GEOSAT software and provided by Halfdan Pascal Kierulf from the Geodetic Institute, Norwegian Mapping Authority

(NMA), Hønefoss, Norway; another one based on the OCCAM software and provided by

Oleg Titov from Geoscience Australia (AUS), Canberra, Australia; and a third one based

on VieVS (Vienna VLBI Software) provided by the Vienna VLBI Group from the Vienna

University of Technology, Austria (TUW).

• Investigation into combination of source coordinates and set up of extended analysis and

combination routines (e.g., the generation of the necessary datum conditions).

• Extending the Web-based data analysis feature on the IVS Combination Center Web pages

([7]).

• Providing more products and information resulting from the combination process.

References

[1] Heinkelmann, R., B ̈ohm J., Bolotin S., Engelhardt G., Haas R., Lanotte R., MacMillan D.S.,

Negusini M., Skurikhina E., Titov O., Schuh H., VLBI-derived troposphere parameters during

CONT08, J Geod, SI CONT08, submitted.

[2] Kutterer, H., Kr ̈ugel M., Tesmer V., Towards an improved assessment of the quality of terrestrial reference frames, in: Drewes H. (ed.) Geodetic Reference Frames, IAG Symposia 143, doi:

10.1007/978-3-642-00860-3 10, Springer-Verlag Berlin Heidelberg, 2009.

[3] Nothnagel, A., B ̈ockmann, S., Artz, T., Analysis Coordinator Report, in: International VLBI

Service for Geodesy and Astrometry 2007 Annual Report, NASA/TP-2008-214162, D. Behrend

and K. D. Baver (eds.), 16–17, 2008.

[4] Nothnagel, A., B ̈ockmann, S., Artz, T., Analysis Coordinator Report, in: International VLBI

Service for Geodesy and Astrometry Annual Report 2009, NASA/TP-2010-215860, D. Behrend

and K. D. Baver (eds.), 45–47, 2010.

IVS 2012 Annual Report 247
BKG/DGFI Combination Center BKG and DGFI

[5] Schwegmann, W., Gerstl, M., Heinkelmann, R., BKG/DGFI Combination Center Annual Report 2008, in: International VLBI Service for Geodesy and Astrometry Annual Report 2008,

NASA/TP-2009-214183, D. Behrend and K. D. Baver (eds.), 250–252, 2009. BKG/DGFI Combination Center results at Analysis Coordinator’s Web page.

[6] http://ilrs.dgfi.badw.de/fileadmin/dogs/cs manual.ps

DOGS CS software manual (German version only).

[7] http://ccivs.bkg.bund.de/

BKG Combination Center Web page.

248 IVS 2012 Annual Report
Centro di Geodesia Spaziale (CGS) - e-geos SpA Matera CGS VLBI Analysis Center

Matera CGS VLBI Analysis Center

Roberto Lanotte

Abstract

This paper reports the VLBI data analysis activities at the Space Geodesy Center (CGS), Matera,

from January 2012 through December 2012, and the contributions that the CGS intends to provide for

the future as an IVS Analysis Center.

1. General Information

The Matera VLBI station became operational at the Space Geodesy Center (CGS) of the Italian

Space Agency (ASI) in May 1990. Since then, it has been active in the framework of the most

important international programs. The CGS, operated by e-geos (a Telespazio/ASI company)

on behalf of ASI, provides full scientific and operational support using the main space geodetic

techniques: VLBI, SLR, and GPS.

2. Staff at CGS Contributing to the IVS Analysis Center

- Dr. Giuseppe Bianco, responsible for CGS/ASI (primary scientific/technical contact).

- Dr. Rosa Pacione, responsible for scientific activities, e-geos.

- Dr. Roberto Lanotte, geodynamics data analyst, e-geos.

3. Current Status and Activities

3.1. Global VLBI Solution cgs2010a

The main VLBI data analysis activities at the CGS in the year 2012 were directed towards

the realization of a global VLBI solution, named cgs2010a, using the CALC/SOLVE software

developed at GSFC. The solution activities started at the end of 2011, and they ended in March

2012, when the solution sections (crf, trf, and eop) were published in the IVS archives. The final

characteristics of this solution are:

• Data span:

1980.04.11 - 2011.12.29 (3594 sessions).

• Estimated Parameters:

– Celestial Frame:

Right ascension and declination as global parameters for 845 sources.

– Terrestrial Frame:

Coordinates and velocities for 81 stations as global parameters.

– Earth Orientation:

Unconstrained X pole, Y pole, UT1, Xp rate, Yp rate, UT1 rate, dpsi, and deps.

IVS 2012 Annual Report 249
Matera CGS VLBI Analysis Center Centro di Geodesia Spaziale (CGS) - e-geos SpA

3.2. IVS Tropospheric Products

Regular submission of tropospheric parameters (wet and total zenith path delays, and east

and north horizontal gradients) for all VLBI stations observing in the IVS R1 and R4 sessions

continued during 2012. Currently, 1161 sessions have been analyzed and submitted, covering the

period from 2002 to 2012. The results are available at the IVS products ftp site.

3.3. IVS Product “Time Series of Baseline Lengths”

Regular submission of station coordinate estimates, in SINEX files, continued during 2012 for

the IVS product “Time Series of Baseline Lengths”. This is composed of 3833 sessions, from 1979

to 2012.

3.4. CGS Contribution to IERS EOP Operational Series

Since 2008, CGS has been delivering IERS R1 and R4 session EOP estimates as a regular

contribution to the IERS EOP operational series. The whole cgs2007a solution, available when

the contribution started, has been delivered to IERS as a reference series updated by periodic EOP

solution submissions.

4. Future Plans

• Continue to improve the realization of our global VLBI solution, providing its regular update

on time.

• Continue to participate in IVS analysis projects, providing datum-free normal equations.

250 IVS 2012 Annual Report
DGFI, Deutsches Geod ̈atisches Forschungsinstitut DGFI Analysis Center

DGFI Analysis Center Annual Report 2012

Robert Heinkelmann, Manuela Seitz, Julian Andres Mora-Diaz, Mathis Bloßfeld,

Michael Gerstl, Ralf Schmid

Abstract

This report summarizes the activities of the DGFI Analysis Center in 2012 and outlines the planned

activities for 2013.

1. General Information and Component Description

The German Geodetic Research Institute (Deutsches Geod ̈atisches Forschungsinstitut, DGFI)

is an independent research institute hosted at the Bavarian Academy of Sciences and Humanities

(BAdW) in Munich, Germany. It is directly funded by the Free State of Bavaria. The research

covers all fields of geodesy and includes participation in national and international projects and

working groups, as well as functions in international bodies (http://dgfi.badw.de). The Institut

f ̈ur Astronomische und Physikalische Geod ̈asie (IAPG) and the Forschungseinrichtung Satellitengeod ̈asie (FESG)(including FESG personnel at the Geodetic Observatory Wettzell), the geodetic

part of the Commission for Geodesy and Glaciology (KEG), and the DGFI of the German Geodetic

Commission cooperate within the Center of Geodetic Earth System Research1(CGE). IAPG and

FESG are a part of Technische Universit ̈at M ̈unchen (TUM). KEG is a commission of BAdW,

and DGFI is located at BAdW. CGE’s main goal is the research of global change through the

measurement of changes in the solid Earth, oceans, cryosphere, and atmosphere, as well as the

analysis of changes with regard to the triggering physical processes. DGFI has been active as an

Analysis Center (AC) of IVS since its foundation in 1999. For several years DGFI has been a

reliable operational AC.

2. Staff

The DGFI IVS AC2is run by Robert Heinkelmann and Manuela Seitz. Julian Andres MoraDiaz is working in a project for the establishment of space geodetic analysis software in Chile

sponsored by the International Bureau of the Federal Ministry of Education and Research. In

2012, Mathis Bloßfeld started a promising and very interesting scientific comparison of the quality

of various IVS networks and Michael Gerstl worked on the software developments and numerical

optimizations of our VLBI analysis software DOGS-RI, which is about to be finished soon. Ralf

Schmid (Figure 1) joined our VLBI group in July 2012. With his thorough background in space

geodesy and his experience in GNSS and VLBI analysis and software development, Ralf is a great

gain for DGFI’s VLBI group. We are happy to have him on board. Robert Heinkelmann left DGFI

to become the head of the VLBI group at GFZ, Potsdam. Manuela Seitz has been appointed as a

member of the new IAU Division A Working Group on the ‘Third Realization of the International

Celestial Reference Frame’.

1http://dgfi.badw.de/index.php?id=323&L=0

2http://dgfi.badw.de/index.php?id=126&L=0

IVS 2012 Annual Report 251
DGFI Analysis Center DGFI, Deutsches Geod ̈atisches Forschungsinstitut

Figure 1. Our new colleague: Dr. Ralf Schmid.

3. Current Status and Activities

• IVS Operational Analysis Center at DGFI

During 2012, we analyzed 404 sessions. Among them 265 were Intensive (IN112, IN212, and

IN312), and 139 were regular observing sessions (73 IVS-R1 sessions, 52 IVS-R4 sessions, 10

astrometric type sessions, e.g. IVS-CRF, IVS-CRDS, etc., and four geodetic type sessions,

e.g. IVS-T2). Several new telescopes became operational in 2012, and needed to be included

in the software and catalog files. We thank the IVS colleagues, who provided initial a priori

coordinates. For the operational analysis and for the preparation of normal equations in

SINEX format OCCAM and DOGS-CS are used. CS is the module of the DGFI Orbit and

Geodetic Parameter Estimation Software (DOGS) [1] for the handling and solution of normal

equation systems. The entire process runs on DGFI-owned hardware.

• Rearrangement of the VLBI software used at DGFI

The VLBI analysis software used at DGFI is currently being revised and will be a part

of DOGS, named DOGS-RI (Radio Interferometry). In 2012, the inclusion of IERS 2010

conventional models was completed. In contrast to OCCAM, the theoretical VLBI model of

DOGS-RI will directly refer to the Geocentric Celestial Reference System (GCRS) without

application of the pole coordinates.

• Consistent computation of ITRF and ICRF from homogeneously processed observation data

The main goal is the investigation of the effect of the combination of station coordinates

and EOP of the space geodetic techniques (VLBI, GNSS, SLR) on the Celestial Reference

Frame (CRF) [2]. In particular the combination of the ERP (terrestrial pole and LOD)

has an impact on the CRF. The sources affected most are the sources observed by VLBA

Calibrator Survey (VCS) sessions only. A systematic effect was found in right ascension for

some of the VCS sources with declinations between −40◦ and +30◦(see Figure 2). This

work will be related to the new IAU Division A Working Group on the ‘Third Realization

of the International Celestial Reference Frame,’ but it is on the IUGG agenda (Resolution 3

adopted in 2011) as well.

252 IVS 2012 Annual Report
DGFI, Deutsches Geod ̈atisches Forschungsinstitut DGFI Analysis Center

Figure 2. Position differences of radio sources of a TRF-CRF solution w.r.t. a VLBI-only CRF: (top)

declination (DE), (bottom) right ascension (RA).

• The role of VLBI in the weekly inter-technique combination

In the case of the standard ITRF computation, VLBI and SLR observations are used for

the realization of the scale, and VLBI is the only technique which provides the full set of

transformation parameters (terrestrial pole, UT1-UTC, celestial pole) necessary for transformations between the ITRS and the GCRS. Current terrestrial reference frames approximate

the station coordinates by a position and a constant velocity after the well-known geophysical

effects, e.g. tidal variations, have been reduced directly at the observation level. Other nonlinear motions such as deformations caused by oceanic, atmospheric, and hydrologic mass

loading deformations are still not sufficiently modeled and are thus not reduced at the observation level. This leads to larger observation residuals and introduces systematics, mainly

seasonal signals, into the estimated parameters of the reference frame, e.g. if observations

do not cover a complete season or are not evenly distributed within the seasonal cycle. In

particular, this is the case for stations with short observation time spans. Besides the station

coordinates, the neglected motions affect epoch-wise parameters as well, e.g. the EOP. To

overcome this problem, reference frames can be based on much shorter time spans, e.g. by

computing weekly reference frames. This approach is called epoch reference frame. In this

case, non-linear station motions are approximated very well and, consequently, the EOP are

not affected. An additional advantage of epoch reference frames is the significantly better

timeliness after an episodic motion (earthquake or other seismic event, antenna repair, etc.),

provided that the stations are still operating and a recent local tie measurement is available.

Challenges within the epoch reference frame computation are the low average number of

VLBI observations per week. The limited number of local tie measurements is a general

problem for terrestrial reference frame determination; epoch reference frames are affected

by the local ties even more. One week is practically the minimum supporting time base.

Further studies will follow based on slightly longer time spans, e.g. two or four weeks. Based

on those intervals we expect a significant increase in the stability of the solution but, of

course, at the expense of a slightly worse approximation. The optimum interval length needs

to be assessed. Probably it will comprise a trade-off between the stability and the quality of

the approximation. Here, we investigate a sequence of epoch reference frames, all of which

IVS 2012 Annual Report 253
DGFI Analysis Center DGFI, Deutsches Geod ̈atisches Forschungsinstitut

are determined by a combination of VLBI, GNSS, and SLR normal equations on a weekly

basis [3]. For each VLBI session, the relative weighting of the techniques is achieved by

estimating variance components (VC). Figure 3 shows the estimated VC for different types

of IVS sessions between the beginning of 2000 and the end of 2006. The VC of the IVS-R1

sessions show a significant seasonal variation. The reasons for this seasonal variation are not

completely understood.

Figure 3. Left: posterior VCs of the techniques GPS (top), SLR (middle), and VLBI (bottom). In the

case of VLBI, one VC per session is estimated. Right: zoom of the VLBI plot for 2000.0–2007.0. All VLBI

sessions are shown for 2000 and 2001. Data shown for 2002.0–2007.0: all VLBI sessions (top), IVS-R4

sessions only (middle), and IVS-R1 sessions only (bottom). In addition, the lower right plot contains the

posterior VCs of the VLBI-only solutions for the IVS-R1 sessions for comparison.

4. Future Plans

At the DGFI AC we will continue our operational contributions to IVS, but with our new

VLBI analysis software DOGS-RI. After extensive comparisons we will switch to DOGS-RI, and

the maintenance of OCCAM will cease. Investigations into the gain of CRF through an intertechnique combination and the quality of different types of IVS sessions will go on as well.

References

[1] Gerstl M., R. Kelm, H. M ̈uller, W. Ehrnsperger: DGFI Orbit and Geodetic Parameter Estimation

Software. Combination and Solution. Deutsches Geod ̈atisches Forschungsinstitut, Interner Bericht Nr.

MG/01/1995/DGFI, in German, 2000.

[2] Seitz M., P. Steigenberger, T. Artz: Consistent Realization of ITRS and ICRS. In: IVS 2012 General

Meeting Proceedings, D. Behrend and K. D. Baver (eds.), NASA/CP-2012-217504 (2012).

[3] Bloßfeld M., M. Seitz: The role of VLBI in the weekly inter-technique combination. In: IVS 2012

General Meeting Proceedings, D. Behrend and K. D. Baver (eds.), NASA/CP-2012-217504 (2012).

254 IVS 2012 Annual Report
GFZ German Research Center for Geosciences GFZ Analysis Center

GFZ Analysis Center

Robert Heinkelmann, Maria Karbon, Tobias Nilsson, Virginia Raposo, Harald Schuh

Abstract

This report briefly provides general information and a component description of the recently established IVS Analysis Center at GFZ and outlines the planned activities.

1. General Information and Component Description

Helmholtz Centre Potsdam, GFZ German Research Center for Geosciences, is the national

research center for Earth Sciences in Germany. The main tasks of GFZ according to its Web site

(www.gfz-potsdam.de) are:

We investigate System Earth at locations all over the world with all the geological,

physical, chemical and biological processes which occur at its surface and in its interior.

The goal of our interdisciplinary research is to understand these processes on all scales

of time and space, whether they occur at the level of atoms and molecules or galaxies,

and independently of whether they take place faster than [...] nanoseconds or if they

happen infinitely slowly over billions of years. We not only investigate the processes

within the planet itself, but also study the multitude of interactions between solid earth,

the atmosphere, the hydrosphere and the inhabited world. We also analyse how man,

living at the Earth’s surface, affects our planet. In sum, our research deals with the

entire ‘Earth System’ including the influence of mankind.

At this research facility within Department 1 ‘Geodesy and remote sensing’ and its Section 1.1

‘GPS/GALILEO Earth observation’ a new VLBI group was established in November 2012.

2. Staff

At the GFZ IVS AC the operational work is done by Robert Heinkelmann and Tobias Nilsson.

In addition, Maria Karbon works in a project about the application of Kalman filter to VLBI

analysis, and Virginia Raposo works on the ICRF and related systematic effects. Harald Schuh

is managing our group, and, as long as his schedule allows, he is still very active for the IVS. A

photo of our group is shown in Figure 1.

3. Future Plans

• IVS Associate Analysis Center at GFZ

At GFZ we will use VieVS for VLBI data analysis starting at DB version 4 or a higher level.

We will develop VieVS together with the IVS Analysis Center at the Department of Geodesy

and Geoinformation, Vienna University of Technology.

• Space applications

Our scientific work will focus on VLBI applications in space, on space navigation by differential VLBI, and on co-location in space of the various space geodetic techniques (VLBI,

GNSS, SLR, and DORIS).

IVS 2012 Annual Report 255
GFZ Analysis Center GFZ German Research Center for Geosciences

Figure 1. The GFZ VLBI group in January 2013.

• Kalman filtering for VLBI analysis with VieVS

We will implement a Kalman filter solution in VieVS. It will be optimized in order to be

able to analyze VLBI data in near real-time, and it will also allow for inclusion of data from

other sensors, such as water vapor radiometers.

• Rapid troposphere combined product

It is planned to take over the rapid troposphere combination from DGFI (Deutsches

Geod ̈atisches Forschungsinstitut) at GFZ.

References

[1] Heinkelmann R.: VLBI geodesy: observations, analysis, and results. In: Geodetic sciences – observations,

modeling and applications. S. Jin (ed.), InTech open, ISBN 980-953-307-595-7, accepted (2012).

[2] Schuh H. and Behrend D.: VLBI: A fascinating technique for geodesy and astrometry. J Geodyn 61,

DOI:10.1016/j.jog.2012.07.007, 68–80, 2012.

[3] Schuh H. and B ̈ohm J.: Very Long Baseline Interferometry for Geodesy and Astrometry. In: Sciences

of Geodesy – II, Innovations and Future Developments, G. Xu (ed.), DOI:10.1007/978-3-642-28000-9,

Springer Berlin Heidelberg, 339–376, 2013.

256 IVS 2012 Annual Report
Bundesamt f ̈ur Kartographie und Geod ̈asie BKG/IGGB Analysis Center

The BKG/IGGB VLBI Analysis Center

Volkmar Thorandt, Axel Nothnagel, Gerald Engelhardt, Dieter Ullrich, Thomas Artz,

Judith Leek

Abstract

In 2012, the activities of the BKG/IGGB VLBI Analysis Center, as in previous years, consisted of

routine computations of Earth orientation parameter (EOP) time series and of a number of research

topics in geodetic VLBI. The VLBI group at BKG continued its regular submissions of time series

of tropospheric parameters and the generation of daily SINEX (Solution INdependent EXchange format) files. Quarterly updated solutions have been computed to produce terrestrial reference frame

(TRF) and celestial reference frame (CRF) realizations. Routine computations of the UT1–UTC Intensive observations include all sessions of the Kokee–Wettzell and Tsukuba–Wettzell baselines and

the networks Kokee–Svetloe–Wettzell and Ny- ̊Alesund–Tsukuba–Wettzell. The VLBI group at BKG

developed a procedure to get the most probable station positions of Tsukuba after the earthquake on

March 11, 2011 for the epochs of the Intensive sessions. The analysis of the Intensive sessions with

station Tsukuba could be resumed in February 2012. At IGGB, the emphasis has been placed on

individual research topics.

1. General Information

The BKG/IGGB VLBI Analysis Center has been established jointly by the analysis groups of

the Federal Agency for Cartography and Geodesy (BKG), Leipzig, and the Institute of Geodesy

and Geoinformation of the University of Bonn (IGGB). Both institutions cooperate intensely in the

field of geodetic VLBI. The responsibilities include both data analysis for generating IVS products

and special investigations with the goal of increasing accuracy and reliability. BKG is responsible

for the computation of time series of EOP and tropospheric parameters, for the generation of

SINEX files for 24-hour VLBI sessions and one-hour Intensive sessions, and for the generation of

quarterly updated global solutions for TRF and CRF realizations. Besides data analysis, the BKG

group is also responsible for writing schedules for the Tsukuba-Wettzell Int2 UT1-UTC observing

sessions. IGGB continues to host the office of the IVS Analysis Coordinator and carries out special

investigations within the technique of geodetic and astrometric VLBI. Details of the research topics

of IGGB are listed in Section 3.

2. Data Analysis at BKG

At BKG, the Mark 5 VLBI data analysis software system Calc/Solve, release 2010.05.21 [1], has

been used for VLBI data processing. It is running on a Linux operating system. As in the previous

releases, the Vienna Mapping Function (VMF1) has been implemented in a separate Solve version.

This modified version was used for all data analysis. The VMF1 data were downloaded daily

from the server of the Vienna University of Technology. Additionally, the technological software

environment for Calc/Solve has been refined to link the Data Center management with the preand post-interactive parts of the EOP series production and to monitor all Analysis and Data

Center activities.

• Processing of correlator output

The BKG group continued the generation of calibrated databases for the sessions correlated at

IVS 2012 Annual Report 257
BKG/IGGB Analysis Center Bundesamt f ̈ur Kartographie und Geod ̈asie

the MPIfR/BKG Astro/Geo Correlator at Bonn (e.g., EURO, OHIG, and T2) and submitted

them to the IVS Data Centers.

• Scheduling

BKG continued scheduling the Int2 Intensive sessions, which are observed on the TSUKUBAWETTZELL baseline. Altogether 86 schedule files for this baseline were created in 2012.

Furthermore 30 schedule files for baseline KOKEE-WETTZELL (Int1 Intensive sessions on

weekends) were made available in the first half of the year 2012.

• BKG EOP time series

The BKG EOP time series bkg00013 was continued. The main features of this solution were

not changed. But three new VLBI stations (HART15M in South Africa, KOGANEI, and

UCHINOUR in Japan) could be included successfully in data processing.

Each time after the preprocessing of any new VLBI session (correlator output database

version 1), a new global solution with 24-hour sessions since 1984 was computed, and the

EOP time series bkg00013 was extracted. Altogether 4391 sessions were processed. The

main parameter types in this solution are globally estimated station coordinates and velocities together with radio source positions. The datum definition was realized by applying

no-net-rotation and no-net-translation conditions for 25 selected station positions and velocities with respect to VTRF2008a and a no-net-rotation condition for 295 defining sources

with respect to ICRF2. The station coordinates of the telescopes AIRA (Japan), CHICHI10

(Japan), CTVASTJ (Canada), DSS13 (USA), HOBART12 (Australia), KASHIM34 (Japan),

KATH12M (Australia), PT REYES (USA), SEST (Chile), SINTOTU3 (Japan), TIGOCONC (Chile), TSUKUB32 (Japan), WIDE85 3 (USA), VERAISGK (Japan), VERAMZSW

(Japan), WARK12M (New Zealand), YARRA12M (Australia), and YEBES40M (Spain) were

estimated as local parameters in each session. The three new VLBI stations HART15M

(South Africa), KOGANEI (Japan), and UCHINOUR (Japan) were modeled in the same

way.

• BKG UT1 Intensive time series

Regular analysis of the UT1-UTC Intensive time series bkgint09 was continued. The series

bkgint09 was generated with fixed TRF (VTRF2008a) and fixed ICRF2. The a priori EOP

were taken from finals USNO series [2]. The estimated parameter types were only UT1-TAI,

station clock, and zenith troposphere.

A semi-automatic process for handling the Intensive sessions (Int2/3) with station TSUKUBA

after the Japan earthquake has been developed. Using the latest global solution with 24-hour

sessions, including all available sessions with the station TSUKUBA, a particular a priori

coordinate file for each TSUKUBA Intensive session is created by interpolating the values

of the 24-hours TSUKUBA sessions. These files are used as input for the session by session

TSUKUBA Intensive cycle run. Finally, an IVS formatted EOP list is created and mixed

with the non-TSUKUBA IVS EOP list. These algorithms are included in the BKG post solve

procedure for establishing the IVS EOP solutions.

A total of 4048 UT1 Intensive sessions were analyzed for the period from 1999.01.01 to

2012.12.31.

• Quarterly updated solutions for submission to IVS

In 2012, one quarterly updated solution was computed for the IVS products TRF and CRF.

258 IVS 2012 Annual Report
Bundesamt f ̈ur Kartographie und Geod ̈asie BKG/IGGB Analysis Center

There are no differences in the solution strategy compared to the continuously computed

EOP time series bkg00013. The results of the radio source positions were submitted to

IVS in IERS format. The TRF solution is available in SINEX format, version 2.1, and

includes station coordinates, station velocities, and radio source coordinates together with

the covariance matrix, information about constraints, and the decomposed normal matrix

and vector.

• Tropospheric parameters

The VLBI group of BKG continued regular submissions of long time series of tropospheric

parameters to the IVS (wet and total zenith delays and horizontal gradients) for all VLBI

sessions since 1984. The tropospheric parameters were extracted from the standard global

solution bkg00013 and transformed into SINEX format.

• Daily SINEX files

The VLBI group of BKG also continued regular submissions of daily SINEX files for all available 24-hour sessions for the IVS combined products and for the IVS time series of baseline

lengths. In addition to the global solutions, independent session solutions were computed for

the station coordinates, radio source coordinates, and EOP parameters including the X,Ynutation parameters. The a priori datum for TRF was defined by VTRF2008a, and ICRF2

was used for the a priori CRF information.

• SINEX files for Intensive sessions

The parameter types are station coordinates, pole coordinates and their rates, and UT1-TAI

and its rate. But only the normal equations stored in the SINEX files are important for

further intra-technique combination or combination with other space geodetic techniques.

3. Research Topics at IGGB

• Measurements of paraboloid deformations of the Effelsberg 100-m telescope with

a laser scanner

Variations in the focal length of a radio telescope have a direct effect on the delay observables

and on the position estimates. To study this, the paraboloid of the Effelsberg 100-m telescope

was scanned with a Leica HDS 6100 terrestrial Laser scanner. The scanner was mounted

head-down on an empty prime focus receiver box. Putting the receiver box in place gave the

scanner an almost unobstructed view of the main paraboloid. Scans were repeated in various

telescope elevation angles down to 7.5◦ with each data set consisting of 370 million points with

three polar components each. This is equivalent to one data point every 64 mm2. Proprietary

software of the instrument’s manufacturer was not able to handle this large amount of data;

thus, a dedicated C++ program running on a computer cluster was developed. As a first

result, the estimated focal length variations agree very well with the empirical model for

the sub-reflector displacement corrections. Since the accuracy of the individual distance

measurements of the scanner is only a few millimeters at a distance of 50-m, the ultimate

insight into the deformations cannot be achieved from individual data points but from a

surface fitting procedure to the residuals. Figure 1 shows the smoothed surface of the solid

part of the paraboloid at 30◦elevation after a best fit paraboloid has been subtracted. In the

second and third quadrant, two reflector panels can be identified which had been displaced

on purpose by plus and minus 3 mm for a holography survey some time ago, validating the

IVS 2012 Annual Report 259
BKG/IGGB Analysis Center Bundesamt f ̈ur Kartographie und Geod ̈asie

−40 −20 0 20 40

−40

−30

−20

−10

0

10

20

30

40

x [m]

y [m]

w [mm]

−5

−4

−3

−2

−1

0

1

2

3

4

5

Figure 1. Smoothed surface of the solid part of the paraboloid at 30◦elevation after a best fit paraboloid

has been subtracted.

correctness of the whole procedure. The second blue spot at the third quadrant persists at

other elevation angles as well and must, thus, be a real local deformation.

• Automatic scheduling based on Singular Value Decomposition

The automatic scheduling method which selected the observations successively by means

of their impact factors has been developed to create schedules for VLBI Intensive sessions

replacing the participating single telescopes by twin telescopes successfully. For assessment

reasons, observations related to the created schedules have been simulated. The simulation

has been adapted for the special features of twin telescopes. However, the simulation has to

be improved some more to reach a well-founded evaluation of twin telescope observations in

Intensive sessions.

4. Personnel

Table 1. Personnel at BKG/IGGB Analysis Center.

Thomas Artz IGGB +49-228-733563 artz@igg.uni-bonn.de

Gerald Engelhardt BKG +49-341-5634438 gerald.engelhardt@bkg.bund.de

Judith Leek IGGB +49-228-733565 judith.leek@igg.uni-bonn.de

Axel Nothnagel IGGB +49-228-733574 nothnagel@uni-bonn.de

Volkmar Thorandt BKG +49-341-5634285 volkmar.thorandt@bkg.bund.de

Dieter Ullrich BKG +49-341-5634328 dieter.ullrich@bkg.bund.de

Reiner Wojdziak BKG +49-341-5634286 reiner.wojdziak@bkg.bund.de

References

[1] GSFC, NASA (2010): Release of Mark 5 VLBI Analysis Software Calc/Solve from May 21, 2010 (Web

reference: http://gemini.gsfc.nasa.gov/solve).

[2] USNO (2011): Earth orientation parameters series from finals USNO series 2011, (Web reference:

http://gemini.gsfc.nasa.gov/500/oper/solve apriori files/usno finals.erp).

260 IVS 2012 Annual Report
NASA Goddard Space Flight Center GSFC Analysis Center

GSFC VLBI Analysis Center

David Gordon, Chopo Ma, Dan MacMillan, John Gipson, Sergei Bolotin, Karine Le Bail,

Karen Baver

Abstract

This report presents the activities of the GSFC VLBI Analysis Center during 2012. The GSFC

VLBI Analysis Center analyzes all IVS sessions, makes regular IVS submissions of data and analysis

products, and performs research and software development aimed at improving the VLBI technique.

1. Introduction

The GSFC VLBI Analysis Center is located at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. It is part of a larger VLBI group which also includes the IVS Coordinating Center,

the CORE Operation Center, a Technology Development Center, and a Network Station. The

Analysis Center participates in all phases of geodetic and astrometric VLBI analysis, software development, and research. We maintain a Web site at http://lupus.gsfc.nasa.gov. We also provide

a pressure loading service to the geodetic community at http://gemini.gsfc.nasa.gov/results/aplo.

We now provide additional services described below for hydrology loading, nontidal ocean loading,

and meteorological data. These time series can be found by following the links on the GSFC VLBI

group Web site: http://lupus.gsfc.nasa.gov/dataresults main.htm.

2. Activities

2.1. Analysis Activities

The GSFC VLBI Analysis Center analyzes all IVS sessions, using the Calc/Solve system, and

it performs the fringe fitting and Calc/Solve analysis of the VLBA-correlated RDV sessions. The

group submits the analyzed databases to IVS for all R1, RDV, R&D, APSG, AUST, CONT11,

INT01, and INT03 sessions. During 2012, GSFC analyzed 189 24-hour (54 R1, 55 R4, 15 CONT11,

11 RDV, 9 R&D, 3 AUST, 1 APSG, 5 EURO, 4 T2, 5 OHIG, 7 CRF, 9 CRDS, and 11 JADE)

sessions, and 371 one-hour UT1 (244 INT01, 83 INT02, and 44 INT03) sessions, and we submitted

updated EOP and daily Sinex files to IVS immediately following analysis. One update was made

in 2012 of our 24-hr and Intensive EOP series. Also, as part of the RDV program, we observed 17

requested sources for the astronomical community.

2.2. Research Activities

• Meteorological Data Analysis: Because of the inhomogeneity of the pressures and temperatures in the Mark III databases, we derived a set of meteorological data time series, named

G-ECM, from the ERA-Interim reanalysis model of the ECMWF for all VLBI stations.

These series are available online (http://lacerta.gsfc.nasa.gov/met) and are updated when

new data becomes available from ECMWF. When applied as a replacement for met data in

VLBI databases, VLBI solutions are improved. For the R1 and R4 sessions from 2002 to

2011, use of the G-ECM pressures a) reduces baseline length weighted RMS for 55% of the

baselines, with an average reduction of 0.06 mm, and b) reduces position weighted RMS for

IVS 2012 Annual Report 261
GSFC Analysis Center NASA Goddard Space Flight Center

nine out of 19 stations by an average of 0.22 mm, with no conclusive improvement or degradation for eight stations. Using the G-ECM temperatures, a) 47% of the baseline lengths

have a reduced weighted RMS and an average reduction of 0.01 mm, b) ten out of 19 stations

show reduced weighted RMS position scatter of up to 0.08 mm, with five stations showing

no conclusive improvement or degradation, and c) the amplitudes of the annual signal are

significantly reduced, by up to 0.27 mm.

• Analysis of LOD Time Series with SSA: In [1], we studied an LOD time series obtained

from VLBI measurements and extracted its principal components using Singular Spectrum

Analysis (SSA). After removing the long-term trend, which explains 73.8% of the signal, three

remaining components explain a further 22.0% of the signal: an annual and a semi-annual

signal as well as a second trend. Using the complex demodulation method, we obtained

the variations in the amplitudes of the annual and semiannual components. We compared

the Multivariate ENSO Index (MEI) with these series and with the second trend obtained

by the SSA. The correlations are significant: 0.58 for the annual component, -0.48 for the

semi-annual component, and 0.46 for the second trend.

• Nutation Analysis: We focus on the two nutation parameters. We developed nutkal2012.f, a

FORTRAN routine that uses the Kalman filter to regularize these irregular time series into

a daily time series. The model is defined by a linear trend and specified harmonics, and

we included an indicator of the quality of the estimate (goodness of fit). After investigating

the various characteristics of the initial time series (Free Core Nutation component, periodic

components, level and type of noise), we set up the parameters of the Kalman filter to fit

the nutation data [2].

• Source Monitoring: Together with USNO we continued monitoring all ICRF2 defining

sources. Our goal is to schedule and observe each geodetic source in at least 12 sessions

over the preceding 12 months. In April 2012 the observing target for non-geodetic sources

was increased from three to five sessions per year. The R1, R4, and RDV sessions participate

in the source monitoring program.

• Intensive Scheduling: We continued to study the Uniform Sky Strategy (USS), the alternative

INT01 scheduling strategy proposed and tested in 2009 and 2010 and in use for the INT01s

operationally on alternating days since mid-2010. We compared the 2011 USS sessions to the

non-USS 2011 sessions, and we found that the USS provided better overall protection against

source loss and noise than the original strategy did. The USS also improved the UT1 formal

errors at a time of the year (early October) that typically has bad sky coverage and high UT1

formal errors. But during some periods of the year, the USS produced a larger average UT1

formal error than the original strategy, generated higher UT1 formal errors, and provided

worse protection against noise. We investigated the effect of schedule characteristics (e.g.,

the temporal distribution of the observations) on results, as a first step towards refining the

USS.

• Astronomical Source Catalog and Source Time Series: A new astronomical source catalog,

gsf2012a astro, was generated. This catalog contains positions of 3708 sources, of which

3589 are X/S sources, 103 are X/GPS-ionosphere sources, and 16 are X-only sources. A new

source time series, gsf2012a ts, was also generated. It contains single session positions of

1563 sources in the ICRF2 time series format. Both files will be updated regularly and are

available at http://lupus.gsfc.nasa.gov/dataresults main.htm.

262 IVS 2012 Annual Report
NASA Goddard Space Flight Center GSFC Analysis Center

• VLBA Correlator Support: D. Gordon spent three weeks at NRAO in Socorro, N.M. as

a ‘resident shared risk observer’ (RSRO). While there, he set up a script for automated

conversion of DiFX correlator output into Mark IV format, and he modified an existing

script to archive the Mark IV files. VLBA observers can now request Mark IV output for

further processing with fourfit in addition to the normal fits.idi output.

• Non-tidal ocean loading: We computed non-tidal ocean loading series at VLBI sites using

ocean bottom pressures from the ECCO model maintained at JPL. At coastal VLBI sites,

typical peak-to-peak vertical loading variations are 3-6 mm, and vertical annual amplitudes

are 1 mm. When these loading series are applied in VLBI analysis, the baseline length

scatter, the site position scatter, and the annual vertical amplitude are reduced at these

sites.

• Loading services: We set up hydrology loading (http://lacerta.gsfc.nasa.gov/hydlo/) and

non-tidal ocean loading (http://lacerta.gsfc.nasa.gov/oclo/) services at GSFC. Monthly hydrology loading series based on the NASA/GSFC GLDAS hydrology model are available

with a latency of about 1.5 months for 170 VLBI stations as well as for a 1x1 degree gridded

map with loading series for each lattice point. Non-tidal ocean loading series derived from

the JPL ECCO ocean model are available with a latency of about two months for 170 VLBI

stations with 12-hour resolution.

• Tsukuba postseismic motion: To compute an a priori position for TSUKUB32 in analysis,

we set up a Tsukuba position service that provides a post-earthquake nonlinear correction series based on GPS position data generated by JPL. The series is updated every day

with the latest GPS data with a latency of 8-14 days depending on the day of the week

and when GPS final orbits were available for the JPL solution. The service location is

ftp://gemini.gsfc.nasa.gov/pub/misc/dsm/tsukuba/.

2.3. Software Development

The GSFC VLBI Analysis Center develops and maintains the Calc/Solve analysis system, a

package of approximately 120 programs and 1.2 million lines of code. Work began on Calc 11 for

compliance with the IERS 2010 Conventions and will be finished in 2013.

We continued developing and refining the new “openDB” data format to store VLBI data. We

modified Solve to use the openDB format instead of superfiles, and we reproduced our 2011a (and

other) solutions in the new format. Large solutions using most of the VLBI data take about the

same amount of time using the openDB format or superfiles. In timing tests with larger data

sets, such as the CONT11s, Solve runs about twice as fast using the openDB format. In addition,

we wrote several utilities which produce, use, and modify the openDB format. We also began

work on openDBmake, a partial replacement for dbedit, to make “version 1” openDB sessions from

fourfit fringe files. We also began work on openDB96, a plug-compatible replacement library for

the dbase96 library. The goal is to allow programs which use the Mark III database handler to

use openDB files with no or minimal changes to the code.

Developing the new VLBI data analysis software νSolve has reached its final stage. After

thorough comparisons of SOLVE and νSolve, we started using νSolve in our routine data processing

of Intensive and IVS-R4 sessions. Currently we are focused on the implementation of openDB in

all parts of CALC/SOLVE. νSolve can now import and analyze a VLBI session in openDB format.

IVS 2012 Annual Report 263
GSFC Analysis Center NASA Goddard Space Flight Center

3. Staff

During 2012, the Analysis Center staff consisted of one GSFC civil servant, Dr. Chopo Ma, six

NVI, Inc. employees who work under contract to GSFC, and four half-year student interns from

Chalmers University of Technology (Sweden). Dr. Ma oversees the GSFC VLBI project for GSFC,

and he is also the IVS co-representative to the IERS and the current chair of the IERS Directing

Board. Dr. John Gipson is the GSFC VLBI Project Manager and also the chair of IVS Working

Group 4 on VLBI Data Structures. Table 1 lists the staff members and their main areas of activity.

Table 1. Staff members and their main areas of activity.

Ms. Karen Baver Intensive analysis, monitoring, and improvement; software development; Web site development; quarterly nuvel updates.

Dr. Sergei Bolotin Database analysis, νSolve development.

Dr. John Gipson Source monitoring, high frequency EOP, parameter estimation, new

data structure, station dependent noise.

Dr. David Gordon Database analysis, RDV analysis, ICRF2 and astronomical catalogs,

K/Q reference frame, Calc development, quarterly ITRF updates.

Dr. Karine Le Bail Time series statistical analysis (EOP, nutation, source positions),

database meteorological data analysis.

Dr. Chopo Ma ICRF2, CRF/TRF/EOP, K/Q reference frame.

Dr. Daniel MacMillan CRF/TRF/EOP, mass loading, antenna deformation, VLBI2010 and

SGP simulations, VLBI/SLR/GPS combinations.

Mr. David Eriksson Mass loading, troposphere raytracing (through June).

Ms. Johanna Juhl Meteorological data analysis, troposphere ray tracing (through

June).

