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Front cover: The year 2010 marks the beginning of construction of the IVS next generation VLBI network. The network will consist of fast slewing 12-meter 

class antennas with signal electronics that have been completely revised to process four bands each independently settable to any frequency in 

the full 2-14 GHz range. The new broadband system was designed to achieve extremely precise delays at modest SNR and to have the 

frequency flexibility to avoid RFI. The network is expected to grow over the next several years. The use of four frequency bands within the 2-14 

GHz range to determine the phase delay is likely to require correction for the structure of the radio sources as part of the VLBI2010 

observations and data analysis. This volume contains several reports from components that describe advances in VBLI2010 technology 

and network evolution.
NASA/TP—2011–21

 

International VLBI Service for Geodesy 

and Astrometry 2010 Annual Report 

Dirk Behrend (ed.)

NVI, Inc., Greenbelt, Maryland 

 

Karen D. Baver (ed.)

NVI, Inc., Greenbelt, Maryland 

 Click here: Press F1 key (Windows) or Help key (Mac) for help 

National Aeronautics and 

Space Administration 

Goddard Space Flight Center 

Greenbelt, MD 20771-0001 

May 2011
Available from:

NASA Center for AeroSpace Information

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Price Code: A10
Preface

This volume of reports is the 2010 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 2010 Annual Report documents the work of the IVS components for the calendar year

2010, our twelfth 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.

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

http://ivscc.gsfc.nasa.gov/publications/ar2010

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 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 2010.

• 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

IVS Coordination ............................................................... 11

Coordinating Center Report ..........................................................................13

Analysis Coordinator Report ......................................................................... 16

Network Coordinator Report ......................................................................... 18

IVS Technology Coordinator Report ..................................................................21

Network Stations ............................................................... 25

Fortaleza Station: 2010 Status and Antenna Repair .................................................. 27

Goddard Geophysical and Astronomical Observatory ................................................. 31

Hartebeesthoek Radio Astronomy Observatory (HartRAO) ........................................... 35

Hobart, Mt. Pleasant Station and AuScope VLBI Project Report .....................................39

Kashima 34-m Radio Telescope .......................................................................42

Kashima and Koganei 11-m VLBI Stations ........................................................... 46

Kokee Park Geophysical Observatory .................................................................50

Matera CGS VLBI Station ........................................................................... 54

The Medicina Station Status Report ................................................................. 58

VERA Geodetic Activities ........................................................................... 60

Noto Station Status Report .......................................................................... 64

Ny- ̊Alesund 20-meter Antenna ....................................................................... 68

German Antarctic Receiving Station (GARS) O’Higgins .............................................. 71

Onsala Space Observatory – IVS Network Station .................................................... 75

Parkes 2010 IVS Report ..............................................................................79

Sheshan VLBI Station Report for 2010 ............................................................... 83

Stations of Space Geodesy and Geodynamics of CrAO: Simeiz VLBI, Simeiz-1873 SLR, CrAO-GPS ...85

JARE Syowa Station 11-m Antenna, Antarctica ...................................................... 89

Geodetic Observatory TIGO in Concepci ́on .......................................................... 93

Tsukuba 32-m VLBI Station ......................................................................... 97

Nanshan VLBI Station Report for 2010 ............................................................. 101

Warkworth 12-m VLBI Station: WARK12M ........................................................ 105

Westford Antenna .................................................................................. 109

Geodetic Observatory Wettzell: 20-m Radio Telescope and Twin Telescope .......................... 113

Instituto Geogr ́afico Nacional of Spain .............................................................. 117

Operation Centers ............................................................. 121

The Bonn Geodetic VLBI Operation Center .........................................................123

CORE Operation Center Report .................................................................... 125

NEOS Operation Center ............................................................................ 129

v
Correlators .... ................................................................. 131

The Bonn Astro/Geo Correlator .................................................................... 133

Haystack Observatory VLBI Correlator ............................................................. 137

IAA Correlator Center .............................................................................. 141

VLBI Correlators in Kashima ....................................................................... 144

Tsukuba VLBI Correlator ...........................................................................147

Washington Correlator ..............................................................................151

Data Centers ................................................................... 155

BKG Data Center .................................................................................. 157

CDDIS Data Center Summary for the IVS 2010 Annual Report ..................................... 159

Italy INAF Data Center Report .....................................................................162

Data Center at NICT ............................................................................... 163

Paris Observatory (OPAR) Data Center .............................................................167

Analysis Centers ............................................................... 171

Analysis Center of Saint Petersburg University ...................................................... 173

Geoscience Australia Analysis Center ............................................................... 175

Report for 2010 from the Bordeaux IVS Analysis Center ............................................ 179

BKG/DGFI Combination Center Annual Report 2010 ...............................................183

Matera CGS VLBI Analysis Center ................................................................. 187

DGFI Analysis Center Annual Report 2010 ......................................................... 189

FFI Analysis Center ................................................................................ 192

The BKG/IGGB VLBI Analysis Center ............................................................. 194

GSFC VLBI Analysis Center ........................................................................198

Haystack Observatory Analysis Center .............................................................. 202

IAA VLBI Analysis Center Report 2010 .............................................................205

Vienna IGG Special Analysis Center Annual Report 2010 ........................................... 209

Italy INAF Analysis Center Report ................................................................. 213

JPL VLBI Analysis Center Report for 2010 ......................................................... 215

KASI Combination Center Report .................................................................. 219

KTU-GEOD IVS Analysis Center Annual Report 2010 .............................................. 223

IVS Analysis Center at Main Astronomical Observatory of National Academy of Sciences of Ukraine 227

Analysis Center at National Institute of Information and Communications Technology ...............229

NMA Analysis Center ...............................................................................233

Paris Observatory Analysis Center OPAR: Report on Activities, January—December 2010 .......... 236

Onsala Space Observatory – IVS Analysis Center ....................................................240

New Associate Analysis Center Established at PMD .................................................244

Pulkovo IVS Analysis Center (PUL) 2010 Annual Report ............................................247

SAI VLBI Analysis Center Report 2010 ............................................................. 250

SHAO Analysis Center 2010 Annual Report .........................................................252

Tsukuba VLBI Analysis Center ..................................................................... 253

U.S. Naval Observatory VLBI Analysis Center ...................................................... 257

USNO Analysis Center for Source Structure Report ................................................. 261

Technology Development Centers ........................................... 265

Canadian VLBI Technology Development Center ....................................................267

FFI Technology Development Center—Software Development ....................................... 268

GSFC Technology Development Center Report ......................................................269

Haystack Observatory Technology Development Center ..............................................272

Technology Development Center at NICT ........................................................... 276

Onsala Space Observatory – IVS Technology Development Center ................................... 280

vi
Bibliography .... ............................................................... 285

Bibliography ........................................................................................ 287

IVS Information ................................................................ 303

IVS Terms of Reference ............................................................................. 305

IVS Member Organizations ......................................................................... 315

IVS Affiliated Organizations ........................................................................ 317

IVS Associate Members ............................................................................. 318

IVS Permanent Components ........................................................................ 328

Addresses of Institutions of Authors Contributing to this Report .................................... 332

List of Acronyms ....................................................................................340

vii

About IVS

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

• 27 Network Stations, acquiring high performance 

VLBI data,

• 3 Operation Centers, coordinating the activities of a 

network of Network Stations,

• 6 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,

• 26 Analysis Centers, analyzing the data and producing 

the results and products,

• 7 Technology Development Centers, developing new 

VLBI technology,

• 1 Coordinating Center, coordinating daily and long 

term activities.