Ms. Julia Ringsby openDB development (starting in June).

Mr. Ronny Videkull openDB development (starting in June).

4. Future Plans

Plans for the next year include ICRF2 maintenance, astronomical catalog expansion in preparation for ICRF3, participation in VLBI2010 development, continued development of νSolve and

the new “openDB” data format, upgrade of program Calc for the IERS 2010 Conventions, and

further research aimed at improving the VLBI technique.

References

[1] K. Le Bail, J. M. Gipson, and D. S. MacMillan, Quantifying the Correlation Between the MEI and

LOD Variation by Decomposing LOD with Singular Spectrum Analysis, accepted for publication in

IAG Symp. 139, Earth on the Edge: Science for a Sustainable Planet, Chris Rizos, Pascal Willis (Eds),

ISBN 978-3-642-37221-6, 2012.

[2] K. Le Bail, J. M. Gipson, and S. Bolotin, Regularization of Nutation Time Series at GSFC, (submitted

to the proceedings of the 7th IVS General Meeting in Madrid, Spain), 2012.

264 IVS 2012 Annual Report
MIT Haystack Observatory Haystack Analysis Center

Haystack Analysis Center

Arthur Niell, Roger Cappallo, Brian Corey, Mike Titus

Abstract

Analysis activities at Haystack Observatory are directed towards improving the accuracy of geodetic

measurements, whether these are from VLBI, GNSS, SLR, or any other technique. Those analysis

activities that are related to technology development are reported elsewhere in this volume. In this

report, a preliminary analysis of the first geodetic sessions with the new broadband geodetic VLBI

system is reported.

1. Introduction

The broadband instrumentation for the next generation geodetic VLBI system, previously

called VLBI2010 but now referred to as VGOS (for VLBI2010 Geodetic Observing System), has

been implemented on a new 12-m antenna at the Goddard Space Flight Center near Washington,

D.C., and on the Westford 18-m antenna at Haystack Observatory near Boston, Massachusetts,

USA. In October 2012, the first two serious geodetic observing sessions were conducted using the

broadband system.

The new features for the VGOS system are:

• four bands of 512 MHz each, rather than the two (S and X) for the Mark IV systems

• dual linear polarization in all bands

• more than 30 scans per hour due to the short scans and relatively high slew rates of the

smaller antennas proposed for VGOS systems

• multitone phase cal delay for every channel in both polarizations

• group delay estimation from the full spanned bandwidth (∼2.2 GHz to potentially 14 GHz)

• simultaneous estimation of the group delay and the ionosphere TEC difference between sites,

using the phases across all four bands

The features indicated in the last three bullets have required changes in analysis of the geodetic

delays, and these have been implemented in the post-correlation fringe-detection software fourfit.

2. Observations

For these two sessions the frequency range spanned by the four bands was limited by the

hardware capability at the time of the observations. The lower band edges for the lowest and

highest bands were chosen to be 3200 MHz and 9344 MHz. A simulation by Bill Petrachenko

found that the best frequencies for the other two bands were 5248 MHz and 6272 MHz.

While the goal for the VLBI2010 systems is to reduce the scan length to the minimum in order

to obtain the greatest temporal density of scans, for these sessions the minimum scan length was

chosen to be 30 seconds to ensure high SNR. This was necessary because of uncertainty in the

measured sensitivity of the antennas and in the scaling factors used for the SEFDs in sked. These

considerations resulted in an observation rate of approximately 33 scans per hour, about double

the usual IVS R1 schedule.

IVS 2012 Annual Report 265
Haystack Analysis Center MIT Haystack Observatory

A problem that was not anticipated until observations were first made with the MV3 proof-ofconcept system at GGAO is the strong impact of the SLR aircraft avoidance radar on the VLBI

system. The radar signal, at about 9.3 GHz, is strong enough to damage the VLBI front end. It

is now known that the VLBI antenna must avoid pointing too close to the radar when the SLR

system is tracking. This means that a cone of the sky with an opening angle of about 40 degrees

must be excluded.

The two six-hour sessions were scheduled for October 4 and 5, 2012. On the first day the SLR

systems at GGAO did not observe, so the radar was off and a mask on the sky available to the

VLBI observations was not required. On the second day the SLR system was observing, the radar

was on, and the VLBI schedule avoided the danger zone. The same number of observations was

obtained on the two days, but there is a decrease in geometric strength on the second day along

the direction to the SLR system (azimuth 195◦) because of the loss of scheduled observations in

that direction.

Each of the four bands was sampled and formatted in an RDBE-H digital backend running

FPGA code version 1.4 which produced eight 32 MHz channels in each polarization. The output

from each RDBE was recorded on a Mark 5C.

Phase calibration pulses were injected between the feed and the low noise amplifier to produce

tones every 5 MHz in the spectrum.

3. Correlation and Observable Extraction (Fourfit)

The data were correlated on the DiFX software correlator at Haystack Observatory. A separate

correlation pass was required for each band, although both the polarization parallel-hands and

cross-hands of a scan were correlated at the same time. For each scan fourfit was used to obtain a

coherent fit to all phase and amplitude observables for all one-second accumulation periods in the

scan.

The instrumental delay from the pulse cal injection point to the digitization point was corrected

within fourfit for each channel using all of the phase cal phases in that channel.

The estimation of the coherent amplitude, delay, and TEC difference was achieved using recent

improvements in the program fourfit. The new processing requires several steps.

The steps are:

a) fourfit the H and V polarizations separately for each band to obtain amplitude, delay, phase,

and delay rate (eight values of each); b) merge the data from the four bands and two polarizations

into one file; c) input an a priori station delay from the point of phase cal pulse insertion on

the antenna to the digitization point in the control room based on the length of the cable; d)

input an a priori difference in TECs between the sites; for this session the estimation appears to

be insensitive to the value used; more work is needed on how to generate the a priori value; e)

fourfit the merged data for each polarization for one or more strong sources to verify (or adjust)

the station delays and to determine the phase and delay offsets among the bands; f) fourfit the

merged data for all bands and polarizations for a combined amplitude, the coherent delay (called

pseudo-I delay because it is analogous to the I Stokes parameter), phase, delay rate, and ∆TEC.

The extracted observables were exported to GSFC, where a database was generated by David

Gordon; this required modification of the dbedit software in order to bring in the delay with

ionosphere (charged particle dispersion) already estimated.

266 IVS 2012 Annual Report
MIT Haystack Observatory Haystack Analysis Center

4. Analysis

The geodetic analysis was done using nuSolve, a new GUI-based program for editing and

parameter estimation that is being developed by Sergei Bolotin of NVI, Inc. nuSolve was used

because of the potential to model the clocks and atmospheres as stochastic processes. However,

for the period covered by this report the temporal modeling of all parameters was piecewise linear

(PWL). The estimated parameters for the results reported below are the position of GGAO12M,

and atmosphere zenith delays and gradients and clock values for both sites. Various time intervals

from two hours down to ten minutes were tested for all of the atmosphere and clock parameters.

This process was applied to H, V, and I for both sessions. However, the H and V delays did not

include estimation of the ionosphere.

A series of trials with varying intervals for atmospheres, atmosphere gradients, and clocks

indicated that consistent results and minimum RMS delay scatter could be obtained using 20-

minute intervals for the atmosphere zenith delays and clocks and 40 minutes for the atmosphere

gradients. The default constraints included in the nuSolve setup were not adjusted. Outliers

were excluded in an iterative process of estimation, outlier rejection, and re-estimation, leaving

approximately 140 of the original 178 points in the solution. These observations should be examined

carefully to determine if the cause for being an outlier can be ascertained.

The delay uncertainties for all observations have a median value of less than one picosecond. After arriving at a set of estimated parameters and retained observations, the additional

quadratically-added delay required to obtain chi-square per degree of freedom of 1.0 was calculated within nuSolve (a process known as re-weighting). The additive delay value for both sessions

is about 12 psec. This is not unexpected due at least in part to the PWL parameterization of the

atmosphere and clock values.

5. Results

The H and V polarization observables are statistically independent as far as system noise is

concerned, and thus they provide two separate solutions. However, other sources of noise, such as

the atmosphere delay, source structure and positions, and clock variations, are almost completely

correlated. Therefore the agreement of the estimated parameters for H and V should be much

better than the formal uncertainties. On the other hand, the I solution, for which the delay is a

combination of all polarization products, may differ slightly because the TEC difference between

the stations was estimated.

The topocentric offsets from the a priori position for GGAO12M, as well as the changes in

baseline length, are shown in Figure 1. The agreement among the components and length for H

and V is reasonable, but the differences for I among the components on the two days is larger

than expected. One possible source of the additional scatter is the estimation of the ionosphere.

The additional ionosphere delay parameter, which is a quadratic function of frequency, makes the

estimated parameters susceptible to systematic phase errors among the different bands. Clearly,

a closer look at the data is required.

Delays obtained from the multiple phasecal tones in each channel indicate that there is a large

dependence on the direction the antenna is pointing for both Westford and GGAO12M. If the

variations were in the signal path from the receiver to the digital back end, the multitone delays

would correct them. However there is evidence that the variation occurs in the 5 MHz uplink cable,

IVS 2012 Annual Report 267
Haystack Analysis Center MIT Haystack Observatory

Figure 1. Adjustments to the topocentric position of the GGAO12M antenna and to the length of the

baseline. Ionosphere was estimated for I but not for H and V.

in which case it is not corrected. Most of the variation is in azimuth for Westford. Discovery of

this effect emphasizes the need for a cable calibration system for the broadband antennas.

6. Outlook

Regular broadband observations using the 12-m and Westford are scheduled to begin in mid2013. Operational procedures for correlation and data analysis (correlator/fourfit/solve) for both

stand-alone Broadband observations and Broadband-Mark IV observations need to be developed.

In order to facilitate development of these procedures we hope to install the new openDB/

calc/solve data handling and parameter estimation packages at Haystack. This will allow us to

experiment with, understand, and verify the entire data chain from scheduling through parameter

estimation.

Acknowledgements

We thank the Broadband Development group for their efforts in constructing, implementing,

and operating the systems at GGAO and at Westford and for assisting in the testing and observations; John Gipson for guidance in getting sked to work; David Gordon for getting the broadband

output into databases; and Sergei Bolotin for developing nuSolve and for help getting it to work

with the new broadband observable.

268 IVS 2012 Annual Report
Institute of Applied Astronomy of Russian Academy of Sciences (IAA) IAA Analysis Center

IAA VLBI Analysis Center Report 2012

Elena Skurikhina, Sergey Kurdubov, Vadim Gubanov

Abstract

This report presents an overview of IAA VLBI Analysis Center activities during 2012 and the plans

for the coming year.

1. General Information

The IAA IVS Analysis Center (IAA AC) is located at the Institute of Applied Astronomy

of the Russian Academy of Sciences in St. Petersburg, Russia. The IAA AC contributes to IVS

products, such as daily SINEX files, TRF, CRF, rapid and long-term series of EOP, baseline

lengths, and tropospheric parameters. EOP, UT1, and station positions were estimated from

domestic observation programs Ru-E and Ru-U. The IAA AC generates NGS files.

2. Component Description

The IAA AC performs data processing of all kinds of VLBI observation sessions. For VLBI

data analysis we use the QUASAR and the OCCAM/GROSS software packages. All reductions

are performed in agreement with IERS Conventions (2010). Both packages use NGS files as input

data.

The IAA AC submits to the IVS Data Center all kinds of products: daily SINEX files for

EOP and EOP-rates and station position estimates, TRF, CRF, baseline length, and tropospheric

parameters.

The QUASAR and the OCCAM/GROSS software packages are supported and developed.

IVS NGS files are generated in automatic mode on a regular basis.

3. Staff

– Vadim Gubanov, Prof.: development of the QUASAR software and development of the

methods of stochastic parameter estimation.

– Sergey Kurdubov, Dr.: scientific researcher: development of the QUASAR software, global

solutions, and DSNX file calculation.

– Elena Skurikhina, Dr.: team coordinator, VLBI data processing, and OCCAM/GROSS

software development.

4. Current Status and Activities

• Software Development for VLBI Processing

The QUASAR software is capable of calculating all types of IVS products. A new release of

the QUASAR software was developed in 2012 by S. Kurdubov and has the ability to estimate

a generous amount of new parameters (tidal waves, for example).

IVS 2012 Annual Report 269
IAA Analysis Center Institute of Applied Astronomy of Russian Academy of Sciences (IAA)

• Routine Analysis

During 2012 the IAA AC continued to submit daily SINEX files for the IVS-R1 and IVS-R4

sessions as rapid solution (iaa2010a.snx) and SINEX files based on all 24-hour experiments

for the quarterly solution.

A new global solution was calculated.

The routine data processing was performed with the OCCAM/GROSS software using a

Kalman Filter. The IAA AC operationally processed the “24h” and Intensive VLBI sessions

and submitted the results to the IERS and IVS on a regular basis. Processing of the Intensive

sessions is fully automated. The EOP series iaa2007a.eops and iaa2005a.eopi, baseline lengths

iaa2007a.bl (until November 2012), and troposphere parameters iaa2007a.trl were continued.

Long-time series of station coordinates, baseline lengths, and tropospheric parameters (ZTD,

gradients) were computed with the station position catalog ITRF2005.

• EOP Parameter Calculation from Domestic QUASAR Network Observations

Regular determinations of Earth orientation parameters with the QUASAR VLBI Network

Svetloe-Zelenchukskaya-Badary and single baseline one-hour observations for UT1 with eVLBI transfer were performed weekly. On July 1st, daily Ru-U sessions began. Correlation

is performed at the IAA correlator ARC. For 2012 the mean RMS EOP deviations from the

IERS 08 C04 series in the Ru-E program were 0.72 mas for X-Pole position, 0.97 mas for

Y-Pole position, 36 μs for UT1-UTC, and 0.29 mas for Celestial Pole position for 36 Ru-E

sessions. The RMS deviation of the Universal Time values from the IERS C04 series for

187 sessions of the Ru-U program was 65 μs. We used station positions from the QUASAR

global solution in our calculations.

5. Future Plans

We plan to:

• Continue to submit all types of IVS product contributions.

• Continue investigations of VLBI estimation of EOP, station coordinates, and troposphere

parameters, and comparison with satellite techniques.

• Further improve algorithms and software for processing VLBI observations.

• Contribute to ICRF3 Working group study.

270 IVS 2012 Annual Report
Istituto di Radioastronomia–Bologna Italy INAF Analysis Center

Italy INAF Analysis Center Report

M. Negusini, P. Sarti

Abstract

This report summarizes the activity of the Italian INAF VLBI Analysis Center. Our Analysis

Center is located in Bologna, Italy and belongs to the Institute of Radioastronomy, which is part of the

National Institute of Astrophysics. IRA runs the observatories of Medicina and Noto, where two 32-m

VLBI AZ-EL telescopes are situated. This report contains the AC’s VLBI data analysis activities and

shortly outlines the investigations into the co-locations of space geodetic instruments.

1. Current Status and Activity

A thorough investigation into the local stability of the geodetic monuments at the Medicina site

and the determination of local, intra-site motions was completed in 2012. The data sets used in the

investigation were those acquired during the terrestrial surveys of the GPS-VLBI tie vector during the period 2001-2010. These precise terrestrial observations allowed us to determine the local

stability of the local ground control network over a decade. The intra-site motions are remarkable,

with rates of 1.7 mm/yr over baselines not exceeding a few tens of meters. The variation of the

VLBI-GPS tie vector was also determined and is 0.4±0.4 mm/yr. The results derived by the analysis of the terrestrial data were cross-checked against those obtained by the analysis of the GPS data

acquired by the two permanent EUREF [1] stations MEDI and MSEL over the period 2004-2010.

The GPS results show a non-negligible, statistically significant relative motion of the two permanent stations, especially in the horizontal component. GPS and terrestrial results are consistent

over the common time span. A thorough description of the analysis and a discussion of the results

can be found in [2], (http://gji.oxfordjournals.org/content/early/2013/01/07/gji.ggs092.full). In

2012 we published a paper ([3]) where VLBI was used in order to study the Etna volcano’s activity by means of the crustal deformations between Noto and Matera (located on the African and

the Eurasian Plates, respectively). By analyzing European VLBI experiments, we obtained the

behavior of the baseline that crosses the Etnean area. VLBI data are very sparse even if the time

series is quite long; therefore, to fill gaps in the information, we analyzed GPS continuous observations at the two sites, and we were able to highlight both extensions and compressions in detail.

Comparisons between the trend of Noto-Matera baseline length variations, volcanic activity, and

seismicity in the Mt. Etna area show the complexity of the development over time and space of

these phenomena, which are caused deep in the earth by a catalyst that can be traced, in our

opinion, to the interaction between the asthenospheric mantle, deep crust, and surface crust.

2. Data Analysis and Results

The IRA started to analyze VLBI geodetic databases in 1989, using a CALC/SOLVE package

on the HP1000 at the Medicina station. In subsequent years, the same software was installed

first on an HP360 workstation and later on an HP715/50 workstation. In more recent years,

two HP785/B2600 workstations and an HP282 workstation were used. In 2007, a new Linux

workstation was set up for the migration of all the VLBI data analysis, and Mark 5 Calc/Solve

was installed. During 2012, we stored all the 1999-2012 databases available on the IVS data

centers. All the databases were processed and saved with the best selection of parameters for the

IVS 2012 Annual Report 271
Italy INAF Analysis Center Istituto di Radioastronomia–Bologna

final arc solutions. The most recent IRA solution for crustal deformation comprises all the Europe

sessions analyzed at IRA from 1987 to 2009, and the estimated horizontal and vertical velocities

are presented in [4].

Our Analysis Center has participated in the IVS TROP Project on Tropospheric Parameters

since the beginning of the activities. Tropospheric parameters (wet and total zenith delay and

horizontal gradients) of all IVS-R1 and IVS-R4 24-hour VLBI sessions were regularly submitted.

In 2012 we submitted our results to IVS.

3. Outlook

We will continue with the regular submission of INAF tropospheric parameters to the IVS data

centers, also studying the impact of the Vienna Mapping Function on the geodetic results. We will

submit a long time series of troposphere parameters using all VLBI sessions available in our catalog

in order to estimate the variations over time of the content of water vapor in the atmosphere.

References

[1] Bruyninx, C (2004). The EUREF Permanent Network; a Multidisciplinary Network Serving Surveyors

as well as Scientists. GEOInformatics 7(5), 32-35.

[2] Sarti, P., C. Abbondanza, J. Legrand, C. Bruyninx, L. Vittuari, J. Ray. (2013) Intrasite motions and

monument instabilities at Medicina ITRF co-location site. Geophys J Int, doi: 10.1093/gji/ggs092,

[3] La Delfa, S., M. Negusini, S. Di Martino, G. Patan ́e. (2012) Improved geodetic European very-longbaseline interferometry solution using models of antenna gravitational deformation. Int J Earth Sci 101

(4), 1065-1075

[4] Sarti, P., M. Negusini, C. Abbondanza. (2010) Improved geodetic European very-long-baseline interferometry solution using models of antenna gravitational deformation. Ann Geophys 53(5-6) doi

10.4401/ag-4739.

272 IVS 2012 Annual Report
Jet Propulsion Laboratory, California Institute of Technology JPL Analysis Center

JPL VLBI Analysis Center Report for 2012

Chris Jacobs

Abstract

This report describes the activities of the JPL VLBI Analysis Center for the year 2012. The

highlight of the year was the successful MSL rover Mars landing, which was supported by VLBI-based

navigation using our combined spacecraft, celestial reference frame, terrestrial reference frame, earth

orientation, and planetary ephemeris VLBI systems. We also supported several other missions with

VLBI navigation measurements. A combined NASA-ESA network was demonstrated with first Kaband fringes to ESA’s Malarg ̈ue, Argentina 35 m. We achieved first fringes with our new digital back

end and Mark 5C recorders.

1. General Information

The Jet Propulsion Laboratory (JPL) Analysis Center is in Pasadena, California. Like the rest

of JPL, the center is operated by the California Institute of Technology under contract to NASA.

JPL has done VLBI analysis since about 1970. We focus on spacecraft navigation, including:

1. Celestial Reference Frame (CRF) and Terrestrial Reference Frame (TRF) are efforts which

provide infrastructure to support spacecraft navigation and Earth orientation measurements.

2. Time and Earth Motion Precision Observations (TEMPO) measures Earth orientation parameters based on single baseline semi-monthly measurements. These VLBI measurements

are then combined with daily GPS measurements as well as other sources of Earth orientation

information. The combined product provides Earth orientation for spacecraft navigation.

3. Delta differenced one-way range (∆DOR) is a differential VLBI technique which measures

the angle between a spacecraft and an angularly nearby extragalactic radio source. This

technique thus complements the radial information from spacecraft doppler and range measurements by providing plane-of-sky information for the spacecraft trajectory.

2. Technical Capabilities

The JPL Analysis Center acquires its own data and supplements it with data from other

centers. The data we acquire are taken using NASA’s Deep Space Network (DSN).

1. Antennas: Most of our work uses 34-m antennas located near Goldstone (California, USA),

Madrid (Spain), and Tidbinbilla (Australia). These include the following Deep Space Stations

(DSS): the “High Efficiency” subnet comprised of DSS 15, DSS 45, and DSS 65 which has

been the most often used set of JPL antennas for VLBI. More recently, we have been using

the DSN’s beam waveguide (BWG) antennas: DSS 13, DSS 24, DSS 25, DSS 26, DSS 34,

DSS 54, and DSS 55. Less frequent use is made of the DSN’s 70-m network (DSS 14, DSS

43, and DSS 63). Typical X-band system temperatures are 35K on the HEF antennas. The

IVS 2012 Annual Report 273
JPL Analysis Center Jet Propulsion Laboratory, California Institute of Technology

70-m and BWG temperatures are about 20K. Antenna efficiencies are typically well above

50% at X-band.

2. Data acquisition: We use the Mark IV DAT and Mark 5A VLBI recorders. In addition,

we have JPL-unique systems called the VLBI Science Recorder (VSR) and the Wideband

VSRs (WVSR) which have digital baseband converters and record directly to hard disk. The

data are later transferred via network to JPL for processing with our software correlator.

ROACH-based Digital Back Ends and Mark 5C recorders are now being tested for deployment

in 2013.

3. Correlators: JPL VLBI Correlator has been exclusively based on the SOFTC software which

handles the ∆DOR, TEMPO, and CRF correlations as well as tests of antenna arraying.

4. Solution types: We run several different types of solutions. For ∆DOR spacecraft tracking

we make narrow field (≈ 10◦) differential solutions. The TEMPO solutions typically have a

highly constrained terrestrial (TRF) and celestial frame (CRF) as a foundation for estimating

Earth orientation parameters. These reference frames are produced from global solutions

which then provide the framework needed for use by TEMPO and ∆DOR.

3. Staff

Our staff are listed below along with areas of concentration. Note that not all of the staff listed

work on VLBI exclusively, as our group is involved in a number of projects in addition to VLBI.

• Durgadas Bagri: TEMPO and Ka-band phase calibrators.

• James Border: ∆DOR spacecraft tracking.

• Cristina Garc ́ıa-Mir ́o: Madrid data acquisition, NASA-ESA southern declination collaboration, educational outreach.

• Shinji Horiuchi: Canberra data acquisition, NASA-ESA southern declination collaboration.

• Chris Jacobs: NASA-ESA southern declination collaboration, X/Ka CRF, TRF, S/X CRF.

• Christina King: source stability studies.

• Peter Kroger: ∆DOR spacecraft tracking.

• Gabor Lanyi: MODEST, fringe fitting and correlation support, ∆DOR, and TRF.

• Steve Lowe: Software correlator, fringe fitting software, ∆DOR.

• Walid Majid: pulsars, ∆DOR, VLBA phase referencing.

• Chuck Naudet: NASA-ESA southern declination collaboration, source stability studies.

• Andres Romero-Wolf: ∆DOR, CRF and TRF, MODEST scripts, source stability studies.

• Lawrence Snedeker: Goldstone data acquisition, NASA-ESA southern declination collaboration.

• Ioana Sotuela: Madrid antenna calibration, NASA-ESA southern declination collaboration.

• Ojars Sovers: S/X and X/Ka CRFs and TRF. Maintains MODEST analysis code.

• Alan Steppe: TEMPO and TRF.

274 IVS 2012 Annual Report
Jet Propulsion Laboratory, California Institute of Technology JPL Analysis Center

4. Current Status and Activities

TEMPO EOP and S/X CRF work continues. X/Ka-band (8.4/32 GHz) CRF took a major

step forward with the integration of ESA’s Malarg ̈ue, Argentina antenna into our network thus

adding much needed southern coverage.

VLBI spacecraft tracking continues to provide measurements of angular position in support of

mission navigation and planetary ephemeris development. The New Horizons trajectory toward

Pluto was verified in May-June. MSL was targeted to a near perfect aim point at the top of

the Martian atmosphere in August. The Juno Deep Space Maneuver in August-September was

supported to target the Earth flyby in October 2013. Dawn is being supported during its low

thrust cruise from Vesta to Ceres. Monthly measurements of MRO and Mars Odyssey continue to

improve the ephemeris of Mars.

5. Future Plans

In 2013, we hope to improve our VLBI system by increasing data rates to 2048 Mbps. Operational Ka-band phase calibrators have been built and are planned for deployment in 2013. Work

on the Digital Back End (DBE) continues. Our next generation fringe fitting program is also

expected to come online. We expect the combined NASA-ESA deep space network to start producing Ka-band CRF results. On the spacecraft front, we plan to continue supporting a number

of operational missions while further improving techniques for using VLBI for spacecraft tracking.

Acknowledgements

Research described herein done in part under contract with NASA. Government sponsorship

acknowledged. Copyright 
c 2013. All Rights Reserved.

References

[1] C.S. Jacobs, A. Romero-Wolf, C. Garc ́ıa-Mir ́o, S. Horiuchi, W.A. Majid, L.G. Snedeker, I. Sotuela,

‘Dual Frequency VLBI Monitoring of Large Sample of Compact Extragalactic Sources at 8 & 32 GHz,’

219th AAS, 435.09, BAAS, 44, 2, Austin TX, 12 Jan 2012.

[2] C.S. Jacobs, et al, ‘The Potential for a Ka-band (32 GHz) Worldwide VLBI Network,’ IVS 2010

Workshop on Technical Specifications, Wettzell, Germany, 1-2 March 2012. http:/www.fs.wettzell.de

[3] C. Garc ́ıa-Mir ́o, S. Rogstad, R. Navarro, J.E. Clark, C.J. Naudet, C.S. Jacobs, C.E. Goodhart, L.A.

White, J. Trinh, M. Soriano, D. Wang, E. Sigman, J. Luvalle, I. Sotuela, P. Pope, S. Horiuchi, J. Lobo,

‘VLBI Data Acquisition Terminal modernization at the Deep Space Network,’ IVS General Meeting,

Madrid, 4-9 March 2012. http://www.oan.es/gm2012/pdf/oral id 36.pdf

[4] A. Romero-Wolf, C.S. Jacobs, ‘The Effect of Correlated Noise on the Analysis of Space Geodetic Data,’

IVS General Meeting, Madrid, 2012. http://www.oan.es/gm2012/pdf/oral id 119.pdf

[5] C.S. Jacobs, J.E. Clark, C. Garc ́ıa-Mir ́o, S. Horiuchi, A. Romero-Wolf, L. Snedeker, I. Sotuela, ‘Celestial Reference Frame at X/Ka-band (8.4/32 GHz),’ IVS General Meeting, Madrid, 4-9 March 2012.

http://www.oan.es/gm2012/pdf/oral id 89.pdf

[6] C.S. Jacobs, et al., ‘The Potential for a Ka-band (32 GHz) Worldwide VLBI Network,’ IVS General

Meeting, Madrid, 4-9 March 2012. http://www.oan.es/gm2012/pdf/poster id 91.pdf

IVS 2012 Annual Report 275
JPL Analysis Center Jet Propulsion Laboratory, California Institute of Technology

[7] W.A. Majid, C. Garc ́ıa-Mir ́o, S. Horiuchi, C.S. Jacobs, A. Romero-Wolf, L. Snedeker, I. Sotuela, ‘Dual

Frequency VLBI Flux Monitoring of a Large Sample of Compact Extragalactic Sources at 8 and 32

GHz,’ IVS General Meeting, Madrid, 4-9 March 2012. http://www.oan.es/gm2012/pdf/oral id 60.pdf

[8] S. Horiuchi, C. Phillips, I. Sotuela, C.S. Jacobs, C. Garc ́ıa-Mir ́o, ‘32 GHz Celestial Reference Frame

Survey for Dec < −45◦,’ IVS General Meeting, Madrid, 4-9 March 2012.

http://www.oan.es/gm2012/pdf/oral id 85.pdf

[9] A. Romero-Wolf, O. Lutz, C.S. Jacobs, ‘Capturando Susurros del Universo con la Red de Espacio

Lejano,’ (Capturing Whispers from Space: The Deep Space Network),’ MDSCC Visiting Scientist

Seminar, Robledo de Chavela, Spain, 8 March 2012. http://www.mdscc.org/web/index.php/noticias

[10] C.S. Jacobs,‘A Boy becomes a Scientist,’ Educational outreach, Robledo de Chavela, Spain, Mar 2012.

[11] M.J. Molina, C. Garc ́ıa-Mir ́o, C.S. Jacobs, ‘Una cita con... radioastr ́onomos,’ Madrid DSN (MDSCC

Newsletter), 1 Apr 2012.

[12] C.S. Jacobs, ‘Celestial Reference Frames for Deep Space Navigation,’ Sec 343 Seminar: Numerical

Algorithms for Space Flight 31 May and 4 June 2012, JPL, Pasadena, CA.

http://nasf.jpl.nasa.gov/data/talk053112/053112.pdf

[13] S. Horiuchi, C. Phillips, C. Jacobs, I. Sotuela, C. Garc ́ıa-Mir ́o, ‘Towards an All-Sky 32 GHz Celestial

Reference Frame,’ Astronomical Society of Australia, U. New S. Wales, Sydney, Australia, July 2012.

http://www.asa2012.phys.unsw.edu.au/pdfs/POSTERS-1.pdf

[14] C.S. Jacobs, ‘Celestial Reference Frame Realizations at Multiple Radio Frequency Bands,’ IAU General

Assembly, Joint Discussion 7, Beijing, China, 28 August 2012.

http://referencesystems.info/uploads/3/0/3/0/3030024/4-02.pdf

[15] C.S. Jacobs, J. Alonso, J.E. Clark, L. Gamborino, C. Garc ́ıa-Mir ́o, S. Horiuchi, J. Lobo, R. Madd`e,

M. Mercolino, C.J. Naudet, L. Snedeker, I. Sotuela, L. White ‘The Celestial Reference Frame at

X/Ka-band: Status & Prospects for Improving the South,’ 11th European VLBI Network Symposium,

Bordeaux, France, 10 Oct 2012.

http://evn2012.obs.u-bordeaux1.fr/documents/presentations/121 Jacobs EVN2012 Oral.pdf

[16] C.S. Jacobs, C. Garc ́ıa-Mir ́o, E. Hoar, ‘El “GPS” Estelar: Navegando por el Sistema Solar,’ (Stellar-GPS: Navigating in the Solar System),’ MDSCC Visiting Scientist Seminar, Centro de Entrenamiento y Visitantes INTA-NASA, Robledo de Chavela, Spain, 17 Oct 2012.

http://www.mdscc.org/index.php?Section=Noticias&Id=74

Conferencia, Planetario de Madrid, Madrid, Spain, 18 Oct 2012.

http://www.planetmad.es/PDFs/CONFERENCIA%20CHRIS%20JACOBS(2).pdf

[17] C.S. Jacobs, W.A. Majid, A. Romero-Wolf, C. Garc ́ıa-Mir ́o, S. Horiuchi, L.G. Snedeker, I. Sotuela,

‘Frequent VLBI Monitoring on Parsec-Scales of 450+ Extragalactic FERMI Sources at 8 and 32 GHz,’

4th FERMI Symposium, Monterey CA, 29 Oct 2012.

http://fermi.gsfc.nasa.gov/science/mtgs/symposia/2012/

[18] C.S. Jacobs, J.E. Clark, C. Garc ́ıa-Mir ́o, S. Horiuchi, A. Romero-Wolf, L.G. Snedeker, I. Sotuela ‘A

Celestial Reference Frame at X/Ka-band (8.4/32 GHz) for Deep Space Navigation,’ 23rd International

Symposium on Space Flight Dynamics, Pasadena CA, 30 Oct 2012.

https://issfd.jpl.nasa.gov/home/assets/papers/ISSFD23 IMD1 1.pdf

[19] S. Horiuchi, C.S. Jacobs. C. Phillips, I. Sotuela, C. Garc ́ıa-Mir ́o, ‘VLBI monitoring of SgrA* at 32

GHz,’ ALMA-JAXA Workshop, Japan, Nov 2012.

276 IVS 2012 Annual Report
Korea Astronomy and Space Science Institute KASI Combination Center

KASI Combination Center Report

Younghee Kwak, Jungho Cho

Abstract

This report presents the activities of the Korea Astronomy and Space Science Institute (KASI) as

an IVS Combination Center during 2012, and it sketches the intended tasks for 2013.

1. General Information

As a goverment-funded research institute, KASI is in charge of operating an IVS Combination

Center. It has a wide range of research areas observing the Earth, the Sun, stars, and galaxies

based on various instruments. Concerning the Earth observations, KASI operates GNSS, VLBI,

and SLR. Space geodesy is one of the important research fields of KASI.

2. Component Description

KASI has prepared for regular combination analysis after it was designated as an IVS Combination Center. KASI has rich experience for GPS data processing and analysis using the Bernese

GNSS Software (Bernese). Bernese, especially the subprogram ADDNEQ2, supports stacking of

the normal equations and estimation of parameters [1]. We adopted Bernese to combine the sessionwise VLBI products of the IVS Analysis Centers (ACs) at the normal equation level. We

altered the software, which was developed for GPS data processing and analysis, to handle IVS

products appropriately. The inputs to the Bernese are the normal equation matrices and vectors

from the daily SINEX files of the individual ACs (see Table 2). The outputs are daily SINEX files

including combined station coordinates and Earth orientation parameters (EOPs). The missions

of the KASI Combination Center are to create high quality combination products, to verify the

combination solution of the BKG/DGFI Combination Center through cross-checking, to control

the quality of the ACs’ results, to provide feedback to the Analysis Centers, and to adhere to the

IERS Conventions.

3. Staff

The staff members of the KASI Combination Center are listed below.

Table 1. Personnel of the KASI Combination Center.

Jungho Cho +82-42-865-3234 jojh@kasi.re.kr

Younghee Kwak +82-42-865-2031 bgirl02@kasi.re.kr

IVS 2012 Annual Report 277
KASI Combination Center Korea Astronomy and Space Science Institute

Table 2. Products of individual ACs for the combination.

AC BKG DGFI GSFC IAA OPA USNO

Solution bkg2010a dgf2009a gsf2010a iaa2010a opa2010c usn2007b

4. Current Status and Activities

(1) Removing systematic variations of X and Y pole rates

In the IVS 2011 Annual Report [2], we reported that there were systematic variations of polar

rates between individual and combined solutions. They looked like sine curves, so we expected

that they might be caused by one of the EOPs. Most of the IVS ACs (BKG, DGFI, IAA, GSFC,

and OPA) provide the SINEX format which has celestial pole offsets dX and dY as nutation parameters. The Bernese 5.0 version, however, handles nutation angles in obliquity and longitude,

and thus the nutation part of the normal equations were not combined properly. Therefore, we

fixed the nutation parameters of five ACs (BKG, DGFI, IAA, GSFC, and OPA) and pre-reduced

the nutation parameters of USN to keep the nutation information. Finally, we could remove the

systmatic variation in X-pole and Y-pole rate as shown in Figure 1.

(2) Automation using BPE

KASI uses Bernese for combining individual ACs. Bernese provides an automation tool, the

Bernese Processing Engine (BPE), which is able to do routine processing. The routine processes

include converting the SINEX format to the NQ0 Bernese input format, transforming the normal

equations to refer to identical a priori values (reference frame and EOPs) and parameter epochs,

and combining sessionwise products of ACs. Due to naming conventions of input and output files

in Bernese, complete automation is restricted. Using additional scripts made BPE extensively

support long-term processing, e.g. 10 years. Figure 2 shows the functions of the scripts for VLBI

combination.

5. Future Plans for 2013

In 2013, we will focus on the following tasks:

• Rejecting outliers

• Weighting the individual solutions

• Combining whole period IVS products (1984-present)

• Comparing with BKG/DGFI Combination Center [3], IERS 08C04 [4], and IGS solutions [5]

• Providing IVS EOP format solutions [3] (Rapid and Quarterly)

278 IVS 2012 Annual Report
Korea Astronomy and Space Science Institute KASI Combination Center

Figure 1. Internal comparison between individual solutions and the KASI combination solution (Individual

solutions - Combined solution). + : BKG, ♦ : DGFI, × : GSFC,  : IAA, N : OPA, ◦ : USNO.

References

[1] Dach, R., Hugentobler, U., Fridez, P., and Meindl, M. (eds.), Bernese GPS Software Version 5.0 User

manual, Astronomical Institute, University of Bern, 2007.

[2] Kwak, Y., Cho, J., KASI Combination Center Report, in International VLBI Service for Geodesy and

Astrometry 2011 Annual Report, edited by K. D. Baver and D. Behrend, NASA/TP-2012-217505, 2012.

IVS 2012 Annual Report 279
KASI Combination Center Korea Astronomy and Space Science Institute

Figure 2. The scripts for KASI combination analysis.

[3] http://ccivs.bkg.bund.de

BKG/DGFI Combination Center Web page.

[4] http://hpiers.obspm.fr/eop-pc

IERS Earth Orientation Center Web page.

[5] http://igscb.jpl.nasa.gov/components/prods.html

IGS Products Table.

280 IVS 2012 Annual Report
Karadeniz Technical University, Department of Geomatics Engineering KTU-GEOD IVS Analysis Center

KTU-GEOD IVS Analysis Center Annual Report 2012

Emine Tanır Kayık ̧cı, Kamil Teke

Abstract

This report summarizes the activities of the KTU-GEOD IVS Analysis Center (AC) in 2012 and

outlines planned activities for 2013. The analysis of the EUROPE sessions is one of our specific interests,

and the combination of different AC solutions for continuous VLBI campaigns, e.g. CONT11, will be

investigated.

1. General Information

The KTU-GEOD IVS Analysis Center (AC) is located at the Department of Geomatics Engineering, Karadeniz Technical University, Trabzon, Turkey.

Figure 1. KTU-GEOD staff at Vienna State Opera.

2. Staff at KTU-GEOD

The staff who are contributing to the research at the KTU-GEOD IVS Analysis Center (AC)

in 2012 are listed in Table 1 with their main focus of research and working location.

3. Current Status and Activities

In 2012, we investigated sub-daily (three-hour) antenna TRF coordinates estimated from the

VLBI observations of the continuous 24h sessions of the CONT11 campaign [8]. We analyzed VLBI

observations using the Vienna VLBI Software (VieVS) which is developed at the Department of

Geodesy and Geoinformation at the Vienna University of Technology [2]. Troposphere zenith wet

delays (ZWD) and total gradients (east and north) were estimated as piecewise linear offsets at

one hour and six hours, respectively. Clock errors were estimated as hourly piecewise linear offsets,

in addition to as quadratic polynomials. Source coordinates were fixed to ICRF2 [3]. The IERS

IVS 2012 Annual Report 281
KTU-GEOD IVS Analysis Center Karadeniz Technical University, Department of Geomatics Engineering

Table 1. Staff members of KTU-GEOD ordered alphabetically.

Name Working location Main focus of res. Contact

Emine Tanır Karadeniz Technical University, Responsibility for etanir@ktu.edu.tr

Kayık ̧cı Dept. of Geomatics the Analysis Center

Engineering, Trabzon, Turkey and data processing

Kamil Teke Hacettepe University, Data processing kteke@hacettepe.edu.tr

Dept. of Geomatics Engineering,

Ankara, Turkey

15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

−5

−3

−1

1

3

5

day of September 2011

radial in cm

15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

−5

−3

−1

1

3

5

day of September 2011

east in cm

15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

−5

−3

−1

1

3

5

day of September 2011

north in cm

Figure 2. Kokee VLBI antenna piecewise (pw) coordinate offsets at three-hour intervals. Weighted means

of pw coordinate offsets were calculated at the overlapping 24h session boundaries. The black, red, and blue

dotted lines denote the pw coordinate estimates when loose relative constraints of 5 cm, 2 cm, and 1 cm

after three hours were imposed [8].

C04 08 series [1] was taken as a priori values of Earth Orientation Parameters, and high frequency

ocean tidal corrections were modeled as recommended by the IERS Conventions 2010 [5]. Earth

orientation parameter residuals were estimated as one offset per 24-hour VLBI session. An a priori

TRF was estimated from a global solution of CONT11 where antenna velocities were fixed to

those of VTRF2008. In the global solution, TRF datum condition equations were introduced on

the accumulated datum-free normal equation system in such a way that the estimated TRF had

no-net-translation (NNT) and no-net-rotation (NNR) with respect to VTRF2008. Atmospheric

loading [6] and tidal ocean loading corrections (FES2004, [4]) to the antenna coordinates were

282 IVS 2012 Annual Report
Karadeniz Technical University, Department of Geomatics Engineering KTU-GEOD IVS Analysis Center

introduced for each observation before the adjustment. All the antenna coordinates were fixed

to the TRF (from global solution) except for one antenna whose coordinates were estimated as

piecewise linear offsets at three-hour intervals. Different loose relative constraints on the coordinate

estimates of this one antenna were imposed for each analysis of the CONT11 campaign as: 5 cm,

2 cm, and 1 cm after three hours (see Figure 2). Readers are referred to [7] and [10] for more

information on the analysis of VLBI observations.

4h 6h 8h 12h 1d 2d 

0

0.2

0.4

0.6

0.8

1

1.2

period in hours

amplitude in cm

Figure 3. Fourier spectra of piecewise (pw) coordinate offsets on radial direction at three-hour intervals

at Kokee. The black, red, and blue dotted lines denote the pw coordinate estimates when loose relative

constraints as 5 cm, 2 cm, and 1 cm after three hours were imposed [8].

The reasons for large unrealistic leaps of three-hour antenna coordinates, especially for radial

components, are investigated (e.g., shown for Kokee in Figure 2). One of the possible reasons

might be the large correlation between certain parameters (e.g., clock errors, troposphere delays,

source coordinates, and Earth rotation parameters) and antenna coordinates at sub-daily intervals.

Another possible reason might be the unreduced tidal effects on the antenna coordinates. In this

case, one might ask whether the radial amplitudes of the tidal variations can reach up to 1 cm (see

black and red lines at one-day period in Figure 3) even though antenna coordinates are corrected

at each observation epoch using state-of-the-art geodynamic models. The correct answer to this

question needs further investigation. In Figure 3, the significant amplitude of 8 mm at 12 hours

(black line) vanishes when 1 cm after 3h relative constraint (blue line) was imposed in the analysis.

Thus, selecting really loose constraints is essential in order to not hide the dependencies (shared

variances) between parameters in the observation equations. Further investigations are discussed

in [8].

4. Future Plans

We will continue to analyze VLBI sessions with different parameterizations, focusing on the

EUROPE sessions by using VieVS. In 2013, we will study intra-technique combination of different

AC solutions of the continuous VLBI campaigns, i.e. CONT02, CONT05, CONT08, and CONT11.

IVS 2012 Annual Report 283
KTU-GEOD IVS Analysis Center Karadeniz Technical University, Department of Geomatics Engineering

Besides, we will do statistical comparisons between certain geodetic parameters, e.g. troposphere

[9].

Acknowledgements

We are thankful to all components of the IVS. We are grateful to Karadeniz Technical University

for their financial support of KTU-GEOD IVS AC research activities. One of the authors, Kamil

Teke, acknowledges the Scientific and Technological Research Council of Turkey (T ̈ubitak) for the

financial support of his postdoctoral research in Vienna.

References

[1] Bizouard, C., D. Gambis, The combined solution C04 for Earth orientation parameters consistent with

International Terrestrial Reference Frame, In: Drewes H. (ed) Geodetic reference frames, IAG symp

134:265-270, doi:10.1007/978-3-642-00860-3-41, 2009.

[2] B ̈ohm, J., S. B ̈ohm, T. Nilsson, A. Pany, L. Plank, H. Spicakova, K. Teke, H. Schuh, The new Vienna

VLBI Software VieVS, In: Proceedings of the 2009 IAG Symposium, Geodesy for Planet Earth, edited

by Steve Kenyon, Maria Christina Pacino, Urs Marti, doi:10.1007/978-3-642-20338-1-126, Vol. 136,

Part 7, 1007-1011, 2012.

[3] Fey, A., D. Gordon, C.S. Jacobs, The Second Realization of the International Celestial Reference

Frame by Very Long Baseline Interferometry, IERS Technical Note; 35, Frankfurt am Main: Verlag

des Bundesamts f ̈ur Kartographie und Geod ̈asie, 204 p., ISBN 3-89888-918-6, 2009.

[4] Lyard, F., F. Lefevre, T. Lettelier, O. Francis, Modelling the global ocean tides, Modern insights from

FES2004, Ocean Dyn 56(6), 394-415, 2006.

[5] Petit, G., B. Luzum, IERS Conventions 2010, IERS Technical Note; 36, Frankfurt am Main: Verlag

des Bundesamts f ̈ur Kartographie und Geod ̈asie, 179 p., ISBN 3-89888-989-6, 2010.

[6] Petrov, L., J.P. Boy, Study of the atmospheric pressure loading signal in Very Long Baseline Interferometry observations, J Geophys Res 109(B3):B03405, doi:10.1029/2003JB002500, 2004.

[7] Schuh, H., J. B ̈ohm, Very Long Baseline Interferometry for Geodesy and Astrometry, In: Sciences

of Geodesy II, Innovations and Future Developments, Guochang Xu (editor), Springer Verlag, ISBN

978-3-642-27999-7, doi:10.1007/978-3-642-28000-9, 339-376, 2013.

[8] Teke, K., J. B ̈ohm, T. Nilsson, H. Kr ́asn ́a, Sub-daily antenna position estimates from the CONT11

campaign, 21st Meeting of European VLBI Group for Geodesy and Astrometry (EVGA), Helsinki,

Finland, 5-8 March, 2013.

[9] Teke, K., J. B ̈ohm, T. Nilsson, H. Schuh, P. Steigenberger, R. Dach, R. Heinkelmann, P. Willis, R. Haas,

S. Garc ́ıa - Espada, T. Hobiger, R. Ichikawa, S. Shimizu, Multi-technique comparison of troposphere

zenith delays and gradients during CONT08, Journal of Geodesy, doi: 10.1007/s00190-010-0434-y,

85(7):395-413, 2011.

[10] Teke, K., Sub-daily parameter estimation in VLBI data analysis, Geowissenschaftliche Mitteilungen,

Heft Nr. 87, Vienna University of Technology, Vienna, Austria, Grafisches Zentrum HTU GmbH, ISSN

1811-8380, 2011.

284 IVS 2012 Annual Report
Main Astronomical Observatory, National Academy of Sciences of Ukraine Analysis Center at MAO

IVS Analysis Center at Main Astronomical Observatory of

National Academy of Sciences of Ukraine

Yaroslav Yatskiv

Abstract

This report summarizes the activities of the VLBI Analysis Center at the Main Astronomical

Observatory of the National Academy of Sciences of Ukraine in 2012.

1. Introduction

The VLBI Analysis Center was established in 1994 by the Main Astronomical Observatory

(MAO) of the National Academy of Sciences of Ukraine (NASU) as a working group of the Department of Space Geodynamics of the MAO. In 1998, the group started its IVS membership as

an IVS Analysis Center. The MAO AC is located at the office building of the observatory in Kiev.

2. Technical Description

VLBI data analysis is performed on two computers: an Intel Core 2 Duo 3.1 GHz box with

4 GB RAM and a 1 TB HDD, and a Pentium-4 3.4 GHz box with 1 GB RAM and two 200 GB

HDDs. Both computers are running under the Linux/GNU Operating System.

For data analysis, we use the SteelBreeze software which was developed at the MAO NASU.

The SteelBreeze software is written in the C++ programming language and uses the Qt 2.x widget library. SteelBreeze makes Least Squares estimation of different geodynamical parameters

with the Square Root Information Filter (SRIF) algorithm (see [1]).

The software analyzes VLBI data (time delays) of a single session or a set of multiple sessions.

The time delay is modeled according to the IERS Conventions (2003) [2], as well as by using

additional models (tectonic plate motion, nutation models, wet and hydrostatic zenith delays,

mapping functions, etc.). The following parameters are estimated: Earth orientation parameters,

coordinates and velocities of a selected set of stations, coordinates of a selected set of radio sources,

clock function, and wet zenith delay. This year we started the refactoring of the software to

implement the newest IERS Conventions [3] and to use the newest version of the Qt library.

3. Staff

The VLBI Analysis Center at Main Astronomical Observatory consists of the following members:

Yaroslav Yatskiv: Head of the Department of Space Geodynamics; general coordination and

support of activity of the Center.

Vasyl Choliy: Head of EOP determination laboratory.

Sergei Bolotin: Scientific consultant.

IVS 2012 Annual Report 285
Analysis Center at MAO Main Astronomical Observatory, National Academy of Sciences of Ukraine

4. Current Status and Activities in 2012

In 2012, we performed regular VLBI data analysis to determine Earth orientation parameters.

“Operational” solutions were produced and submitted to the IVS on a weekly basis. The IERS

Conventions (2003) [2] models were applied in the analysis. In the solutions, station coordinates

and Earth orientation parameters were estimated.

Also this year, we continued to participate in the IVS Tropospheric Parameters project. Estimated wet and total zenith delays for each station were submitted to IVS. The analysis procedure

was similar to the one used for the operational solutions.

5. Plans for 2013

The MAO Analysis Center will continue to participate in operational EOP determination,

as well as in updating the TRF and CRF solutions from VLBI analysis of the full data set of

observations.

Acknowledgements

The work of our Analysis Center would be impossible without the activities of other components

of IVS. We are grateful to all contributors from the Service.

References

[1] Biermann, G. J., 1977, Factorization Methods for Discrete Sequential Estimation, V128, Mathematics

in Science and Engineering Series, Academic Press.

[2] IERS Conventions (2003), 2004, IERS Technical Note 32, eds. D. D. McCarthy and G. Petit, Bundesamt

f ̈ur Kartographie und Geod ̈asie, Frankfurt am Main.

[3] IERS Conventions (2010), 2010, IERS Technical Note 36, eds. G. Petit and B. Luzum, Bundesamt f ̈ur

Kartographie und Geod ̈asie, Frankfurt am Main.

286 IVS 2012 Annual Report
Kashima Space Technology Center, NICT NICT Analysis Center

Analysis Center at National Institute of Information and

Communications Technology

Thomas Hobiger, Mamoru Sekido, Ryuichi Ichikawa

Abstract

This report summarizes the activities of the Analysis Center at National Institute of Information

and Communications Technology (NICT) for the year 2012.

1. General Information

The NICT Analysis Center is operated by the space-time standards group of NICT and is located in Kashima, Ibaraki, Japan as well as at the headquarters in Koganei, Tokyo. The Analysis

Center focuses on the processing of VLBI experiments which are related to NICT’s research goals.

Effort is spent on developing new VLBI technology for time and frequency transfer, the development of a modern multi-technique analysis software package, prototyping of a compact VLBI

system, real-time EOP determination, and atmospheric path delay studies.

2. Staff

Members who are contributing to the Analysis Center at NICT are listed below (in alphabetical

order, with working locations in parentheses):

• HOBIGER Thomas (Koganei, Tokyo): analysis software development, time and frequency

transfer, and software correlator development

• ICHIKAWA Ryuichi (Kashima): compact VLBI system and atmospheric modeling

• KONDO Tetsuro (Bangkok/Thailand and Kashima): software correlator development

• KOYAMA Yasuhiro (Koganei, Tokyo): time and frequency transfer experiments

• SEKIDO Mamoru (Kashima): development of VLBI systems and coordination of activities

3. Current Status and Activities

3.1. Development of a Multi-technique Space-Geodetic Analysis Software Package

In a cooperation between several Japanese institutes the multi-technique space geodetic analysis software “c5++” [3] has been developed over recent years. The software provides consistent

geodetic and geophysical models which can be accessed by single technique space-geodetic applications or can be used to combine several techniques on the observation level (Figure 1). Satellite

Laser Ranging (SLR) and Very Long Baseline Interferometry (VLBI) stand-alone applications

have been realized in the last two years. With the introduction of an option to utilize local tie

information as well as the possibility of estimating common parameters (clock, troposphere, orbits)

the software enables rigorous combination of space geodetic techniques on the observation level.

Moreover, the inclusion of GNSS as a third space geodetic technique since 2012 has increased the

IVS 2012 Annual Report 287
NICT Analysis Center Kashima Space Technology Center, NICT

choice of analysis strategies tremendously. However, rigorous combination of space geodetic data

on the observation level depends on proper handling of inter-technique biases and other offsets

in order to make this approach work well. Moreover, the large number of unknown parameters

requires sophisticated algorithms, as well as a large enough PC memory in which huge matrices

can be stored temporarily.

Figure 1. Combination of space geodetic data on the observation level requires the knowledge of precise

local tie information. Co-located VLBI and GNSS technology often shares the same frequency standard,

which allows estimation of a single clock model for both techniques. In addition troposphere delays are

thought to be identical except for a constant bias (so-called “troposphere tie”).

3.2. Frequency Transfer by Means of VLBI

Space geodetic techniques such as GNSS have been proven to be a useful tool for time and

frequency transfer purposes. Besides SLR, which is currently tested under the name T2L2, VLBI

could be another space geodetic technique that can be utilized for frequency transfer. Unlike

GNSS, VLBI does not require any orbital information as it directly refers to an inertial reference

frame defined by the location of the quasi stellar objects. As summarized by [4], current VLBI

systems can provide a frequency link stability of about 2 x 10-15 @ 1d (ADEV), but due to the

fact that geodetic VLBI networks do not observe for more than 24 hours continuously, no statement about long-term stability can be made. Moreover, as VLBI only provides one observation

per epoch, troposphere and station clocks need to be de-correlated in space geodetic analysis by

estimating these parameters from a batch of several scans. Thus, VLBI can only contribute to

frequency transfer with clock estimates made every 30 minutes or longer. In order to overcome

these drawbacks, NICT’s Space-Time Standards Laboratory has started to work on the realization

of a frequency transfer system based on the principles of VLBI, whereas developments from the

upcoming geodetic VLBI2010 system are expected to help in reaching these goals. VLBI2010 is

288 IVS 2012 Annual Report
Kashima Space Technology Center, NICT NICT Analysis Center

designed to provide observables with a few picoseconds of uncertainty, and once a global station

network is deployed, it is expected to operate 24h/7d which would allow access to long-term frequency stability on intercontinental links. The VLBI2010 short-term frequency transfer limitation

is thought to be improved when VLBI is combined with GNSS (or TWSTFT) in the analysis

processing (see prior section). Our software c5++ has been prepared to combine VLBI and GNSS

data on the observation level. Thereby, the concept of a reference clock within the VLBI station

network needs to be dismissed when VLBI data is combined with GNSS information, which is processed in precise point positioning (PPP) mode. Thus, when combining both techniques, GNSS

data are expected to provide the absolute clock information at each site and contribute to the

short-term frequency stability. On the other side VLBI will provide good long-term stability and

compares station clocks over long baselines.

3.3. Ultra-rapid EOP Experiments

Geospatial Information Authority of Japan (GSI), Onsala Space Observatory, University of

Tasmania, and the Hartebeesthoek Radio Astronomy Observatory carried out several ultra-rapid

EOP experiments which were automatically analyzed with c5++. The analysis process had to be

adopted to handle automated ambiguity resolution of a multi-baseline session and to allow for a

robust estimation of the three EOP components. First results demonstrated that all three EOPs

can be estimated from such a dedicated ultra-rapid observation network. However, small software

updates and bug fixes are still necessary in order to make the automated multi-baseline ambiguity

resolution algorithm work with low SNR data or outliers. In addition to the dedicated ultra-rapid

experiments, GSI regularly submits UT1 results from INT2 sessions that have been automatically

processed by c5++ on an operational basis (see [3] for details on the processing strategy).

3.4. Ray-traced Troposphere Slant Delay Correction for Space Geodesy

A software package, called Kashima Ray-tracing Tools (KARAT), has been developed. It is

capable of transforming numerical weather model data sets to geodetic reference frames, computing

fast and accurate ray-traced slant delays, and correcting geodetic data on the observation level.

KARAT has been extended to support frequency dependency of the refractivity following the

Liebe model [1] with the goal of finding out whether modern space-geodetic microwave techniques

(including VLBI2010 and higher dual-frequency VLBI configurations) should be corrected for

dispersive troposphere delays. By the use of this model it is possible to compute the complex

refractivity based on atmosphere quantities such as pressure, temperature, and relative humidity.

Although the frequency dependent delay contribution appears to be of small order, one has to

consider that signals are propagating through few kilometers of troposphere at high elevations to

hundreds of kilometers at low elevations. Thus, it has been investigated whether such an effect

has a magnitude above the noise floor of current space geodetic instruments or if it can be safely

neglected. It could be shown [2] that dispersive troposphere delays grow inversely proportional

to the cosine of the zenith distance (like any other troposphere delay) and will be absorbed into

the estimated zenith delays during post-processing. Thus frequency dependent troposphere delays

should not affect the geodetic results on a significant level. However, for X/Ka-VLBI the question

remains of the level to which troposphere products are comparable to other estimates from other

space geodetic techniques when a frequency dependent troposphere contribution is neglected.

IVS 2012 Annual Report 289
NICT Analysis Center Kashima Space Technology Center, NICT

4. Future Plans

For the year 2013 the plans of the Analysis Center at NICT include:

• Time and frequency transfer experiments by VLBI and combination with other techniques

such as GNSS or TWSTFT

• Combination of multi-technique space-geodetic data on the observation level with c5++

• Implementation of an interface for c5++, which allows reading and creation of OpenDB data

• Experiments and analysis of multi-baseline networks which allows the determination of all

three EOPs in real-time

• Usage of multi-processors/multi-core processing platforms for the acceleration of space geodetic applications

References

[1] Liebe, H.J., MPM-An atmospheric millimeter-wave propagation model, Int. J. Infrared and Millimeter

Waves, 10, 631-650, 1989.

[2] Hobiger T., P. Baron, and R. Ichikawa, Do we need to consider dispersive troposphere delays for current

and next generation space-geodetic instruments?, Geophysical Research Abstracts, 14, EGU2012-2636,

2012. EGU General Assembly 2012.

[3] Hobiger T., T. Otsubo, M. Sekido, T. Gotoh, T. Kubooka and H. Takiguchi, Fully automated VLBI

analysis with c5++ for ultra-rapid determination of UT1, Earth, Planets, Space, 45, 2, 75–79, 2010.

[4] Rieck C., R. Haas, R.T.K. Jaldehag, and J.M. Johansson, VLBI and GPS-based time-transfer using

CONT08 data, IVS 2010 General Meeting Proceedings, 365-369, NASA/CP-2010-215864, 2010.

290 IVS 2012 Annual Report
Norwegian Mapping Authority (NMA) NMA Associate Analysis Center

NMA Analysis Center

Halfdan Pascal Kierulf, Per Helge Andersen

Abstract

The Norwegian Mapping Authority (NMA) has during the last few years had a close cooperation

with Norwegian Defence Research Establishment (FFI) in the analysis of space geodetic data using

the GEOSAT software. In 2012 NMA has taken over the full responsibility for the GEOSAT software.

This implies that FFI stopped being an IVS Associate Analysis Center in 2012. NMA has been an

IVS Associate Analysis Center since 28 October 2010. NMA’s contributions to the IVS as an Analysis

Centers focus primarily on routine production of session-by-session unconstrained and consistent normal

equations by GEOSAT as input to the IVS combined solution. After the recent improvements, we

expect that VLBI results produced with GEOSAT will be consistent with results from the other VLBI

Analysis Centers to a satisfactory level.

1. Introduction

A number of co-located geodetic stations with more than one observation technique have been

established. In principle, all instruments at a given co-located station move with the same velocity,

and it should be possible to determine one set of coordinates and velocities for each co-located

station. In addition, a constant eccentricity vector from the reference point of the co-located station

to each of the individual phase centers of the co-located instruments is estimated using constraints

in accordance with a priori information given by the ground surveys. One set of Earth orientation

parameters (EOP) and geocenter coordinates can be estimated from all involved data types. The

present dominating error source of VLBI is the water content of the atmosphere, which must be

estimated. The introduction of GPS data with a common VLBI and GPS parameterization of

the zenith wet delay and atmospheric gradients will strengthen the solution for the atmospheric

parameters. The inclusion of SLR data, which is nearly independent of water vapor, gives new

information which will help in the de-correlation of atmospheric and other solve-for parameters

and will lead to more accurate parameter estimates. These, and many more advantages with the

combination of independent and complementary space geodetic data at the observation level, are

fully provided by the GEOSAT software developed by FFI [1, 2]. GEOSAT is also useful for single

technique analysis. The VLBI module of GEOSAT is now further developed by the NMA [5]. The

goals are both to act as an IVS Analysis Center delivering session-by-session unconstrained and

consistent normal equations to the IVS Combination Center and to provide quality control for the

different modules used in GEOSAT.

2. The GEOSAT Software and Analysis Activities in 2012

The NMA has during 2012 continued the work of making the VLBI module of the GEOSAT

software compatible with other VLBI analysis software that delivers results to IVS. In addition,

there is a lot of activity going on at NMA to further develop the multi-technique software GEOSAT

(see the FFI TDC 2011 annual report).

One of the first challenges that had to be solved was how to extract an unconstrained SINEX

solution from the Upper-Diagonal UD Kalman filter solution produced by GEOSAT. A first test

solution was sent to the IVS Combination Center in autumn 2009. During 2010 several solutions

IVS 2012 Annual Report 291
NMA Associate Analysis Center Norwegian Mapping Authority (NMA)

covering all VLBI sessions with at least four stations from the start of 1994 to the end of 2009

were submitted to the IVS Combination Center. The first solution was presented at the 6th IVS

General Meeting, in Hobart, Australia [5]. The overall agreement between the NMA-GEOSAT

solution and the solutions from the other ACs was satisfactory for this first comparison. However,

some discrepancies were found. There were some systematic differences in the nutation parameters,

which in our latest comparisons seem to have vanished. A misinterpretation of the NGS-format

led to systematic differences in UT1-UTC. Systematic differences in station heights have also

disappeared in the latest comparison mostly due to the use of the VMF1 [4] model instead of 3D

ray tracing. We also noticed more noise in the GEOSAT-derived EOP compared to results from

the other software packages. The largest “EOP-outliers” disappeared after some manual editing of

the observations. Some other “EOP-outliers” were removed after a manual introduction of clock

breaks in the analysis.

3. Plans for 2013

Our plan is to go through the VLBI data from the start of 1994 to the present and to perform a

detailed manual editing of outliers. We expect that this will contribute to a reduction of the EOP

“noise level”. When the editing is completed, a new set of normal equations will be submitted

to IVS for a test combination. We hope (and expect) that the results then will be at the level of

the other IVS ACs. As soon as the GEOSAT solution is in satisfactory agreement with the other

solutions, NMA will start to deliver unconstrained normal equations in the SINEX format to the

IVS Combination Center on a routine basis.

Unlike most of the other VLBI analysis software GEOSAT is based on a UD-Kalmanfilter. This

allows the stochastic behavior of the system to be changed. NMA will test different stochastic

parameters especially for the troposphere. Station and epoch dependent stochastic parameters

based on input from numerical weather models and IGS tropospheric products will be tested and

evaluated. Tests of different models are also planned — for instance, a comparison of results using

VMF1 and 3D ray tracing.

Producing VLBI solutions for IVS [3] is the first part of a larger strategic plan from NMA. The

next step is to include other geometric geodetic techniques (GNSS, SLR, and DORIS) in a common

solution where the different techniques are combined at the observation level. The long-term goal

of this large effort is to also include data from the gravity satellites GRACE and GOCE and from

altimeter satellites.

4. Staff

• Dr. Halfdan Pascal Kierulf - Research geodesist of Norwegian Mapping Authority (NMA).

• Dr. Per Helge Andersen - Research Professor of Forsvarets forskningsinstitutt (FFI and

NMA).

• Ann-Silje Kirkvik - Master of Science.

• Lena Pedersen and Ingrid Fausk - Research geodesist of the Norwegian Mapping Authority

(NMA).

• Dr. Oddgeir Kristiansen - Section Manager at the Norwegian Mapping Authority (NMA).

292 IVS 2012 Annual Report
Norwegian Mapping Authority (NMA) NMA Associate Analysis Center

• Reidun Kittelsrud - Section Manager at the Norwegian Mapping Authority (NMA).

References

[1] Andersen, P. H., 1995. High-precision station positioning and satellite orbit determination. PhD Thesis,

NDRE/Publication 95/01094.

[2] Andersen, P. H., 2000. Multi-level arc combination with stochastic parameters. Journal of Geodesy 74:

531-551 (doi: 10.1007/s001900000115).

[3] B ̈ockmann, S., Artz, T., & Nothnagel, A. 2009, VLBI terrestrial reference contribution to ITRF2008.

Journal of Geodesy, 84, 201-219 (doi: 10.1007/s00190-009-0357-7).

[4] Boehm, J., Werl, B., & Schuh, H. 2006, Troposphere mapping functions for GPS and very long baseline

interferometry from European Centre for Medium-Range Weather Forecasts operational analysis data.

Journal of Geophysical Research, 111, B02406, (doi:10.1029/2005JB003629).

[5] Kierulf, H.P., Andersen, P.-H., Boeckmann, S., & Kristiansen, O. 2010, VLBI analysis with the multitechnique software GEOSAT. IVS 2010 General Meeting Proceedings, Edited by Dirk Behrend and

Karen D. Baver (NASA/CP-2010-215864).

IVS 2012 Annual Report 293
Paris Observatory Analysis Center (OPAR) Observatoire de Paris, SYRTE, CNRS/UMR8630

Paris Observatory Analysis Center (OPAR): Report on

Activities, January - December 2012

S ́ebastien Lambert, Christophe Barache

Abstract

We report on activities of the Paris Observatory VLBI Analysis Center (OPAR) for calendar year

2012 concerning the development of operational tasks, the development of our Web site, and various

other activities: monitoring of the Earth’s free core nutation, measuring of the post-seismic displacements of some stations, and the analysis of the recent IVS R&D sessions, including observations of

quasars close to the Sun.

1. Operational Solutions for Diurnal and Intensive Sessions

A reanalysis of the complete diurnal session database was done (identified as opa2012a), and

resulting EOP series and radio source catalogs were sent to the IVS. This solution estimated EOP

and rates as session parameters, station coordinates and velocities as global parameters, and most

of the sources’ coordinates as global parameters. Troposphere and clock parameters were estimated

every 20 minutes and 60 minutes, respectively, and gradients were estimated every six hours (at

all sites). Axis offsets were estimated as global parameters for a list of 80 stations. We used

up-to-date geophysical and astronomical modeling to compute the theoretical delay and partials,

including the IAU 2006 nutation and precession, the Vienna mapping functions 1, the FES 2004

ocean loading model, and the antenna thermal deformations as provided by A. Nothnagel (2009, J.

Geod., 83, 787). Since the solution was released after the March 11, 2011 earthquake that occured

in Japan, the displacement of the 32-m antenna at Tsukuba was modeled by splines, as was done

earlier for Fairbanks and the TIGO antenna at Concepci ́on. Constraints were applied to the 295

ICRF2 defining sources (no-net rotation) and to 24 stations (no-net rotation and no-net translation

of positions and velocities). We used the latest version of the Calc/Solve geodetic VLBI analysis

software package. More details can be found at

http://ivsopar.obspm.fr/earth/glo

Diurnal sessions were analyzed routinely within 24 hours after their version 4 databases were

submitted to the IVS. The operational solution was aligned to the opa2012a global solution. Unconstrained normal equations relevant to EOP, rates, and station and source coordinates were sent

to the IVS in SINEX format for combination in the framework of the IVS analysis coordinator’s

task.

An operational solution analyzing Intensive sessions after 2006, started in 2011, was also continued (opa2011i) together with corresponding SINEX files. The solution opa2011i processed

Intensive sessions in order to produce UT1 consistent with VTRF 2008A, ICRF2, and the IERS

EOP 08 C 04 Earth orientation data.

All the above products, except SINEX files, were also published on the OPAR Web site. The

SINEX files were only sent to the data centers.

294 IVS 2012 Annual Report
Observatoire de Paris, SYRTE, CNRS/UMR8630 Paris Observatory Analysis Center (OPAR)

2. Other Products and Improvements of the Web Site

Station and radio source coordinate time series were also updated. For each source, a page

displays the time series and provides links to source information at various external databases (e.g.,

the French Virtual Observatory software package Aladin that provides the optical counterpart of

the VLBI quasars, or the Bordeaux VLBI Image Database that gives the VLBI structure). In

late 2012, we used Google’s application programming interface (API) to insert Google Earth and

Google Sky views in our Web pages to display telescopes and radio sources on Earth and sky maps.

These features are available in the sections ‘Radio Sources’ and ‘Stations’ of the OPAR Web site.

We used also the dygraphs JavaScript visualization library to plot recent EOP data and TIGO

and Tsukuba coordinates. This interface offers interactive, zoomable charts of the time series, so

that the user can easily manipulate, explore, and interpret them.

3. Follow-up of Various Phenomena

3.1. Assessment of R&D Sessions Including Observations Close to the Sun

In late 2011, the IVS decided to re-observe quasars at low angular distances to the Sun, typically

lower than 15◦(whereas this lower limit has been imposed on all schedules since 2002). These

observations were scheduled during R&D experiments, at a rate of about 5 to 10 sources out of a

total of a hundred sources observed in the session, in order to check that they do not degrade the

other VLBI products.

In dedicated pages on the OPAR Web site, the R&D experiments are analyzed with a standard

parameterization as used for the operational analysis. The Calc/Solve analysis software package

is used in independent mode. All Earth orientation parameters (EOP) and rates are estimated

as session parameters together with station and source coordinates. To avoid degeneracy of the

solution of the system of equations, no-net rotation and no-net translation conditions are applied

to the station coordinates (with respect to VTRF 2008A), excluding TIGO at Concepci ́on and the

Japanese stations within the Tokyo area because of the strong 2010 and 2011 earthquakes. For

similar reasons, a loose no-net rotation condition (σ = 2 mas) is applied to the source coordinates

with respect to ICRF2, excluding the 39 sources which needed special handling in the ICRF2

work. Troposphere parameters are estimated every 20 minutes and gradients every six hours.

Clock parameters are estimated every 30 minutes. The post-Newtonian parameter γ is fixed to

unity. The results of the analysis of nine R&D sessions (November 2011 to September 2012) can

be seen at

http://ivsopar.obspm.fr/rd

This analysis work will be continued for all upcoming R&D sessions that observe sources close to

the Sun.

3.2. Free Core Nutation

The free core nutation (FCN) is a free oscillation of the Earth’s figure axis in space due to the

presence of a liquid core rotation inside the viscoelastic mantle. Its period is close to 430 days and

is retrograde. Understanding the excitation of the FCN and its amplitude and phase variations is

still an open question, although the community generally believes that the key resides in improved

IVS 2012 Annual Report 295
Paris Observatory Analysis Center (OPAR) Observatoire de Paris, SYRTE, CNRS/UMR8630

2011.8 2012 2012.2 2012.4 2012.6 2012.8

0

20

40

60

80

100

120

140

160

180

200

11NOV29XA11DEC06XA12JAN24XA12APR03XA12MAY30XA12JUN19XA12JUL10XA12AUG28XA12SEP25XA

Sun Spot Number

2011.8 2012 2012.2 2012.4 2012.6 2012.8

0

20

40

60

80

100

120

Postfit RMS Delay (ps)

Nutation Offset to IAU 2000A (0.01 mas)

Sun Spot Number

Figure 1. Left: the Sun Spot Number as given by the Solar Influence Data Center (SIDC) at Royal

Observatory of Belgium, and the IVS R&D experiments. Right: the postfit RMS delay and nutation offsets

to IAU 2000A estimated from the R&D sessions, along with the Sun Spot Number.

atmospheric and oceanic circulation modeling at diurnal and subdiurnal frequencies. At OPAR,

we maintain a FCN model directly fitted to routinely estimated nutation offsets (Figure 2).

In addition to the FCN, amplitudes and phases of a set of 42 prograde and retrograde tidal

waves are also fitted to the data. These tidal terms are interpreted as small deficiencies of the

IAU 2000A nutation model. More explanations and material can be found at

http://ivsopar.obspm.fr/nutation

3.3. Huge Post-seismic Displacements

Still using the routinely analyzed diurnal sessions, we monitored the displacements of the

station of TIGO at Concepci ́on after the 27 February 2010 earthquake and of the radio telescope

at Tsukuba after the 11 March 2011 earthquake. Figure 3 displays the East coordinates of the two

sites with respect to the mean position as given in the VTRF 2008A. The monitoring is continued

at

http://ivsopar.obspm.fr/eq

4. Staff Members

Staff members who contributed to the OPAR analysis and data centers in 2012 are listed below:

• S ́ebastien Lambert, Analysis Center manager, responsible for data analysis, development of

GLORIA analysis software,

• Christophe Barache, Data Center manager, data analysis,

• Daniel Gambis, responsible for the IERS Earth Orientation Center, interface with IERS

activities.

296 IVS 2012 Annual Report
Observatoire de Paris, SYRTE, CNRS/UMR8630 Paris Observatory Analysis Center (OPAR)

1980 1985 1990 1995 2000 2005 2010

−0.5

0

0.5

dX (mas)

1980 1985 1990 1995 2000 2005 2010

−0.5

0

0.5

dY (mas)

Figure 2. The free core nutation fitted to opa2012a nutation offset time series with respect to the IAU 2000A

nutation and IAU 2006 precession models.

2010 2010.5 2011 2011.5 2012 2012.5 2013

−340

−335

−330

−325

−320

−315

−310

−305

−300

−295

−290

East (cm)

TIGOCONC

2011 2011.5 2012 2012.5 2013

60

65

70

75

80

85

90

95

East (cm)

TSUKUB32

Figure 3. The East coordinates of the TIGOCONC and TSUKUB32 antennas with respect to the VTRF

2008A solution.

IVS 2012 Annual Report 297
Onsala Space Observatory (OSO) Analysis Center Onsala Space Observatory (OSO)

Onsala Space Observatory – IVS Analysis Center

R ̈udiger Haas, Hans-Georg Scherneck, Gunnar Elgered, Tong Ning, Johan L ̈ofgren

Abstract

This report briefly summarizes the activities of the IVS Analysis Center at the Onsala Space

Observatory during 2012 and gives examples of results of ongoing work.

1. Introduction

We concentrate on research topics that are relevant for space geodesy and geosciences. These

research topics are related to data observed with geodetic VLBI and complementary techniques.

2. VLBI and GPS Frequency Link Stabilities

We analyzed the two continuous campaigns CONT08 and CONT11 to study the frequency link

stabilities that can be achieved today with VLBI and GPS [1], [2]. Our analysis shows that VLBI

and GPS perform today equally well for frequency comparisons. We achieved overlapping Allan

Deviations for 1 day on the order of 1.2·10−15 and better, and the VLBI and GPS derived frequency

estimates agree in most cases with common clocks at a level of 5 · 10−16. As an example, Figure 1

depicts the overlapping Allan Deviations for CONT11. The residual phase differences in a rootmean-square sense were on the order of 100 ps. The result is that VLBI is an interesting alternative

for frequency transfer since it is completely independent of the usual techniques applied. The

upcoming VLBI2010 system could thus be of interest for continuous time and frequency transfer.

Figure 1. Frequency link instability for CONT11. The reference clock is the H-maser at Onsala.

298 IVS 2012 Annual Report
Onsala Space Observatory (OSO) Onsala Space Observatory (OSO) Analysis Center

3. Atmospheric Water Vapor from CONT Campaigns

We analyzed the four continuous campaigns CONT02, CONT05, CONT08, and CONT11 and

compared the atmospheric water vapor results derived from the co-located equipment available

at the participating stations [3]. All VLBI stations contributing to the CONT campaigns are

co-located with GPS stations, and several of the stations also operated water vapor radiometers

(WVR) during the CONT campaigns, see Table 1.

Table 1. Co-located instrumentation (V - VLBI, G - GPS, W - water vapor radiometer), operated at the

stations contributing to the four continuous campaigns CONT02, CONT05, CONT08, and CONT11.

Station continuous campaign

CONT02 CONT05 CONT08 CONT11

Hartebeesthoek (South Africa) V G V G W V G V G

Kokee Park (Hawaii, USA) V G W V G W V G V G

Ny- ̊Alesund (Svalbard, Norway) V G V G V G V G

Onsala (Sweden) V G W V G W V G W V G W

Westford (Massachusetts, USA) V G V G V G V G

Wettzell (Germany) V G W V G W V G V G

Algonquin Park (Canada) V G V G W

Gilcreek (Alaska, USA) V G V G

Svetloe (Russia) V G V G

Tigo Concepci ́on (Chile) V G V G V G

Tsukuba (Japan) V G W V G W V G W

Medicina (Italy) V G

Zelenchukskaya (Russia) V G V G

Fortaleza (Brazil) V G

Hobart (Tasmania, Australia) V G

Yebes (Spain) V G

In general, we found good agreement between the zenith wet delay (ZWD) results derived from

VLBI and GPS for all stations in all four CONT campaigns. The biases are on the order of ±5 mm,

and the standard deviations are on the order of 5−10 mm. The biases are however not constant for

a given station, but vary from campaign to campaign. The comparison between VLBI and WVR

is heavily dependent on the WVR instrument operated. The Onsala Space Observatory is the only

station that had three co-located techniques for all four CONT sessions. The comparison between

VLBI and WVR at Onsala showed biases on the order of 1 − 5 mm and standard deviations on

the order of 5 − 15 mm. As an example, Figure 2 shows times series of zenith wet delay (ZWD)

values derived from the co-located techniques at Onsala for all four CONT campaigns.

4. Ocean Tide Loading

The Automatic Ocean Tide Loading service has been moved to a new machine and can now

be found at http://holt.oso.chalmers.se/loading. There have only been slight improvements

during 2012, such as to the graphics display.

IVS 2012 Annual Report 299
Onsala Space Observatory (OSO) Analysis Center Onsala Space Observatory (OSO)

15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

50

100

150

200

250

Day in October 2002

ZWD (mm)

GPS

VLBI

WVR

12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28

50

100

150

200

250

ZWD (mm)

Day in September 2005

GPS

VLBI

WVR

12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27

50

100

150

200

250

Day in August 2008

ZWD (mm)

GPS

VLBI

WVR

15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

50

100

150

200

250

Day in September 2011

ZWD (mm)

GPS

VLBI

WVR

Figure 2. Zenith Wet Delay (ZWD) values derived from the co-located techniques GPS (red dots), VLBI

(blue squares), and WVR (green diamonds) at Onsala for the continuous campaigns CONT02, CONT05,

CONT08, and CONT11.

5. Gravimetric Laboratory

The Superconducting Gravimeter GWR 054 has been running without interruption during

2012. Since December 2012, one-second data has been available through a monitoring Web interface

with a maximum latency of two minutes. The address is http://holt.oso.chalmers.se/hgs/

SCG/monitor-plot.html, see Figure 3.

From June 6 to September 11 a calibration project with Leibniz University Hannover, Germany,

was carried out. A portable ZLS Burris gravimeter was operated continuously in parallel with the

GWR 054. The portable meter was calibrated before and after the project on the calibration line

in Hannover. The result was somewhat disappointing because the GWR 054 calibration factor was

achieved at a similar precision level as previous calibration attempts by short, parallel recordings

with an absolute FG5 gravimeter.

300 IVS 2012 Annual Report
Onsala Space Observatory (OSO) Onsala Space Observatory (OSO) Analysis Center

Figure 3. http://holt.oso.chalmers.se/hgs/SCG/monitor-plot.html, the monitoring site for the Superconducting Gravimeter at Onsala with links to power spectrograms, earthquake information, and numerical

data. Earlier segments of the data can be visualized interactively.