Altogether

• 79 Permanent Components, representing 41 institutions in 19 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

performance feedback

data bases

Coordinating

Center

Analysis

Centers

Analysis

Coordinator

Network

Stations

Operation

Centers

Technology

Development

Centers

Users

Network

Coordinator

Technology

Coordinator

• Publications

• Web Site

• Master Schedule

raw data 10-20Gb/s

(disks, ftp)

performance feedback

correlated data bases

analyzed results and products

schedules

products for EOP, TRF, CRF

Data

Centers

Correlators

IAG IAU IVS Directing

Board
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

Observatoire de Paris France

Observatoire 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

Istituto di Radioastronomia INAF Italy

Agenzia Spaziale Italiana Italy

Politecnico di Milano DIIAR Italy

Geographical Survey Institute 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 Defence Research 

Establishment

Norway

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

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 3

France 3

Germany 8

Italy 8

Japan 12

Norway 4

Russia 9

South Africa 1

South Korea 1

Spain 1

Sweden 3

Turkey 1

Ukraine 2

USA 16

Total 79

A complete list of IVS Permanent

Components is in the IVS Information

section of this volume.

O'Higgins

NEOS

GGAO

Canadian VLBI

Haystack

USNO

GSFC

JPL

Kokee Park

O'Higgins

Fortaleza

NEOS

GGAO

Canadian VLBI

Haystack

USNO

GSFC

JPL

Kokee Park

TIGO Network Station

Former Station

Operation Center

Correlator

Data Center

Analysis Center

Technology Development Center

Coordinating Center

Network Station

Former Station

Operation Center

Correlator

Data Center

Analysis Center

Technology Development Center

Coordinating Center

Gilmore Creek

Yellowknife

Algonquin
5

Syowa

Hartebeesthoek

Seshan

Nanshan

Shanghai

Kashima 11

Koganei

Tsukuba

NICT

Mizusawa

Kashima34

TU Vienna

Yebes

Noto

Wettzell

Simeiz

DGFI

INAF

Matera

BKG

Svetloe

IAA

MAO

AIStPbU

Bordeaux

Paris

FGS(BKG,IGGB)

IGGB

FFI Onsala

Ny Ålesund

Seshan

Nanshan

Badary

Shanghai

Kashima 11

Koganei

Tsukuba

NICT

Mizusawa

GA

Kashima34

Medicina

TU Vienna

Yebes

Noto

DGFI Wettzell

INAF

Matera

BKG

Svetloe

IAA

MAO

KTU

AIStPbU

Bordeaux

Paris

FGS(BKG,IGGB)

IGGB

FFI

NMA

PMD

Onsala

Ny Ålesund

Syowa

Hartebeesthoek

Simeiz

Hobart

Parkes

Zelenchukskaya

KASI

PUL

SAI
6

IVS Directing Board

NAME: Hayo Hase

AFFILIATION: Bundesamt für 

Kartographie und Geodäsie/

TIGO, Germany/Chile

POSITION: Networks 

Representative

TERM: Feb 2007 to Feb 2011

NAME: Ed Himwich

AFFILIATION: NVI, Inc./Goddard 

Space Flight Center, USA

POSITION: Network

Coordinator

TERM: permanent

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: Chair and IAG 

Representative

TERM: ex officio

NAME: Andrey Finkelstein

AFFILIATION: Institute of

Applied Astronomy, Russia

POSITION: At Large Member

TERM: Feb 2009 to Feb 2011

NAME: Patrick Charlot

AFFILIATION: Bordeaux Observatory, France

POSITION: IAU Representative

TERM: ex officio
7

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: Xiuzhong Zhang

AFFILIATION: Shanghai Astronomical Observatory, China

POSITION: At Large Member

TERM: Feb 2009 to Feb 2011

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: Kazuhiro Takashima

AFFILIATION: Geographical 

Survey Institute, Japan

POSITION: At Large Member

TERM: Feb 2009 to (Feb 2011)

NAME: Kerry Kingham

AFFILIATION: U.S. Naval

Observatory, USA

POSITION: Correlators

and Operation Centers

Representative

TERM: Feb 2007 to Feb 2011
8

IVS Chair’s Report

Harald Schuh

Institute of Geodesy and Geophysics, Vienna University 

of Technology

With the 2010 Annual Report the IVS components report 

about their progress and activities which were conducted 

during the service’s twelfth 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 2010 IVS observing activities were slightly reduced with 

respect to previous years, mostly because of major station repair work at Wettzell and Fortaleza. Nonetheless, 

the remainder of the 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 2010 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). GGOS will 

provide the most precise terrestrial and celestial reference frames based on the well-established, international 

space-geodetic services. 

Integration and combination in the framework of GGOS 

is the main challenge for the international geodesy in the 

new 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. Eventually 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 2010 

was to continue its contribution as an efficient partner 

within GGOS. Several GGOS events were attended in 

2010 with presentations about the IVS and its next generation VLBI2010 system; the IVS is well represented in 

the GGOS Steering Committee. 

VLBI2010 and the VLBI2010 Committee 

(V2C)

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 

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.

VLBI2010 is supposed to provide not only the visions 

but also very detailed specifications for future VLBI systems. Right now several countries have already decided 

to develop or purchase new VLBI systems. We highly 

appreciate that Geoscience Australia (GA), Australia; 

Auckland University of Technology (AUT), New Zealand; 

Korea Astronomy & Space Science Institute (KASI) and 

National Geographic Information Institute (NGII), Korea; 

the NASA Goddard Space Flight Center (GSFC), USA; 
9

IVS Working Group 5 on “Space Science 

Applications” 

The current mandate of the WG5, chaired by Leonid Gurvits, 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.

IVS Working Group 6 on “VLBI Education 

and Training” 

The IVS Directing Board established at its meeting in Bordeaux 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.

the Norwegian Mapping Agency (NMA); the Bundesamt 

für Kartographie und Geodäsie (BKG), Germany; Instituto Geográfico Nacional (IGN), Spain together with the 

Regional Government of the Azores, Portugal; and the 

National Astronomy and Ionosphere Center (NAIC), operated by Cornell University at Arecibo, Puerto Rico, started 

or continued their activities to implement new telescopes 

of the VLBI2010 type. I would like to congratulate them 

on the ambitious projects and wish them success for the 

realization in the next years. Thus, already now twelve 

VLBI2010 antennas have been approved with more proposals under consideration or even in review in countries 

like Russia, Finland, France, Saudi Arabia, and Sweden. 

With new antennas and the expected re-opening of the 

Fairbanks radio telescope, the global coverage of geodetic 

VLBI is getting better, but it is still far from being optimal, 

in particular more VLBI sites in the southern hemisphere 

would be more than welcome. 

After providing the detailed description of the VLBI2010 

concept the current task for the IVS is its realization. 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, which was established in March 

2009, continued its activities in 2010. Several letters of support were sent to government bodies and funding agencies 

all over the world and a so-called station survey was sent 

to the IVS network stations in December 2010. 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. 

IVS Working Group 4 on “VLBI Data 

Structures”

The IVS Working Group on “VLBI Data Structures” established in September 2007 is a response to the strong 

need of new, common VLBI data structures. This Working 

Group examines the data structure currently used in VLBI 

data processing and investigates what data structure is 

likely to be needed in the future. It designs a data structure 

that meets current and anticipated future requirements 

including a cataloging, archiving, and distribution system. 

Further, it prepares the transition capability through conversion of the current data structure as well as cataloging 

and archiving softwares to the new VLBI2010 system. The 

chair of Working Group 4, John Gipson, gave a presentation about the new format, which is based on the Network 

Common Data Format (NetCDF), at the IVS General 

Meeting in Hobart. The final release of the new format is 

scheduled for 2011.
10

IVS Chair’s Report Continued

Events in 2010

In February 2010, we held our sixth General Meeting in 

Hobart, Tasmania, Australia. In conjunction with the General Meeting, an IVS Analysis Workshop, a V2C meeting, 

and the 23rd Directing Board Meeting were organized. 