6. Outlook

The IVS Analysis Center at the Onsala Space Observatory will continue its efforts to work on

specific topics relevant to space geodesy and geosciences. For the future we plan to intensify our

activities, in particular concerning horizontal gradients in the atmosphere using VLBI, GNSS, and

radiometers.

References

[1] Haas R, Rieck C, Jarlemark P (2012) VLBI and GNSS Frequency Link Instabilities during CONT Campaigns. In: D. Behrend and K. Baver (eds.): International VLBI Service for Geodesy and Astrometry

2012 General Meeting Proceedings “Launching the Next-Generation IVS Network”, NASA/CP-2012-

217504, 425–429.

[2] Rieck C, Haas R, Jarlemark POJ, Jaldehag RTK (2012) VLBI Frequency Transfer using CONT11.

In: Proc. of the 26th European Frequency and Time Forum, Gothenburg, Sweden, 24-26 April, 2012,

163–165.

[3] Haas R (2012) Atmospheric water vapour from CONT-campaigns. EGU General Assembly 2012,

EGU2012-11432.

IVS 2012 Annual Report 301
PMD Analysis Center Politecnico di Milano, DIIAR

PMD IVS Analysis Center

Vincenza Tornatore

Abstract

The main activities carried out at the PMD (Politecnico di Milano DIIAR) IVS Analysis Center

during 2012 are briefly higlighted, and future plans for 2013 are sketched out.

We principally continued to process European VLBI sessions using different approaches to evaluate

possible differences due to various processing choices. Then VLBI solutions were also compared to the

GPS ones as well as the ones calculated at co-located sites.

Concerning the observational aspect, several tests were performed to identify the most suitable

method to achieve the highest possible accuracy in the determination of GNSS (GLOBAL NAVIGATION SATELLITE SYSTEM) satellite positions using the VLBI technique.

1. General Information

The Department DIIAR (Dipartimento di Ingegneria Idraulica, Ambientale, Infrastrutture

viarie e Rilevamento) belongs to the Technical University of Milan (Politecnico di Milano). The

‘Rilevamento’ research unit deals with various areas of research that concern, e.g., classical topography and photogrammetry surveying, numeric cartography, GIS (Geographic Information Systems)

data processing, remote sensing, GNSS static and real time positioning, and mathematical and

physical geodesy (space geodesy included). In this framework, the PMD IVS AC and the IAG

(International Association of Geodesy) Service: IGES (International Geoid Service) are hosted and

operated.

DIIAR continues to support all office supplies, hardware, and personnel necessary to manage

the PMD IVS AC since its establishment in October 2010 [1]. Part of the work here described

was developed also with the support of MIUR (Ministry of Education, University, and Research)

under the framework of a project with considerable national interest.

2. Current Status and Activities

All the European sessions available since 1990 through the end of 2011 have been processed

under the same modeling conditions and analogous parameterizations. To calculate solutions, we

used the VieVS (Vienna VLBI Software) software [2] developed by the members of the VLBI group

of the Institute of Geodesy and Geophysics (IGG) at the Vienna University of Technology (TU

Wien).

Among the different approaches used to process European sessions, we report on the investigations made on seven VLBI stations that had longer historical data series and were co-located with

GPS stations. The period used in this preliminary study starts in 1993 and ends in 2007. European site coordinates and baseline lengths (with respective variance-covariance matrices), have

been estimated to study their temporal evolution. The adjustments were performed using the

single session approach. The baseline lengths, used to infer European crustal deformations, were

calculated with respect to the Wettzell station due to its stable position in the European network

and its barycentric location with respect to the other six stations selected for the study (Onsala,

Ny- ̊Alesund, Madrid, Medicina, Matera, and Noto).

The results were compared with those calculated in another previously performed study [3].

302 IVS 2012 Annual Report
Politecnico di Milano, DIIAR PMD Analysis Center

The principal crustal motions identified in that work were post-glacial rebound in Northern Europe

(baseline Wettzell-Ny- ̊Alesund) and compression motion in southern Europe (baselines of Wettzell

with the Italian stations). These motions were also confirmed by our investigations.

Another analysis of GPS and VLBI time series was performed on the velocities estimated by

a least squares adjustment for each of the seven selected VLBI European stations using a linear

trend as a deterministic model. Once the estimated trend was removed, the method of Empirical

Covariance [4] was applied to the residuals, to look for the presence of a possible residual signal;

it was found only for the Matera, Medicina, Noto, and Wettzell GPS stations, but not for the

co-located VLBI ones. This difference in behavior between the VLBI and the GPS time series was

reported also in other studies, e.g. [5], that made the comparisons using the SLR series also, and

residual correlation was not found in the SLR time series either. According to these studies, it is

possible to confirm that the presence of residual correlation in the GPS series does not indicate

possible geophysical reasons but could instead be related to intrinsic GPS data processing.

During 2012, a strong activity to realize observational tests of GLONASS satellites with VLBI

techniques took place. In contrast to previous years, when only two VLBI stations (Medicina and

Onsala) were used during the tests (see for example [6] and [7]), another VLBI antenna, Noto, was

added to increase data redundancy and to make it possible to cross-check among different baselines.

Data are still undergoing processing, but one of the main problems that was found is related to

a strong emitted satellite signal that entered through the secondary lobes during the observation

of a nearby calibrator (a natural radio source). Usually natural calibrators have a flux lower than

that of the GNSS satellites by about six orders of magnitude. Therefore the contamination due to

the caught satellite signal made the data from the calibrator, which had been observed with the

aim of correcting main systematic effects that were corrupting satellite observations, useless also.

3. Future Plans

Completion of the study described for European time series of baselines and site coordinates

for data analysis is foreseen. A comparison with results of other ACs also involved in the studies

of Europe campaigns would be worthwhile. The upgrade to the new VieVS version 2.0 is devised,

and comparisons with results obtained with the previous VieVS version are also foreseen.

Concerning the problem of the observation of GNSS satellites through the VLBI technique,

one objective is to use the same experience gained for GLONASS satellite observations to observe

also the GPS constellation. The installation under the FS (Field System) of software dedicated to

satellite tracking is of very high priority.

Simulations to evaluate the best procedure to be followed to observe GNSS satellites and nearby

natural calibrators are also under development to gain the possibility of using the precious information coming from calibrator observations to correct systematic effects common to the satellites

and the calibrators in L-band.

Acknowledgements

The work described was in part performed under the national Project PRIN 2008 ‘Il nuovo di

sistema di riferimento geodetico italiano: monitoraggio continuo e applicazioni alla gestione e al

controllo del territorio’.

The author wishes to thank the International VLBI Service for Geodesy and Astrometry (IVS)

IVS 2012 Annual Report 303
PMD Analysis Center Politecnico di Milano, DIIAR

for coordinating the EUROPE campaigns and providing the data.

The VLBI satellite observations are based from Medicina and Noto radio telescopes, operated

by INAF, Istituto di Radioastronomia, Italy, and the Onsala85 radio telescope, operated by the

Swedish National Facility for Radio Astronomy, Sweden. The author thanks the personnel at the

VLBI stations of Medicina, Noto, and Onsala25, and the processing center at the Joint Institute

for VLBI in Europe (JIVE) for supporting the experiments.

References

[1] Tornatore V. (2011), New Associate Analysis Center Established at PMD, in International

VLBI Service for Geodesy and Astrometry 2010 Annual Report, Eds. D. Behrend and K.

D. Baver, Greenbelt, MD 20771-0001, USA, NASA/TP-2011-215880, 2011, pp. 244-246, URL:

ftp://ivscc.gsfc.nasa.gov/pub/annual-report/2010/pdf/acpmd.pdf

[2] Nilsson T., Boehm J., Boehm S., Madzak M., Nafisi V., Plank L., Spicakova H., Sun J., Tierno

Ros J., Schuh H. (2011), Status and future plans for the Vienna VLBI Software VieVS, In: W. Alef,

S. Bernhart, A. Nothnagel (eds.): Proc. 20th Meeting of the European VLBI Group for Geodesy and

Astrometry, 93-96

[3] Haas R., Nothnagel A., Campbell J., Gueguen E. (2003), Recent crustal movements observed with the

European VLBI network: geodetic analysis and results. J. Geodyn., 35(4), 391-414, doi:10.1016/S0264-

3707(03)00003-6

[4] Barzaghi R., Sans`o F. (1983), Sulla Stima Empirica della Funzione di Covarianza, Bollettino di Geodesia

e Scienze Affini, Anno XLII, No.4, pp. 389-415, Eds. IGM

[5] Ray J., Altamimi A., Collilieux X, Van Dam T. (2008), Anomalous harmonics in the spectra of GPS

position estimates, GPS Solutions, vol. 12, number 1, doi:10.1007/s10291-007-0067-7

[6] Tornatore V., Haas R. (2009), Considerations on the observation of GNSS-signals with the VLBI2010

system. In: G. Bourda, P. Charlot, A. Collioud (eds.): Proc. 19th Meeting of the European VLBI Group

for Geodesy and Astrometry pp. 151-155

[7] Tornatore V., Haas R., Duev D., Casey S., Pogrebenko S., Molera-Calves G., Duev D. (2010),

Tracking of GLONASS satellites by VLBI radio telescopes, in 5th ESA Workshop on Tracking,

Telemetry and Command Systems for Space Application (TTC 2010) Proceedings, ESA-ESTEC,

Noordwijk, The Netherlands, September 21-23, 2010, WPP-318, Eds ESA, Electronic version

http://www.congrex.nl/10A07/

304 IVS 2012 Annual Report
Pulkovo Observatory PUL Analysis Center

Pulkovo IVS Analysis Center (PUL) 2012 Annual Report

Zinovy Malkin, Julia Sokolova

Abstract

This report briefly presents the PUL IVS Analysis Center activities during 2012 and plans for the

coming year. The main topics of the investigations of PUL staff in that period were ICRF related

studies, computation and analysis of EOP series, celestial pole offset (CPO) modeling, and VLBI2010

related issues.

1. General Information

The PUL IVS Analysis Center (AC) was organized in September 2006 and is located at and

sponsored by the Pulkovo Observatory of the Russian Academy of Sciences. It is a part of the

Pulkovo EOP and Reference Systems Analysis Center (PERSAC) [1]. The main topics of our IVS

related activity are:

• Improvement of the International Celestial Reference Frame (ICRF).

• Computation and analysis of the Earth orientation parameters (EOP) from Intensives and

24-hour IVS sessions.

• Modeling of the celestial pole offset (CPO) and free core nutation (FCN).

• Comparison of VLBI products, primarily as Earth orientation parameters (EOP), with results

of other space geodesy techniques.

• Computation and analysis of observation statistics.

The PUL AC’s Web page [2] is supported. It contains the following sections:

• General Information on the PUL AC. Includes brief history, activity overview, and a scientific

staff list.

• VLBI data analysis. Includes results of VLBI data analysis, such as UT1 Intensive series,

CPO/FCN series, and mean Pole coordinates. These data are updated daily.

• OCARS catalog. Includes the latest version of the catalog of optical characteristics of astrometric radio sources (OCARS) [3]. The catalog is continually updated as new information

becomes available.

• Approaches and occultations. Includes tables for forthcoming mutual events of planets and

astrometric radio sources, such as close angular approaches and occultations for the period

until 2050 [4].

• PUL members’ publications and presentations.

• VLBI technology overview.

• Links to the VLBI World. Includes links to (primarily geodetic and astrometric) VLBI

coordinating bodies, stations, analysis centers, software, etc.

• Contact information.

IVS 2012 Annual Report 305
PUL Analysis Center Pulkovo Observatory

2. Scientific Staff

In 2012 the following persons contributed to the PUL activity:

1. Zinovy Malkin (70%) — PUL coordinator, EOP and CRF analysis;

2. Natalia Miller (5%) — EOP analysis;

3. Julia Sokolova (100%, since August 2012) — CRF analysis.

3. Activities and Results

The main activities and results of the PUL IVS Analysis Center during 2012 included:

• Operational processing of the IVS Intensive sessions in automated mode and submission of

results to IVS was continued.

• ICRF related research was continued. The main directions of this activity were comparison

and combination of radio source catalogs and investigation of their stochastic and systematic

errors. In 2012, the following results were obtained.

– A new Pulkovo combined catalog was computed [5]. Using CRF realizations from seven

IVS ACs (bkg, cgs, gsf, igg, opa, sha, and usn) we computed two combined catalogs

PUL(2012)C01 and PUL(2012)C02. Besides using more data, several developments

were realized as compared with the previous version of Pulkovo combined catalog of

2007 [6]. The PUL(2012)C01 catalog is constructed in the ICRF2 system and is aimed

at improvement of the ICRF2 random errors, and the PUL(2012)C02 catalog is constructed in an independent system and thus provides both stochastic and systematic

improvement of the ICRF2.

– Several related studies were conducted [7, 8].

• CPO and FCN related researches. The main activities and results in 2012 were the following.

– Two CPO and two FCN series were updated daily and made available at the PERSAC

Web site. One CPO and one FCN series were started at the end of 2012.

– Comparison of several CPO series were made from the eight individual ones computed at

IVS ACs (aus, bkg, cgs, gsf, iaa, opa, sopu, and usn) and combined solutions of IVS and

IERS (C04 and NEOS) [9]. It has been shown that significant random and systematic

errors beween these series do exist and in turn lead to differences and inconsistencies

between results of users’ applications. This situation requires clear IVS and IERS

recommendations on using different CPO series.

– Joint analysis of the Polar Motion and CPO time series was made along with time

series of two geomagnetic indices, Kp and Dst [10]. Two groups of common principal

components (PCs) were found: trends, and quasi-harmonic terms with near-Chandlerian

frequencies for PM, Kp, and Dst series, and near-FCN frequency for CPO series (both

periods are near 430 days). Comparison of the spectra of the investigated series and their

amplitude and phase variations showed some interesting common features. However,

the obtained results are still not sufficient to quantify the effects of interconnections of

the Chandler Wobble (CW), FCN, and the geomagnetic field.

306 IVS 2012 Annual Report
Pulkovo Observatory PUL Analysis Center

• Investigations of the impact of the Galactic aberration on the ICRS realization and EOP

were continued in cooperation with Paris Observatory and Nanjing University [11, 12]. It

was shown that the effect of the Galactic aberration strongly depends on the distribution of

the sources that are used to realize the ICRS. According to different distributions of sources

the amplitude of the apparent rotation of the ICRS is between about 0.2 and 1 μas/yr. This

rotation has no component around the axis pointing to the Galactic center and has zero

amplitude in the case of uniform distribution of sources. The effect on the coordinates of the

Celestial intermediate pole (CIP) is between about 1 to 100 μas/cy, and the effects on the

Earth rotation angle (ERA) are from four to several tens of μas/cy.

• Studies have been conducted in the framework of the IAG SC 1.4 activity on investigation

of the mutual impact of celestial and terrestrial reference frame and related issues such

as systematic errors of the ICRF, impact of astronomical and geophysical modeling on the

CRF and TRF results, and future prospects of improvement of the ICRF systematic accuracy

[13, 14, 15].

• The work on the OCARS catalog [3] was continued. The current basic statistics of the catalog

are the following.

OCARS ICRF2 ICRF2 def.

Sources 7174 3414 295

Sources with known redshift 3927 (54.7%) 2199 (64.4%) 257 (87.1%)

Sources with known magnitude 4861 (67.8%) 2589 (75.8%) 284 (96.3%)

• A catalog of approaches of planets to radio sources and occultations of astrometric radio

sources by planets through the year 2050 was updated [4].

• The PUL archive of VLBI data and products is supported. At present, all available databases

and corresponding NGS cards for 1979-2012 have been stored (about 9.4 million observations)

along with the main IVS and IERS products. These archives are continually updated as new

databases becomes available.

• Development of algorithms and software for data processing and analysis continued.

• PUL staff members participated in activities of several IERS, IAG, and IVS projects, committees, and working groups.

4. Outlook

Plans for the coming year include:

• Continue VLBI related studies.

• Continue UT1 Intensive processing.

• Continue OCARS catalog support.

• Continue development of algorithms and software for data processing.

• Continue support of the PUL archives of data and products.

IVS 2012 Annual Report 307
PUL Analysis Center Pulkovo Observatory

References

[1] http://www.gao.spb.ru/english/as/persac/index.htm

[2] http://www.gao.spb.ru/english/as/ac vlbi/

[3] http://www.gao.spb.ru/english/as/ac vlbi/ocars.txt

[4] http://www.gao.spb.ru/english/as/ac vlbi/occultations approaches.pdf

[5] Sokolova Ju., Malkin Z. New Pulkovo combined catalogs of the radio source positions. Presented at the

IAU XXVIII General Assembly, Beijing, China, August 2012.

[6] Sokolova Ju., Malkin Z. On comparison and combination of catalogs of radio source positions. Astron.

Astrophys., 2007, 474, 665–670.

[7] Sokolova Ju., Malkin Z. Impact of covariance information on the orientation parameters between radio

source position catalogs. In: IVS 2012 General Meeting Proceedings, ed. D. Behrend, K.D. Baver,

NASA/CP-2012-217504, 2012, 339-341.

[8] Malkin Z. On assessment of stochastic errors of radio source position catalogs. Presented at the IAU

XXVIII General Assembly, Beijing, China, August 2012.

[9] Malkin Z. Celestial pole offsets: from initial analysis to end user. IVS 2012 General Meeting Proceedings,

ed. D. Behrend, K.D. Baver, NASA/CP-2012-217504, 2012, 375-379.

[10] Miller N., Malkin Z. Joint analysis of the Polar Motion and Celestial Pole Offset time series. In: IVS

2012 General Meeting Proceedings, ed. D. Behrend, K.D. Baver, NASA/CP-2012-217504, 2012, 385-389.

[11] Malkin Z. On the impact of the Galactic aberration on VLBI-derived precession model. In: Schuh H.,

Boehm S., Nilsson T., Capitaine N. (Eds.) Proc. Journees 2011: Earth rotation, reference systems and

celestial mechanics: Synergies of geodesy and astronomy, Vienna, Austria, September 19-21, Vienna:

Vienna University of Technology, 2012, 168–169.

[12] Liu J.-C., N. Capitaine, S.B. Lambert, Z. Malkin, Z. Zhu. Systematic effect of the Galactic aberration

on the ICRS realization and the Earth orientation parameters. Astron. Astrophys., 2012, v. 548, A50.

[13] Malkin Z., Schuh H., Ma C., Lambert S. Interaction between celestial and terrestrial reference frames

and some considerations for the next VLBI-based ICRF. In: Schuh H., Boehm S., Nilsson T., Capitaine

N. (Eds.) Proc. Journees 2011: Earth rotation, reference systems and celestial mechanics: Synergies of

geodesy and astronomy, Vienna, Austria, September 19-21, Vienna: Vienna University of Technology,

2012, 66–69.

[14] Boehm J., Malkin Z., Lambert S., Ma C. Challenges and Perspectives for TRF and CRF Determination.

In: IVS 2012 General Meeting Proceedings, ed. D. Behrend, K.D. Baver, NASA/CP-2012-217504, 2012,

309-313.

[15] Malkin Z. Connecting terrestrial to celestial reference frames. Presented at the IAU XXVIII General

Assembly, Beijing, China, August 2012.

308 IVS 2012 Annual Report
Sternberg State Astronomical Institute (SAI) of Lomonosov Moscow State University SAI Analysis Center

SAI VLBI Analysis Center Report 2012

Vladimir Zharov

Abstract

This report presents an overview of the SAI VLBI Analysis Center activities during 2012 and

the plans for 2013. The SAI AC analyzes all IVS sessions for computations of the Earth orientation

parameters (EOP) and time series of the ICRF source positions and performs research and software

development aimed at improving the VLBI technique.

1. General Information

The SAI VLBI Analysis Center is located at Sternberg State Astronomical Institute of

Lomonosov Moscow State University in Moscow, Russia. The Analysis Center participates in

geodetic and astrometric VLBI analysis, software development, and research aimed at improving

the VLBI technique, especially for support of the Radioastron mission.

2. Component Description

SAI AC performs data processing of all kinds of VLBI observation sessions. For VLBI data

analysis we use the ARIADNA software package developed at SAI. Version 4 was finished and

tested in 2012. All reductions are performed in agreement with the IERS Conventions (2010).

The package uses files in the NGS format as input data.

The ARIADNA package (v. 4) is the basis of software named ORBITA installed on the correlator of the AstroSpace Center of Lebedev Physical Institute. It is used for correlation of the

ground-space interferometer data during the Radioastron mission.

3. Staff

• Vladimir Zharov, Professor: development of the ARIADNA software, development of the

methods of parameter estimation;

• Dmitry Duev, post-graduate student: VLBI data processing, troposphere modeling;

• Nikolay Voronkov, scientific researcher: global solution;

• Svetlana Nosova, engineer: VLBI data processing;

• Natalya Shmeleva, engineer: VLBI data processing.

4. Current Status and Activities

• Software Development for VLBI Processing

The ARIADNA software is being developed to provide contributions to IVS products. The

software is used for calculating all types of IVS products. Version 4 was developed in 2012.

The main features of this version are the performance of all reductions in agreement with the

IERS Conventions (2010), the generation of the SINEX files, and the combination of some

of the SINEX files to stabilize solutions.

IVS 2012 Annual Report 309
SAI Analysis Center Sternberg State Astronomical Institute (SAI) of Lomonosov Moscow State University

A new model for delay was developed for the ground-space interferometer. It was realized

as software ORBITA, which is used for correlation and routine analysis of the Radioastron

observations.

• Routine Analysis

During 2012 the routine data processing was performed with the ARIADNA software using

the least-squares method with rigid constraints, and non-rigid constraints were used for

generation of SINEX files.

SAI AC operationally processed the 24-hour and Intensive VLBI sessions. Creation of

databases of the VLBI sessions and processing of all sessions is fully automated. The EOP

series sai2012a.eops and sai2012a.eopi were calculated. These series were computed with the

catalog VTRF2008 of station positions and velocities. Experimental series sai2012b.eops was

calculated with the experimental catalog of radio sources with non-zero velocities. New EOP

series will be used in 2013 for generation of new nutation series.

• Global Solution

An experimental catalog of the radio source positions and velocities was obtained by

N.Voronkov.

• Troposphere Modeling

At the stations with the meteorological data missing, we used surface data files (temporal coverage: four times daily, spatial coverage: 2.5 degrees latitude x 2.5 degrees longitude global grid) from NCEP/NCAR Reanalyzes (http://www.cdc.noaa.gov/data/gridded/

data.ncep.reanalysis.surface.html) for calculating air temperature, pressure, and relative humidity. For that purpose a program was written to interpolate these data to the given

coordinates of the station at the time of observations.

This method was used for generation of air temperature, pressure and relative humidity for

the ground stations that participate in observations with the space radio telescope.

310 IVS 2012 Annual Report
SHAO, Chinese Academy of Sciences Shanghai Astronomical Observatory VLBI Analysis Center

SHAO Analysis Center 2012 Annual Report

Guangli Wang,Jinling Li,Minghui Xu,Li Guo,Li Liu,Fengchun Shu,Zhihan Qian,Liang Li

Abstract

The Shanghai Astronomical Observatory (SHAO) Analysis Center in 2012 continued routine VLBI

data analysis and produced earth orientation parameter (EOP), terrestrial reference frame (TRF), and

celestial reference frame (CRF) information, which was submitted to the IVS quarterly. The activities

of SHAO also consisted of data reduction of the Chinese VLBI Network (CVN), spacecraft navigation

using the VLBI technique, and some research activities.

1. General Information

SHAO is responsible for the data processing and analysis of the CVN sessions which aim to

monitor the crustal movement of the Chinese Mainland. This work includes the computation of

the group delay and the analysis of these observations. Quarterly solutions of the IVS 24hr sessions

were conducted to generate the time series of EOP and to realize the TRF and CRF. The software

used for VLBI data analysis is Calc/Solve, released on 21 May 2010 [1]. We tried to model the

movement of TIGOCONC after the big earthquake in Chile, and added the modeling into the

Calc/Solve software. As in 2010 and 2011, SHAO continued to conduct the real-time navigation

of the ChangE-2 (CE-2) satellite using the VLBI technique [2]. Research topics are outlined in

Section 3. The members involved in these activities are Guangli Wang, Jinling Li, Minghui Xu, Li

Guo, Li Liu, Liang Li, Fengchun Shu, and Zhihan Qian.

2. Activities and Data Analysis at SHAO

SHAO is in charge of the CVN and is an Analysis Center of the IVS. Routine VLBI activities

at SHAO included:

-Data processing and analysis of the CVN geodetic experiments

The related work contains the calculation of the delay and delay rate of the CVN observations

at every band, resolving group delay ambiguities, and computation of ionosphere calibrations. In

addition, SHAO is responsible for the generation of the VLBI group delay in the NGS format

and for the analysis of all CVN sessions by the software shops, which has been developed based

on the software OCCAM6.1E(Linux) with modifications mainly to VLBI data processing models.

-Regular data analysis of the IVS 24h sessions and product submission

We continued to routinely analyze all IVS 24h sessions using the Calc/Solve software, and

during this year we regularly submitted our analysis products (EOP, TRF, and CRF) to the IVS

Data Centers. For the movements of stations after earthquakes, especially for core stations such

as TIGOCONC, modeling of the movements was built and added into the software.

-Analysis of EOP Determination via the Chinese VLBI Network

The EOPs are determined from the IVS observations in which Sheshan station in Shanghai

and Nanshan station in Urumqi were involved. The precision is comparable to that of the IERS

IVS 2012 Annual Report 311
Shanghai Astronomical Observatory VLBI Analysis Center SHAO, Chinese Academy of Sciences

EOP series. The current precision of UT1 determined from single baseline observations of the two

stations is in the middle level of the international precision. The determination of precisions of

UT1 either from the IVS Intensive sessions in 2011 with Sheshan included or from international

EOP observations with the two stations included, meets the requirements of the 100-m positioning

precision of the satellite of Mars to UT1 [3].

3. Research Topics at SHAO

3.1. Determination of the Solar Acceleration

Due to the acceleration of the known Solar system barycenter (SSB), the velocity vector of

the origin of the International Celestial Reference System (ICRS) [4] is no longer constant but

varies with time, which consequently causes a systematic variation in the direction of the observed

object. This phenomenon is referred to as the secular aberration drift [5]. Based on the relationship

between this effect and the acceleration of the SSB, the acceleration can be determined directly

from VLBI measurements without any available kinematic or dynamic models of the Milky Way.

We developed two approaches to estimate the acceleration vector. One is to treat the Solar

acceleration vector as a global parameter, which we call the global solution. The second method is

to estimate the time series of the velocity variations through the solution and fit the acceleration

from the time series. Although the latter method lacks the ability to effectively separate the

velocity from other error sources, such as the influences of the position errors of the radio sources,

the time series solution can clearly show the details and trends of the velocity variations of the

SSB, and it can be taken as a validation for the first method. In total, 4,632 sessions, 3,492 radio

sources, and approximately 7,100,000 group delay observables were analyzed.

We obtained the acceleration vector in the three components in the Galactic coordinate system

(7.47±0.46, 0.17±0.57, 3.95±0.47) mm·s

−1

·yr−1[6,7]. Figure 1 shows the velocity variation time

series and the acceleration. The result from the two methods are consistent with each other.

Traditionally it was generally believed that the acceleration component in the direction normal to

the Galactic plane was too small to be detected and thus the acceleration vector should nearly

point to the Galactic center [8], but our results show that the vertical acceleration is notable. And

the vertical component is likely to be explained by three potential possibilities. Please refer to our

paper [7] for details.

3.2. The Epoch ICRF

Due to the acceleration of the solar system, the radio source positions in the ICRF2 catalog

measured by a fictitious observer located at the origin of the ICRS vary with time. It is technically

incorrect, then, to state that the ICRF has no dependence on time. We propose the epoch ICRF

as a new concept to consider the effect of apparent proper motion of the positions of radio sources.

This apparent proper motion has a magnitude of approximately 5.8 microarcseconds (μas) per

year, and for the 30-year Very Long Baseline Interferometry (VLBI) observational history these

position variations will exceed 100 μas. We show that the dipole structure of the apparent proper

motions leads to global rotation in the ICRF2, and the main term, the shift of the direction of

the origin of right ascension, reaches 25 μas per century. The epoch ICRF is constructed using

epoch positions at J2000.0 and apparent proper motions of radio sources [9]. Figure 2 shows the

apparent proper motion field for 295 ICRF2 [10] defining sources.

312 IVS 2012 Annual Report
SHAO, Chinese Academy of Sciences Shanghai Astronomical Observatory VLBI Analysis Center

−0.4

−0.2

0.0

0.2

Galactic center (m/s)

1984 1988 1992 1996 2000 2004 2008 2012

Year

−0.4

−0.2

0.0

0.2

Second component (m/s)

1984 1988 1992 1996 2000 2004 2008 2012

−0.4

−0.2

0.0

0.2

Galactic pole (m/s)

1984 1988 1992 1996 2000 2004 2008 2012

Figure 1. The velocity time series and its linear trend obtained from the time series solution [7].

−60 ̊ −60 ̊

−30 ̊ −30 ̊

0 ̊ 0 ̊

30 ̊ 30 ̊

60 ̊ 60 ̊

6 μas/yr

90ο

180ο

270ο

Figure 2. Apparent proper motion field for 295 ICRF2 defining sources based on the model of secular

aberration drift [9]. It is plotted in right ascension and declination coordinates.

IVS 2012 Annual Report 313
Shanghai Astronomical Observatory VLBI Analysis Center SHAO, Chinese Academy of Sciences

4. Plans for 2013

We will continue to submit our analysis products to the IVS Data Centers regularly and to

develop software to transfer the data format of CVN observations, NGS, to netcdf. The research

activities will focus on the effect of the Solar acceleration on the ICRF and the ICRS and on the

study of the high frequency variations of EOP using VLBI observations. The processing strategy

and treatment of irregularly moving stations, such as TSUKUB32 and KASHIM11 after a big

earthquake, will also be considered in the near future.

5. References

1. GSFC, NASA (2010): Release of Mark 5 VLBI Analysis Software Calc/Solve from May 21,

2010 (Web reference: http://gemini.gsfc.nasa.gov/solve).

2. Li, J.L., Liu, L., Zheng W.M., and Sun Z.M., Positioning reduction in the realtime phase of Chang’E-2 satellite. Science China Physics, Mechanics & Astronomy,

2012. 55(2): p. 371-374.

3. Zhang, Z.B., Wang, G.L., Liu X., and Tang, Z.H., Analysis of the EOP Determination via the Chinese VLBI Network, Geomatics and Information Science of Wuhan

University (in press).

4. Arias, E.F., M. Feissel, and V.K. Abalakin, The Celestial System of the International Earth

Rotation Service, in Inertial Coordinate System on the Sky, J.H. Lieske, Editor 1990. p. 119.

5. Titov, O., S.B. Lambert, and A.M. Gontier, VLBI measurement of the secular aberration

drift. Astronomy & Astrophysics, 2011. 529.

6. Xu, M.H., Wang, G.L., and Zhao, M., Direct estimation of the Solar acceleration

using geodetic astrometric VLBI observations. Science China-Physics Mechanics &

Astronomy, 2012. 55(2): p. 329-332.

7. Xu, M.H., Wang, G.L., and Zhao, M., The solar acceleration obtained by VLBI

observations. Astronomy and Astrophysics, 2012. 544: p. 135.

8. Kopeikin, S.M. and Makarov V.V., Astrometric effects of secular aberration. Astronomical

Journal, 2006. 131(3): p. 1471-1478.

9. Xu, M.H., Wang, G.L., and Zhao, M., A new concept of the International

Celestial Reference Frame: the epoch ICRF. MNRAS (in press).

10. Fey A., Gordon D., Jacobs C., eds, 2009, IERS Technical Note 35, The second realization

of the international celestial reference frame by very long baseline interferometry.

314 IVS 2012 Annual Report
Geospatial Information Authority of Japan Tsukuba Analysis Center

Tsukuba VLBI Analysis Center

Shinobu Kurihara, Kentaro Nozawa

Abstract

The Tsukuba Analysis Center is funded by the Geospatial Information Authority of Japan (GSI).

The c5++ analysis software is regularly used for the IVS-INT2 analysis and the ultra-rapid EOP

experiments.

1. Introduction

The Tsukuba Analysis Center located in Tsukuba, Japan, is operated by the Geospatial Information Authority of Japan (GSI). One of our major roles is to analyze the weekend IVS Intensives

(INT2) using the fully automated VLBI analysis software c5++ developed by the National Institute of Information and Communications Technology (NICT) regularly. It should be noted that

the dUT1 solution becomes available within a few minutes after the end of the last scan of the

session. A 10 Gbps dedicated link to the SINET4 operated by the National Institute of Informatics

(NII) and various process management programs enable the rapid dUT1 derivation. In addition,

the ultra-rapid EOP experiments consisting of 23 regular IVS 24-hour sessions and three dedicated

experiments were implemented.

2. Component Description

2.1. Fully Automated VLBI Analysis Software C5++

c5++, which is a space-geodetic analysis software that handles SLR, GNSS, and VLBI, has

been undergoing several modifications and updates by NICT, and it was installed on some hosts at

the Tsukuba Analysis Center in the summer of 2012 [1]. Since before then, the program c5UT1 that

has partial functionality of c5++ has been used and has provided dUT1 solutions for the regular

INT2 sessions. The newly installed c5++ enables flexible parameterization (X-pole, Y-pole, dUT1,

nutation, station clocks, and troposphere) and SINEX input/output with the covariance matrix.

Currently only two data formats (NGS and KOMB) are supported for analysis, but the import and

export of the new IVS Open DB format will be available in the near future, as well as estimation

of station and source coordinates and troposphere gradients. Now the c5++ solutions have been

evaluated, and consistency with the current c5UT1 solutions has been confirmed. c5++ will start

to be used operationally in place of c5UT1 at the start of 2013.

2.2. Calc/Solve

Calc/Solve has been in continuous use since the early days of VLBI work at GSI. It is used for

the analysis of JADE in its interactive mode and for global analysis in its batch mode, which is

reserved for our internal use and is not used to generate IVS Analysis Center products.

2.3. Potential to Use VieVS

VieVS, which has been developed by the Institute of Geodesy and Geophysics (IGG) of the

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Tsukuba Analysis Center Geospatial Information Authority of Japan

Vienna University of Technology, has already been installed at the Tsukuba Analysis Center, but it

has not been made operational yet [2]. VieVS is quite interesting VLBI analysis software, having

some unique features that are not seen in other software. We would like to start utilizing the

features in 2013.

2.4. Analysis Center Hardware Capabilities

Both c5++ and Calc/Solve are installed on some general purpose and commercially-produced

Linux computers (Table 1). MATLAB as a platform for VieVS is also available on a host. Individual RAIDs are mounted on each host for storing a lot of VLBI data files, e.g. Mark III databases.

Table 1. Analysis Center hardware capabilities.

Number of servers four for VLBI analysis (c5+, Calc/Solve, and VieVS)

Operating System CentOS version 5.2, 5.4, or 5.5

CPU Intel Xeon 3.80 GHz quad CPU / Intel Xeon

3.00 GHz quad CPU / Intel Xeon 2.83 GHz quad CPU

Total storage capacity individual RAIDs: 1.22 Tbytes in total

3. Staff

The technical staff members in the Tsukuba Analysis Center are:

• Shinobu Kurihara: correlator/analysis chief, software design and development.

• Kentaro Nozawa (AES): correlator/analysis operator, software development.

• Takashi Nishikawa (AES): correlator/analysis operator.

Kensuke Kokado, who was correlator/analysis chief until the end of May 2012, moved to another

division.

4. Analysis Operations

4.1. IVS-INT2

In 2012, 107 IVS-INT2 sessions were correlated at the Tsukuba VLBI Correlator that is also

operated by GSI. 83 of them observed the Tsukuba-Wettzell baseline. The observed data at

Wettzell is transferred to the correlator in real-time with the VDIF/SUDP protocol. The correlated

data is rapidly analyzed by c5++ as soon as all of the correlator output becomes available, and

then a dUT1 solution is derived. Figure 1 shows in how many sessions their analyses are completed

within a short latency. Due to some sort of trouble on the station’s side, nine sessions are excluded

from the total number of sessions. 90% of the total sessions derived dUT1 solutions within four

minutes after the end of the last scan, and 50% were within two minutes. The ending time of the

IVS-INT2 sessions is 8:30 UT on every Saturday and Sunday. Thus, the dUT1 solution becomes

available at 8:40 UT at the latest. This is really an advantage of the Tsukuba Analysis Center.

316 IVS 2012 Annual Report
Geospatial Information Authority of Japan Tsukuba Analysis Center

The eopi file that is a product of the Intensives from the Analysis Center is submitted immediately after the analysis and becomes accessible as an IVS product. The U.S. Naval Observatory

(USNO) operates as the IERS Rapid Service/Prediction Center, which is responsible for providing

earth orientation parameters on a rapid turnaround basis, primarily for real-time users and others

needing the highest quality EOP information sooner than that available in the final EOP series.

0

10

20

30

40

50

60

70

80

90

100

0 1 2 3 4 5 6 7 8 9 10

Number of sessions (%) 

Latency (min.) 

Figure 1. Latency vs. percentage of sessions (out of 74 sessions, excluding nine sessions with some sort of

trouble during these sessions).

4.2. Ultra-rapid EOP Sessions

This session type started in 2007 as a joint project of Japan (Tsukuba and Kashima) and

Fennoscandia (Onsala and Mets ̈ahovi). It aims to derive consecutive time series of EOP as soon as

possible taking advantage of the strategy which is that the observed data is sent in real-time via

the international optical fiber backbone to Tsukuba, where the data is correlated and analyzed in

near real-time. c5++ is used in the whole analysis (see section 2.1).

Nowadays four countries — Japan, Sweden, Australia, and South Africa — are involved in

association with Hobart and HartRAO, which recently joined in 2012. 23 regular IVS 24-hour

sessions that involved at least two stations from Hobart, HartRAO, Onsala, and Tsukuba were

operated with the ultra-rapid strategy. Eight which were originally scheduled with HartRAO,

Onsala, and Tsukuba added Hobart as the fourth station by using the tag-along function of SKED

and performed with a four-station/six-baseline network in order to derive not only dUT1 but also

two polar motion parameters more accurately with a very low latency by better network geometry.

However, since the regular IVS 24-hour session schedule is optimized for networks consisting

of the originally involved stations, the network geometry throughout the whole duration of the

experiment does not improve obviously even if Hobart is added. Therefore we planned three

dedicated experiments and carried out them from November to December (Table 2).

In particular, the ultra-rapid processing in UR1203, which had a duration of 35 hours, worked

very well for most of the time except the periods when some sort of trouble on the station’s side

happened. Figure 2 presents time series of EOP derived from this experiment. You can see some

points with a large error bar and gaps, which might be caused by failure in the analyses in this

period.

IVS 2012 Annual Report 317
Tsukuba Analysis Center Geospatial Information Authority of Japan

Table 2. The ultra-rapid EOP experiments with dedicated schedules that are optimized for all involved

stations in 2012.

Experiment Date Time Duration Stations #obs. (skd) #obs. (cor)

UR1201 NOV29 18:00 24 HbHtTs 822 382

UR1202 DEC06 18:00 24 HbHtTs 482 363

UR1203 DEC17 07:30 35 HbHtOnTs 1033 846

 160

 180

 200

 220

 240

 260

 280

 300

 320

 340

08:00 12:00 16:00 20:00 00:00 04:00 08:00 12:00 16:00

UT1-UTC [msec]

Time (December 17-18, 2012)

prediction

UT1-UTC

-0.2

-0.1

0.0

0.1

0.2

0.3

0.4

0.5

0.6

08:00 12:00 16:00 20:00 00:00 04:00 08:00 12:00 16:00

Polar motion [arcsec]

Time (December 17-18, 2012)

prediction

X-pole

Y-pole

Figure 2. The time series of EOP estimation derived from the UR1203 experiment with the prediction

(Rapid Service/Prediction of Earth Orientation, finals2000A.daily).

5. Outlook

Analyses of all INT2 sessions are being performed as in 2011, and dUT1 solutions will be

produced with a low latency. In addition, the ultra-rapid EOP experiments will be continued.

References

[1] Hobiger, T., et al.: Fully automated VLBI analysis with c5++ for ultra-rapid determination of UT1,

Earth Planets Space, 62, 933-937, 2010.

[2] B ̈ohm, J., et al.: The New Vienna VLBI Software VieVS, In Proceedings of IAG Scientific Assembly

2009, International Association of Geodesy Symposia Series, 136, edited by S. Kenyon, M. C. Pacino,

and U. Marti, doi: 10.1007/978-3-642-20338-1 126, 1007-1011, 2012.

318 IVS 2012 Annual Report
United States Naval Observatory USNO VLBI Analysis Center

U.S. Naval Observatory VLBI Analysis Center

David A. Boboltz, Alan L. Fey, Nicole Geiger, Chris Dieck, David M. Hall

Abstract

This report summarizes the activities of the VLBI Analysis Center at the United States Naval

Observatory for the 2012 calendar year. Over the course of the year, Analysis Center personnel continued analysis and timely submission of IVS-R4 databases for distribution to the IVS. During the 2012

calendar year, the USNO VLBI Analysis Center produced two VLBI global solutions designated as

usn2012a and usn2012b. Earth orientation parameters (EOP) based on this solution and updated by

the latest diurnal (IVS-R1 and IVS-R4) experiments were routinely submitted to the IVS. Sinex files

based upon the bi-weekly 24-hour experiments were also submitted to the IVS.

During the 2012 calendar year, Analysis Center personnel continued a program to use the Very Long

Baseline Array (VLBA) operated by the NRAO for the purpose of measuring UT1–UTC. Routine daily

1-hour duration Intensive observations were initiated using the VLBA antennas at Pie Town, NM and

Mauna Kea, HI. High-speed network connections to these two antennas are now routinely used for

electronic transfer of VLBI data over the Internet to a USNO point of presence. A total of 270 VLBA

Intensive experiments were observed and electronically transferred to and processed at USNO in 2012.

1. Introduction

The USNO VLBI Analysis Center is supported and operated by the United States Naval

Observatory (USNO) in Washington, DC. The primary services provided by the Analysis Center

are the analysis of diurnal experiments and the production of periodic VLBI global solutions for

estimation of the Terrestrial Reference Frame (TRF), the Celestial Reference Frame (CRF) and

Earth Orientation Parameters (EOP). The Analysis Center continued the submission to the IVS

of Intensive (EOP-I) and session-based (EOP-S) Earth orientation parameters based on USNO

VLBI global solutions. Analysis Center personnel maintain the necessary software required to

continue these services to the IVS including periodic updates of the GSFC CALC/SOLVE software

package. In addition to operational VLBI analysis, Analysis Center personnel are actively engaged

in research related to future reference frames, the electronic transfer of VLBI data, and software

correlation.

2. Current Analysis Center Activities

2.1. IVS Experiment Analysis and Database Submission

During the 2012 calendar year, personnel at the USNO VLBI Analysis Center continued to

be responsible for the timely analysis of the IVS-R4 experiments, with the resulting databases

submitted within 24 hours of correlation for dissemination by the IVS. Analysis Center personnel

continue to be responsible for the analysis and database submission for the periodic IVS-CRF

experiments. In 2012, USNO scheduled and analyzed 16 CRF related experiments including IVSCRF67 through IVS-CRF72, IVS-CRDS56 through IVS-CRDS62, and IVS-CRMS09 through IVSCRMS11. The analyzed databases were submitted to the IVS. Analysis Center personnel also

continued analyzing IVS Intensive experiments for use in the USN-EOPI time series, and they

initiated a new series of Intensive sessions using the VLBA antennas at Pie Town, NM and Mauna

Kea, HI.

IVS 2012 Annual Report 319
USNO VLBI Analysis Center United States Naval Observatory

2.2. Global VLBI Solutions, EOP, and Sinex Submission

USNO VLBI Analysis Center personnel continued to produce periodic global TRF/CRF/EOP

solutions over the course of the 2012 calendar year. Two solutions (usn2012a and usn2012b) were

produced and submitted to the IVS. Analysis Center personnel continued to submit the USNEOPS series, which is based upon the current global solution and updated with new IVS-R1/R4

experiments. The updated EOPS series is submitted to the IVS twice weekly within 24 hours

of experiment correlation and is included in the IERS Bulletin A. Analysis Center personnel also

continued routine submission of Sinex format files based upon the 24-hour VLBI sessions. In

addition to EOPS and Sinex series, USNO VLBI Analysis Center personnel continued to produce

and submit an EOPI series based upon the IVS Intensive experiments.

2.3. Software Correlator

Over the course of the 2012 calendar year, Analysis Center personnel continued the implementation, testing, and evaluation of the DiFX software correlator. In March 2012, a contract was

awarded to the National Radio Astronomy Observatory (NRAO) for the procurement of a full-up

software correlator based on the DiFX software correlator package. In September 2012, Phase

I of the software correlator was delivered to USNO. This correlator has two management nodes

and 33 compute nodes (with each node having a 2.9 GHz dual-core processor with eight cores

per processor for a total of 528 processing cores), and it is capable of simultaneous processing of

data from 15 VLBI antennas at a recorded data rate of 2 Gbps at each antenna. Phase II of the

software correlator contract is expected to be delivered in 2013 and will double the processing

power of the Phase I correlator. Post-correlation calibration and analysis of software correlated

data is now routinely performed using the standard geodetic data reduction path including the use

of the Haystack Observatory Post-processing System (HOPS) for data calibration and the GSFC

CALC/SOLVE package for data analysis.

Analysis Center personnel continue to interface with colleagues from various institutions within

the DiFX consortium and attended the DiFX workshop at the ATNF in Sydney, Australia in

September 2012. Work continued on a graphical user interface (GUI) to the software correlator.

A beta version was released to the user community in June 2012.

2.4. VLBA Intensive Experiments

During the 2012 calendar year, Analysis Center personnel continued a program to use the Very

Long Baseline Array (VLBA) operated by the NRAO for the purpose of measuring UT1–UTC.

Routine daily Intensive sessions of one-hour duration were initiated using the VLBA antennas at

Pie Town, NM and Mauna Kea, HI. High-speed network connections to these two antennas are

now routinely used for electronic transfer of VLBI data over the Internet to a USNO point of

presence.

These VLBA Intensive sessions use the newly available digital backends with sixteen 32 MHz

wide channels at a data rate of 2 Gbps. VLBA Intensive sessions run for 40 minutes with approximately 12 seconds per scan on source resulting in roughly 30-35 scans per session. The 12-second

scan length allows the data size to be ∼100 GB per station per session, which makes for more

manageable e-transfers. The VLBA Intensive sessions are correlated on the new USNO DiFX

software correlator. Mark IV style output is generated using the difx2mark4 software and the data

320 IVS 2012 Annual Report
United States Naval Observatory USNO VLBI Analysis Center

are fringe-fitted using FOURFIT/HOPS. Geodetic style databases are generated with DBEDIT

and analyzed within CALC/SOLVE. A total of 270 VLBA Intensive experiments were observed

and electronically transferred to and processed at USNO in 2012. Once fully operational, these

VLBA Intensive sessions will be scheduled as IVS-INT4, and data will be released to the IVS for

community-wide distribution.

Figure 1 shows the differences between the VLBA MK-PT baseline UT1–UTC results and

IERS C04 from October 15, 2011 through January 31, 2012. Differences between IERS C04 and

the USN-EOPI and USN-EOPS series are also shown for comparison.

Figure 1. Differences in UT1-UTC between data from the VLBA Intensive test sessions using the MKPT baseline and IERS C04. Also shown are differences between IERS C04 and both the USN-EOPI and

USN-EOPS standard series for comparison. Error bars are 1σ formal uncertainties.

3. Staff

The staff of the VLBI Analysis Center is drawn from individuals in both the Astrometry and

Earth Orientation departments at the U.S. Naval Observatory. The staff and their responsibilities

are as follows:

IVS 2012 Annual Report 321
USNO VLBI Analysis Center United States Naval Observatory

Name Responsibilities

David Boboltz VLBA Intensive program; software correlator implementation; VLBI

data analysis.

Alan Fey Periodic global CRF/TRF/EOP solutions and comparisons; CRF

densification research; software correlator implementation; VLBI

data analysis.

Nicole Geiger software correlator implementation; VLBI data analysis; EOP,

database, and Sinex submission.

Chris Dieck software correlator implementation; VLBI data analysis; EOP,

database, and Sinex submission.

David Hall Hardware correlator interface; software correlator implementation;

VLBI data analysis.

4. Future Activities

The following activities for 2013 are planned:

• Continue analysis and submission of IVS-R4 experiments for dissemination by the IVS.

• Continue the production of periodic global TRF/CRF/EOP solutions and the submission of EOP-S estimates to the IVS updated by the IVS-R1/R4 experiments.

• Continue submission of Sinex format files based on the 24-hour experiments and begin

production of a Sinex series based upon the Intensive experiments.

• Continue the analysis of IVS Intensive experiments and the submission of EOP-I estimates to the IVS.

• Continue the scheduling, analysis, and database submission for IVS-CRF, IVS-CRMS,

and IVS-CRDS experiments.

• Continue testing and evaluation of the USNO implementation of the DiFX software

correlator. Streamline pre- and post-correlation processing.

• Continue routine electronic transfer, correlation, post-processing, and analysis of VLBI

Intensive data from the MK and PT VLBA stations.

• Continue graphical user interface (GUI) development for the USNO implementation of

the DiFX software correlator.

322 IVS 2012 Annual Report
United States Naval Observatory USNO Analysis Center for Source Structure

USNO Analysis Center for Source Structure Report

Alan L. Fey, David A. Boboltz, Ralph A. Gaume

Abstract

This report summarizes the activities of the United States Naval Observatory Analysis Center for

Source Structure for the 2012 calendar year and the activities planned for the year 2013.

1. Analysis Center Operation

The Analysis Center for Source Structure is supported and operated by the United States

Naval Observatory (USNO). The charter of the Analysis Center is to provide products directly

related to the IVS determination of the “definition and maintenance of the celestial reference

frame.” These include, primarily, radio frequency images of International Celestial Reference

Frame (ICRF) sources, intrinsic structure models derived from the radio images, and an assessment

of the astrometric quality of the ICRF sources based on their intrinsic structure.

The Web server for the Analysis Center is hosted by the USNO and can be accessed by pointing

your browser to

http://rorf.usno.navy.mil/ivs saac/

The primary service of the Analysis Center is the Radio Reference Frame Image Database

(RRFID), a Web accessible database of radio frequency images of ICRF sources. The RRFID

contains 7,279 Very Long Baseline Array (VLBA) images of 782 sources at radio frequencies of

2.3 GHz and 8.4 GHz. Additionally, the RRFID contains 1,867 images of 285 sources at frequencies

of 24 GHz and 43 GHz. The RRFID can be accessed from the Analysis Center Web page or directly

at

http://rorf.usno.navy.mil/rrfid.shtml

The RRFID also contains 74 images of 69 Southern Hemisphere ICRF sources using the Australian Long Baseline Array (LBA) at a radio frequency of 8.4 GHz.

Images of ICRF sources can also be obtained from the Bordeaux VLBI Image Database (BVID)

at

http://www.obs.u-bordeaux1.fr/m2a/BVID/

2. Current Activities

VLBA high frequency sessions BL166A (2011JAN14) and BL166B (2011FEB05) were calibrated and imaged, adding 161 images at 24 GHz to the RRFID including three sources not

previously imaged.

We maintained the Radio Reference Frame Image Database as a Web accessible database of

radio frequency images of ICRF sources.

3. Staff

The staff of the Analysis Center is drawn from individuals who work at the USNO. The staff

are Alan L. Fey, David A. Boboltz, and Ralph A. Gaume.

IVS 2012 Annual Report 323
USNO Analysis Center for Source Structure United States Naval Observatory

4. Future Activities

The Analysis Center currently has a program of active research investigating the effects of

intrinsic source structure on astrometric position determination. Results of this program are

published in the scientific literature.

The following activities for 2013 are planned:

• Continue imaging and analysis of VLBA 2.3/8.4/24/43 GHz experiments.

• Maintain the Radio Reference Frame Image Database (RRFID) as a Web accessible database

of radio frequency images of ICRF sources.

5. Relevant Publications

Publications of relevance to Analysis Center activities were:

• “Relativistic Jets in the Radio Reference Frame Image Database. II. Blazar Jet Accelerations

from the First 10 Years of Data (1994-2003),” Piner, B. G., Pushkarev, A. B., Kovalev, Y.

Y., Marvin, C. J., Arenson, J. G., Charlot, P., Fey, A. L., Collioud, A., & Voitsik, P. A.

2012, ApJ, 758, 84.

• “Characterization of long baseline calibrators at 2.3 GHz,” Hungwe, F., Ojha, R., Booth, R.

S., Bietenholz, M. F., Collioud, A., Charlot, P., Boboltz, D., & Fey, A. L. 2011, MNRAS,

418, 2113.

• “The Position/Structure Stability of Four ICRF2 Sources,” Fomalont, Ed, Johnston, Kenneth, Fey, Alan, Boboltz, Dave, Oyama, Tamoaki, & Honma, Mareki 2011, AJ, 141, 91.

324 IVS 2012 Annual Report
Department of Geodesy and Geoinformation/Vienna University of Technology VIE Analysis Center

Vienna Special Analysis Center Annual Report 2012

Johannes B ̈ohm,Sigrid B ̈ohm,Hana Kr ́asn ́a,Matthias Madzak,Tobias Nilsson,Lucia Plank,

Virginia Raposo, Harald Schuh, Benedikt Soja, Jing Sun, Kamil Teke, Claudia Tierno Ros

Abstract

The main activities of the VLBI group at the Department of Geodesy and Geoinformation of the

Vienna University of Technology were related to the development of the Vienna VLBI Software VieVS

(http://vievs.hg.tuwien.ac.at/) and its application for various studies. For example, we dealt with

scheduling, satellite tracking, and the estimation of geodynamical and astronomical parameters from

VLBI observations. One highlight was the release of VieVS 2.0 just before the third VieVS User

Workshop in September 2012.

1. General Information

Since October 2012, we have been part of the Department of Geodesy and Geoinformation

(GEO) in the Faculty of Mathematics and Geoinformation of the Vienna University of Technology.

GEO is divided into seven research units, one of them focusing on advanced geodesy (mathematical

and physical geodesy, space geodesy). Within this research unit, one group (out of three) is dealing

with geodetic VLBI.

Figure 1. Excursion to Wettzell in June 2012 with staff members and students of the master course.

2. Staff

Personnel at GEO associated with the IVS Special Analysis Center in Vienna and their main

research fields and activities are summarized in Table 1.

IVS 2012 Annual Report 325
VIE Analysis Center Department of Geodesy and Geoinformation/Vienna University of Technology

Table 1. Staff members ordered alphabetically.

Johannes B ̈ohm VLBI2010, atmospheric effects

Sigrid B ̈ohm Earth orientation, global solution

Hana Kr ́asn ́a global solution, solid Earth tides, sources

Matthias Madzak GUIs and special files in VieVS

Tobias Nilsson VLBI2010, troposphere

Lucia Plank satellite tracking with VLBI

Virginia Raposo celestial reference frame

Harald Schuh (moved to GFZ in November 2012) IVS activities (Acting Chair)

Benedikt Soja Sun corona studies with VLBI

Jing Sun scheduling and simulation

Kamil Teke (from July 2012) least-squares, tropospheric parameters

Claudia Tierno Ros European VLBI sessions, simulations

3. Current Status and Activities

• Vienna VLBI Software VieVS Development

A new graphical user interface (GUI) has been developed which contains all components in

one window, from scheduling to the global solution. The GUI also includes a plotting tool

where users can visualize analysis statistics and estimated parameters, and in a beta-version

we provide the possibility of plotting station networks, covariance matrices, baseline length

repeatabilities, or scheduling information. All static information for the stations is now

stored in one superstation file, which makes the reading of many different files from different

directories obsolete. In the future, we will work on a similar file for sources containing static

information for radio sources. Additionally, a scan-wise update mode has been added to

the least-squares tool in VieVS, which allows the analysis of huge observation files. More

information about the Vienna VLBI Software and the most recent release 2.0 (VieVS, B ̈ohm

et al., 2012 [1]) can be found at http://vievs.hg.tuwien.ac.at.

• Global solutions with VieVS

The parameter setup and the global solution of VieVS were modified in order to estimate

coefficients of tidal variations in the Earth rotation parameters. The altered version of

the global solution enables the determination of 76 diurnal and semi-diurnal terms in polar

motion and UT1 and of 63 zonal terms with periods from five days to 18.6 years in UT1. Due

to certain restrictions concerning the calculation of the a priori UT1 values, the zonal tidal

variations were derived only up to the monthly period from a global solution using selected

sessions from 1984 to 2011.

Additionally, we determined solid Earth tide parameters, Love and Shida numbers, from

VLBI global solutions with VieVS. We estimated complex frequency-dependent Love and

Shida numbers of degree two from 27 years of geodetic VLBI observations. The estimates

of the Love and Shida numbers are notably improved in terms of precision and accuracy

(Kr ́asn ́a et al., 2013 [2]). Another area of research was a comprehensive study on free core

nutation (FCN). We computed the period of the FCN in a rigorous least-squares adjustment

326 IVS 2012 Annual Report
Department of Geodesy and Geoinformation/Vienna University of Technology VIE Analysis Center

of VLBI data simultaneously from two phenomena: from the resonance effect in solid Earth

tides and from the nutation motion of the Earth rotation axis (Kr ́asn ́a, 2013b [3]).

13.0 13.5 14.0 14.5 15.0 15.5 16.0 16.5

0.4

0.6

0.8

1

1.2

Real part of h21

Q1 O1 M1

π

1

P1

K1

K ́1

ψ1

φ

1

θ

1

J

1

Oo1

Figure 2. Real part of the Love numbers versus frequency in degrees/hour for twelve diurnal tides estimated

from two solutions with different a priori ocean tidal loading models (FES2004 in red, AG06a in light blue).

• Combining VLBI and Ring Laser Data

We have continued investigating the possibilities for combining data from VLBI and ring

laser gyroscopes for the estimation of Earth rotation parameters (Nilsson et al., 2012a [4] and

Nilsson et al., 2012b [5]). For the CONT11 campaign we combined VLBI with observations

from the G ring laser in Wettzell. The combination did work; however, since only one ring

laser was used, there was only a minor improvement in the results compared to what is

achieved by VLBI only. One ring laser only senses one component of the Earth rotation

vector; thus at least three ring lasers are needed in order to sense the full Earth rotation

vector. We made simulations testing the impact of having more than one ring laser. If every

VLBI station in CONT11 was equipped with a ring laser similar to that in Wettzell, an

improvement of about 25% could be expected.

• VLBI Satellite Tracking

The employment of the VLBI technique to near Earth satellites is a research topic in Vienna.

Therefore, various parts of VieVS were extended to be applicable for moving sources at finite

distance. In particular, this includes the scheduling of satellite targets, the processing of

an alternative observation file, the delay modeling, and the estimation part. In combination

with the VieVS simulator, observations to satellites can now be simulated, and investigations

concerning observation interval, tracking network, and expected accuracies have been started.

• Scheduling with VieVS

The module vie sched is designed to fully exploit the possibilities of the future VLBI2010

system. In 2012, vie sched was validated by scheduling real IVS sessions. We generated seven

sessions (RD1204 to RD1210) for a solar corona study on the basis of the RD session setup.

All these sessions have been observed successfully, and the data files are already available in

the IVS Data Centers after being correlated at Haystack and analyzed by Goddard. Studies

on the optimum scheduling strategies are still ongoing, e.g., we assess the application of

source-based schedules compared to station-based schedules.

• European VLBI Sessions

As a Special Analysis Center for Specific Observing Sessions (SAC-SOS), we have analyzed

IVS 2012 Annual Report 327
VIE Analysis Center Department of Geodesy and Geoinformation/Vienna University of Technology

the European VLBI sessions, and we have used them for the investigation of crustal motion

in Europe.

• Comparison of tropospheric parameters

We compared zenith total delays and troposphere gradients as determined from VLBI,

GNSS, and DORIS observations at co-located sites in the CONT campaigns in October

2002, September 2005, August 2008, and September 2011. We did not find an improved

standard deviation between the series from the various techniques over time, nor did we find

a seasonal dependence. On the other hand, the agreement and thus the accuracy of the

troposphere parameters clearly depend on the latitude and the amount of humidity in the

atmosphere.

4. Future Plans

In 2013 we will continue the development of VieVS, with special focus on satellite tracking,

scheduling, and the estimation of terrestrial and celestial reference frames. Additionally, we will

contribute to the ongoing activities within VLBI2010.

Acknowledgements

We are very grateful to the Austrian Science Fund (FWF) for supporting our work by projects

P21049 (‘SCHED2010’), P23143 (‘Integrated VLBI’), and P24813 (‘SPOT’). We also acknowledge

the German Research Foundation (DFG) for funding projects SPEED2 (SCHU 1103/3-2) and

D-VLBI (SCHU 1103/4-1).

References

[1] B ̈ohm, J., B ̈ohm, S., Nilsson, T., Pany, A., Plank, L., Spicakova, H., Teke, K., Schuh, H., The New

Vienna VLBI Software, Proceedings of the 2009 IAG Symposium, Buenos Aires, Argentina, 31 August

2009 - 4 September 2009, International Association of Geodesy Symposia Series, Vol. 136, ed. by

Kenyon, S., Pacino, M.C., Marti, U., ISBN 978-3-642-20337-4, pp. 1007-1012, 2012.

[2] Kr ́asn ́a, H., B ̈ohm, J., Schuh, H., Tidal Love numbers estimated by geodetic VLBI, submitted to

Journal of Geodynamics, 2013a.

[3] Kr ́asn ́a, H., Estimation of solid Earth tidal parameters and FCN with VLBI, PhD thesis TU Vienna,

158 pages, 2013b.

[4] Nilsson, T., B ̈ohm, J., Schuh, H., Schreiber, U., Gebauer, A., Kl ̈ugel, T., Combining VLBI and ring

laser observations for determination of high frequency Earth rotation variation, J. Geodyn. Vol 62, pp.

69-73, doi:10.1016/j.jog.2012.02.002, 2012a.

[5] Nilsson, T., B ̈ohm, J., Schuh, H., Determination of Earth rotation by combining VLBI and ring laser

observations, Proc. Journes 2011, ed. by Schuh, H., B ̈ohm, S., Nilsson, T., Capitaine, N., pp 152-155,

2012b.

328 IVS 2012 Annual Report
Technology 

Development 

Centers

Geodetic Survey Division, Natural Resources Canada Canadian TD Center

Canadian VLBI Technology Development Center

Bill Petrachenko

Abstract

The Canadian VLBI Technology Development Center (TDC) is involved in activities related to the

realization of the VLBI2010 Global Observing System (VGOS).

1. Introduction

The Canadian TDC is a collaborative effort of the National partners interested in the advancement of VLBI technology, namely the Geodetic Survey Division of Natural Resources Canada

(GSD/NRCan) and the Dominion Radio Astrophysical Observatory (DRAO) of the National Research Council of Canada (DRAO/NRC).

2. VGOS

The Canadian TDC is primarily focused on encouraging the realization of VGOS. This is done

by Bill Petrachenko of NRCan, who is the IVS Technology Development Coordinator, chairman

of the VLBI2010 Committee (V2C), and a member of the VLBI2010 Project Executive Group

(V2PEG). In collaboration with others, this year’s activity focused on the following areas:

• Development of FPGA code for VGOS digital back ends.

• Compilation of a comparison of VGOS digital back ends.

• Compilation of a comparison of VGOS feeds.

• Execution of studies into the mitigation of intra-site RFI from DORIS and SLR aircraft

avoidance radar.

• Analysis of V2PEG RFI survey responses.

3. NRC Activities in Support of the Square Kilometer Array (SKA)

Under the leadership of Brent Carlson, NRC is lead of SKA central signal processing encompassing the SKA correlator, beam former, and pulsar processing.

Under the leadership of Gordon Lacy, a light, stiff, and cost effective 15-m off-axis Gregorian

top-fed composite antenna is being fabricated.

Under the leadership of Gary Hovey, development progresses in the areas of focal plane arrays

and a general purpose high-capacity multi-FPGA signal processing platform.

IVS 2012 Annual Report 331
GSFC Technology Development Center NASA Goddard Space Flight Center

GSFC Technology Development Center Report

Ed Himwich, John Gipson

Abstract

This report summarizes the activities of the GSFC Technology Development Center (TDC) for

2012 and forecasts planned activities for 2013. The GSFC TDC develops station software including

the Field System (FS), scheduling software (SKED), hardware including tools for station timing and

meteorology, scheduling algorithms, and operational procedures. It provides a pool of individuals to

assist with station implementation, check-out, upgrades, and training.

1. Technology Center Activities

The GSFC IVS Technology Development Center (TDC) develops hardware, software, algorithms, and operational procedures. It provides manpower for station visits for training and

upgrades. Other technology development areas at GSFC are covered by other IVS components

such as the GSFC Analysis Center. The current staff of the GSFC TDC consists of John Gipson,

Ed Himwich, and Rich Strand, all employed by NVI, Inc. The remainder of this report covers the

status of the main areas supported by the TDC.

2. Field System

The GSFC TDC is responsible for development, maintenance, and documentation of the Field

System (FS) software package. The FS provides equipment control at VLBI stations. It interprets

the .snp schedule and .prc procedure files (both as prepared by DRUDG from the .skd schedule).

The FS controls the antenna, data acquisition hardware, and related ancillary equipment needed

for making VLBI measurements. All major VLBI data acquisition backends are supported. The

FS is customizable to allow it to control station specific equipment. It is used at almost all the IVS

Network Stations (more than 35) and also at many stations that do VLBI only for astronomical

observations. The only major VLBI facilities not using it are the VLBA and VERA.

There were no new releases of the FS during this period. However, several development projects

were underway:

• Patriot 12-m Interface. Development of the interface for Patriot Antenna Control Unit

(ACU) continued. Several improvements were made including wind-stow automatic recovery

and systematic error reporting with classification of errors and documentation on how to

respond to them.

• DBBC Support. FS support for the DDC personality of the DBBC was developed and tested.

It will be released in early 2013. This will support DBBC use for recording with Mark 5B

recorders and is compatible with “legacy” VLBI observing.

• Miscellaneous. Many small improvements and bug fixes were made for the new release

expected in early 2013. These included a new, faster version of gnplt for antenna gain

calibration and a work-around for the “day 49” kernel “feature”/bug.

332 IVS 2012 Annual Report
NASA Goddard Space Flight Center GSFC Technology Development Center

2.1. Plans for Next Year

Several other improvements are expected in future releases, including:

• Support for RDBE racks

• Support for DBBC PFB personality

• Support for Mark 5C and Mark 6 recorders

• Use of idl2rpc for remote operation

• A complete update to the documentation and conversion to a more modern format that will

be easier to use and maintain

• Conversion of the FORTRAN source to use the gfortran compiler, which will enable use of

the source level debugger, gdb, for development and field debugging

• Chekr support for Mark 5A and Mark 5B systems

• FS Linux 9 (based on Debian wheezy, skipping squeeze) distribution

• Support for periodic firing of the noise diode during observations.

3. SKED and DRUDG

The GSFC TDC is responsible for the development, maintenance, and documentation of SKED

and DRUDG. These two programs are very closely related, and they operate as a pair for the

preparation of the detailed observing schedule for a VLBI session and its proper execution in the

field. In the normal data flow for geodetic schedules, first SKED is run at the Operation Centers

to generate the .skd file that contains the full network observing schedule. Then stations use the

.skd file as input to DRUDG for making the control files and procedures for their station. Catalogs

are used to define the equipment, stations, sources, and observing modes which are selected when

writing a schedule with SKED.

Changes to SKED and DRUDG are driven by changes in equipment and by feedback from the

users. The following summarizes some of the important changes to these programs in 2012.

3.1. SKED Changes

• Release of completely re-written SKED documentation in May 2012. The documentation

includes examples of all commands. The last time the documentation was updated was in

1996.

• Added “source cull” command to remove sources that are only observed a few times in a

session.

• Added support for Mark 5B in VEX files.

• Added list of catalogs used to the schedule file. This will help in debugging.

3.2. DRUDG Changes

• Better support of Mark 5B.

IVS 2012 Annual Report 333
GSFC Technology Development Center NASA Goddard Space Flight Center

• Limited support of DBBCs

• Treatment of VEX as a default file type. Users no longer have to include ‘.vex’ in the filename.

3.3. Plans for Next Year

Plans for next year include:

• In 2012 we began work on making VEX the native format for SKED. We plan to finish this

project in 2013.

• We also plan to expand support for RDBEs and DBBCs. This will involve changes to SKED,

DRUDG, and the catalogs.

• If time permits we will convert SKED to compile using a freely available compiler such as

gfortran.

334 IVS 2012 Annual Report
MIT Haystack Observatory Haystack Technology Center

Haystack Observatory Technology Development Center

Chris Beaudoin, Brian Corey, Arthur Niell, Roger Cappallo, Alan Whitney

Abstract

Technology development at MIT Haystack Observatory were focused on four areas in 2012:

• VGOS developments at GGAO

• Digital backend developments and workshop

• RFI compatibility at VLBI stations

• Mark 6 VLBI data system development

1. VGOS Developments at GGAO

1.1. New Receiver Installation

A proof-of-concept (PoC) VLBI2010 receiver incorporating the Quadruple-ridged flared horn

(QRFH) designed by Caltech was installed in spring 2011. The sensitivity of this PoC receiver met

theoretical expectations in the 3-12 GHz spectrum [1], and it enabled processing of the first geodetic

broadband VLBI observables. However, this system still did not meet the receiver requirements

set forth for VLBI20101. Firstly, the PoC receiver required a post-LNA 3.1 GHz filter to reject

strong RFI that would otherwise saturate the receiver stages following the low-noise amplifier

(LNA); this placed a 3 GHz lower limit on observing frequencies. The PSI-1601 fiber optic links

incorporated in the PoC receiver were not specified for operation above 12 GHz and thus place

a maximum observing sky frequency of 12 GHz. Furthermore, it was unknown at the time that

these fiber optic links exhibited a noise figure that varied significantly (as much as 15 dB) across

the operational frequency range. This introduces a significant loss of dynamic range in the PoC

receiver and complicates the requirement to maintain a uniform 2500 Jy system-equivalent flux

density (SEFD) uniformly across the 2-12 GHz spectrum. Lastly, the PoC frontend was not easy

to service and maintain. In order to truly meet the VLBI2010 specified receiver requirements and

to realize a system that can be easily serviced and maintained, Haystack Observatory initiated a

receiver upgrade project that was focused on addressing these shortcomings. The following outline

presents the high-level requirements of the receiver upgrade:

Upgrade Requirements:

• S-band coaxial downlink

• Electronic control of feed position

– feed positioning uncertainty < 1mm

• Remote servicing of cryogenics

– control vacuum pumps and valve

• Monitor

– Cryogenic refrigerator temperature

1

12-m radio telescope capable of 2-14 GHz observations with SEFD < 2500 Jy [2].

IVS 2012 Annual Report 335
Haystack Technology Center MIT Haystack Observatory

– Supply/return helium pressure

– Air pressure in vacuum vessel

– Crosshead motor electrical drive power

• Ease of receiver removal for servicing outside antenna

• In-situ access to the following components:

– LNA power supply and cryo temperature sensor connectors

– Bias box adjustments/test points

– SMA connectors accessible to 5/16” wrench

– Coupler outputs for RF sampling

– Fiber optic connectors

The receiver upgrade was installed in mid-November 2012, and the sensitivity of the receiver

will be characterized in early 2013.

2. Digital Backend Developments and Intercomparison Workshop

The MIT Haystack Observatory digital engineering staff have also developed new FPGA bitcode

personalities for both the geodesy and astronomy applications. The latest versions are enhancements to the RDBE v1.4, which is a Polyphase Filter Bank (PFB) design producing real-valued

samples in Mark 5B format that is detailed in [1]. The following new RDBE personalities were

developed in 2012:

2.1. RDBE v1.5

This personality quantizes to two bits the full 512 MHz bandwith of each of the two IF input

signals. Each IF input signal is formatted as Mark 5B and output as a TCP/IP transmission over

a single network interface card (NIC) at a data rate of 2 Gbps. Since the data processed for each

IF are transmitted over independent NICs, the aggregate output data rate of this personality is 4

Gbps.

2.2. RDBE v2.0

This personality processes four 512 MHz bandwidth IF input signals. The signal processor

routes all thirty-two 32-MHz channels derived from a pair of IF input signals into a VDIF packet

stream as complex-valued time samples at 4 Gbps. Each 4 Gbps VDIF stream is transmitted over

an independent NIC using TCP/IP network communications, so the aggregate output data rate is

8 Gbps.

2.3. RDBE v2.5

This is a derivative of the RDBE v2.0 that processes only two 512 MHz IF inputs, so the

aggregate output data rate is 4 Gbps. Two IF inputs were deleted from the v2.0 personality to

accommodate the limited resources on the ROACH board so that diagnostics critical to geodetic

VLBI operations could be incorporated into this personality. The diagnostics include:

336 IVS 2012 Annual Report
MIT Haystack Observatory Haystack Technology Center

• Pulse calibration detection from raw 1024 MHz ADC samples

• Synchronous raw capture of the raw ADC samples relative to the RDBE 1 PPS epoch

• MASER-RDBE 1PPS and GNSS-RDBE 1PPS time delay monitoring

2.4. DBE Intercomparison Workshop

The second DBE intercomparison workshop was held at Haystack Observatory on 25-26 October 2012. This workshop provided a forum to explicitly address validation and interoperability

issues among independent global developers of DBE equipment The first such workshop was held

at Haystack Observatory in May 2009. The 2012 workshop took advantage of the completion of a

new Instrumentation Lab at Haystack Observatory that provided the space and signal connections

needed to efficiently support the comparison exercise. The results of this workshop can be found

at the following link:

http://www.haystack.mit.edu/workshop/ivtw/2012.12.17 DBE testing memo final.pdf

3. RFI Compatilibitity at VLBI Stations

The IVS appointed a task force comprised of IVS members Bill Petrachenko, Brian Corey, and

Christopher Beaudoin to evaluate Radio Frequency Interference (RFI) power levels at current and

prospective VLBI stations in order to assess the feasibility of broadband geodetic VLBI observations at these stations. In 2012, stations were requested by the IVS to provide RFI data, and

the task force has conducted preliminary analyses of the data provided by the nine responding

stations. A formal report is expected to be released in 2013.

4. Mark 6 VLBI Data System Development

4.1. First Demonstration of the 16 Gigabit Mark 6 Data Recorder

The availability of inexpensive, commercial-off-the-shelf high performance computing (HPC)

hardware and the parallel development of broadband RF equipment for VLBI has enabled dramatically improved sensitivity for both astronomical and geodetic VLBI. The recognition of these

technological developments provided the motivation for Haystack to develop the Mark 6 16 Gbps

data recorder. In June 2012, a VLBI experiment utilizing a single Mark 6 recorder at each end of

the Westford/GGAO baseline demonstrated 16 Gbps VLBI capability. The correlation amplitudes

and signal-to-noise ratios for the 2 GHz bandwidth, dual polarization observations were within the

expected range [3].

4.2. Current Capabilities

During this report period, operational Mark 6 software was developed, based upon the principles refined in the prototype software, but with an entirely new code base. The Mark 6 software

is currently at revision 2; it splits the workload into modules that are called the control and data

planes. The control plane software, which implements control and monitor functions, is written in

python for ease of maintenance.

The data plane software performs the time-critical tasks of receiving the high-speed packetized

IVS 2012 Annual Report 337
Haystack Technology Center MIT Haystack Observatory

data-streams, organizing them, and writing to disk files, and it is thus coded in C.

Two file-writing modes are supported: a single-file RAID mode and a multiple (1-32) disk

scattered mode. The scattered mode allows disks to record data at whatever rate they are able,

with the intent that it will be more robust in the face of slow or non-functioning disks. There

is currently a stand-alone program, called gather, to recombine the separate files into a seamless

single file for the correlator. It is expected that this functionality will eventually be built into the

file-reading portion of the DiFX correlator, and perhaps into a general-purpose FUSE/Mark 6 file

interface.

References

[1] Beaudoin, C., Corey, B., Niell, A., Whitney, A., (2011) Haystack Observatory Technology Development

Center, IVS 2011 Annual Report, NASA/TP-2012-217505, p. 283-286.

[2] Petrachenko, B.; Niell, A.; Behrend, D.; Corey, B.; Boehm, J.; Charlot, P.; Collioud, A.; Gipson, J.;

Haas, R.; Hobiger, T.; Koyama, Y.; MacMillan, D.; Malkin, Z.; Nilsson, T.; Pany, A.; Tuccari, G.;

Whitney, A.; Wresnik, J., (2009) Design Aspects of the VLBI2010 System. Progress Report of the IVS

VLBI2010 Committee, June 2009, NASA/TM-2009-214180, 2009, 62 pages.

[3] Whitney, A.R., Beaudoin, C.J., Cappallo, R.J., Corey, B.E., Crew, G.B., Doeleman, S.S., Lapsley, D.E.,

Hinton, A.A., McWhirter, S.R., Niell, A.E. Rogers, A.E.E., Ruszczyk, C.A., Smythe, D.L., SooHoo, J.,

Titus, M., (2013) Demonstration of a broadband-RF VLBI system at 16 Gbps data rate per station,

PASP, 125, PP. 196-203.

338 IVS 2012 Annual Report
Institute of Applied Astronomy of Russian Academy of Sciences IAA Technology Development Center

IAA Technology Development Center Report 2012

Dmitry Marshalov, Evgeny Nosov, Leonid Fedotov

1. Development of the Broadband Russian Acquisition System (BRAS)

The new data acquisition system BRAS is being developed for radio telescopes with 13-m

diameter antennas [1]. Researches on the creation of such a system were spent in IAA RAS since

2010 [2]. BRAS is the digital backend terminal, which consists of eight Digital Signal Processing

Units (DSP Units), one Clock Unit, and a Power supply (see Figure 1).

ADC FPGA Optical 

Transceiver

DSP Unit 1 1-1,5GHz

DSP Unit 2 

DSP Unit 8 

1024MHz Clock

Control

Clock Unit 

Power 

supply 

220 V 100MHz 1PPS Ethernet

10GE

10GE

10GE

IF inputs

8

2

1

.

.

.

.

.

.

Figure 1. Simplified structure of BRAS.

BRAS inputs are connected to IF outputs of receivers. In every DSP unit the signal of 1-1.5

GHz frequency range is transformed to a VDIF data stream. After that it is translated to a special

data buffering device by means of 10 G Ethernet for transmission to the correlator. The Clock

unit is intended for formation and distribution of clock signals between all DSP units. Phases of

these signals are synchronized with 100 MHz signal from H-maser and 1PPS from the time scale

of a radio telescope. The distributed control system of BRAS is realized via controllers in the

FPGA of the DSP units and the Clock Unit. The interface for communication with a computer

is located in the Clock Unit. BRAS provides an expansion of channel bandwidth up to 512 MHz

IVS 2012 Annual Report 339
IAA Technology Development Center Institute of Applied Astronomy of Russian Academy of Sciences

and an increase of the total rate of a data stream up to 16 Gbps (Table 1).

Table 1. R1002M DAS specification.

Input frequency range 1 to 1.5 GHz

Number of IF-inputs 8

Number of channels (BBCs) 8

Bandwidth 512 MHz

Output data format VDIF

Output data rate 16 Gbps

Output interface 10 G Ethernet

Control interface Ethernet

Total dimension 376 x 233 x 200 mm

The modular design of BRAS provides convenience of operation. The special case with electromagnetic protection allows placement of this system directly on the antenna near to outputs of

receivers. Two one-channel prototypes of BRAS have been made (see Figure 2). They have been

placed in VLBI Network “Quasar” observatories and connected to IF outputs of usual receivers.

Figure 2. The single channel prototype of BRAS (left) and the interface of control software (right).

It has allowed observation of an experimental VLBI observing session on the Svetloe-Zelenchukskaya

baseline with the recording of signals in 512 MHz frequency bandwidth by means of a Mark 5C

recording system. On eight observed sources with flux densities from 0.1 Jy up to 2 Jy good fringe

responses have been obtained with SNRs from 42 up to 1737 (see Figure 3). Experimental research

has validated the technical and program decisions, which are incorporated into BRAS. The end of

development and the commissioning of BRAS samples is planned for 2015.