The Proceedings of the 6th IVS General Meeting have 

been printed already on almost 500 pages with Dirk Behrend and Karen D. Baver as editors, demonstrating that 

the IVS is a fast and efficient organization. I would like to 

thank the Local Organizing Committee, whose members 

were John Dickey, Karen Bradford, Jim Lovell, Richard 

Coleman, Christopher Watson, Simon Ellingsen, Gary 

Johnston, Oleg Titov, and Sergei Gulyaev for the excellent organization. I thank also the session conveners and 

all other individuals who contributed to the great success 

of the meeting. The University of Tasmania is deeply 

acknowledged for providing the meeting facilities and 

for the great hospitality we received from the Australian 

colleagues. A special highlight was certainly the official 

dedication ceremony of the 12-m AuScope antenna held 

at Hobart station. The memorable inauguration done by 

the Governor of Tasmania, His Excellency, The Honourable 

Sir Peter Underwood, was attended by almost 200 people, 

VLBI specialists as well as members of the University of 

Tasmania and other local representatives. 

On 23 October 2010, the 24th Directing Board Meeting 

was held in Shanghai, in connection with the Joint GGOS/

IAU Workshop on Observing and Understanding Earth 

Rotation. I take this opportunity to thank our dear colleague 

and member of the Directing Board, Prof. Xiuzhong Zhang, 

Shanghai Astronomical Observatory, for the excellent 

organization and making the stay a very pleasant one. 

One new IVS Operational Analysis Center (Geospatial 

Information Authority of Japan) and two new IVS Associate Analysis Centers were approved in 2010 (Norwegian 

Mapping Agency, Norway and Politecnico di Milano, Italy); 

one new ‘Special Analysis Center for Specific Observing 

Sessions’ SAC-SOS (Institute of Geodesy and Geophysics, Vienna, Austria), and one Observing Station (Parkes 

CSIRO Radio Telescope, Australia) were also accepted 

as new IVS components. 

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

nasa.gov and in the IVS Newsletters 26, 27, and 28. 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 Directing Board in 2010

In 2010 the Directing Board member Kazuhiro Takashima, 

GSI, Japan, withdrew for personal reasons and was replaced by Shinobu Kurihara (GSI). The elections of new 

Directing Board members for the term 2011 to 2015 were 

held in December 2010. The elected representatives are: 

- Networks representative: Hayo Hase, TIGO Concepción 

(Chile)

- Correlators and Operations Centers representative: Alessandra Bertarini, Bonn Correlator (Germany)

For the at-large positions (term 2011 to 2013), Shinobu 

Kurihara, Geospatial Information Authority of Japan; 

Fengchun Shu, Shanghai Astronomical Observatory, 

China; and Jesús Gómez-González, National Geographical Institute of Spain were chosen to complement the 

Directing Board. I am very pleased that the IVS Directing 

Board is well balanced in its composition with respect to 

global coverage, with respect to component representation, and with respect to a good mixture of experienced 

and young members.

IVS Highlights in the Coming Year 2011

In the week from March 28, 2011 the 20th European VLBI 

for Geodesy and Astrometry (EVGA) Working Meeting will 

be held in Bonn (Germany) organized by Max-PlanckInstitute for Radio Astronomy (MPIfR) together with the 

VLBI group at the Institute of Geodesy and Geoinformation 

(IGG) of Bonn University. It will be a great pleasure to return to the location where the first European VLBI meeting 

took place more than 30 years ago under the leadership of 

James Campbell. James will also attend the event in Bonn 

and tell us about the history of European VLBI.

Finally, I would like to mention the next continuous VLBI 

session (CONT11) that will take place in the second half 

of September 2011 and is anticipated to be observed on a 

network of 16 stations. As the CONT sessions have always 

shown the best possible performance of international VLBI 

and provided the most interesting and valuable results 

we expect another bunch of extremely useful VLBI data. 

It should also be mentioned here that a special issue of 

Journal of Geodesy about the scientific usage of CONT08 

data is in preparation and will be published soon. 
IVS Coordination

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 2010 and

forecasts activities planned for the year 2011.

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 2010

During the period from January through December 2010, the Coordinating Center supported

the following IVS activities:

• Directing Board support: Coordinated, with local committees, two IVS Directing Board

meetings, in Hobart, Tasmania, Australia (February 2010) and Shanghai, China (October

2010). Notes from each meeting were published on the IVS Web site.

• Communications support: Maintained the Web pages, e-mail lists, and Web-based mail

archive files. Included analysis reports on the 24-hour session Web pages. Maintained Intensive session Web pages.

• Publications: Published the 2009 Annual Report in summer 2010. Published three editions

of the IVS Newsletter in April, August, and December, 2010. 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.

• 2010 Master Schedule: Generated and maintained the master observing schedule for 2010.

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.

• 2011 Master Schedule: Generated the proposed master schedule for 2011 and received approval from the Observing Program Committee.

• VLBI2010: Supported the activities of the VLBI2010 Committee (V2C) and the VLBI2010

Project Executive Group (V2PEG). Coordinated the program of the VLBI2010 Developers

and Analysis meeting in Hobart.

IVS 2010 Annual Report 13
IVS Coordinating Center NASA Goddard Space Flight Center

• Meetings: Coordinated, with the Local Committee, the sixth IVS General Meeting, held in

Hobart, Tasmania, Australia in February 2010. Chaired the Program Committee for the

meeting.

Figure 1. Inauguration event of the Hobart 12-m antenna during the sixth IVS General Meeting.

Assisted with the organization of the workshop “VLBI and GNSS: New Zealand and Australian Perspectives” held in Auckland, New Zealand. Served on the Scientific Organizing

Committee of the workshop.

Figure 2. Participants of the workshop “VLBI and GNSS: New Zealand and Australian Perspectives” at

Auckland University of Technology.

14 IVS 2010 Annual Report
NASA Goddard Space Flight Center IVS Coordinating Center

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.

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

4. Plans for 2011

The Coordinating Center plans for 2011 include the following:

• Maintain IVS Web site and e-mail system.

• Publish the 2010 Annual Report (this volume).

• Coordinate, with the local committee, the sixth IVS Technical Operations Workshop to be

held at MIT Haystack Observatory in May 2011.

• Support Directing Board meetings in 2011.

• Coordinate the 2011 master observing schedules and IVS resources.

• Publish Newsletter issues in April, August, and December.

• Support the VLBI2010 activities of the V2C and the V2PEG.

IVS 2010 Annual Report 15
IVS Analysis Coordinator Institut f ̈ur Geod ̈asie und Geoinformation der Universit ̈at Bonn

Analysis Coordinator Report

A. Nothnagel, S. Tesmer n ́ee B ̈ockmann, T. Artz

Abstract

IVS 2010 analysis coordination issues that may also cause noticeable impacts for the future are

reported here. Routine Earth orientation parameter combinations on the basis of datum-free normal

equations were transfered to the IVS Combination Center at BKG, Frankfurt a.M., Germany.

1. General Issues

The “Eleventh IVS Analysis Workshop” was hosted by the University of Tasmania, School of

Mathematics and Physics, Hobart, Australia, on February 11, 2010, in connection with the Sixth

IVS General Meeting. The coordination of IVS routine data analysis was discussed as well as

developments for improving geodetic and astrometric data analysis in general.