340 IVS 2012 Annual Report
Institute of Applied Astronomy of Russian Academy of Sciences IAA Technology Development Center

Figure 3. Amplitude of the search function on the group-delay and fringe-frequency plane, obtained from

the VLBI observation of 0901+697 source at frequency range 8.6-9.1 GHz with 512 MHz bandwidth.

References

[1] A. Finkelstein, A. Ipatov, S. Smolentsev, V. Mardyshkin, L. Fedotov, I. Surkis, D. Ivanov, I. Gayazov.

The New Generation Russian VLBI Network. IVS 2010 General Meeting Proceedings. December 2010.

Pp. 106 – 110.

[2] L. Fedotov, E. Nosov, S. Grenkov, D. Marshalov. The Digital Data Acquisition System for the Russian

VLBI Network of New Generation. IVS 2010 General Meeting Proceedings. December 2010. Pp. 400 –

404.

IVS 2012 Annual Report 341
Technology Development Center at NICT Kashima Space Technology Center, NICT

Technology Development Center at NICT

Kazuhiro Takefuji, Hideki Ujihara

Abstract

The National Institute of Information and Communications Technology (NICT) is developing and

testing VLBI technologies and conducts observations with this new equipment. This report gives an

overview of the Technology Development Center (TDC) at NICT and summarizes recent activities.

1. NICT as IVS-TDC and Staff Members

The National Institute of Information and Communications Technology (NICT) publishes the

newsletter “IVS NICT-TDC News (former IVS CRL-TDC News)” at least once a year in order to

inform readers about the development of VLBI related technology as an IVS Technology Development Center. The newsletter is available at the URL http://www2.nict.go.jp/w/w114/

stmg/ivstdc/news-index.html. Table 1 lists the staff members at NICT who are contributing

to the Technology Development Center.

Table 1. Staff Members of NICT TDC as of January 2013 (listed alphabetically).

HASEGAWA, Shingo HOBIGER, Thomas ICHIKAWA, Ryuichi KAWAI, Eiji

KONDO, Tetsuro KOYAMA, Yasuhiro MIYAUCHI, Yuka SEKIDO, Mamoru

TAKEFUJI, Kazuhiro TSUTSUMI, Masanori UJIHARA, Hideki ————————–

2. Current Status and Activities

We report about the progress of VLBI technology development hereafter.

2.1. Development of Gala-V: Brand New VLBI System

In order to conduct time and frequency transfer with a compact and portable VLBI system,

NICT has been developing a system with a 1.5 meter antenna. As expected, the SEFDs of such

a small antenna are quite large due to the size of the antenna and the ambient temperature of

the receiver. Thus, we are developing a broadband VLBI system, which meets the requirements

of VLBI2010, in order to improve the signal-to-noise ratio of the compact VLBI system. Because

fringes will only be detected with the compact antenna if the second antenna on the baseline is

large enough, our 34-meter antenna will also be upgraded with a broadband system. Before we

started with the development, we measured the RFI conditions, in particular at Kashima, Ibaraki

and Koganei, Tokyo. Figures 1 to 3 show the results of the RFI measurements in a range from

2 GHz to 18 GHz. It can be seen that RFI is very strong on the roof of our headquarters in Tokyo,

but there are still some quiet frequency bands.

We designed the system so that it utilizes only bands in the RFI quiet zones and still provides

a narrow delay function. We fixed the four bands with the zero redundancy array technique

[Moffet(1968)] to be set with frequency differences in a 1:3:2 proportion at 3.2-4.8 GHz, 4.8-6.4

342 IVS 2012 Annual Report
Kashima Space Technology Center, NICT Technology Development Center at NICT

 0.1

 1

 10

 100

 1000

 10000

 100000

 1e+06

 1e+07

 1e+08

 2 4 6 8 10 12 14 16 18

North

East

West

South

Temperature (K)

Freq. (GHz)

Figure 1. RFI survey in Kashima.

 0.1

 1

 10

 100

 1000

 10000

 100000

 1e+06

 2 4 6 8 10 12 14 16 18

Temperature (K)

Freq. (GHz)

North

East

West

Zenith

South

Koganei-11m

Figure 2. RFI survey near the 11-meter antenna in Koganei, Tokyo.

 0.1

 1

 10

 100

 1000

 10000

 100000

 1e+06

 1e+07

 1e+08

 2 4 6 8 10 12 14 16 18

Temperature (K)

Freq. (GHz)

North

East

West

Zenith

South

Koganei-2Goukan

Figure 3. RFI survey on the headquarters roof in Koganei, Tokyo.

IVS 2012 Annual Report 343
Technology Development Center at NICT Kashima Space Technology Center, NICT

GHz, 9.6-11.2 GHz, and 12.8-14.4 GHz, in accordance with frequency ranges of VLBI2010. The

proportion of 1:3:2 shows the differences between the starting values of the four bands, so, (4.8-

3.2 GHz):(9.6-4.8 GHz):(12.8-9.6 GHz) = 1.6 GHz:4.8 GHz:3.2 GHz = 1:3:2. Then we started to

develop the broadband system based on these fixed bands. We named the whole broadband VLBI

system the Gala-V (Galapagos VLBI, which we hope will be a unique evolution in VLBI.) The

effective frequency of the Gala-V bands becomes 4.4 GHz. Also the Gala-V bands have a great

advantage for sampling. In the case of 12.8 GHz, they can be covered with high order sampling

without any analog frequency conversion. Thus, we are developing a new digital A/D sampler

with a sampling speed of 16 GHz. The sampler has two input channels, in order to sample four

bands (1-1.6 GHz wide) at two polarizations.

2.2. Development of Wideband Feeds

Wideband feeds have been developed at NICT, NAOJ (National Astronomical Observatory of

Japan), and universities in Japan for VLBI2010 and SKA. SKA is an international project in radio

astronomy to construct a Square Kilometer Array. In this fiscal year, a novel wideband feed is

being developed for the Kashima 34-m antenna, which will be used for our time and frequency

transfer project and also for radio astronomy.

The feed, named the IGUANA feed, has unique specifications and structure. Operational

frequency bands of the feed are carefully selected to avoid RFI and to satisfy the Gala-V bands

and also the feasibility conditions of a nested feed (Figure 4). The beam size of the feed is nearly

proportional to the operational frequency. Thus the frequencies for each of the nested feeds must

be separated, and the inner feed must be small to prevent it from decreasing the beam patterns

in the outer feed. To receive the four fixed bands and to achieve a sharp beam pattern for the

installation at the Kashima 34-m antenna, a nested feed is the only candidate feed. The lower two

channels are received with the outer IGUANA feed, which is a corrugated horn. Currently we will

use the original C band of the Kashima 34-m to check the effectivness of the nested structure. The

higher two channels are received with the inner IGUANA feed, which is a multi-mode horn and

was derived from designs of multi-mode horns for the ASTRO/VSOP-2 and VERA projects. The

feed is currently being manufactured, after a half year of development with numerical simulations

(Figure 5) and it will hear the first radio noise from the universe in spring 2013.

Figure 4. Conceptual model of the IGUANA feed. Figure 5. Experimental results of the Ey field

in the Mom feed at 4.8 GHz with COMSOL.

344 IVS 2012 Annual Report
Kashima Space Technology Center, NICT Technology Development Center at NICT

2.3. Kashima Flexible Correlator (KFC)

In order to process the growing amount of data that comes along with the implementation of

the VLBI2010 technology, NICT has started to develop the “Kashima Flexible Correlator (KFC)”.

This software correlator is expected to operate in a similar way as other existing correlators by

making use of the Message Passing Interface (MPI) for distribution of the workload across several

computing nodes. KFC will consist of three components (see Figure 6), i.e. one master control,

several data streamers, and a certain number of correlators. The master control oversees the correlation process and manages all other components. Data streamers extract PCAL signals, decode

the sampling data depending on bit resolution and the number of channels, and send the data

to the packetized correlators where auto- and cross-correlation are computed. The initial development will only rely on CPU nodes, but the flexible software design will support heterogeneous

CPU-GPU (or other multi-processor) platforms in the future as well.

Figure 6. Basic concept of KFC.

References

[Moffet(1968)] A. Moffet, “Minimum-redundancy linear arrays,” Antennas and Propagation, IEEE Transactions on, vol. 16, no. 2, pp. 172 – 175, March 1968.

IVS 2012 Annual Report 345
Onsala Space Observatory (OSO), TDC Onsala Space Observatory (OSO)

Onsala Space Observatory – IVS Technology Development Center

Miroslav Pantaleev, Ulf Kylenfall, Leif Helldner, Karl- ̊Ake Johansson, R ̈udiger Haas,

Marianna Ivashina, Oleg Iupikov

Abstract

We report 2012 activities and plans for 2013.

1. Improved Eleven Feed for VLBI2010

We completed the mechanical implementation and prototype fabrication of a new circular

Eleven feed designed by the Antenna Group at Chalmers. Figure 1 shows a photo of the first

prototype. The circular Eleven feed is constructed of curved folded dipoles on a flat printed circuit

board (PCB), with the aim of making this antenna structure more rotationally symmetrical at

a low manufacturing cost. The measurements showed an efficiency of better than −1 dB over a

decade bandwidth of 1.3 − 14 GHz [1].

Figure 1. Left: The circular Eleven feed. Right: Simulated and measured reflection coefficient.

2. Broadband Feed Comparison

Following up on the decision of the IVS Technical Workshop in Wettzell in March 2012, we

did extensive work to compare the performance of two broadband feeds considered for VLBI2010,

the Eleven feed and the QRFH feed. Figure 2 depicts a comparison of the two feeds in a real

VLBI2010 system, a 12-m shaped reflector system manufactured by Intertronics Solutions. The

efficiency plot for the QRFH is calculated via physical optics software at JPL using measured

feed beam patterns as input. The efficiency plot for the Eleven feed is calculated using GRASP

software, also using measured feed patterns as input.

The performance of the feeds is comparable: the Eleven feed has slightly higher efficiency

than the QRFH over the 3 − 5 GHz band, while the QRFH has slightly higher efficiency over the

346 IVS 2012 Annual Report
Onsala Space Observatory (OSO) Onsala Space Observatory (OSO), TDC

2 4 6 8 10 12 14

0.4

0.5

0.6

0.7

0.8

0.9

1

Frequency [GHz]

Efficiency, [%]

Eleven feed

QRFH 

Figure 2. Comparison of the aperture efficiencies of the Eleven feed and the QRFH in a 12-m Cassegrain

shaped reflector antenna system. The red curve shows the results for the Eleven feed, calculated with the

GRASP software using simulated far field patterns. The green curve shows the calculated aperture efficiency

for the QRFH calculated with physical optics software using measured beam patterns.

Figure 3. Left: calculated aperture efficiency and its sub-efficiencies based on a simulated radiation function

when the circular feed illuminates a dual-reflector antenna (including a sub-reflector) with a subtended angle

of 2 × 80◦for the main reflector. Right: geometry of the main and the sub-reflector.

IVS 2012 Annual Report 347
Onsala Space Observatory (OSO), TDC Onsala Space Observatory (OSO)

9 − 11 GHz band. Data for the QRFH for the 12 − 14 GHz were unfortunately not made available

for us for this study.

We have also studied the performance of the Eleven feed in a dual-reflector antenna with subtended angles of 2 × 67◦ and 2 × 80◦

for the sub-reflector and the main reflector, respectively.

The reflection coefficient of the feed is almost not affected by the sub-reflector, and the aperture

efficiency of the whole antenna is calculated, as shown in Figure 3, which indicates a good performance. As reported in [2], Eleven feeds provide an optimal performance when the subtended angle

is from 2×55◦to 2×70◦for the primary reflector systems. By using a dual-reflector arrangement,

the Eleven feed can be used in an optimal performance for different subtended angles.

3. Characterization of the RFI Environment at Onsala

In order to characterize the RFI environment and its potential impact on the future broadband

observations for VLBI2010, we have carried out a survey over the frequency band from 0.85 −

26.5 GHz. The setup used for the test (see Figure 4) was borrowed from Yebes Observatory. The

measurements were performed on the location of the new twin-telescope (see Figure 4).

The measurement setup and the calibration are described in detail in [3]. Each spectrum has

been taken with the analyzer in MAX-HOLD mode (which keeps the maximum measured value)

during one complete turn in azimuth of the antenna. The measurements were performed at 0◦

elevation angle and used vertical polarization. For this antenna location the nearby trees obscure

about 15◦ − 20◦ of the sky above the horizon for more than 180◦in azimuth, but probably the

attenuation and scattering effects are negligible. The full spectrum is presented in Figure 5 to

give an overall impression of the situation. There are interferences from GSM/UMTS links, flight

radars (around 1.1 GHz), GPS signals, WLAN (2.6 GHz), navy radars and military applications

(2.9 − 3.1 GHz), radio links and navy radars (9.25 − 9.5 GHz), and radio links (22.5 GHz).

Figure 4. Left: setup for RFI-measurements. Right: map showing the location of the setup.

348 IVS 2012 Annual Report
Onsala Space Observatory (OSO) Onsala Space Observatory (OSO), TDC

Figure 5. Measured spectrum over the 0.85 − 26.5 GHz band. See text for an explanation of the observed

RFI signals.

4. Improvement of the IF-distribution for S/X-band

As part of the transition to a fully digital system using the DBBC and Mark 5B+ we had to

improve the IF-distribution for S/X-band. An interdigital filter was designed for S-band following [4], using the software CST Microwave Studio and tuning for the proper frequency range. The

results from the simulation matched well to the actually produced filter. An amplification and

attenuation system was installed for X-band to counteract the slope of the bandpass. After several

tests with parallel observations and recording with both the analog system (Mark IV rack and

Mark 5A recorder) and the new digital system (DBBC and Mark 5B+ recorder), fringes could be

found successfully.

5. Outlook and Future Plans

We will continue to work on the development of an Eleven feed for VLBI2010. Starting in

2013, we will extensively work with the establishment of the Onsala Twin Telescope. We also aim

at keeping the 20-m telescope interoperable for geodetic observations with the twin telescope.

References

[1] Yang J, Kildal P-S, Pantaleev M (2012) Overview of Developments of Eleven Feeds. Accepted for

publication at EuCAP 2013, Gothenburg.

[2] Yang J, Pantaleev M, Kildal P-S, Klein B, Karandikar Y, Helldner L, Wadefalk N, Beaudoin C (2012)

Cryogenic 2—13 GHz Eleven feed for reflector antennas in future wideband radio telescopes. IEEE

Transactions on Antennas and Propagation, 59(6), 1918–1934.

[3] Lopez-Perez J-A, Lopez-Fernandez J-A (2011) Radio-frequency interference measurements in Tenerife island for the selection of the RAEGE antenna site, available on-line at http://www1.oan.es/

informes/archivos/IT-OAN-2012-4.pdf.

[4] Metcalf W. S. (1967) Graphs speed design of Interdigital Filters. Microwaves Magazine.

IVS 2012 Annual Report 349

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1. Introduction

The following bibliography compiles papers that were published in the field of geodetic and

astrometric VLBI during the year 2012. There is no distinction between peer-reviewed, reviewed,

or proceedings publications. This list is by no means exhaustive.

2. Geodetic and Astrometric VLBI Publications of 2012

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P. Andersen: “FFI Technology Development Center – Software Development”. In: International

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Y. Aoyama, K. Doi, K. Shibuya: “JARE Syowa Station 11-m Antenna, Antarctica”. In:

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T. Artz, J. Leek, A. Nothnagel, M. Schumacher: “VLBI Intensive Sessions Revisited”.

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S. Bachmann, M. Losler:  ̈ “IVS Combination Center at BKG – Recent Activities”. In: International VLBI Service for Geodesy and Astrometry 2012 General Meeting Proceedings ‘Launching the Next-Generation IVS Network’, edited by D. Behrend and K. Baver, NASA/CP-2012-

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S. Bachmann, M. Losler:  ̈ “IVS Combination Center at BKG – Robust Outlier Detection and

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S. Bachmann, M. Losler, R. Heinkelmann, M. Gerstl:  ̈ “BKG/DGFI Combination Center

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C. Barache, S. Lambert: “Paris Observatory (OPAR) Data Center”. In: International VLBI

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K. Baver, J. Gipson, M.S. Carter, K. Kingham: “Assessment of the First Use of the Uniform

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IVS 2012 Annual Report 369

IVS Information

Terms of Reference

IVS Terms of Reference

1. Summary

1.1. Charter

The International VLBI Service for Geodesy and Astrometry (IVS) is an international collaboration of organizations which operate or support Very Long Baseline Interferometry (VLBI)

components. IVS provides a service which supports geodetic and astrometric work on reference

systems, Earth science research, and operational activities. IVS is a Service of the International

Association of Geodesy (IAG) and of the International Astronomical Union (IAU).

1.2. Objectives

IVS fulfills its charter through the following objectives:

1. foster and carry out VLBI programs. This is accomplished through close coordination of the

participating organizations to provide high-quality VLBI data and products.

2. promote research and development activities in all aspects of the geodetic and astrometric

VLBI technique.

3. advance the education and training of VLBI participants through workshops, reports, and

other means.

4. support the integration of new components into IVS.

5. interact with the community of users of VLBI products. IVS represents VLBI in the Global

Geodetic Observing System (GGOS) of the IAG and interacts closely with the International

Earth Rotation and Reference Systems Service (IERS).

In support of these objectives, IVS coordinates VLBI observing programs, sets performance

standards for VLBI stations, establishes conventions for VLBI data formats and data products,

issues recommendations for VLBI data analysis software, sets standards for VLBI analysis documentation, and institutes appropriate VLBI product delivery methods to ensure suitable product

quality and timeliness. IVS coordinates its activities with the astronomical community because of

the dual use of many VLBI facilities and technologies for both astronomy and astrometry/geodesy.

1.3. Data Products

VLBI data products contribute uniquely to these important activities:

• defining and maintaining the celestial reference frame,

• monitoring universal time (UT1), and

• monitoring the coordinates of the celestial pole (nutation and precession).

These results are the foundation of many scientific and practical applications requiring the use

of an accurate quasi-inertial reference frame, such as high-precision positioning, navigation, and

timing. In addition IVS provides a variety of VLBI products with differing applications, timeliness,

detail, and temporal resolution, such as:

IVS 2012 Annual Report 373
Terms of Reference

• all components of Earth orientation parameters,

• terrestrial reference frame,

• baseline lengths, and

• tropospheric parameters.

All VLBI data and products are publicly available in appropriate formats from IVS Data

Centers.

1.4. Research

The IVS data and products are used for research in many areas of geodesy, geophysics, and

astronomy, such as:

• UT1 and polar motion excitation over periods of hours to decades,

• solid Earth interior research (e.g., mantle rheology, anelasticity, libration, and core modes),

• characterization of celestial reference frame sources and improvements to the frame,

• tidal variations (solid Earth, oceanic, and atmospheric),

• improvements in the terrestrial reference frame, especially in the scale,

• climate studies (e.g., sea level change, deglaciation, and water vapor),

• regional and global geodynamics, and

• general relativity.

To support these activities, there are ongoing research efforts to improve and extend the VLBI

technique in areas such as:

• instrumentation, data acquisition, and correlation,

• data analysis techniques,

• spacecraft tracking and navigation (Earth-orbiting and interplanetary), and

• combination of VLBI data and results with other techniques.

2. Permanent Components

IVS acquires, correlates, and analyzes VLBI data to produce geodetic, astrometric, and other

results that are archived and publicized. IVS accomplishes its objectives through the following

permanent components:

• Network Stations,

• Operation Centers,

• Correlators,

• Analysis Centers,

• Data Centers,

• Technology Development Centers, and

• Coordinating Center.

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Terms of Reference

2.1. Network Stations

The IVS observing network consists of high performance VLBI stations.

• Stations may either be dedicated to geodesy or have multiple uses (including astronomical

observations or satellite tracking applications).

• Stations comply with performance standards for data quality and operational reliability

specified by the Directing Board.

• Stations provide local tie information, timing and meteorological data to the IVS Data Centers.

• VLBI data acquisition sessions are conducted by groups of Network Stations that may be

distributed either globally or over a geographical region.

2.2. Operation Centers

The IVS Operation Centers coordinate the routine operations of specific networks. Operation

Center activities include:

• planning network observing programs,

• supporting the network stations in improving their performance,

• generating the detailed observing schedules for use in data acquisition sessions by IVS Network Stations, and

• posting the observing schedule to an IVS Data Center for distribution and archiving.

IVS Operation Centers follow guidelines from the Coordinating Center for timeliness and schedule file formats.

2.3. Correlators

The IVS Correlators process raw VLBI data. Their other tasks are to:

• provide timely feedback to the Network Stations about data quality,

• jointly maintain the geodetic/astrometric community’s media pool and transport,

• manage electronic data transfer,

• make processed data available to the Data Centers, and

• regularly compare processing techniques, models, and outputs to ensure that data from

different Correlators are identical.

2.4. Analysis Centers

The IVS coordinates VLBI data analysis to provide high-quality products for its users. The

analyses are performed by:

• Operational Analysis Center,

• Associate Analysis Centers,

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Terms of Reference

• Special Analysis Centers for Specific Observing Sessions, and

• Combination Centers.

All Analysis Centers maintain and/or develop appropriate VLBI analysis software.

Operational Analysis Centers are committed to producing results to the specifications of the

IVS Analysis Coordinator and always on schedule to meet IVS requirements. In addition, Operational Analysis Centers may produce Earth orientation parameters, station coordinates, and

source positions in regular intervals.

Operational Analysis Centers place their final results in IVS Data Centers for dissemination

to researchers and other users. They adhere to IVS recommendations for the creation of highquality products and their timely archiving and distribution. Any deviations that an Operational

Analysis Center makes from IVS recommendations are properly documented. Operational Analysis

Centers provide timely feedback about station performance. In addition to these regular services,

Operational Analysis Centers may also perform any task of an Associate Analysis Center.

Associate Analysis Centers are committed to regularly submit specialized products using complete series or subsets of VLBI observing sessions. The analysis is performed for specific purposes

as recognized by the Directing Board, such as exploitation of VLBI data for new types of results,

investigations of regional phenomena, reference frame maintenance, or special determinations of

Earth orientation parameters. The Associate Analysis Centers place their final results in IVS Data

Centers for dissemination to researchers and other users. They adhere to IVS recommendations for

the creation of high-quality products and their timely archiving and distribution. Any deviations

that an Associate Analysis Center makes from IVS recommendations are properly documented.

Special Analysis Centers for Specific Observing Sessions have responsibility for ongoing seriesrelated investigations of one or more existing session types. They perform detailed and comparative

analyses of each session of a series within a reasonable time after correlation. In addition, they

report deficits and technical complications to the observing sites, the correlators, and to the schedulers as well as to the IVS Network and Analysis Coordinators.

Combination Centers are committed to produce combination results from the individual submissions of the Operational Analysis Centers as official IVS products. For this purpose they

monitor the quality of the submissions. The official IVS products include, but are not limited

to, EOP time series derived from session-based results for 24-hour network sessions and one-hour

Intensive sessions. Combination Centers also contribute to the generation of the official IVS input

to International Terrestrial Reference Frame (ITRF) computations. The combination work is done

in a timely fashion and in close cooperation with the IVS Analysis Coordinator.

2.5. Data Centers

The IVS Data Centers are repositories for VLBI observing schedules, station log files, data and

products. Data Centers may mirror other Data Centers to make the distribution and maintenance

of data more efficient and reliable.

• Data Centers are the primary means of distributing VLBI products to users.

• Data Centers work closely with the Coordinating Center and with the Analysis Centers to

ensure that all the information and data required by IVS components are quickly and reliably

available.

Data Centers provide the following functions:

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Terms of Reference

• receive and archive schedule files from Operation Centers,

• receive and archive log files and ancillary data files from the Network Stations,

• receive and archive data products from the Analysis Centers, and

• provide access and public availability to IVS data products for all users.

2.6. Technology Development Centers

The IVS Technology Development Centers contribute to the development of new VLBI technology for improvement of the VLBI technique. They:

• investigate new equipment and approaches,

• develop, test, and document new hardware, firmware, and software for operations,

• assist with deployment, installation, and training for any new approved technology, and

• maintain and support operational equipment.

2.7. Coordinating Center

The IVS Coordinating Center is responsible for coordination of both the day-to-day and the

long-term activities of IVS, consistent with the directives and policies established by the Directing

Board. Specifically, the Coordinating Center monitors, coordinates, and supports the activities

of the Network Stations, Operation Centers, Correlators, Data Centers, Analysis Centers, and

Technology Development Centers. The Coordinating Center works closely with the Technology

Coordinator, the Network Coordinator, and the Analysis Coordinator to coordinate IVS activities.

The primary functions of the Coordinating Center are to:

• coordinate observing programs approved by the Directing Board,

• create and maintain the master schedule of observing sessions in coordination with IVS

Network Stations and astronomical observing programs,

• foster communications among all components of the IVS,

• coordinate the best use of community resources,

• develop standard procedures for IVS components,

• organize training in VLBI techniques,

• organize workshops and meetings, including IVS technical meetings,

• produce and publish reports of activities of IVS components,

• maintain the IVS information system and archive all documents, standards, specifications,

manuals, reports, and publications,

• coordinate IVS outreach and educational activities,

• provide liaison with the IAU, IAG, GGOS, IERS, and other organizations, and

• provide the Secretariat of the Directing Board.

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Terms of Reference

2.8. Becoming a Permanent Component

IVS will accept proposals at any time to become a permanent component. Such proposals will

be reviewed for approval by the Directing Board.

3. Coordinators

Specific IVS activities regarding network data quality, products, and technology are accomplished through the functions performed by three coordinators: a Network Coordinator, an Analysis Coordinator, and a Technology Coordinator.

3.1. Network Coordinator

The IVS Network Coordinator is selected by the Directing Board from responses to an open

solicitation to all IVS components. The Network Coordinator represents the IVS Network Stations

on the Directing Board and works closely with the Coordinating Center. The Network Coordinator

is responsible for stimulating the maintenance of a high quality level in the station operation and

data delivery. The Network Coordinator performs the following functions:

• monitors adherence to standards in the network operation,

• participates in the quality control of the data acquisition performance of the network stations,

• tracks data quality and data flow problems and suggests actions to improve the level of

performance, and

• coordinates software development for station control and monitoring.

The Network Coordinator works closely with the geodetic and astronomical communities who

are using the same network stations for observations. The Network Coordinator takes a leading

role in ensuring the visibility and representation of the network stations.

3.2. Analysis Coordinator

The IVS Analysis Coordinator is selected by the Directing Board from responses to an open

solicitation to the IVS Analysis Centers. The Analysis Coordinator is responsible for coordinating

the analysis activities of IVS and for stimulating VLBI product development and delivery. The

Analysis Coordinator performs the following functions:

• fosters comparisons of results from different VLBI analysis software packages and different

analysis strategies,

• encourages documentation of analysis and combination software,

• participates in comparisons of results from different space geodetic techniques,

• monitors Analysis Centers’ products for high quality results and for adherence to IVS standards and IERS Conventions,

• ensures that IVS analysis and combination products from all Analysis Centers are archived

and are available to the scientific community, and

• supervises the formation of the official IVS products specified by the IVS Directing Board.

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Terms of Reference

The Analysis Coordinator plays a leadership role in the development of methods for generation

and distribution of VLBI products so that the products reach the users in a timely manner. The

Analysis Coordinator interacts with GGOS and the IERS and promotes the use of VLBI products

by the broader scientific community. The Analysis Coordinator works closely with the astronomical

communities who are using some of the same analysis methods and software.

3.3. Technology Coordinator

The IVS Technology Coordinator is selected by the Directing Board from responses to an open

solicitation to the IVS Technology Development Centers. The Technology Coordinator performs

the following functions:

• stimulates advancement of the VLBI technique,

• maintains awareness of all current VLBI technologies and ongoing development,

• coordinates development of new technology among all IVS Technology Development Centers,

• encourages technical compatibility with the astronomical community,

• encourages and oversees development of VLBI-related technical standards,

• coordinates the distribution of and access to technical documents and standards, and

• helps promulgate new technologies to the IVS community.

The Technology Coordinator works closely with the astronomical community, both to maintain

technical compatibility between the geodetic and astronomical communities and to take advantage

of technology development activities in the astronomical community.

4. Directing Board

4.1. Roles and Responsibilities

The Directing Board sets objectives, determines policies, adopts standards, and sets the scientific and operational goals for IVS. The Directing Board exercises general oversight of the activities

of IVS including modifications to the organization that are deemed appropriate and necessary to

maintain efficiency and reliability. The Directing Board may determine appropriate actions to

ensure the quality of the IVS products.

The Directing Board will receive and review proposals for non-IVS research programs that

request IVS resources.

4.2. Membership

The Directing Board consists of representatives of the IVS components, members at-large,

appointed members, and ex officio members. The members are:

Representatives of IVS Components (see below):

• Correlators and Operation Centers representative (1)

• Analysis and Data Centers representatives (2)

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Terms of Reference

• Networks representatives (2)

• Technology Development Centers representative (1)

Elected by the Directing Board upon recommendation from the Coordinating Center (see below):

• Members at large (3)

Selected by Directing Board upon review of proposals from IVS Member Organizations:

• Coordinating Center Director

• Network Coordinator

• Analysis Coordinator

• Technology Coordinator

Appointed members:

• IAU representative

• IAG representative

• IERS representative

Through a reciprocity agreement between IVS and IERS, the IVS serves as the VLBI Technique

Center for IERS, and as such its designated representative(s) serve on the IERS Directing Board.

In turn, the IERS Directing Board designates a representative to the IVS Directing Board. This

arrangement is to assure full cooperation between the two services.

Total number: 16

The members appointed by IAU, IAG, and IERS are not subject to institutional restrictions.

The six members who are the representatives of the IVS components are elected by the IVS

Associate Members. All elected members serve staggered four-year terms once renewable.

At-large members are intended to ensure representation on the Directing Board of each of the

components of IVS and to balance representation from as many countries and institutions and IVS

interests as possible. At-large members serve two-year terms once renewable.

A Directing Board member who departs before the end of his/her term is replaced by a person

selected by the Directing Board. The new member will serve until the next official elections. The

position will then be filled for a full term.

An individual can only serve two consecutive full terms on the Board in any of the representative

and at-large positions. Partial terms are not counted to this limit. After serving two consecutive

full terms, an individual becomes eligible again for a position on the Board following a two-year

absence.

The three Coordinators are selected by the Directing Board on the basis of proposals from

IVS Member Organizations. On a two-thirds vote the Directing Board may call for new proposals

for any Coordinator when it determines that a new Coordinator is required. Coordinators are

encouraged to give at least six months notice before resigning.

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Terms of Reference

4.3. Elections

Election of Board members from the IVS components shall be conducted by a committee of

three Directing Board members, the chair of which is appointed by the chair of the Directing Board.

The committee solicits nominations for each representative from the relevant IVS components. For

each position, the candidate who receives the largest number of votes from the Associate Members

will be elected. In case of a tie the Directing Board will make the decision.

4.4. Chair

The chair is one of the Directing Board members and is elected by the Board for a term

of four years with the possibility of reelection for one additional term. The chair is the official

representative of IVS to external organizations.

4.5. Decisions

Most decisions by the Directing Board are made by consensus or by simple majority vote of the

members present. In case of a tie, the chair decides how to proceed. If a two-thirds quorum is not

present, the vote shall be held later by electronic mail. A two-thirds vote of all Board members is

required to modify the Terms of Reference, to change the chair, or to replace any of the members

before their normal term expires.

4.6. Meetings

The Directing Board meets at least annually, or more frequently if meetings are called by the

chair or at the request of at least three Board members. The Board will conduct periodic reviews

of the IVS organization and its mandate, functions, and components.

5. Definitions

5.1. Member Organizations

Organizations that support one or more IVS components are IVS Member Organizations.

Individuals associated with IVS Member Organizations may become IVS Associate Members.

5.2. Affiliated Organizations

Organizations that cooperate with IVS on issues of common interest, but do not support an

IVS component, are IVS Affiliated Organizations. Affiliated Organizations express an interest in

establishing and maintaining a strong working association with IVS to mutual benefit. Individuals

affiliated with IVS Affiliated Organizations may become IVS Corresponding Members.

5.3. Associate Members

Individuals associated with organizations that support an IVS component may become IVS

Associate Members. Associate Members take part in the election of the incoming members of the

Directing Board representing the IVS components.

IVS 2012 Annual Report 381
Terms of Reference

5.4. Corresponding Members

IVS Corresponding Members are individuals who express interest in receiving IVS publications,

wish to participate in workshops or scientific meetings organized by IVS, or generally are interested

in IVS activities. Ex officio Corresponding Members are the following:

• IAG Secretary General

• Chair of GGOS

• President of IAG Commission 1 – Reference Frames

• President of IAG Commission 3 - Earth Rotation and Geodynamics

• President of IAU Division I – Fundamental Astronomy

• President of IAU Commission 8 – Astrometry

• President of IAU Commission 19 – Rotation of the Earth

• President of IAU Commission 31 – Time

• President of IAU Commission 40 – Radio Astronomy

• President of URSI Commission 52 – Relativity in Fundamental Astronomy

• President of URSI Commission J – Radio Astronomy

Individuals are accepted as IVS Corresponding Members upon request to the Coordinating

Center.

Last modified: 23 September 2011

382 IVS 2012 Annual Report
Members

IVS Member Organizations

(alphabetized by country)