The timeliness of the submission of the SINEX files from the operational IVS Analysis Centers

to the IVS Data Centers has remained an issue of constant annoyance. The reason is that the

combination process has to wait until at least four centers have submitted their results. The

irregular composition of contributions generates an additional component of noise to the combined

products. At the same time, the IERS Earth Orientation Product Center and the IERS Rapid

Service and Prediction Center are delayed in including the VLBI results in their combinations as

well. This leads to a constant downweighting of the IVS products in the IERS combinations.

During the Analysis Workshop, it was shown that the treatment of the subdaily tidal Earth rotation parameter variations and the introduction of harmonic site position variations may generate

alias effects in the daily EOP time series. Especially the pole rates and the nutation components

are affected by model differences by up to 100 μas/d and 50 μas, respectively. The Analysis

Coordinator emphasized that the Analysis Centers should strictly follow the IERS Conventions

including Tab. 5.1 in their routine EOP determinations.

A number of tests have been carried out to support endeavors to achieve suitability of analysis

packages and their results for the combination. Furthermore, the implementations of the Vienna

Mapping Function 1 (VMF1) in Calc/Solve by GSFC and BKG have been tested and compared.

2. IVS Operational Data Analysis and Combination

From October 1, 2009, the operational combination has been taken over 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 are datum-free (constraintfree) normal equation systems in SINEX format (Solution Independent Exchange format). The

transition from the nutation representation in the ecliptic system through nutation in longitude

dψ and obliquity dε to the nutation representation in the IAU2000 paradigm, dX and dY , has

been realized successfully in most of the analysis software packages. Therefore, the combination

is now solely based on this new representation. For users of the old system, a separate table is

generated through a transformation.

The next steps of combination, in particular with respect to future computations of the International Terrestrial Reference Frame (ITRF), are planned to also include the elements for the

16 IVS 2010 Annual Report
Institut f ̈ur Geod ̈asie und Geoinformation der Universit ̈at Bonn IVS Analysis Coordinator

radio source positions in the normal equation systems. All software developers have been informed

by the Analysis Coordinator that this step is imminent.

3. UT1 Intensive Sessions

At present, the results of the 1h UT1-UTC Intensive sessions are reported by the analysis

centers in the IVS EOP exchange format (for more details see IVS Analysis Coordinator’s Web

page). Due to a lack of resources, a combination of the Intensive results is not foreseen in the near

future. However, the individual results are still very valuable since they have been used by various

agencies for further processing. In order to make optimal use of these results, it is necessary to

also report the polar motion a prioris in the result files (eopi files). All analysts dealing with the

analysis of Intensive sessions are kindly asked to also report their polar motion a prioris in the

respective files.

In the not too distant future, all of the Intensive observing sessions will be operated in an

e-VLBI mode for the transmission of the raw data. This is already the case for the INT2 and

INT3 sessions. With this in place, the latency between observations and data analysis will be as

short as a few hours only. At this time, some of the necessary auxiliary data like polar motion or

mapping functions from numerical weather models, like VMF1, will not yet be available and will

have to be replaced by predictions. Therefore, the initial results can only be considered as being

preliminary, and a mechanism of UT1 products with staggered latencies and accuracies will have

to be introduced. For the purpose of developing a plan for a properly organized setup, a ‘Task

Force on Intensives’ was established under the lead of R ̈udiger Haas.

4. Thermal Expansion of Radio Telescopes

Further details of radio telecopes have been collected in the antenna-info file under the url

http://vlbi.geod.uni-bonn.de/IVS-AC/Conventions. The background of the thermal expansion

models is described in [1].

5. Personnel

Table 1. Personnel at the IVS Analysis Coordinator’s office

Axel Nothnagel +49-228-733574 nothnagel@uni-bonn.de

Thomas Artz +49-228-733563 thomas.artz@uni-bonn.de

Sarah Tesmer +49-228-733563 boeckmann@uni-bonn.de (until Dec. 15, 2010)

n ́ee B ̈ockmann

References

[1] Nothnagel A. (2009) Conventions on thermal expansion modelling of radio telescopes for geodetic and

astrometric VLBI. J. Geod 83(8):787–792, doi:10.1007/s00190-008-0284-z

IVS 2010 Annual Report 17
Network Coordinator NVI, Inc./GSFC

Network Coordinator Report

Ed Himwich

Abstract

A brief report on network performance is presented. Most of network operations went well. Some

positive developments are identified. There were a few significant problems, mostly with antennas. New

antennas have been or are being built by Australia, New Zealand, and the USA. There are prospects

for Korea, India, and Saudi Arabia to start contributing to IVS.

1. Network Performance

The overall network performance was for the most part good. This year’s report does not

include the usual detailed assessment of overall network performance. However, the usual average

single station loss of 10-20% probably occurred again this year.

One of several positive developments this year was the increased usage of e-transfer. This

speeds data transfer and reduces shipping costs. Another positive development was that Mark

5B recorders were installed at several stations. This will improve correlator efficiency. A third

development is that digital back-ends are starting to be used for operations. The DBBC developed

by the EVN is being used at Hobart in Australia (which in another positive development has just

started observing) and will be used at Katherine and Yarragadee as well and in New Zealand. The

Haystack/NRAO developed RDBE is nearing readiness for observations and is expected to start

being used in 2011.

Overall, while the network operated well for the most part, there are a few notable issues (in

alphabetical order):

• Fortaleza was down with antenna problems the whole year. They are expected to begin

observing again in spring 2011.

• Kokee Park is operating on a single (damaged) azimuth gearbox while the other one is

repaired. The repair is expected to be completed in 2011, and then the other azimuth

gearbox will be repaired.

• The HartRAO 26-m antenna started observing again in August after being off-line almost

two years due to a bearing problem.

• Matera had a warm X-band receiver all year. It is expected to be repaired in spring 2011.

• The receiver at Medicina warmed up in November. It is not clear when it will be repaired.

• Noto suffered a bearing failure and was unable to observe from April onward. Repair is

expected to be completed no sooner than fall 2011.

• Ny- ̊Alesund has had higher than normal SEFDs since about May 2011. The cause of this is

being investigated.

• The O’Higgins burst had to be canceled due to illness.

• TIGO had been having a significant number of quality factor zero scans. This was traced to

a source modeling problem on baselines involving TIGO in the scheduling process, and the

problem was corrected. TIGO has for several years had higher than normal SEFDs. There

has been no success in resolving this issue.

18 IVS 2010 Annual Report
NVI, Inc./GSFC Network Coordinator

• Svetloe has antenna problems dating from the previous year but began observing again in

July.

• The Tsukuba antenna was damaged by a lightning strike and missed observing from approximately August through September.

• Wettzell required antenna repairs, and they were out of operation from September through

November. They also had a reduced observing load for the months of April through August

while waiting for the repairs.

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):

• In Australia, the new 12-m antenna at Hobart has been completed and started initial observations. New antennas at Katherine and Yarragadee are under construction. It is expected

that all three of these antennas will be contributing to IVS in 2011.

• In New Zealand, the station at Warkworth has its antenna in place. It is expected that this

antenna will start observing for IVS in 2011.

• 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 VLBI2010 systems, it is expected

that it will eventually join the network for regular observing.

• At Arecibo in Puerto Rico a new 12-m antenna has been erected and is expected to be used

for geodetic observing.

• At Wettzell in Germany, construction of the new Twin Telescope Wettzell (TTW) for

VLBI2010 is underway.

• 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 VLBI2010 specifications: Yebes (1), Canary Islands (1), and

Azores (2).

• In Norway, the Norwegian Mapping Authority (NMA) has applied for a project to establish

a fundamental station at Ny- ̊Alesund, which will include a twin telescope of the Wettzell

type.

• Onsala is also applying for funds for a twin telescope system.

• In Russia, an effort is underway to get 12-m VLBI2010 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 with construction to be completed in 2011. 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.