Organization Country

Commonwealth Scientific and Industrial Research Organisation (CSIRO) Australia

Geoscience Australia Australia

University of Tasmania Australia

Vienna University of Technology Austria

Centro de R ́adio Astronomia e Aplica ̧c ̃oes Espaciais Brazil

Dominion Radio Astrophysical Observatory Canada

Geodetic Survey Division, Natural Resources Canada Canada

Instituto Geogr ́afico Militar Chile

Universidad de Concepci ́on Chile

Chinese Academy of Sciences China

Finnish Geodetic Institute, Aalto University Finland

Laboratoire d’Astrophysique de Bordeaux France

Observatoire de Paris France

Bundesamt f ̈ur Kartographie und Geod ̈asie Germany

Deutsches Geod ̈atisches Forschungsinstitut Germany

Forschungseinrichtung Satellitengeod ̈asie, TU Munich Germany

Institut f ̈ur Geod ̈asie und Geoinformation der Universit ̈at Bonn Germany

Max-Planck-Institut f ̈ur Radioastronomie Germany

GeoForschungsZentrum Potsdam Germany

Agenzia Spaziale Italiana Italy

Istituto di Radioastronomia INAF Italy

Politecnico di Milano DIIAR Italy

Geospatial Information Authority of Japan Japan

National Astronomical Observatory of Japan Japan

National Institute of Information and Communications Technology Japan

National Institute of Polar Research Japan

Auckland University of Technology New Zealand

Norwegian Mapping Authority Norway

Astronomical Institute of St.-Petersburg University Russia

Institute of Applied Astronomy Russia

Pulkovo Observatory Russia

Sternberg State Astronomical Institute, Lomonosov Moscow State University Russia

Hartebeesthoek Radio Astronomy Observatory South Africa

Korea Astronomy and Space Science Institute South Korea

National Geographic Information Institute South Korea

Instituto Geogr ́afico Nacional Spain

Chalmers University of Technology Sweden

IVS 2012 Annual Report 383
Members

Organization Country

Karadeniz Technical University Turkey

Laboratory of Radioastronomy of Crimean Astrophysical Observatory Ukraine

Main Astronomical Observatory, National Academy of Sciences, Kiev Ukraine

Jet Propulsion Laboratory USA

NASA Goddard Space Flight Center USA

U. S. Naval Observatory USA

384 IVS 2012 Annual Report
Affiliates

IVS Affiliated Organizations

Organization Country

Australian National University Australia

University of New Brunswick Canada

FOMI Satellite Geodetic Observatory  ̈ Hungary

Joint Institute for VLBI in Europe (JIVE) Netherlands

Westerbork Observatory Netherlands

National Radio Astronomy Observatory USA

IVS 2012 Annual Report 385
Associate Members

IVS Associate Members

Name Institution Country E-mail

Alef, Walter Max-Planck-Institut f ̈ur

Radioastronomie

Germany walef@mpifr-bonn.mpg.de

Amagai, Jun National Institute of Information

and Communications Technology

Japan amagai@nict.go.jp

Andersen, Per

Helge

Norwegian Defence Research

Establishment

Norway per-helge.andersen@ffi.no

Andreeva,

Tatiana

Institute of Applied Astronomy Russia ats@osvtl.spb.ru

Artz, Thomas Institut f ̈ur Geod ̈asie und

Geoinformation der Universit ̈at

Bonn

Germany thomas.artz@uni-bonn.de

Bachmann,

Sabine

Bundesamt f ̈ur Kartographie

und Geod ̈asie

Germany sabine.bachmann@bkg.bund.de

Barache,

Christophe

Observatoire de Paris France Christophe.Barache@obspm.fr

Baudry, Alain Laboratoire d’Astrophysique de

Bordeaux

France baudry@obs.u-bordeaux1.fr

Bauernfeind,

Erhard

Fundamentalstation Wettzell Germany bauernfeind@fs.wettzell.de

Baver, Karen NVI, Inc. USA karen.d.baver@nasa.gov

Beaudoin,

Christopher

MIT Haystack Observatory USA cbeaudoin@haystack.mit.edu

Behrend, Dirk NVI, Inc. USA Dirk.Behrend@nasa.gov

Bellanger,

Antoine

Laboratoire d’Astrophysique de

Bordeaux

France bellanger@obs.u-bordeaux1.fr

Berdnikov,

Anton

Institute of Applied Astronomy Russia anton ipa@rambler.ru

Bergman, Per Onsala Space Observatory Sweden per.bergman@chalmers.se

Bernhart,

Simone

Institut f ̈ur Geod ̈asie und

Geoinformation der Universit ̈at

Bonn

Germany simone@mpifr-bonn.mpg.de

Bertarini,

Alessandra

Institut f ̈ur Geod ̈asie und

Geoinformation der Universit ̈at

Bonn

Germany abertari@mpifr-bonn.mpg.de

Bianco,

Giuseppe

Agenzia Spaziale Italiana Italy giuseppe.bianco@asi.it

Bielmaier,

Ewald

Fundamentalstation Wettzell Germany bielmaier@fs.wettzell.de

Boboltz, David U. S. Naval Observatory USA dboboltz@usno.navy.mil

B ̈ohm, Johannes Department of Geodesy and

Geoinformation/Vienna

University of Technology

Austria johannes.boehm@tuwien.ac.at

386 IVS 2012 Annual Report
Associate Members

Name Institution Country E-mail

B ̈ohm, Sigrid Department of Geodesy and

Geoinformation/Vienna

University of Technology

Austria sigrid.boehm@tuwien.ac.at

Boer, Armin BKG/Project TIGO Chile armin.boer@bkg.bund.de

Bolotin, Sergei NVI, Inc. USA sergei.bolotin@nasa.gov

Bougeard,

Mireille

Observatoire de Paris France mireille.bougeard@obspm.fr

Bourda,

Geraldine

Laboratoire d’Astrophysique de

Bordeaux

France bourda@obs.u-bordeaux1.fr

Buttaccio, Salvo Istituto di Radioastronomia

INAF

Italy s.buttaccio@ira.inaf.it

Cannizzaro,

Letizia

Politecnico di Milano Italy letizia.cannizzaro@polimi.it

Cappallo, Roger MIT Haystack Observatory USA rcappallo@haystack.mit.edu

Carlson, Brent Dominion Radio Astrophysical

Observatory

Canada Brent.Carlson@nrc-cnrc.gc.ca

Carter, Merri

Sue

U. S. Naval Observatory USA msc@nofs.navy.mil

Charlot, Patrick Laboratoire d’Astrophysique de

Bordeaux

France charlot@obs.u-bordeaux1.fr

Chen, Chenyu Urumqi Astronomical

Observatory

China chency@uao.ac.cn

Chen,

Maozheng

Urumqi Astronomical

Observatory

China mzchen@uao.ac.cn

Cho, Jungho Korea Astronomy & Space

Science Institute

Korea jojh@kasi.re.kr

Clark, Thomas NVI, Inc. USA tom.k3io@gmail.com

Collioud,

Arnaud

Laboratoire d’Astrophysique de

Bordeaux

France collioud@obs.u-bordeaux1.fr

Colomer,

Francisco

Instituto Geogr ́afico Nacional Spain f.colomer@oan.es

Colucci,

Giuseppe

Telespazio SpA Italy giuseppe.colucci@e-geos.it

Combrinck,

Ludwig

Hartebeesthoek Radio

Astronomy Observatory

South

Africa

ludwig@hartrao.ac.za

Conway, John Onsala Space Observatory Sweden john.conway@chalmers.se

Corey, Brian MIT Haystack Observatory USA bcorey@haystack.mit.edu

Curtis, Ronald ITT Exelis USA ronald.curtis@exelisinc.com

Dassing, Reiner Bundesamt f ̈ur Kartographie

und Geod ̈asie

Germany reiner.dassing@bkg.bund.de

Davis, Maria U. S. Naval Observatory USA madavis@usno.navy.mil

de-Vicente,

Pablo

Instituto Geogr ́afico Nacional Spain p.devicente@oan.es

Diakov, Alexey Institute of Applied Astronomy Russia ipazel@mail.svkchr.ru

Dickey, John University of Tasmania Australia John.Dickey@utas.edu.au

IVS 2012 Annual Report 387
Associate Members

Name Institution Country E-mail

Diegel, Irv Honeywell TSI USA irv.diegel@honeywell-tsi.com

Doi, Koichiro National Institute of Polar

Research

Japan doi@nipr.ac.jp

Drewes,

Hermann

Deutsches Geod ̈atisches

Forschungsinstitut

Germany drewes@dgfi.badw.de

Dube, Maurice SSAI USA maurice.p.dube@nasa.gov

Elgered, Gunnar Onsala Space Observatory Sweden gunnar.elgered@chalmers.se

Engelhardt,

Gerald

Bundesamt f ̈ur Kartographie

und Geod ̈asie

Germany gerald.engelhardt@bkg.bund.de

Evangelista,

Mark

Honeywell TSI USA mark.evangelista@honeywelltsi.com

Fan, Qingyuan Shanghai Astronomical

Observatory

China qyfan@shao.ac.cn

Fedotov, Leonid Institute of Applied Astronomy Russia flv@ipa.nw.ru

Fey, Alan U. S. Naval Observatory USA afey@usno.navy.mil

Figueroa,

Ricardo

ITT Exelis USA Ricardo.Figueroa@exelisinc.com

Fukuzaki,

Yoshihiro

Geospatial Information

Authority of Japan

Japan fukuzaki@gsi.go.jp

Gambis, Daniel Observatoire de Paris France daniel.gambis@obspm.fr

Garc ́ıa–Espada,

Susana

Instituto Geogr ́afico Nacional Spain s.gespada@oan.es

Gaume, Ralph U. S. Naval Observatory USA rgaume@usno.navy.mil

Gaylard,

Michael

Hartebeesthoek Radio

Astronomy Observatory

South

Africa

mike@hartrao.ac.za

Geiger, Nicole U. S. Naval Observatory USA nicole.geiger@usno.navy.mil

Gipson, John NVI, Inc. USA john.m.gipson@nasa.gov

Gomez, Frank Raytheon USA frank.g.gomez@nasa.gov

G ́omezGonz ́alez,

Jes ́us

Instituto Geogr ́afico Nacional Spain gomez@oan.es

Gordon, David NVI, Inc. USA david.gordon-1@nasa.gov

Govind, Ramesh Geoscience Australia Australia ramesh.govind@ga.gov.au

Gubanov,

Vadim

Institute of Applied Astronomy Russia gubanov@ipa.nw.ru

Gulyaev, Sergei Auckland University of

Technology

New

Zealand

sergei.gulyaev@aut.ac.nz

Haas, R ̈udiger Onsala Space Observatory Sweden rudiger.haas@chalmers.se

Hall, David U. S. Naval Observatory USA dhall@usno.navy.mil

Halsig,

Sebastian

Institut f ̈ur Geod ̈asie und

Geoinformation der Universit ̈at

Bonn

Germany sebastian.halsig@igg.uni-bonn.de

Hammargren,

Roger

Onsala Space Observatory Sweden roger.hammargren@chalmers.se

388 IVS 2012 Annual Report
Associate Members

Name Institution Country E-mail

Hase, Hayo BKG/Project TIGO Chile hayo.hase@bkg.bund.de

Heinkelmann,

Robert

GeoForschungsZentrum Potsdam Germany rob@gfz-potsdam.de

Helldner, Leif Onsala Space Observatory Sweden leif.helldner@chalmers.se

Herrera,

Cristian

TIGO/Universidad de

Concepci ́on

Chile cristian.herrera@tigo.cl

Himwich, Ed NVI, Inc. USA Ed.Himwich@nasa.gov

Hobiger,

Thomas

National Institute of Information

and Communications Technology

Japan hobiger@nict.go.jp

Holst,

Christoph

Institut f ̈ur Geod ̈asie und

Geoinformation der Universit ̈at

Bonn

Germany holst@igg.uni-bonn.de

Hong, Xiaoyu Shanghai Astronomical

Observatory

China xhong@center.shao.ac.cn

Honma, Mareki National Astronomical

Observatory of Japan

Japan honmamr@cc.nao.ac.jp

Huang, Xinyong Shanghai Astronomical

Observatory

China xhuang@center.shao.ac.cn

Hugentobler,

Urs

Fundamentalstation Wettzell Germany urs.hugentobler@bv.tu-muenchen.de

Ichikawa,

Ryuichi

National Institute of Information

and Communications Technology

Japan richi@nict.go.jp

Iddink, Andreas Institut f ̈ur Geod ̈asie und

Geoinformation der Universit ̈at

Bonn

Germany aiddink@uni-bonn.de

Ihde, Johannes Bundesamt f ̈ur Kartographie

und Geod ̈asie

Germany johannes.ihde@bkg.bund.de

Ilijin, Gennadiy Institute of Applied Astronomy Russia igen@ipa.nw.ru

Ipatov,

Alexander

Institute of Applied Astronomy Russia ipatov@ipa.nw.ru

Ipatova, Irina Institute of Applied Astronomy Russia ipatova@isida.ipa.rssi.ru

Ishihara, Misao Geospatial Information

Authority of Japan

Japan misao-i@gsi.go.jp

Ivanov, D.V. Institute of Applied Astronomy Russia ltf@ipa.rssi.ru

Jacobs, Chris Jet Propulsion Laboratory USA chris.jacobs@jpl.nasa.gov

Jike, Takaaki National Astronomical

Observatory of Japan

Japan jike@miz.nao.ac.jp

Johansson,

Karl- ̊Ake

Onsala Space Observatory Sweden karl-ake.johansson@chalmers.se

Johnson, Heidi MIT Haystack Observatory USA hjohnson@haystack.mit.edu

Johnston,

Kenneth

U. S. Naval Observatory USA kjj@astro.usno.navy.mil

Ju, Hyunhee National Geographic

Information Institute

Korea hee919@korea.kr

IVS 2012 Annual Report 389
Associate Members

Name Institution Country E-mail

Karasawa,

Masao

Geospatial Information

Authority of Japan

Japan karasawa@gsi.go.jp

Kaufmann,

Pierre

Centro de R ́adio Astronomia e

Aplica ̧c ̃oes Espaciais

Brazil kaufmann@usp.br

Kawabata,

Ryoji

Geospatial Information

Authority of Japan

Japan r-kawabata@gsi.go.jp

Kawaguchi,

Noriyuki

National Astronomical

Observatory of Japan

Japan kawagu.nori@nao.ac.jp

Kawai, Eiji National Institute of Information

and Communications Technology

Japan kawa@nict.go.jp

Kaydanovsky,

Michael

Institute of Applied Astronomy Russia kmn@ipa.rssi.ru

Kayık ̧cı, Emine

Tanır

Karadeniz Technical University Turkey etanir@ktu.edu.tr

Kharinov,

Mikhail

Institute of Applied Astronomy Russia kharinov@ipa.rssi.ru

Kobayashi,

Hideyuki

National Astronomical

Observatory of Japan

Japan hideyuki.kobayashi@nao.ac.jp

Kokado,

Kensuke

Geospatial Information

Authority of Japan

Japan kokado@gsi.go.jp

Kondo, Tetsuro National Institute of Information

and Communications Technology

Japan kondo@nict.go.jp

Korkin, Edward Institute of Applied Astronomy Russia korkin@isida.ipa.rssi.ru

Koyama,

Yasuhiro

National Institute of Information

and Communications Technology

Japan koyama@nict.go.jp

Kr ́asn ́a, Hana Department of Geodesy and

Geoinformation/Vienna

University of Technology

Austria hana.krasna@tuwien.ac.at

Kronschnabl,

Gerhard

Bundesamt f ̈ur Kartographie

und Geod ̈asie

Germany gerhard.kronschnabl@bkg.bund.de

Kurdubov,

Sergey

Institute of Applied Astronomy Russia ksl@ipa.nw.ru

Kurihara,

Shinobu

Geospatial Information

Authority of Japan

Japan skuri@gsi.go.jp

Kuroda, Jiro Geospatial Information

Authority of Japan

Japan kuroda@gsi.go.jp

Kwak,

Younghee

Korea Astronomy & Space

Science Institute

Korea bgirl02@kasi.re.kr

La Porta, Laura Max-Planck-Institut f ̈ur

Radioastronomie

Germany laporta@mpifr-bonn.mpg.de

Labelle, Ruth SSAI USA ruth.e.labelle@nasa.gov

Lamb, Doug ITT Exelis USA Doug.Lamb@exelisinc.com

Lambert,

S ́ebastien

Observatoire de Paris France sebastien.lambert@obspm.fr

Langkaas, Line Norwegian Mapping Authority Norway Line.Langkaas@kartverket.no

390 IVS 2012 Annual Report
Associate Members

Name Institution Country E-mail

Lanotte,

Roberto

Telespazio SpA Italy roberto.lanotte@e-geos.it

Lavrov, Alexey Institute of Applied Astronomy Russia lexslavrov@yandex.ru

Le Bail, Karine NVI, Inc. USA karine.lebail@nasa.gov

Leek, Judith Institut f ̈ur Geod ̈asie und

Geoinformation der Universit ̈at

Bonn

Germany judith.leek@igg.uni-bonn.de

Li, Bing Shanghai Astronomical

Observatory

China bing@center.shao.ac.cn

Li, Huihua Shanghai Astronomical

Observatory

China hhl@center.shao.ac.cn

Li, Jinling Shanghai Astronomical

Observatory

China jll@center.shao.ac.cn

Liang, Shiguang Shanghai Astronomical

Observatory

China sgliang@center.shao.ac.cn

Lindqvist,

Michael

Onsala Space Observatory Sweden Michael.Lindqvist@chalmers.se

Liu, Xiang Urumqi Astronomical

Observatory

China liux@uao.ac.cn

L ̈osler, Michael Bundesamt f ̈ur Kartographie

und Geod ̈asie

Germany michael.loesler@bkg.bund.de

Long, Jim NASA Goddard Space Flight

Center

USA james.l.long@nasa.gov

Lonsdale, Colin MIT Haystack Observatory USA clonsdale@haystack.mit.edu

Lovell, Jim University of Tasmania Australia Jim.Lovell@utas.edu.au

Lowe, Stephen Jet Propulsion Laboratory USA steve.lowe@jpl.nasa.gov

Lucena, Antonio Centro de R ́adio Astronomia e

Aplica ̧c ̃oes Espaciais

Brazil macilio@roen.inpe.br

Luzum, Brian U. S. Naval Observatory USA brian.luzum@usno.navy.mil

Ma, Chopo NASA Goddard Space Flight

Center

USA chopo.ma-1@nasa.gov

Ma, Jun Urumqi Astronomical

Observatory

China majun@uao.ac.cn

Maccaferri,

Giuseppe

Istituto di Radioastronomia

INAF

Italy g.maccaferri@ira.inaf.it

Machida,

Morito

Geospatial Information

Authority of Japan

Japan machida@gsi.go.jp

MacMillan, Dan NVI, Inc. USA daniel.s.macmillan@nasa.gov

Madzak,

Matthias

Department of Geodesy and

Geoinformation/Vienna

University of Technology

Austria matthias.madzak@tuwien.ac.at

Malkin, Zinovy Pulkovo Observatory Russia malkin@gao.spb.ru

Manabe, Seiji National Astronomical

Observatory of Japan

Japan manabe@miz.nao.ac.jp

IVS 2012 Annual Report 391
Associate Members

Name Institution Country E-mail

Mantovani,

Franco

Istituto di Radioastronomia

INAF

Italy f.mantovani@ira.inaf.it

Mardyshkin,

Vyacheslav

Institute of Applied Astronomy Russia vvm@isida.ipa.rssi.ru

Marshalov,

Dmitry

Institute of Applied Astronomy Russia dam@ipa.rssi.ru

Mathiassen,

Geir

Norwegian Mapping Authority Norway matgei@kartverket.no

Matsuzaka,

Shigeru

Geospatial Information

Authority of Japan

Japan shigeru@gsi.go.jp

McCarthy,

Dennis

U. S. Naval Observatory USA mccarthy.dennis@usno.navy.mil

Melnikov,

Alexey

Institute of Applied Astronomy Russia melnikov@ipa.nw.ru

Michailov,

Andrey

Institute of Applied Astronomy Russia agm@ipa.rssi.ru

Miller, Natalia Pulkovo Observatory Russia natm@gao.spb.ru

Mora-Diaz,

Julian Andres

Deutsches Geod ̈atisches

Forschungsinstitut

Germany mora@dgfi.badw.de

M ̈uskens, Arno Institut f ̈ur Geod ̈asie und

Geoinformation der Universit ̈at

Bonn

Germany mueskens@mpifr-bonn.mpg.de

Mukai, Yasuko Geospatial Information

Authority of Japan

Japan mukai@gsi.go.jp

Nanni, Mauro Istituto di Radioastronomia

INAF

Italy m.nanni@ira.inaf.it

Natusch, Tim Auckland University of

Technology

New

Zealand

tim.natusch@aut.ac.nz

Negusini, Monia Istituto di Radioastronomia

INAF

Italy m.negusini@ira.inaf.it

Neidhardt,

Alexander

Fundamentalstation Wettzell Germany neidhardt@fs.wettzell.de

Nicolson,

George

Hartebeesthoek Radio

Astronomy Observatory

South

Africa

george@hartrao.ac.za

Niell, Arthur MIT Haystack Observatory USA aniell@haystack.mit.edu

Nikitin, Pavel Crimean Astrophysical

Observatory

Ukraine nikitin@crao.crimea.ua

Nilsson, Tobias Department of Geodesy and

Geoinformation/Vienna

University of Technology

Austria tobias.nilsson@tuwien.ac.at

Ning, Tong Onsala Space Observatory Sweden tong.ning@chalmers.se

Nishikawa,

Takashi

Geospatial Information

Authority of Japan

Japan nishikawa@gsi.go.jp

Noll, Carey NASA Goddard Space Flight

Center

USA Carey.Noll@nasa.gov

392 IVS 2012 Annual Report
Associate Members

Name Institution Country E-mail

Nothnagel, Axel Institut f ̈ur Geod ̈asie und

Geoinformation der Universit ̈at

Bonn

Germany nothnagel@uni-bonn.de

Nozawa,

Kentarou

Geospatial Information

Authority of Japan

Japan nozawa@gsi.go.jp

Ogaja, Clement Geoscience Australia Australia Clement.Ogaja@ga.gov.au

Oh, Hongjong National Geographic

Information Institute

Korea stockoh11@korea.kr

Olofsson, Hans Onsala Space Observatory Sweden hans.olofsson@chalmers.se

Opseth, Per

Erik

Norwegian Mapping Authority Norway Per.Erik.Opseth@kartverket.no

Orfei, Sandro Istituto di Radioastronomia

INAF

Italy a.orfei@ira.inaf.it

Pacione, Rosa Telespazio SpA Italy rosa.pacione@e-geos.it

Pazamickas,

Katherine

ITT Exelis USA Katherine.Pazamickas@exelisinc.com

Petrachenko,

William

Natural Resources Canada Canada Bill.Petrachenko@nrc-cnrc.gc.ca

Pettersson, Lars Onsala Space Observatory Sweden lars.pettersson@chalmers.se

Pino, Pedro TIGO/Universidad de

Concepci ́on

Chile pedro.pino@tigo.cl

Plank, Lucia Department of Geodesy and

Geoinformation/Vienna

University of Technology

Austria lucia.plank@tuwien.ac.at

Pl ̈otz, Christian Bundesamt f ̈ur Kartographie

und Geod ̈asie

Germany christian.ploetz@bkg.bund.de

Poirier, Michael MIT Haystack Observatory USA mpoirier@haystack.mit.edu

Poutanen,

Markku

Mets ̈ahovi Radio Observatory Finland Markku.Poutanen@fgi.fi

Qian, Zhihan Shanghai Astronomical

Observatory

China qzh@center.shao.ac.cn

Quick, Jonathan Hartebeesthoek Radio

Astronomy Observatory

South

Africa

jon@hartrao.ac.za

Rahimov, Ismail Institute of Applied Astronomy Russia rahimov@osvtl.spb.ru

Redmond, Jay Honeywell TSI USA jay.redmond@honeywell-tsi.com

Reid, Brett University of Tasmania Australia brett.reid@utas.edu.au

Reynolds, John ATNF CSIRO Australia John.Reynolds@csiro.au

Richter, Bernd Bundesamt f ̈ur Kartographie

und Geod ̈asie

Germany bernd.richter@bkg.bund.de

Rioja, Maria Instituto Geogr ́afico Nacional Spain mj.rioja@oan.es

Romero-Wolf,

Andres

Jet Propulsion Laboratory USA andrew.romero-wolf@jpl.nasa.gov

Ruszczyk,

Chester

MIT Haystack Observatory USA chester@haystack.mit.edu

IVS 2012 Annual Report 393
Associate Members

Name Institution Country E-mail

Salnikov,

Alexander

Institute of Applied Astronomy Russia salnikov@isida.ipa.rssi.ru

Sarti, Pierguido Istituto di Radioastronomia

INAF

Italy p.sarti@ira.inaf.it

Schatz,

Raimund

Fundamentalstation Wettzell Germany schatz@fs.wettzell.de

Scherneck,

Hans-Georg

Onsala Space Observatory Sweden hans-georg.scherneck@chalmers.se

Schiavone,

Francesco

Telespazio SpA Italy francesco.schiavone@e-geos.it

Schreiber,

Ulrich

Fundamentalstation Wettzell Germany schreiber@fs.wettzell.de

Schuh, Harald GeoForschungsZentrum Potsdam Germany schuh@gfz-potsdam.de

Schwarz, Walter Bundesamt f ̈ur Kartographie

und Geod ̈asie

Germany walter.schwarz@bkg.bund.de

Sciarretta,

Cecilia

Telespazio SpA Italy cecilia.sciarretta@e-geos.it

Searle, Anthony Natural Resources Canada Canada asearle@NRCan.gc.ca

Seitz, Manuela Deutsches Geod ̈atisches

Forschungsinstitut

Germany seitz@dgfi.badw.de

Sekido, Mamoru National Institute of Information

and Communications Technology

Japan sekido@nict.go.jp

Shao, Minghui Urumqi Astronomical

Observatory

China shaomh@uao.ac.cn

Shibuya, Kazuo National Institute of Polar

Research

Japan shibuya@nipr.ac.jp

Shu, Fengchun Shanghai Astronomical

Observatory

China sfc@center.shao.ac.cn

Sieber, Moritz Norwegian Mapping Authority Norway moritz.sieber@kartverket.no

Skjaeveland,

Asmund

Norwegian Mapping Authority Norway asmund.skjaeveland@kartverket.no

Skurikhina,

Elena

Institute of Applied Astronomy Russia sea@ipa.nw.ru

Smolentsev,

Sergey

Institute of Applied Astronomy Russia smolen@ipa.nw.ru

Smythe, Dan MIT Haystack Observatory USA dsmythe@haystack.mit.edu

Sousa, Don MIT Haystack Observatory USA dsousa@haystack.mit.edu

Sovers, Ojars Remote Sensing Analysis Inc. USA ojars@oregonfast.net

Stanford, Laura Geoscience Australia Australia Laura.Stanford@ga.gov.au

Stanghellini,

Carlo

Istituto di Radioastronomia

INAF

Italy c.stanghellini@ira.inaf.it

Steppe, Alan Jet Propulsion Laboratory USA as@logos.jpl.nasa.gov

Strand, Rich NVI, Inc. USA richkl7ra@gmail.com

394 IVS 2012 Annual Report
Associate Members

Name Institution Country E-mail

Sun, Jing Department of Geodesy and

Geoinformation/Vienna

University of Technology

Austria jing.sun@tuwien.ac.at

Surkis, Igor Institute of Applied Astronomy Russia surkis@ipa.nw.ru

Takashima,

Kazuhiro

Geospatial Information

Authority of Japan

Japan takasima@gsi.go.jp

Takefuji,

Kazuhiro

National Institute of Information

and Communications Technology

Japan takefuji@nict.go.jp

Takiguchi,

Hiroshi

Auckland University of

Technology

New

Zealand

hiroshi.takiguchi@aut.ac.nz

Tamura,

Yoshiaki

National Astronomical

Observatory of Japan

Japan tamura@miz.nao.ac.jp

Tanabe, Tadashi Geospatial Information

Authority of Japan

Japan tanabe@gsi.go.jp

Tao, An Shanghai Astronomical

Observatory

China antao@center.shao.ac.cn

Tateyama,

Claudio

Centro de R ́adio Astronomia e

Aplica ̧c ̃oes Espaciais

Brazil tateyama@craam.mackenzie.br

Teke, Kamil Hacettepe University Turkey kteke@hacettepe.edu.tr

Thomas,

Cynthia

NVI, Inc. USA cynthia.c.thomas@nasa.gov

Thorandt,

Volkmar

Bundesamt f ̈ur Kartographie

und Geod ̈asie

Germany volkmar.thorandt@bkg.bund.de

Thornton,

Bruce

U. S. Naval Observatory USA blt@usno.navy.mil

Tierno Ros,

Claudia

Department of Geodesy and

Geoinformation/Vienna

University of Technology

Austria claudia.ros@tuwien.ac.at

Titov, Oleg Geoscience Australia Australia Oleg.Titov@ga.gov.au

Titus, Mike MIT Haystack Observatory USA mtitus@haystack.mit.edu

Tomasi, Paolo Istituto di Radioastronomia

INAF

Italy tomasi@ira.inaf.it

Tornatore,

Vincenza

Politecnico di Milano Italy vincenza.tornatore@polimi.it

Trigilio,

Corrado

Istituto di Radioastronomia

INAF

Italy ctrigilio@oact.inaf.it

Trofimov,

Dmitriy

Astronomical Institute of

St.-Petersburg

Russia dm.trofimov@gmail.com

Tsutsumi,

Masanori

National Institute of Information

and Communications Technology

Japan tsutsumi@nict.go.jp

Tuccari, Gino Istituto di Radioastronomia

INAF

Italy g.tuccari@ira.inaf.it

Tzioumis, Tasso ATNF CSIRO Australia Tasso.Tzioumis@csiro.au

Ujihara, Hideki National Institute of Information

and Communications Technology

Japan ujihara@nict.go.jp

IVS 2012 Annual Report 395
Associate Members

Name Institution Country E-mail

Ullrich, Dieter Bundesamt f ̈ur Kartographie

und Geod ̈asie

Germany dieter.ullrich@bkg.bund.de

Uunila, Minttu Mets ̈ahovi Radio Observatory Finland minttu.uunila@aalto.fi

Venturi, Tiziana Istituto di Radioastronomia

INAF

Italy t.venturi@ira.inaf.it

Vespe,

Francesco

Agenzia Spaziale Italiana Italy francesco.vespe@asi.it

Vityazev,

Veniamin

Astronomical Institute of

St.-Petersburg

Russia vityazev@list.ru

Volvach,

Alexandr

Crimean Astrophysical

Observatory

Ukraine volvach@crao.crimea.ua

Vytnov,

Alexander

Institute of Applied Astronomy Russia vytnov@isida.ipa.rssi.ru

Wang, Guangli Shanghai Astronomical

Observatory

China wgl@center.shao.ac.cn

Wang, Jinqing Shanghai Astronomical

Observatory

China jqwang@center.shao.ac.cn

Wang, Lingling Shanghai Astronomical

Observatory

China llwang@center.shao.ac.cn

Wang, Na Urumqi Astronomical

Observatory

China na.wang@uao.ac.cn

Wang, Shiqiang Urumqi Astronomical

Observatory

China wangshq@uao.ac.cn

Wei, Wenren Shanghai Astronomical

Observatory

China wwr@center.shao.ac.cn

Weston, Stuart Auckland University of

Technology

New

Zealand

stuart.weston@aut.ac.nz

Whitney, Alan MIT Haystack Observatory USA awhitney@haystack.mit.edu

Wojdziak,

Reiner

Bundesamt f ̈ur Kartographie

und Geod ̈asie

Germany reiner.wojdziak@bkg.bund.de

Yatskiv,

Yaroslav

Main Astronomical Observatory Ukraine yatskiv@mao.kiev.ua

Yang, Wenjun Urumqi Astronomical

Observatory

China yangwj@uao.ac.cn

Ye, Shuhua Shanghai Astronomical

Observatory

China ysh@center.shao.ac.cn

Yi, Sangoh National Geographic

Information Institute

Korea sangoh.yi@korea.kr

Yusup, Aili Urumqi Astronomical

Observatory

China aliyu@uao.ac.cn

Zapata, Octavio TIGO/Universidad de

Concepci ́on

Chile octavio.zapata@tigo.cl

Zeitlh ̈ofler,

Reinhard

Fundamentalstation Wettzell Germany zeitlhoefler@fs.wettzell.de

396 IVS 2012 Annual Report
Associate Members

Name Institution Country E-mail

Zhang, Hua Urumqi Astronomical

Observatory

China zhangh@uao.ac.cn

Zhang, Ming Urumqi Astronomical

Observatory

China zhangming@uao.ac.cn

Zhang,

Xiuzhong

Shanghai Astronomical

Observatory

China xzhang@shao.ac.cn

Zhao, Rongbing Shanghai Astronomical

Observatory

China zhaorb@shao.ac.cn

Zheng, Weimin Shanghai Astronomical

Observatory

China zhwm@shao.ac.cn

Zhou, Ruixian Shanghai Astronomical

Observatory

China zrx@center.shao.ac.cn

Zubko, Nataliya Mets ̈ahovi Radio Observatory Finland nataliya.zubko@fgi.fi

IVS 2012 Annual Report 397
IVS Permanent Components

IVS Permanent Components

(listed by types, within types alphabetical by component name)

Network Stations

Component Name Sponsoring Organization Country

Radioastronomical Observatory Badary Institute of Applied Astronomy RAS Russia

Fortaleza, Radio Observat ́orio Espacial do

Nordeste (ROEN)

Centro de R ́adio Astronomia e Aplica ̧c ̃oes

Espaciais

Brazil

Goddard Geophysical and Astronomical

Observatory

NASA Goddard Space Flight Center USA

Hartebeesthoek Radio Astronomy

Observatory

Foundation for Research and Development South Africa

Hobart 12-m and 26-m, Katherine and

Yarragadee

University of Tasmania Australia

Kashima 34-m National Institute of Information and

Communications Technology (NICT)

Japan

Key Stone Project Kashima 11-m National Institute of Information and

Communications Technology (NICT)

Japan

Key Stone Project Koganei National Institute of Information and

Communications Technology (NICT)

Japan

Kokee Park Geophysical Observatory National Earth Orientation Service

(NEOS)

USA

Matera Agenzia Spaziale Italiana (ASI) Italy

Medicina Istituto di Radioastronomia Italy

Mets ̈ahovi Radio Observatory Aalto University, Finnish Geodetic

Institute

Finland

Mizusawa 10-m National Astronomical Observatory of

Japan (NAOJ)

Japan

Noto (Sicily) Istituto di Radioastronomia Italy

Ny- ̊Alesund Geodetic Observatory Norwegian Mapping Authority Norway

ERS/VLBI Station O’Higgins Bundesamt f ̈ur Kartographie und

Geod ̈asie (BKG)

Germany

Onsala Space Observatory Chalmers University of Technology Sweden

Parkes Observatory CSIRO Astronomy and Space Science Australia

Sejong Station National Geographic Information Institute

(NGII)

South Korea

Seshan Joint Laboratory for Radio Astronomy

(JLRA), CAS and Shanghai Observatory,

CAS

China

398 IVS 2012 Annual Report
IVS Permanent Components

Simeiz Laboratory of Radioastronomy of Crimean

Astrophysical Observatory

Ukraine

Svetloe Radio Astronomy Observatory Institute of Applied Astronomy RAS Russia

JARE Syowa Station National Institute of Polar Research Japan

Transportable Integrated Geodetic

Observatory (TIGO)

Universidad de Concepci ́on (UdeC),

Instituto Geogr ́afico Militar (IGM),

Bundesamt f ̈ur Kartographie und

Geod ̈asie (BKG)

Germany,

Chile

Tsukuba VLBI Station Geospatial Information Authority of Japan

(GSI)

Japan

Nanshan VLBI Station Chinese Academy of Sciences China

Warkworth Observatory Auckland University of Technology New Zealand

Westford Antenna, Haystack Observatory NASA Goddard Space Flight Center USA

Geod ̈atisches Observatorium Wettzell Bundesamt f ̈ur Kartographie und Geod ̈asie

(BKG) and Forschungseinrichtung

Satellitengeod ̈asie der Technischen

Universit ̈at M ̈unchen (FESG)

Germany

Observat ́orio Astron ́omico Nacional -

Yebes

Instituto Geogr ́afico Nacional Spain

Radioastronomical Observatory

Zelenchukskaya

Institute of Applied Astronomy RAS Russia

Operation Centers

Component Name Sponsoring Organization Country

Institut f ̈ur Geod ̈asie und Geoinformation

(IGGB)

Universit ̈at Bonn Germany

CORE Operation Center NASA Goddard Space Flight Center USA

NEOS Operation Center National Earth Orientation Service

(NEOS)

USA

Correlators

Component Name Sponsoring Organization Country

Astro/Geo Correlator at MPI Bundesamt f ̈ur Kartographie und

Geod ̈asie, Institut f ̈ur Geod ̈asie und

Geoinformation der Universit ̈at Bonn,

Max-Planck-Institut f ̈ur Radioastronomie

Germany

MIT Haystack Correlator NASA Goddard Space Flight Center USA

IVS 2012 Annual Report 399
IVS Permanent Components

Institute of Applied Astronomy Correlator Institute of Applied Astronomy RAS Russia

National Institute of Information and

Communications Technology (NICT)

National Institute of Information and

Communications Technology (NICT)

Japan

Shanghai Correlator Shanghai Astronomical Observatory China

Tsukuba VLBI Center Geospatial Information Authority of Japan

(GSI)

Japan

Washington Correlator National Earth Orientation Service

(NEOS)

USA

Data Centers

Component Name Sponsoring Organization Country

BKG, Leipzig Bundesamt f ̈ur Kartographie und Geod ̈asie Germany

Crustal Dynamics Data Information

System (CDDIS)

NASA Goddard Space Flight Center USA

GeoDAF Agenzia Spaziale Italiana (ASI) Italy

Italy INAF Istituto di Radioastronomia INAF Italy

National Institute of Information and

Communications Technology

National Institute of Information and

Communications Technology

Japan

Observatoire de Paris Observatoire de Paris France

Analysis Centers

Component Name Sponsoring Organization Country

Astronomical Institute of St.-Petersburg

University

Astronomical Institute of St.-Petersburg

University

Russia

Geoscience Australia Geoscience Australia Australia

BKG/DGFI Combination Center Bundesamt f ̈ur Kartographie und

Geod ̈asie and Deutsches Geod ̈atisches

Forschungsinstitut

Germany

Laboratoire d’Astrophysique de Bordeaux Laboratoire d’Astrophysique de Bordeaux France

Centro di Geodesia Spaziale (CGS) Agenzia Spaziale Italiana Italy

DGFI Deutsches Geod ̈atisches Forschungsinstitut Germany

GFZ Potsdam GFZ German Research Center for

Geosciences

Germany

IGGB-BKG Analysis Center Institut f ̈ur Geod ̈asie und Geoinformation

der Universit ̈at Bonn and Bundesamt f ̈ur

Kartographie und Geod ̈asie

Germany

400 IVS 2012 Annual Report
IVS Permanent Components

Goddard Space Flight Center NASA Goddard Space Flight Center USA

Haystack Observatory MIT Haystack Observatory and NASA

Goddard Space Flight Center

USA

Institute of Applied Astronomy Analysis

Center

Institute of Applied Astronomy RAS Russia

Italy INAF Istituto di Radioastronomia INAF Italy

Jet Propulsion Laboratory Jet Propulsion Laboratory USA

Karadeniz Technical University (KTU) Karadeniz Technical University Turkey

Korea Astronomy and Space Science

Institute

Korea Astronomy and Space Science

Institute

South Korea

Main Astronomical Observatory Main Astronomical Observatory, National

Academy of Sciences, Kiev

Ukraine

National Astronomical Observatory of

Japan

National Astronomical Observatory of

Japan

Japan

National Institute of Information and

Communications Technology

National Institute of Information and

Communications Technology

Japan

Norwegian Mapping Authority (NMA) Norwegian Mapping Authority (NMA) Norway

Observatoire de Paris Observatoire de Paris France

Onsala Space Observatory Chalmers University of Technology Sweden

Politecnico di Milano DIIAR Politecnico di Milano DIIAR (PMD) Italy

Pulkovo Observatory Pulkovo Observatory Russia

Sternberg State Astronomical Institute Lomonosov Moscow State University Russia

Shanghai Observatory Shanghai Observatory, Chinese Academy

of Sciences

China

Tsukuba VLBI Analysis Center Geospatial Information Authority of Japan

(GSI)

Japan

U. S. Naval Observatory Analysis Center U. S. Naval Observatory USA

U. S. Naval Observatory Analysis Center

for Source Structure

U. S. Naval Observatory USA

VIE Analysis Center Department of Geodesy and

Geoinformation/Vienna University of

Technology

Austria

Technology Development Centers

Component Name Sponsoring Organization Country

Canadian VLBI Technology Development

Center

NRCan, DRAO Canada

IVS 2012 Annual Report 401
IVS Permanent Components

Goddard Space Flight Center NASA Goddard Space Flight Center USA

Haystack Observatory MIT Haystack Observatory and NASA

Goddard Space Flight Center

USA

Institute of Applied Astronomy

Technology Development Center

Institute of Applied Astronomy RAS Russia

National Institute of Information and

Communications Technology

National Institute of Information and

Communications Technology

Japan

Onsala Space Observatory Chalmers University of Technology Sweden

402 IVS 2012 Annual Report
Contributing Institutions

Addresses of Institutions of Authors Contributing to this Report

(listed alphabetically by country)

CSIRO Astronomy and Space Science

PO Box 76

Epping

NSW 1710

Australia

http://www.atnf.csiro.au

Geoscience Australia

PO Box 378

Canberra ACT

2601

Australia

http://ga.gov.au

University of Tasmania

School of Mathematics and Physics

University of Tasmania

Private Bag 37

Hobart 7001

Australia

http://auscope.phys.utas.edu.au

Department of Geodesy and Geoinformation/Vienna University of Technology

Gusshausstrasse 27-29

1040 Vienna

Austria

http://www.hg.tuwien.ac.at

CRAAM-INPE, R ́adio-observat ́orio Espacial do Nordeste

CRAAM

Instituto Presbiteriano Mackenzie

Rua da Consola ̧c ̃ao 896

01302-907 S ̃ao Paulo

SP

Brazil

http://www.craam.mackenzie.br

Instituto Nacional de Pesquisas Espaciais

Estrada do Fio 6000

Bairro Tupui ́u

1760-000 Eus ́ebio

CE

Brazil

http://www.roen.inpe.br

IVS 2012 Annual Report 403
Contributing Institutions

Geodetic Survey Division, Natural Resources Canada

615 Booth St.

Ottawa

Ontario

Canada K1A 0E9

http://www.geod.nrcan.gc.ca

Bundesamt f ̈ur Kartographie und Geod ̈asie - TIGO

Casilla 4036

Correo 3

Concepci ́on

Chile

http://www.bkg.bund.de

Universidad de Concepci ́on - TIGO

Concepci ́on

Chile

http://www.udec.cl

Shanghai Astronomical Observatory, Chinese Academy of Sciences

80 Nandan Road

Shanghai 200030

China

http://www.shao.ac.cn/

Aalto University Mets ̈ahovi Radio Observatory

Mets ̈ahovintie 114

FIN-02450 Kylm ̈al ̈a

Finland

http://www.metsahovi.fi/

Finnish Geodetic Institute

Geodeetinrinne 2

FI-02430 Masala

Finland

http://www.fgi.fi/fgi/

Laboratoire d’Astrophysique de Bordeaux

2 rue de l’Observatoire

BP 89

33271 Floirac Cedex

France

http://www.obs.u-bordeaux1.fr

Observatoire de Paris, SYRTE, CNRS/UMR8630

61 avenue de l’Observatoire

75014 Paris

France

http://www.obspm.fr

404 IVS 2012 Annual Report
Contributing Institutions

Bundesamt f ̈ur Kartographie und Geod ̈asie

Richard-Strauss-Allee 11

60598 Frankfurt am Main

Germany

http://www.bkg.bund.de

Deutsches Geod ̈atisches Forschungsinstitut

Alfons-Goppel-Strasse 11

80539 M ̈unchen

Germany

http://www.dgfi.badw.de

Geod ̈atisches Observatorium Wettzell

Bundesamt f ̈ur Kartographie und Geod ̈asie (BKG) and

Forschungseinrichtung Satellitengeod ̈asie (FESG)

Sackenrieder Str. 25.