IVS 2010 Annual Report 19
Network Coordinator NVI, Inc./GSFC

• 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 VLBI2010.

20 IVS 2010 Annual Report
MIT Haystack Observatory IVS Technology Coordinator Report

IVS Technology Coordinator Report

Alan Whitney

Abstract

The efforts of the Technology Coordinator in 2010 include the following areas: 1) support of work

to implement the new VLBI2010 system, 2) e-VLBI development, 3) continuing development of global

VLBI standards, and 4) DiFX software correlator for geodetic VLBI. We will briefly describe each of

these activities.

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 report; here we briefly

report some of the highlights:

1.1. Development of the VLBI2010 Broadband System

The VLBI2010 system continues to develop at several locations:

1. Completion and demonstration at Haystack of an RDBE personality for geodetic VLBI

observations: The current working version accepts two 512mHz IFs, channelizes each into

fifteen adjacent 32mHz-wide channels using polyphase filter band (PFB) technology; the user

can choose any 16 of these channels to be sent to a 10GigE data link at an aggregate rate

of 2 Gbps, which is then recorded on a Mark 5C data system in Mark 5B+ data format. A

version of this RDBE supporting the VDIF output format is currently under development,

as well as an RDBE version capable of supporting up to four 512mHz IFs. Support for Tsys

calibration is also being added to the RDBE firmware.

2. Mark 5C VLBI data system: Mark 5C is now used routinely at 2 Gbps to a single 8-

disk module. Mark 5C has been successfully tested at 4 Gbps to dual 8-disk modules,

and operational support software for this mode will be released in early 2011. A new SATAmodule PCB backplane is being developed by Conduant that will allow 4 Gbps to be recorded

to a single 8-disk module; this module will have a different module connector and will not

be compatible with the current Mark 5 systems.

3. Development of firmware for the FILA10G board for the dBBC continues at MPIfR. This

board is installed in the dBBC developed by Gino Tuccari to support 10GigE output to Mark

5C or other similar VLBI data recording systems.

4. The new ‘Eleven’ broadband feed for VLBI2010 developed at Chalmers University in Sweden

has been successfully tested between the 18-m antenna at Westford Observatory and the 5-m

antenna at NASA/GSFC. Another broadband feed concept, developed at Caltech and called

‘QRFH’, has recently been tested and is being considered.

5. A new 12-m antenna from Patriot Antenna Systems has been installed at NASA/GSFC in

Maryland and will be commissioned in early 2011. Installation of two new 13-m VLBI2010

antennas is underway at Wettzell.

IVS 2010 Annual Report 21
IVS Technology Coordinator Report MIT Haystack Observatory

6. A number of VLBI2010 data-taking sessions between Westford and NASA/GSFC were undertaken during 2010. Most were recorded onto four Mark 5B+ units at each station using

older DBE1 backend units as data sources, at an aggregate data rate of 8 Gbps/station.

Late in 2010, a successful experiment using a prototype RDBE and Mark 5C was conducted.

Most data were processed on the Mark IV correlator at Haystack Observatory, though successful correlations have also been performed on the DiFX software correlator at Haystack

Observatory.

2. e-VLBI Development

2.1. Continuing Expansion and Development of Routine e-VLBI Data Transfers

MPIfR continues regular e-VLBI transfers of data for which the Bonn correlator is the correlation target. This includes data from Japan, Onsala, Ny- ̊Alesund, and Wettzell. All data recorded

on K5 systems at Tsukuba and Kashima are transferred either to MPIfR or Haystack depending on

the target correlator. Syowa K5 data are physically shipped to Japan and electronically transferred

to Haystack or MPIfR. UT1 Intensive data from Wettzell, Japan, and Ny- ̊Alesund are transferred

to either MPIfR or the Washington correlator. Welcome news! After a long and tortured process,

the Kokee station was finally connected to the world at 100 Mbps. This connection is helping to

lower the processing latency for time-critical UT1 data from days to hours. Efforts are underway

to significantly increase the data-rate capability to support higher-bandwidth observations and

still lower latencies.

2.2. 9th International e-VLBI Workshop Held at Perth, Australia

The 9th International e-VLBI Workshop was held 18-20 October 2010 in Perth, Australia,

hosted by the International Centre for Radio Astronomy Research (ICRAR) and Curtin University.

The workshop was attended by more than 50 participants from 10 countries.

The focus of the meeting was “e-VLBI and the Path to the Square Kilometre Array.” Within

this context, e-VLBI has a lot to offer as a pathfinder technology for the proposed SKA telescope,

and the presentations from both the e-VLBI and the SKA communities made for a particularly

interesting forum. The workshop was three days in duration, with the first two days dedicated to

scientific and technical presentations. The third day was a networking forum for representatives

of networking organizations and scientists to discuss current and future trends in high-speed data

transport and relevance to e-VLBI and the SKA.

Many presentations from the Perth workshop are available on-line at

http://cira.ivec.org/dokuwiki/doku.php/events/evlbi2010/start

The 10th International e-VLBI Workshop will be held in South Africa in Q3 2011.

3. Global VLBI Standards

3.1. VLBI Standards Web site Established

http://www.vlbi.org has been established as a one-stop shop for access to global VLBI standards.

These include VEX, VSI-H, VSI-S, VDIF, and standardized VLBI file-naming conventions. As new

standards emerge, they will also be included in this Web site.

22 IVS 2010 Annual Report
MIT Haystack Observatory IVS Technology Coordinator Report

Figure 1. Attendees at the 9th International e-VLBI Workshop held in Perth, Australia.

3.2. VDIF Data Format

Adoption of the VLBI Data Interchange Format (VDIF), ratified in 2008 at the Madrid e-VLBI

workshop, continues to accelerate. The VLBI2010 project has adopted VDIF as the standard

data format, and work is proceeding to fully implement it. Several other data systems now in

development have also embraced the VDIF format, and VDIF is now moving strongly into the

astronomical world as well. Broad adoption of VDIF across various VLBI disciplines will allow for

more standardization and inter-operational capabilities that will benefit all of VLBI.

The VDIF specification is available at http://www.vlbi.org. A VTP Task Force, led by Chris

Phillips of ATNF, has been appointed to lead the development of the second half of this standardization effort, which is now on-going. The members of the VTP Task Force are Richard

Hughes-Jones, Mark Kettenis, Chris Phillips (chair), Mamoru Sekido, and Alan Whitney.

3.3. VEX2 Task Force Continues Work

The VEX file format is a standardized method to prescribe a complete description of a VLBI

experiment, including setup, scheduling, data-taking and correlation, independent of any particular VLBI data-acquisition system or correlator. VEX has gained broad acceptance and is used

to support a large fraction of global VLBI observations, but needs updating as new technologies

and equipment become available. The VEX2 Task Force was created in late 2009 to undertake

this job. The members of the VEX2 Task Force are Walter Brisken (NRAO, chair), Ed Himwich

(NASA/GSFC), Mark Kettenis (JIVE), Cormac Reynolds (Curtin University), and Alan Whitney (MIT Haystack). This group continues working to craft the needed VEX updates and to

incorporate them into several VLBI-support software packages.

IVS 2010 Annual Report 23
IVS Technology Coordinator Report MIT Haystack Observatory

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. Since

the original DiFX development several years ago, the use of the DiFX correlator has spread, and

a global DiFX user group has been formed to coordinate continued improvements and additions.

Several institutions that support geodetic VLBI correlation processing now have DiFX correlators

(MPIfR, USNO, 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 correlator

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

integrate accurate multi-tone phase-calibration processing into the DiFX correlator, a task that is

often not important for astronomical VLBI. Progress towards developing the necessary additions

and improvements to DiFX for geodetic VLBI has been rapid, allowing the DiFX correlator to

take over the job of current hardware correlators. MPIfR closed its Mark IV hardware correlator

at the end of CY2010. Haystack Observatory is planning to phase out its Mark IV correlator by

the end of 2011, with USNO likely to follow soon thereafter.

24 IVS 2010 Annual Report
Network Stations

Network Stations

CRAAM, Universidade Presbiteriana Mackenzie, S ̃ao Paulo Fortaleza

Fortaleza Station: 2010 Status and Antenna Repair

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 2010 until January 2011. The main activities concentrated on the repair of the antenna

azimuth bearing and are described in detail in this report. They were successfully finalized on January

29, 2011. Regular GPS observations and new tests of the high speed network for e-transfers for e-VLBI

were also performed in the period.

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 erecting antenna and instrumental facilities, 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, Engineering School, Mackenzie Presbyterian University, S ̃ao Paulo, in agreement

with the Brazilian National Space Research Institute, 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, AEB. 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.

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 9.9.2. 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 that 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 one of the authors (PK), who is Brazil’s

AEB representative in the NASA-AEB Agreement. The coordination receives support from the

IVS 2010 Annual Report 27
Fortaleza CRAAM, Universidade Presbiteriana Mackenzie, S ̃ao Paulo

S ̃ao Paulo office at CRAAM/Instituto and Universidade Presbiteriana Mackenzie, with administrative support from Valdomiro S. Pereira and Luc ́ıola Russo. e-VLBI connectivity tests have been

conducted with the assistance of Dr. C. Guillermo Gimenez de Castro, of Mackenzie. The Fortaleza

Station facilities and geodetic VLBI and GPS operations are managed on site by Dr. A. M. P. de

Lucena (CRAAE/INPE), assisted by Eng. Adeildo Sombra da Silva (CRAAE/Mackenzie), and the

technicians Avicena Filho (CRAAE/INPE) and Carlos Fabiano B. Moreira (CRAAE/Mackenzie).

4. Current Status and Activities

4.1. Operational and Maintenance Activities

The summary of activities performed in the period is listed below:

1) Contracting and supervising services for the update of the cryogenic system;

2) Operation and maintenance of geodetic GPS (NOAA within the scope of NASA contract);

3) Review and update of all technical documentation of the observatory (electrical designs,

tables, lists of components, etc.);

4) Realization of high speed connectivity performance tests, connection improvements, national

and international, to allow e-VLBI experiments;

5) Operation and maintenance of power supply equipment at the observatory (main and diesel

driven standby);

6) Procurement and technical discussion with companies and consultants to evaluate and repair

the antenna azimuth bearings;

7) Contracting and supervising services for the antenna azimuth bearing repair (See Figures

1-6);

8) Planning and preparation of documentation needed for electrical cabling disassembly required for the azimuth drives removal;

9) Repair and maintenance of antenna brakes and antenna motor fans;

10) Hiring and supervision of the antenna painting service;

11) Refurbishment of receiver box;

12) Maintenance of the Web site (http://www.roen.inpe.br) and the local server computer.

Figure 1. Antenna ready to be lifted up from

the azimuth base for bearing replacement.

Figure 2. Antenna after being moved to the

side of the pedestal.

28 IVS 2010 Annual Report
CRAAM, Universidade Presbiteriana Mackenzie, S ̃ao Paulo Fortaleza

4.2. Repair of the Antenna Azimuth Bearing

When searching for companies to provide the repair services, we received proposals from four

companies, each offering a different solution. The repair job was awarded to the Brazilian company

Robrasa and their installation company partner Peyrani, who had presented the best and most

technically consistent bid for the job. Their offer exhibited the best solution in terms of risk, cost,

and benefit. The repair consisted of the fabrication of a new bearing, which was performed at

the Robrasa factory in Diadema, near S ̃ao Paulo, and accomplished in six months, and of the

new bearing shipment to Eus ́ebio site (the Fortaleza VLBI facility), followed by the replacement.

For this, the antenna was lifted up and displaced, the old bearing was removed, the new bearing

was put into place, the antenna was relocated, and checks, tests, and azimuth movements were

done for final acceptance. The installation was performed over a period of twelve days. All

phases were performed successfully and on schedule. A pictorial of the work steps can be found

at http://200.129.55.1. A rather unique methodology was used by Robrasa. The entire antenna

structure, without removal of any pieces, was separated from the tower using hydraulic jacks

running on rails, leaving the azimuth area free for the work. Figures 1–6 illustrate the procedure.

Figure 3. Old bearing being removed. Figure 4. Detail of the new bearing installed.

Figure 5. Antenna being moved back. Figure 6. Antenna resting on its base again.

IVS 2010 Annual Report 29
Fortaleza CRAAM, Universidade Presbiteriana Mackenzie, S ̃ao Paulo

5. Future Plans

For the immediate future, plans are to reassemble the receiver antenna at the focus, redo the

electrical connections, and complete the testing and necessary adjustments in order to resume

geodetic VLBI observations in a time scale of 4–6 weeks.

Acknowledgements

We acknowledge the advice on the azimuth repair job received from Prof. Antonio G. de Mello,

head of the Mechanics Dep. of Mackenzie’s Engineering School. These activities have received

partial support from NASA, within an agreement with the Brazilian Space Agency (AEB) and a

contract with Mackenzie, as part of an agreement between Mackenzie and INPE.

30 IVS 2010 Annual Report
NASA Goddard Space Flight Center Goddard Geophysical and Astronomical Observatory

Goddard Geophysical and Astronomical Observatory

Jay Redmond, Irv Diegel

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, and 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).

IVS 2010 Annual Report 31
Goddard Geophysical and Astronomical Observatory NASA Goddard Space Flight Center

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-meter radio telescope for VLBI at GGAO (MV3) was originally built as a mobile or

transportable station; however, it was moved to GGAO in 1991 and has been used as a fixed

station since that time. 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 HTSI

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-meter 12-meter

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(Theoretical)

Bandwidth 512MHz, 4 bands 512MHz, 4 bands

G/T 26 dB/K 43 dB/K

VLBI terminal type VLBI2010 VLBI2010

Recording media Mark 5B Mark 5B

Field System version 9.10.3 9.10.3

32 IVS 2010 Annual Report
NASA Goddard Space Flight Center Goddard Geophysical and Astronomical Observatory

3. Technical Staff of the VLBI Facility at GGAO

GGAO is a NASA R&D and data collection facility, operated under contract by Honeywell

Technology Solutions Incorporated (HTSI). Table 3 lists the HTSI staff that are involved in VLBI

operations and development at GGAO.

Table 3. Staff working at the VLBI station at GGAO.

Name Background Dedication Agency

Jay Redmond Engineering technician 100% HTSI

Irv Diegel Electrical Engineer 50% HTSI

Skip Gordon Engineering technician 20% HTSI

Paul Christopoulos Engineering technician 20% HTSI

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 MIT Haystack Observatory, MV3 has played a critical

role in the advancement of the VLBI2010 project.

Although MV3 is still outfitted with the prototype VLBI2010 equipment installed in 2009, most

of the activities at GGAO have been focused on the construction of the new VLBI2010 12-meter

antenna. However, there were some other activities worth noting:

• Continuation of wideband system testing and characterization of the 5-meter antenna.

• Upgrade of the ethernet infrastructure at MV3.

• Installation of a new Field System computer.

• Installation of a thermal shutdown system to protect the backend equipment from HVAC

failure.

• Procurement of new test equipment for characterization of the wideband RF hardware.

• Re-packaging of the Broadband Phase Cal unit into a temperature-controlled RF-tight enclosure with additional monitor and control capabilities.