D-93444 Bad K ̈otzting

Germany

http://www.fs.wettzell.de

GFZ German Research Center for Geosciences

Telegrafenberg

14473 Potsdam

Germany

http://www.gfz-potsdam.de

Institut f ̈ur Geod ̈asie und Geoinformation der Universit ̈at Bonn

Nussallee 17

53115 Bonn

Germany

http://vlbi.geod.uni-bonn.de

Max-Planck-Institut f ̈ur Radioastronomie

Auf dem H ̈ugel 69

53121 Bonn

Germany

http://www.mpifr-bonn.mpg.de

Agenzia Spaziale Italiana

Centro di Geodesia Spaziale

Contrada Terlecchia

75100 Matera

Italy

http://www.asi.it

Istituto di Radioastronomia–Bologna

Via P. Gobetti 101

40129 Bologna

Italy

http://www.ira.inaf.it

IVS 2012 Annual Report 405
Contributing Institutions

Istituto di Radioastronomia, Medicina

C.P. 14

40060 Villafontana

Bologna

Italy

http://www.med.ira.inaf.it

Istituto di Radioastronomia INAF, Stazione VLBI di Noto

C.P. 161

I-96017 Noto SR

Italy

http://www.noto.ira.inaf.it

Politecnico di Milano, DIIAR

Politecnico di Milano University

DIIAR

Sezione Rilevamento

Piazza Leonardo da Vinci 32

I-20133 Milano

Italy

http://www.diiar.polimi.it

Geospatial Information Authority of Japan

Code 305-0811

Kitasato 1

Tsukuba

Ibaraki

Japan

http://www.spacegeodesy.go.jp/vlbi/en/

Mizusawa VLBI Observatory, NAOJ

2-12 Hoshigaoka-cho

Mizusawa-kuk

Oshu-shi

Iwateken

023-0861

Japan

http://www.miz.nao.ac.jp

National Institute of Information and Communications Technology

893-1 Hirai

Kashima

Ibaraki 314-8501

Japan

http://www2.nict.go.jp/aeri/sts/stmg/index e.html

406 IVS 2012 Annual Report
Contributing Institutions

National Institute of Polar Research

10-3

Midori-cho

Tachikawa-shi

Tokyo 190-8518

Japan

http://www.nipr.ac.jp/

Institute for Radio Astronomy and Space Research, Auckland University of Technology

Private Bag 92006

Auckland 1142

New Zealand

http://www.irasr.aut.ac.nz

Norwegian Mapping Authority

Kartverket

3507 Hønefoss

Norway

http://www.kartverket.no

Institute of Applied Astronomy of Russian Academy of Sciences (IAA)

nab. Kutuzova 10

St. Petersburg

191187

Russia

http://www.ipa.nw.ru

Pulkovo Observatory

Pulkovskoe Ch. 65

St. Petersburg

196140

Russia

http://www.gao.spb.ru

Sobolev Astronomical Institute of Saint Petersburg University

Universitetskii pr. 28

Starii Peterhof

Saint Petersburg

198504

Russia

http://www.astro.spbu.ru

Sternberg State Astronomical Institute (SAI) of Lomonosov Moscow State University

Universitetskij prospekt 13

Moscow

119991

Russia

http://www.sai.msu.ru

IVS 2012 Annual Report 407
Contributing Institutions

HartRAO, NRF

PO Box 443

Krugersdorp

1740

South Africa

http://www.hartrao.ac.za

Korea Astronomy and Space Science Institute

305-348

South Korea

http://www.kasi.re.kr

National Geographic Information Institute

92 Worldcup-Ro

Youngtong-Gu

Suwon-Si

Gyeonggi-Do

443-772

South Korea

http://www.ngii.go.kr

Instituto Geogr ́afico Nacional

Calle General Iba ̃nez de Ibero 3

E-28003 Madrid

Spain

http://www.ign.es/

Observat ́orio Astron ́omico Nacional

Calle Alfonso XII 3

E-28014 Madrid

Spain

http://www.oan.es/

Onsala Space Observatory (OSO)

SE-439 92

Onsala

Sweden

http://www.oso.chalmers.se

Hacettepe University, Department of Geomatics Engineering

Beytepe Campus

06800

Ankara

Turkey

http://geomatik.hacettepe.edu.tr

Karadeniz Technical University, Department of Geomatics Engineering

61080

Trabzon

Turkey

http://www.harita.ktu.edu.tr

408 IVS 2012 Annual Report
Contributing Institutions

Main Astronomical Observatory, National Academy of Sciences of Ukraine

27 Akademika Zabolotnoho St.

Kiev

03680

Ukraine

http://www.mao.kiev.ua

Radio Astronomy Lab of Crimean Astrophysical Observatory

RT-22

Katsively

Yalta Crimea 98688

Ukraine

http://www.crao.crimea.ua

Jet Propulsion Laboratory, California Institute of Technology

Mail Stop 67-115C

4800 Oak Grove Dr.

Pasadena, CA 91109

USA

http://www.jpl.nasa.gov

Kokee Park Geophysical Observatory

USNO and NASA GSFC

Kokee State Park

P.O. Box 538

Waimea Hawaii 96796

USA

http://lupus.gsfc.nasa.gov/kokee park.htm

MIT Haystack Observatory

Off Route 40

Westford MA 01886

USA

http://www.haystack.mit.edu/

NASA Goddard Space Flight Center

Code 698.2

Greenbelt, MD 20771

USA

http://www.nasa.gov

United States Naval Observatory

3450 Massachusetts Avenue NW

Washington, DC 20392

USA

http://www.usno.navy.mil/

IVS 2012 Annual Report 409
Contributing Institutions

U. S. Naval Observatory, Flagstaff Station

10391 West Naval Observatory Rd.

Flagstaff, AZ 86001

USA

http://www.nofs.navy.mil

410 IVS 2012 Annual Report
List of Acronyms

List of Acronyms

AAM Atmosphere Angular Momentum

AARNet Australia Academic and Research Network

AAS American Astronomical Society

AC (IVS) Analysis Center

ACF AutoCorrelation Function

ACU Antenna Control Unit

AD Analog to Digital

ADB Analog to Digital Board

ADC Analog to Digital Converter

ADEV Allan DEViation

AEB Agˆencia Espacial Brasileira (Brazilian Space Agency) (Brazil)

AER Atmospheric and Environmental Research, Inc. (USA)

AES Advanced Engineering Services Co., Ltd (Japan)

AGILE Astro-rivelatore Gamma ad Immagini LEggero satellite (Italy)

AGN Active Galactic Nuclei

AGOS Australian Geophysical Observing System (Australia)

AGU American Geophysical Union

AIPS Astronomical Image Processing System

AIUB Astronomical Institute, University of Bern (Switzerland)

ALMA Atacama Large Millimeter Array

AMRFP Access to Major Research Facilities Program

ANU Australian National University (Australia)

AO Astronomical Object

AOA Allen Osborne Associates

AOC Array Operation Center (Japan)

AOG Auxilliary Output Generator

APEX Atacama Pathfinder EXperiment (Chile)

API Application Programming Interface

APPS Advanced Precise Positioning System

APSG Asia-Pacific Space Geodynamics program

APT Asia Pacific Telescope

APTF Asian Pacific Time and Frequency

ARC Astrometric Radiointerferometric Correlator

ARIES Astronomical Radio Interferometric Earth Surveying program

ARO Algonquin Radio Observatory (Canada)

ASC Astro Space Center (Russia)

ASD Allan Standard Deviation

ASI Agenzia Spaziale Italiana (Italy)

ASKAP Australian Square Kilometre Array Pathfinder (Australia)

ATA Advanced Technology Attachment

ATA Allen Telescope Array (USA)

ATCA Australia Telescope Compact Array (Australia)

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ATM Asynchronous Transfer Mode

ATNF Australia Telescope National Facility (Australia)

AUSLIG AUstralian Surveying and Land Information Group (now Geoscience Australia

(GA)) (Australia)

AUT Auckland University of Technology (New Zealand)

AWI Alfred Wegener Institute for polar and marine research (Germany)

A-WVR Advanced Water Vapor Radiometer

BAAS Bulletin of the American Astronomical Society

BAdW Bayerische Akademie der Wissenschaften (Bavarian Academy of Sciences and

Humanities) (Germany)

BBC Base Band Converter

BdRAO Badary Radio Astronomical Observatory (Russia)

BEK Bayerische Kommission f ̈ur die internationale Erdmessung (Germany)

BIPM Bureau Internacional de Poids et Mesures (France)

BKG Bundesamt f ̈ur Kartographie und Geod ̈asie (Germany)

BMC Basic Module of Correlator

BOR1 Body Of Revolution type 1

BOSSNET BOSton South NETwork

BPE Bernese Processing Engine

BPF Band Pass Filter

BRAS Broadband Russian Acquisition System

BVID Bordeaux VLBI Image Database

BW BandWidth

BWG Beam WaveGuide

CACS Canadian Active Control System

CAGS Council of Astronomical and Geophysical data analysis Services

CARAVAN Compact Antenna of Radio Astronomy for VLBI Adapted Network (Japan)

CAS Chinese Academy of Sciences (China)

CASPER Center for Astronomy Signal Processing and Electronics Research (USA)

CAY Centro Astron ́omico de Yebes (Spain)

CC (IVS) Combination Center

CC (IVS) Coordinating Center

CDAS Chinese vlbi Data Acquisition System

CDDIS Crustal Dynamics Data Information System (USA)

CDP Crustal Dynamics Project

CDT Centro de Desarrollo Tecnol ́ogico at Yebes Observatory (Spain)

CE Conformit ́e Europ ́eene

CE-1 Chang’E-1 (China)

CfA Harvard-Smithsonian Center for Astrophysics (USA)

CGE Centrum f ̈ur Geod ̈atische Erdsystemforschung (Germany)

CGLBI Canadian Geodetic Long Baseline Interferometry

CGPS Continuous GPS

CGS Centro di Geodesia Spaziale (Italy)

CHAMP Challenging Mini-Satellite Payload

CIB Correlator Interface Board

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CIP Celestial Intermediate Pole

CLARA Cooperaci ́on Latino Americana de Redes Avanzadas

CLIWA-NET Cloud LIquid WAter NETwork

CMB Core-Mantle Boundary

CMNOC Crustal Monitoring Network Of the Chinese mainland geological environment

(China)

CMONC Crustal Movement Observation Network of China (China)

CMONOC Crustal Movement Observation Network Of China (China)

CMVA Coordinated Millimeter VLBI Array

CNES Centre National d’Etudes Spatiales (France)

CNIG Centro Nacional de Informaci ́on Geogr ́afica (Spain)

CNR Consiglio Nazionale delle Ricerche (Italy)

CNRS Centre National de la Recherche Scientifique (France)

CNS Communication, Navigation and Surveillance systems, Inc. (USA)

CODA Correlator Output Data Analyzer

COL Combination at the Observation Level

CONGO COoperative Network for GIOVE Observation

CORE Continuous Observations of the Rotation of the Earth

CORS Continuously Operating Reference Stations

COTS Commercial-Off-The-Shelf

CP Circularly Polarized

CPO Celestial Pole Offset

CPOS POSition accuracy on the Centimetre level

CPP IERS Combination Pilot Project

CRAAE Centro de R ́adio Astronomia e Aplica ̧c ̃oes Espaciais (Brazil)

CRAAM Centro de R ́adio Astronomia e Astrof ́ısica Mackenzie (Brazil)

CrAO Crimean Astrophysical Observatory (Ukraine)

CRDS Celestial Reference frame Deep South

CRESTech Centre for Research in Earth and Space Technology (Canada)

CRF Celestial Reference Frame

CRL Communications Research Laboratory (now NICT) (Japan)

CRS Celestial Reference System

CSA Canadian Space Agency (Canada)

C-SART Constrained Simultaneous Algebraic Reconstruction Technique

CSCU Cryogenic System Control Unit

CSIR Council for Scientific and Industrial Research (South Africa)

CSIRO Commonwealth Scientific and Industrial Research Organisation (Australia)

CSRIFS Combined Square Root Information Filter and Smoother

CSRS Canadian Spatial Reference System

CSTnet China Science and Technology Network (China)

CTVA Canadian Transportable VLBI Antenna

CUTE CRL and University Telescopes Experiment (Japan)

CVN Chinese VLBI Network

CW Chandler Wobble

CW Continuous Wave

IVS 2012 Annual Report 413
List of Acronyms

CWDM Coarse Wavelength Division Multiplexer

CYLAR CDT Yebes Laser Ranging

DAO GSFC Data Assimilation Office (USA)

DAQ Data AcQuisition

DAR Data Acquisition Rack

DAS Data Acquisition System

DASOS DAS Operating System

DAT Digital Audio Tape

DB Data Base

DBBC Digital Base Band Converter

DBE Digital BackEnd

DDC Digital DownConverter

DDOR Delta Differenced One-way Range

DeltaDOR Delta Differenced One-way Range

DFG Deutsche Forschungsgemeinschaft (German Research Foundation) (Germany)

DFT Discrete Fourier Transform

DGFI Deutsches Geod ̈atisches ForschungsInstitut (Germany)

DGK Deutsche Geod ̈atische Kommission (Germany)

dGPS differential GPS

DHC De Havilland Canada Company

DIIAR Dipartimento di Ingegneria Idraulica, Ambientale, Infrastrutture viarie,

Rilevamento (Italy)

DIISR Department of Innovation, Industry, Science and Research (Australia)

DIM Data Input Module

DISTART Dipartimento di Ingegneria delle Strutture, dei Trasporti, delle Acque,

del Rilevamento del Territorio (Italy)

DLR Deutsches Zentrum f ̈ur Luft- und Raumfahrt (German Aerospace Center)

DNSC Danish National Space Center (Denmark)

DOGS Dgfi Orbit and Geodetic parameter estimation Software

DOGS-RI Dgfi Orbit and Geodetic parameter estimation Software (Radio Interferometry)

DOM Data Output Module

DOMES Directory Of MERIT Sites

DORIS Doppler Orbitography and Radiopositioning Integrated by Satellite

DPFU Degrees Per Flux Unit

DPN Dual Pseudo-random Noise

DR Dichroic Reflector

DRAGON Dynamic Resource Allocation through GMPLS over Optical Networks

DRAO Dominion Radio Astrophysical Observatory (Canada)

DREN Defense Research and Engineering Network (USA)

DSAMS Direct Sampling Applied for Mixed Signals

DSCB Data Stream Combining Board

DSCIG Direc ̧c ̃ao de Servi ̧cos de Cartografia e Informa ̧c ̃ao Geogr ́afica (Portugal)

DSIF Deep Space Instrumentation Facility

DSN Deep Space Network

DSNA Deep Space Network Array (USA)

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DSP Digital Signal Processor

DSS Deep Space Station

DTU Danmarks Tekniske Universitet (Denmark)

D-VLBI Differential VLBI

EAN Eastern Asia VLBI Network

EAS European Astronomical Society

ECCO Estimating the Circulation and Climate of the Ocean

ECMWF European Centre for Medium-Range Weather Forecasts

EDM Electronic Distance Measurement

EFTF European Frequency and Time Forum

EGAE Experiment Guided Adaptive Endpoint

EGS European Geophysical Society

EGU European Geosciences Union

EIA Environmental Impact Assessment

ELSA European Leadership in Space Astrometry

ENC GNSS European Navigation Conference on Global Navigation Satellite Systems

ENSG L’Ecole Nationale des Sciences G ́eographiques  ́

ENSO El-Ni ̃no/Southern Oscillation

ENVISAT ENVIronmental SATellite

EOP Earth Orientation Parameter

EOP-PC Earth Orientation Parameter Product Center (France)

EOS Earth Observing System

EOT Empirical Ocean Tide

EOT8A Empirical Ocean Tide 2008 model from multi-mission satellite Altimetry

ERA Earth Rotation Angle

ERP Earth Rotation Parameter

ERS European Remote Sensing Satellites

ESA European Space Agency

ESO European Southern Observatory

ESTEC European Space research and TEchnology Centre

ETS-8 Engineering Test Satellite 8

ETSIT Escuela T ́ecnica Superior de Ingenieros de Telecomunicaci ́on

ETS-Lindgren EMC Test Systems-Lindgren (USA)

ETS-VIII Engineering Test Satellite 8

EU European Union

EuCAP European Conference on Antennas and Propagation

EUREF EUropean REFerence Frame

EVGA European Vlbi group for Geodesy and Astrometry

EVLA Expanded Very Large Array

e-VLBI Electronic VLBI

EVN European VLBI Network

EXPReS Express Production Real-time e-VLBI Service

FACH Fuerza A ́erea de Chile (Air Force of Chile) (Chile)

FAGS Federation of Astronomical and Geophysical data analysis Services

FCN Free Core Nutation

IVS 2012 Annual Report 415
List of Acronyms

FEM Finite Element Method

FES Finite Element Solution

FESG Forschungseinrichtung Satellitengeod ̈asie/Technical University of Munich

(Germany)

FFI Forsvarets ForskningsInstitutt (Norwegian Defence Research Establishment)

(Norway)

FFT Fast Fourier Transform

FFTS Fast Fourier Transform Spectrometer

FGI Finnish Geodetic Institute (Finland)

FGS ForschungsGruppe Satellitengeod ̈asie (Germany)

FICN Free Inner Core Nutation

FILA FIrst LAst

FINEP Financiadora de Estudos e Projetos (Brazilian Innovation Agency) (Brazil)

FIR Finite Impulse Response

FITS Flexible Image Transport System

FOV Field Of View

FP7 Seventh Framework Programme (Europe)

FPDP Front Panel Data Port

FPGA Field-programmable Gate Array

FS Field System

FSS Frequency Selective Sub-reflector

FTP File Transfer Protocol

FWF Fonds zur F ̈orderung der wissenschaftlichen Forschung (Austrian Science Fund)

GA Geoscience Australia (Australia)

GALAXY Giga-bit Astronomical Large Array with cross connect

GAPE Great Alaska and Pacific Experiment

GARNET GSI Advanced Radiotelescope NETwork (Japan)

GARR Gruppo per l’Armonizzazione delle Reti della Ricerca

(Italian Academic and Research Network) (Italy)

GARS German Antarctic Receiving Station (Germany)

GASP GLAST-AGILE Support Program

GBT Green Bank Telescope (USA)

GCGO Gilmore Creek Geophysical Observatory (USA)

GCRS Geocentric Celestial Reference System

GD SATCOM General Dynamics SATCOM technologies

GDR altimeter Geophysical Data Record

GEMD Geospatial and Earth Monitoring Division (Australia)

GeoDAF Geodetic Data Archiving Facility (Italy)

GEX Giga-bit series VLBI EXperiment

GFZ GeoForschungsZentrum (Germany)

GGAO Goddard Geophysical and Astronomical Observatory (USA)

GGFC Global Geophysical Fluids Center

GGN Global GPS Network

GGOS Global Geodetic Observing System

GGP Global Geodynamics Project

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GICO GIga-bit COrrelator

GINS G ́eod ́esie par Int ́egrations Num ́eriques Simultan ́ees

GIOVE Galileo In-Orbit Validation Element

GIS Geographic Information System

GISTM GPS Ionospheric Scintillation and TEC Monitor

GIUB Geodetic Institute of the University of Bonn (now IGGB) (Germany)

GLAST Gamma ray Large Area Space Telescope (USA)

GLDAS Global Land Data Assimilation System

GLONASS GLObal NAvigation Satellite System (Russia)

GLORIA GLObal Radio Interferometry Analysis

GMF Global Mapping Function

GMPLS Generalized MultiProtocol Label Switching

GMST Greenwich Mean Sideral Time

GNS Science Geological and Nuclear Sciences Research Institute (New Zealand)

GNSS Global Navigation Satellite Systems

GOCE Gravity field and steady-state Ocean Circulation Explorer

GOES Geostationary Operational Environmental Satellite (USA)

GOT Goddard/Grenoble Ocean Tide

GOW Geodetic Observatory Wettzell

GP-B Gravity Probe B

GPS Global Positioning System

GPT Global Pressure and Temperature

GPU Graphics Processing Unit

GR General Relativity

GRACE Gravity Recovery and Climate Experiment (USA)

GREAT-ESF Gaia Research for European Astronomy Training — European Science

Foundation

GREF German GPS REFerence network

GRGS Groupe de Recherches de G ́eod ́esie Spatiale (France)

GSD/NRCan Geodetic Survey Division of Natural Resources Canada (Canada)

GSFC Goddard Space Flight Center (USA)

GSI GeoSpatial Information authority of japan (Japan)

GSK Generalized Spectral Kurtosis

GSM Global System for Mobile communication

GSOS GPS Surface Observing System

GSS Generator of Synchronization Signals

GST Greenwich Sideral Time

HAMTIDE Hamburg direct data Assimilation Methods for TIDEs

HartRAO Hartebeesthoek Radio Astronomy Observatory (South Africa)

HAT-Lab High Advanced Technology-Lab (Italy)

HEMT High Electron Mobility Transistor

HF High Frequency

HIA Herzberg Institute for Astrophysics (Canada)

HIC Hawaii Intranet Consortium (USA)

HIRLAM High Resolution Limited Area Model

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Honeywell TSI Honeywell Technology Solutions Inc. (USA)

HOPS Haystack Observatory Postprocessing System

HPBW Half Power BeamWidth

HPC High Performance Compute

HSI High Speed Input bus

HSIR High Speed Input Replicated bus

HTS High Temperature Superconductor

HTSI Honeywell Technology Solutions Incorporated (USA)

HVAC Heating, Ventilation, and Air Conditioning

IAA Institute of Applied Astronomy (Russia)

IAG International Association of Geodesy

IAPG Institut f ̈ur Astronomische und Physikalische Geod ̈asie

(Institute for Astronomical and Physical Geodesy) (Germany)

IAR Instituto Argentino de Radioastronom ́ıa (Argentina)

IAU International Astronomical Union

IBGE Instituto Brasileiro de Geografia e Estatistica (Brazil)

IBM International Business Machines Corporation (USA)

iBOB Interconnect Break Out Board

ICRAR International Centre for Radio Astronomy Research (Australia)

ICRF International Celestial Reference Frame

ICRF2 2nd realization of the International Celestial Reference Frame

ICRF3 3rd realization of the International Celestial Reference Frame

ICRS International Celestial Reference System

IDS International DORIS Service

IDV IntraDay Variability

IERS International Earth Rotation and Reference Systems Service

IETF Internet Engineering Task Force

IF Intermediate Frequency

IGeS International Geoid Service

IGFN Italian Space Agency GPS Fiducial Network (Italy)

IGFS2 second International Symposium of the Gravity Field of the earth

IGG Institute of Geodesy and Geophysics (Austria)

IGG Institut f ̈ur Geod ̈asie und Geoinformation der universit ̈at bonn (Germany)

IGGB Institut f ̈ur Geod ̈asie und Geoinformation der Universit ̈at Bonn (Germany)

IGGOS Integrated Global Geodetic Observing System (now GGOS)

IGM Instituto Geogr ́afico Militar (Chile)

IGM Istituto Geografico Militare (Italy)

IGN Institut Geographique National (France)

IGN Instituto Geogr ́afico Nacional (Spain)

IGS International GNSS Service

IISGEO International Institute for Space Geodesy and Earth Observation

I-JUSE Institute of Japanese Union of Scientists and Engineers (Japan)

IKAROS Interplanetary Kite-craft Accelerated by Radiation of the Sun (Japan)

ILRS International Laser Ranging Service

IMC Interface Module of Correlator

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IMF Isobaric Mapping Function

INACH Institute for Antarctic Research Chile

INAF Istituto Nazionale di Astrofisica (Italy)

INGV Institute of Geophysics and Volcanology (Italy)

INPE Instituto Nacional de Pesquisas Espaciais (Brazil)

InSAR Interferometric Synthetic Aperture Radar

INTA Instituto Nacional de T ́ecnica Aeroespacial (Spain)

IP Internet Protocol

IPEV Institut polaire fran ̧cais Paul Emile Victor (France)

IPWV Integrated Precipitable Water Vapor

IRA Istituto di RadioAstronomia (Italy)

IRAM Institut de RAdioastronomie Millim ́etrique (France)

IRAS InfraRed Astronomy Satellite

IRASR Institute for Radio Astronomy and Space Research (New Zealand)

IRIS International Radio Interferometric Surveying

IRP Invariant Reference Point

IRSR Institute for Radiophysics and Space Research (New Zealand)

ISACCO Ionospheric Scintillations Arctic Campaign Coordinated Observation

ISAS Institute of Space and Astronautical Science (Japan)

ISBN International Standard Book Number

ISI Information Sciences Institute (USA)

ISV Instantaneous State Vector

ITIS Istituto di Tecnologia Informatica Spaziale (Italy)

ITRF International Terrestrial Reference Frame

ITRS International Terrestrial Reference System

ITSS (Raytheon) Information Technology and Science Services (USA)

IUGG International Union of Geodesy and Geophysics

IVOA International Virtual Observatory Alliance

IVP Invariant Point

IVS International VLBI Service for Geodesy and Astrometry

IWV Integrated Water Vapor

IYA International Year of Astronomy

JADE JApanese Dynamic Earth observation by VLBI

JARE Japanese Antarctic Research Expedition (Japan)

JAXA Japan Aerospace Exploration Agency (Japan)

JENAM Joint European and National Astronomy Meeting

JGN Japan Gigabit Network (Japan)

JGR Journal of Geophysical Research

JHB JoHannesBurg

JIVE Joint Institute for VLBI in Europe

JLRA Joint Laboratory for Radio Astronomy (China)

JMA Japan Meteorological Agency (Japan)

JPL Jet Propulsion Laboratory (USA)

JSPS Japanese Society for the Promotion of Science (Japan)

JST Japan Standard Time

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KARAT KAshima RAy-tracing Tools (Japan)

KARATS KAshima RAy-Tracing Service (Japan)

KAREN Kiwi Advanced Research and Education Network (New Zealand)

KASI Korea Astronomy and Space Science Institute (Korea)

KAT Karoo Array Telescope (South Africa)

KBR K-Band Ranging

KEG Kommission f ̈ur Erdmessung und Glaziologie

(Commission for Geodesy and Glaciology) (Germany)

KFC Kashima Flexible Correlator

KPGO Kokee Park Geophysical Observatory (USA)

KPSS Kwiatkowski-Phillips-Schmidt-Shin

KSP KeyStone Project (Japan)

KSRC Kashima Space Research Center (Japan)

KSTC Kashima Space Technology Center

KTU Karadeniz Technical University (Turkey)

KTU-GEOD Karadeniz Technical University (KTU), Department of Geomatics Engineering

(Turkey)

KVG Korea VLBI system for Geodesy (Korea)

KVM Keyboard, Video, and Mouse

KVN Korean VLBI Network

LAB Laboratoire d’Astrophysique de Bordeaux (France)

LAGEOS LAser GEOdynamic Satellite

LAMOST Large Sky Area Multi-object Fiber Spectroscopic Telescope (China)

LAREG Laboratoire de Recherches en G ́eod ́esie (France)

LBA Long Baseline Array (Australia)

LCP Left Circular Polarization

LCS Long baseline array Calibrator Survey

LD Laser Diode

LEA Lab of Ephemeris Astronomy (Russia)

LED Light-Emitting Diode

LEIF Large Equipment and Infrastructure Funding

LEO Low Earth Orbit

LHC Left Hand Circular

LIEF Large Infrastructure and Equipment Funding

LINZ Land Information New Zealand (New Zealand)

LLR Lunar Laser Ranging

LNA Low Noise Amplifier

LNMAG Lab of New Methods in Astrometry and Geodynamics (Russia)

LO Local Oscillator

LOC Local Organizing Committee

LOD Length Of Day

LPF Low Pass Filter

LPI Lebedev Physical Institute (Russia)

LRS Laser Ranging System

LSB Lower Side Band

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LSC Least Squares Collocation

LSF Large Scale Facility

LSGER Lab of Space Geodesy and Earth Rotation (Russia)

LSM Least Squares Method

LSQM Least Squares Method

MAO Main Astronomical Observatory (Ukraine)

MARBLE Multiple Antenna Radio-interferometry for Baseline Length Evaluation

MBH Mathews/Buffett/Herring Nutation Model

MCB Monitor and Control Bus

MCI Monitor and Control Infrastructure

MDION Multi-Dimensional IONosphere modeling

MDSCC Madrid Deep Space Communications Complex (Spain)

MEI Multivariate ENSO Index

MERIT Monitoring of Earth Rotation and Intercomparison of the Techniques of

Observation and Analysis

METLAB Microwave Energy Transmission LABoratory (Japan)

MEX Mars Express

MIT Massachusetts Institute of Technology (USA)

MITEQ Microwave Information Transmission EQuipment (USA)

MIUR Ministero dell’Istruzione, dell’ Universit`a e della Ricerca

(Ministry of Education, University and Research) (Italy)

MJD Modified Julian Date

MLRO Matera Laser Ranging Observatory (Italy)

MNHD Mineral and Natural Hazard Division (Australia)

MNRAS Monthly Notices of the Royal Astronomical Society

MOBLAS MOBile LASer

MODEST MODel and ESTimate

MOU Memorandum of Understanding

MPI Max-Planck-Institute (Germany)

MPI Message Passing Interface

MPIfR Max-Planck-Institute for Radioastronomy (Germany)

MPM Millimeter-wave Propagation Model

MRO Mars Reconnaissance Orbiter

MRO Mets ̈ahovi Radio Observatory (Finland)

MSL Mars Science Laboratory

MTLRS Modular Transportable Laser Ranging System

NAO National Astronomical Observatories (China)

NAO National Astronomical Observatory (Japan)

NAOC National Astronomical Observatories of China (China)

NAOJ National Astronomical Observatory of Japan (Japan)

NAR Noise-Adding Radiometer

NAS Network Attached Storage

NASA National Aeronautics and Space Administration (USA)

NASU National Academy of Sciences of Ukraine (Ukraine)

NCAR National Center for Atmospheric Research (USA)

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NCEP National Centers for Environmental Prediction (USA)

NCRIS National Collaborative Research Infrastructure Strategy (Australia)

NDBC National Data Buoy Center

NDRE Norwegian Defence Research Establishment (Norway)

NEA Near-Earth Asteroid

NENS Near Earth Network Services

NEOS National Earth Orientation Service (USA)

NEQ Normal Equation System

NESDIS National Environmental Satellite, Data, and Information Service (USA)

NetCDF Network Common Data Form

NEXPReS Novel EXploration Pushing Robust e-VLBI Services

NGII National Geographic Information Institute (Korea)

NGS National Geodetic Survey (USA)

NGSLR Next Generation Satellite Laser Ranging

NIC Network Interface Card

NICT National Institute of Information and Communications Technology (Japan)

NII National Institute of Informatics (Japan)

NIPR National Institute of Polar Research (Japan)

NMA Norwegian Mapping Authority (Norway)

NMF Niell Mapping Function

NNR No-Net-Rotation

NNT No-Net-Translation

NOAA National Oceanic and Atmospheric Administration (USA)

NOFS U.S. Naval Observatory, Flagstaff Station (USA)

NORAD North American Aerospace Defense Command

NOT Nordic Optical Telescope

NRAO National Radio Astronomy Observatory (USA)

NRC National Research Council of canada (Canada)

NRCan Natural Resources Canada (Canada)

NRF National Research Foundation (South Africa)

NSF National Science Foundation (USA)

NTP Network Time Protocol

NTT New Technology Telescope (Chile)

NTT Nippon Telegraph and Telephone Corporation (Japan)

NVI NVI, Inc. (USA)

NWP Numerical Weather Prediction

NySMAC Ny- ̊Alesund Science Managers Committee

OAM Observatorio Astron ́omico de Madrid (Spain)

OAN Observatorio Astron ́omico Nacional (Spain)

OASU Observatoire Aquitain des Sciences de l’Univers (France)

OCA Observatoire de la Cˆote d’Azur (France)

OCARS Optical Characteristics of Astrometric Radio Sources

OPAR Observatoire de Paris (France)

OPC (IVS) Observing Program Committee

ORCA Optical ReCeiver/splitter/Amplifier

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Orion KL Orion Kleinmann-Low

OS Operating System

OSI Operator Software Impact

OSO Onsala Space Observatory (Sweden)

OTL Ocean Tidal Loading

PARNASSUS Processing Application in Reference to NICT’s Advanced Set of Softwares Usable

for Synchronization

PASJ Publications of the Astronomical Society of Japan

PASP Publications of the Astronomical Society of the Pacific

PATA Parallel Advanced Technology Attachment

PC Principal Component

PCAL Phase CALibration

PCB Printed Circuit Board

PCU Power Control Unit

PEACESAT Pan-Pacific Education and Communication Experiments by Satellite

PERSAC Pulkovo EOP and Reference Systems Analysis Center (Russia)

PF Processing Factor

PFB Polyphase Filter Bank

PIVEX Platform Independent VLBI EXchange format

PLC Programmable Logic Controller

PLO Phase Locked Oscillator

PM Polar Motion

PMD Politecnico di Milano DIIAR (Italy)

PMRF Pacific Missile Range Facility (USA)

PNR Peak to Noise Ratio

POLARIS POLar motion Analysis by Radio Interferometric Surveying

POP Point of Presence

PPN Parameterized Post-Newtonian

PPP Precise Point Positioning

PRAO Pushchino Radio Astronomy Observatory (Russia)

PRARE Precise RAnge and Range-rate Equipment

PSD Power Spectrum Density

PSS Point Source Sensitivity

PTCB Precise Temperature Control Box

PWL PieceWise Linear

QDOR Quadruply Differenced One-way Ranging

QRFH Quad-Ridged Flared Horn

QRHA Quad-Ridge Horn Antenna

QZSS Quasi Zenith Satellite System (Japan)

RAEGE Red Atl ́antica de Estaciones Geodin ́amicas y Espaciales

RAID Redundant Array of Independent Disks

RAS Russian Academy of Sciences (Russia)

RCP Right Circular Polarization

RCU Receiver Control Unit

RDBE Roach Digital Back End

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RDBE-H RDBE Hardware version

RDBE-S RDBE Software version

RDV Research and Development sessions using the VLBA

RedCLARA CLARA (Cooperaci ́on Latino Americana de Redes Avanzadas) network

REFAG Reference Frames for Applications in Geosciences

REGINA REseau GNSS pour l’IGS et la NAvigation (GNSS Receiver Network for IGS and

Navigation) (France)

REPA REsidual Plotting and Ambiguity resolution

REUNA Red Universitaria Nacional (Chile)

RF Radio Frequency

RFCN Retrograde Free Core Nutation

RFI Radio Frequency Interference

RHC Right Hand Circular

ROACH Reconfigurable Open Architecture Computing Hardware

ROEN R ́adio-Observat ́orio Espacial do Nordeste (Brazil)

ROM Real Observatorio de Madrid (Spain)

RRFID Radio Reference Frame Image Database

RS-232C Recommended Standard-232C

RT Radio Telescope

RTCM Radio Technical Commission for Maritime services

RTIS Real-Time Ionospheric Scintillation

RTK Real-Time Kinematic

RTNF Radio Telescope National Facility (New Zealand)

RTP Real-Time Protocol

RTW Radio Telescope in Wettzell

SAC Satellite Application Centre

SAC-SOS Special Analysis Center for Specific Observing Sessions

SAGE Small Advanced Geodetic e-VLBI System

SAI Sternberg State Astronomical Institute (Russia)

SAN Storage Area Network

SANSA South African National Space Agency (South Africa)

SANSA EO South African National Space Agency Earth Observation

SAR Synthetic Aperture Radar

SAS Scandinavian AirlineS

SATA Serial Advanced Technology Attachment

SBIR Small Business Innovation Research

SC Sub-Commission

SCG SuperConducting Gravimeter

SCNS Space Communications Network Services

SCR Silicon Controlled Rectifier

SDK Software Development Kit

SDM Signal Distribution Modules

SDSS Signal Distribution and Synchronization System

SEAC Sociedad Espa ̃nola de Aplicaciones Cibern ́eticas (Spain)

SEFD System Equivalent Flux Density

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SETI Search for Extraterrestrial Intelligence

SG Superconducting Gravimeter

SGL Space Geodynamics Laboratory (Canada)

SGP Space Geodesy Project

SGT Stinger Ghaffarian Technologies (USA)

SHAO SHanghai Astronomical Observatory (China)

SI Special Issue

SI Structure Index

SIDC Solar Influence Data Center (Belgium)

SIMD Single Instruction Multiple Data

SINEX Solution INdependent EXchange

SISMA Seismic Information System for Monitoring and Alert

SK Spectral Kurtosis

SKA Square Kilometre Array

SLR Satellite Laser Ranging

SMA SubMillimeter Array (USA)

SMA SubMiniature type-A

SMART Small Missions for Advanced Research and Technology

SMHI Swedish Meteorological and Hydrological Institute (Sweden)

SMTO SubMillimeter Telescope Observatory (USA)

SNAP Standard Notation for Astronomical Procedures

SNR Signal to Noise Ratio

SNSN Swedish National Seismic Network (Sweden)

SOD Site Occupation Designator

SOSW Satellite Observing System Wettzell (Germany)

SPb Saint-Petersburg (Russia)

SPbU Saint-Petersburg University (Russia)

SPEED Short Period and Episodic Earth rotation Determination

SPU Saint-Petersburg University (Russia)

SPV Signal Path Variation

SRIF Square Root Information Filter

SRT Sardinia Radio Telescope (Italy)

SRTM Shuttle Radar Topography Mission

SSA Singular Spectrum Analysis

SSAI Science Systems and Applications, Inc. (USA)

SSB Solar System Barycenter

STDN Satellite Tracking Data Network (NASA)

STEREO Solar TErrestrial RElations Observatory

SU Station Unit

SUDP Simple User Datagram Protocol

SVD Singular Value Decomposition

SvRAO Svetloe Radio Astronomical Observatory (Russia)

SWT SW Technology (USA)

SYRTE SYst`eme de R ́ef ́erences Temps-Espace

TAC Totally Accurate Clock

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List of Acronyms

TAI Temps Atomique International (International Atomic Time)

TAL Terrestrial Air Link

TANAMI Tracking Active galactic Nuclei with Austral Milliarcsecond Interferometry

(Australia)

TanDEM-X TerraSAR-X add-on for Digital Elevation Measurement (Germany)

TAO Telecommunications Advanced Organization (Japan)

TCE Time Comparison Equipment

TDC (IVS) Technology Development Center

TEC Total Electron Content

TECU Total Electron Content Units

TEIN Trans-Eurasia Information Network

Telecom NZ Telecom New Zealand

TEM Transverse ElectroMagnetic

TEMPO Time and Earth Motion Precision Observations

TENET Tertiary Education and Research Network of South Africa (South Africa)

TERENA Trans-European Research and Education Networking Association

TerraSAR Terra Synthetic Aperture Radars (Germany)

TerraSAR-X Terra Synthetic Aperture Radars X-band (Germany)

TID Traveling Ionospheric Disturbance

TIGA–PP GPS TIde GAuge Benchmark Monitoring Pilot Project

TIGO Transportable Integrated Geodetic Observatory (Germany, Chile)

TLE Two Line Elements

TLRS Transportable Laser Ranging System

TMR Training and Mobility of Researchers program of the European Community

ToR IVS Terms of Reference

TOW Technical Operations Workshop

TRF Terrestrial Reference Frame

TSPM Test Synchronization Pulsar gating Module

TTC Tracking, Telemetry, and Command

TTL Transistor-Transistor Logic

TTW Twin Telescope Wettzell (Germany)

TU Technische Universit ̈at

TUM Technische Universit ̈at M ̈unchen (Technical University of Munich) (Germany)

TWA Travel Wave Antennas

TWSTFT Two-Way Satellite Time and Frequency Transfer

UAO Urumqi Astronomical Observatory (China)

UBB Universidad del B ́ıo B ́ıo (Chile)

UC Berkeley University of California, Berkeley (USA)

UCP Unified Control Point

UD Upper Diagonal

UDC Up-Down Converter

UDMA Ultra Direct Memory Access

UEN Up East North

UMTS Universal Mobile Telecommunications System

UNAVCO University NAVSTAR Consortium

426 IVS 2012 Annual Report
List of Acronyms

UNICAMP Universidade Estadual de Campinas (Brazil)

UNISEC UNIversity Space Engineering Consortium (Japan)

UNITEC-1 UNIsec Technological Experiment Carrier-1 (Japan)

UR Ultra Rapid

UREO Ultra-Rapid Earth Orientation

URSI Union Radio-Scientifique Internationale

USB Unified S-Band

USB Upper Side Band

USNO United States Naval Observatory (USA)

USP Universidade de S ̃ao Paulo (Brazil)

USS Uniform Sky Strategy

UT Universal Time

UT1 Universal Time

UTAS University of TASmania (Australia)

UTC Coordinated Universal Time

u-VLBI Ultra High Sensitivity VLBI

UWB Ultra WideBand

V2PEG VLBI2010 Project Executive Group

VC Variance Components

VC Video Converter

VCS VLBA Calibrator Survey

VDBE VLBA Digital BackEnd

VDIF VLBI Data Interchange Format

VEGA Venus-Halley project (Russia)

VERA VLBI Exploration of Radio Astrometry

VEX Venus EXpress

VEX VLBI EXchange format

VHDL Very High-level Design Language

VieVS Vienna VLBI Software

VGOS Vlbi2010 Global Observing System

VLA Very Large Array (USA)

VLBA Very Long Baseline Array (USA)

VLBI Very Long Baseline Interferometry

VMF Vienna Mapping Function

VMware Virtual Machine software

VO Virtual Observatory

VSI VLBI Standard Interface

VSI-C Mets ̈ahovi VSI-H Converter board

VSI-H VLBI Standard Interface Hardware

VSI-S VLBI Standard Interface Software

VSN Volume Serial Number

VSOP VLBI Space Observatory Program

VSR VLBI Science Recorder

VSSP Versatile Scientific Sampling Processor

VTEC Vertical Total Electron Content

IVS 2012 Annual Report 427
List of Acronyms

VTM Vienna TEC (Total Electron Content) Model

VTP VLBI Transport Protocol

VTRF VLBI Terrestrial Reference Frame

WACO WAshington COrrelator (USA)

WEBT Whole Earth Blazar Telescope

WEGENER Working Group of European Geoscientists for the Establishment of Networks for

Earth-science Research

WG Working Group

WGS84 World Geodetic System 1984

WIDAR Wideband Interferometric Digital ARchitecture

WLAN Wireless Local Area Network

WLRS Wettzell Laser Ranging System (Germany)

WMAP Wilkinson Microwave Anisotropy Probe

WVR Water Vapor Radiometer

WVSR Wideband VLBI Science Recorder

WWW World Wide Web

XDM eXperimental Development Model

ZcRAO Zelenchukskaya Radio Astronomical Observatory (Russia)

ZTD Zenith Total Delay

ZWD Zenith Wet Delay

428 IVS 2012 Annual Report