• Support for a Small Business Innovation Research (SBIR) project to investigate and develop

the use of GPS to measure large radio telescope properties. This was an effort led by NVI,

Inc. with support from HTSI.

• Support for the development and implementation of a holographic imaging capability based

on the VLBI2010 receiving hardware.

The holographic imaging capability is being developed by the MIT Haystack Observatory, with

support from HTSI, in order to understand antenna deformations that could potentially dilute the

accuracy of the VLBI2010 system. Initial holographic data collections were performed using the

5-meter dish as the antenna to be tested and a 1-meter satellite reeiving dish as the phase reference.

IVS 2010 Annual Report 33
Goddard Geophysical and Astronomical Observatory NASA Goddard Space Flight Center

Preliminary results 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 cover, and the subreflector in the center

of the primary as shown in Figure 2.

Figure 2. Holographic imaging of the 5-m antenna.

5. Outlook

GGAO will continue to support VLBI2010, e-VLBI, and other developmental activities during

the upcoming year. Tentative plans for 2011 include:

• Installation of the new VLBI2010 broadband receiver system onto the 12-meter antenna.

• Short baseline ties between the 5 and 12-meter antennas.

• Continued testing of the new broadband phase calibrator for the VLBI2010 system.

• Installation of the new RDBE and Mark 5C, enabling data recording at 4 Gbps.

• Installation of a new Sigma Tau maser in the MV3 trailer.

• Continue holographic imaging of the 5 and 12-meter antennas.

• Continue broadband observations and testing of the VLBI2010 system.

34 IVS 2010 Annual Report
HartRAO, NRF Hartebeesthoek Radio Astronomy Observatory (HartRAO)

Hartebeesthoek Radio Astronomy Observatory (HartRAO)

Ludwig Combrinck, Michael Gaylard, Jonathan Quick, Marisa Nickola

Abstract

HartRAO provides the only fiducial geodetic site in Africa, and it participates in global networks

for VLBI, GNSS, SLR, and DORIS (located at the adjoining Satellite Application Centre). This report

provides an overview of the resumption of geodetic VLBI activities on the 11th of August 2010 after

the repair of the 26-m radio telescope.

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 distant. The

telescope is situated in an isolated valley which affords protection from terrestrial radio frequency

interference. HartRAO 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 Satellite Application Centre (SAC) site.

Figure 1. The 26-m drives again: on the 20th of July 2010 at 10h35 SAST the HartRAO 26-m telescope

was driven for the first time since the 3rd of October 2008’s breakdown due to the failure of the south polar

bearing.

IVS 2010 Annual Report 35
Hartebeesthoek Radio Astronomy Observatory (HartRAO) HartRAO, NRF

2. Technical Parameters of the 26-m Telescope of HartRAO

Table 1 contains the technical parameters of the HartRAO radio telescope and the Karoo Array

Telescope (KAT) prototype, XDM (eXperimental Development Model), while Table 2 contains

technical parameters of the HartRAO 26-m radio telescope’s receivers. The data acquisition system

consists of a Mark IV terminal and a Mark 5A recorder.

Table 1. Antenna parameters.

Parameter HartRAO-26 m KAT 15-m XDM

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 0.424 0.5

Surface error of reflector 0.5 mm ∼ 2.5 mm

Short wavelength limit 1.3 cm 2 cm

Pointing resolution 0.001◦ 0.001◦

Pointing repeatability 0.004◦ not tested

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 receiver parameters with dichroic reflector (DR), used for simultaneous S-X VLBI, off or on.

Parameter X-band S-band

Feeds dual CP conical dual CP conical

Amplifier type cryo HEMT cryo HEMT

Tsys (DR off) (K) 60 44

Tsys (DR on) (K) 70 50

SSEFD (DR off) (Jy) 684 422

SSEFD (DR on) (Jy) 1330 1350

Point source sensitivity (DR off) (Jy/K) 11.4 9.6

Point source sensitivity (DR on) (Jy/K) 19 27

3 dB beamwidth (◦) 0.092 0.332

3. Staff Members Involved in VLBI

Table 3 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.

36 IVS 2010 Annual Report
HartRAO, NRF Hartebeesthoek Radio Astronomy Observatory (HartRAO)

Table 3. Staff supporting geodetic VLBI at HartRAO.

Name Function Program

Ludwig Combrinck Program Leader Geodesy

Jonathan Quick Hardware/Software Astronomy

Jacques Grobler Operator Technical

Lerato Masongwa Operator Technical

Marisa Nickola Logistics/Operations Geodesy

Pieter Stronkhorst Operator Technical

4. Current Status

On the 3rd of October 2008 the HartRAO 26-m radio telescope suffered a critical failure of its

south polar shaft bearing, bringing all observing to a halt and thereby any further participation

in geodetic VLBI sessions.

The bearing is located on the main polar drive shaft, which carries the 26-m’s 200-tonne moving

structure. General Dynamics was contracted to replace the failed bearing. An A-frame jacking

support had to be constructed to hold up the telescope structure above the polar shaft in order to

replace the bearing. On the 23rd of March 2010 groundbreaking for the erection of the A-frame

took place, and on the 30th of June the telescope structure was lifted to remove the polar shaft’s

south end cap. The bearing’s inner race had failed, and fragments of it were still being removed

over the following week. On the 15th of July the new bearing was in place, and the next day the

end cap was back on and the A-frame came down.

On the 20th of July the 26-m drove again for the first time in over 21 months. The first

post-repair geodetic session was the ICRF experiment, CRF60, on the 11th of August 2010. Appropriately, HartRAO’s 26-m was joined again by the Hobart 26-m, the same telescope which

partenered us in our last pre-repair geodetic session, the Deep South experiment, CRDS49, on the

16th of September 2008. During 2010 HartRAO participated in 18 experiments (Table 4).

Table 4. Geodetic VLBI experiments HartRAO participated in during 2010.

Experiment Number of Sessions

R1 12

RDV 4

CRF 1

T2 1

Total 18

During the breakdown the 26-m’s receivers were serviced and updated. Conversion of the 15-

m XDM KAT prototype to be able to do geodetic VLBI to supplement the 26-m continued. A

coaxial S/X (2.3+8.4GHz) cryogenic receiver needs to be fitted to the antenna. Prototyping has

been followed by construction of the operational S/X feeds.

The first wide-band e-VLBIs linking Africa with Europe (at 1024 Mbps) and Australia (at

512 Mbps) were carried out during the latter part of 2010.

IVS 2010 Annual Report 37
Hartebeesthoek Radio Astronomy Observatory (HartRAO) HartRAO, NRF

Figure 2. The new bearing is in place. (Credit: M.

Gaylard)

Figure 3. Test assembly of the XDM’s S/X feeds

and receiver.

Figure 4. The old fragmented bearing on display in

the foyer.

Figure 5. GNSS installation at Hamburg. (Credit:

L. Combrinck)

5. Future Plans

With the prospect of 15 days’ continuous observing during the CONT11 campaign in September

2011, the 26-m will be tested to the limit again. Conversion of the 15-m XDM (KAT prototype)

for use in geodetic VLBI experiments will continue during 2011. We are looking forward to the

acquisition of a Mark 5B+ recorder early in 2011.

During April 2010, a Global Navigation Satellite System (GNSS) was installed for troposphere

calibration at Hamburg in the Eastern Cape. Similar GNSS installations are planned for Willowmore, also in the Eastern Cape, as well as Klerefontein in the Northern Cape during 2011. The

construction of a Lunar Laser Ranger (LLR) housing is planned for early 2011.

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/.

38 IVS 2010 Annual Report
University of Tasmania Hobart, Mt. Pleasant Radio Astronomy Observatory and the AuScope VLBI Project

Hobart, Mt. Pleasant Station and AuScope VLBI Project Report

Jim Lovell, John M. Dickey, Brett Reid, Simon Ellingsen, Jamie McCallum

Abstract

This is a brief report on the activities carried out at the Mt. Pleasant Radio Astronomy Observatory

at Hobart, Tasmania and for the AuScope VLBI Project. During 2010, the Hobart 26-m antenna

continued to make a significant contribution to IVS through participation in 70 observing sessions.

The new Hobart 12-m AuScope antenna was officially opened in February and commenced operations

later in the year, with 16 IVS observations. Construction of the AuScope Katherine and Yarragadee

antennas was completed and fringes successfully obtained between Katherine and Hobart.

1. Introduction

The Mt. Pleasant Observatory is located about 15 km north-east of Hobart at longitude 147.5

degrees East and latitude 43 degrees South. Hobart is the capital city of Tasmania, the island

state of Australia located to the south of the mainland. The station is operated by the School

of Mathematics and Physics at the University of Tasmania. The station has a co-located GPS

receiver and a site which is used for absolute gravity measurements.

2. Brief Description of Hobart 26-m VLBI Facilities

The antenna is a 26-m prime focus instrument with an X-Y mount. The focus cabin has a

feed translator with provision for four different receiver packages which enables rapid change over

between geodetic and astronomical requirements. Standard receiver packages provide for operation

at L band, S, C, X, and K bands. There is also the dual frequency cryogenic S/X geodetic receiver.

All of these receivers are cryogenically cooled. The antenna has a maximum slew rate of 40 degrees

per minute about each axis. The station is equipped with a Mark IV electronics rack and a Mark

5A VLBI recording system. There is another disk based recording system used by other Australian

VLBI antennas.

3. Staff

Staff at the observatory consist of academics, Prof. John Dickey (director), Dr. Simon Ellingsen,

and Prof. Peter McCulloch who has a large input into the receiver design and implementation.

Dr. Jim Lovell is Project Manager for the AuScope VLBI project. Dr. Jamie McCallum is a postdoctoral fellow and has had input into the development and implementation of AuScope-related

hardware at the observatory. Mr. Tim Hoban is employed as a computer programmer for the

AuScope project. Mr. Brett Reid is the Observatory Manager whose position is funded by the

university. In addition we have two electronics technical officers, Mr. Eric Baynes and Mr. Brenton

Jones. For operation of the observatory during geodetic observations we rely heavily on support

from astronomy PhD and post graduate students.

IVS 2010 Annual Report 39
Hobart, Mt. Pleasant Radio Astronomy Observatory and the AuScope VLBI Project University of Tasmania

4. Geodetic VLBI Observations

The Hobart 26-m antenna participated in 70 geodetic VLBI experiments during 2010. These

were divided between the APSG (1), CRF (1), OHIG (2), R1 (38), R4 (21), RDV (2), and T2 (2),

programs plus four additional TQAK observations of 3-h duration each to examine post-seismic

movement at TIGO following the Chilean megaquake. All experiments were recorded using Mark

5A. During 2011 the new Hobart 12-m antenna will take up the majority of the geodetic observing

with the 26-m participating in one observation per month to ensure continuity of the Hobart

timeseries.

Figure 1. The three AuScope VLBI sites as of December 2010 (photos by Jim Lovell and Vince Noyes).

5. The AuScope VLBI Project

AuScope is part of the Australian Government’s National Collaborative Research Infrastructure Strategy (NCRIS). It encompasses NCRIS Capability 5.13: “Structure and Evolution of the

Australian Continent”. An important part of this is the acquisition of three new radio telescopes

and a data processing facility for geodesy. AuScope aims to provide a fundamental reference frame

in Australia to 1-mm accuracy based on the locations of three radio telescopes as established by

VLBI observations. Each site will also host a permanent GPS receiver to tie the telescope reference frame to a denser GPS frame of ∼100 antennas across the continent. The construction

and operation of the array is being managed by the University of Tasmania with data correlation

supported by Curtin University of Technology.

Three 12-m diameter antennas have been supplied by Patriot Products division of Cobham

Satcom. The antennas have surface accuracies of 0.3 mm RMS and slew rates of 5 deg/s in

azimuth and 1.25 deg/s in elevation. Each antenna is being equipped with room temperature

dual-polarization S/X receiver systems (SEFD is 3500 Jy in all bands), Vremya-ch Hydrogen

maser standards, HAT-Lab DBBC samplers, and Conduant Mark 5B+ recorders. Construction of

all three antennas at Hobart, Katherine (Northern Territory), and Yarragadee (Western Australia)

has been completed. The Hobart 12-m antenna was officially opened on February 9, during the

40 IVS 2010 Annual Report
University of Tasmania Hobart, Mt. Pleasant Radio Astronomy Observatory and the AuScope VLBI Project

Sixth IVS General Meeting, hosted by the University of Tasmania. The Hobart 12-m commenced

IVS observations later in the year and participated in 16 sessions: APSG (2), CRF (1), R1 (7), and

R4 (6). Installation of receiver, recording, and control equipment was completed at Katherine and

first fringes detected to Hobart in December. Final installation work is scheduled for Katherine in

early 2011, to be followed by Yarragadee, and both sites are expected to commence IVS observing

in the first half of 2011.

IVS 2010 Annual Report 41
Kashima 34-m Radio Telescope Kashima Space Research Center, NICT

Kashima 34-m Radio Telescope

Ryuichi Ichikawa, Eiji Kawai, Mamoru Sekido

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

Research Center (KSRC) in Japan. This brief report summarizes the status of this telescope, the staff,

and activities during 2010.

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. After that project’s termination, the telescope

has been used not only for geodetic experiments but also for astronomy and other purposes [1].

The station is located about 100 km east of Tokyo, Japan and is co-located with the 11-m radio

telescope and the International GNSS Service station (KSMV) (Figure 1, right). The station is

maintained within the Space-Time Measurement Project of the Space-Time Standards Group,

NICT.

2. Component Description

The receiver equipment of the Kashima 34-m radio telescope is summarized in Table 1 and

Table 2. In particular the S-band receiver is equipped with a high-temperature superconductor

(HTS) band-pass filter for RFI mitigation [2]. We also installed a band-pass filter on July 15, 2008

to cut out signals between 1405 MHz and 1435 MHz for L-band RFI mitigation.

Table 1. Main specifications of the 34-m radio telescope.

Main reflector aperture 34.073 m

Latitude N 35◦ 57’ 21.78”

Longitude E 140◦ 39’ 36.32”

Height of AZ/EL intersection above sea level 43.4 m

Height of azimuth rail above sea level 26.6 m

Antenna design Modified Cassegrain

Mount type AZ-EL mount

Drive range azimuth North ±270◦

Drive range elevation 7

◦

-90◦

Maximum speed azimuth 0.8

◦/sec

Maximum speed elevation 0.64◦/sec

Maximum operation wind speed 13 m/s

Panel surface accuracy r.m.s. 0.17 mm

42 IVS 2010 Annual Report
Kashima Space Research Center, NICT Kashima 34-m Radio Telescope

The Kashima 34-m radio telescope.

34-m radio

Kashima Station

11-m radio

telescope

telescope

GEONET Station

IGS Station

Facilities at Kashima.

Figure 1. The Kashima Station.

Table 2. The receiver specifications of the 34-m radio telescope.

Band frequency (MHz) Trx (K) Tsys (K) Efficiency SEFD (Jy) Polarization

L 1350-1750⋆ 18 45 0.68 200 L/R

S 2193-2350 19 72 0.65 340 L/R

C 4600-5100 100 127 0.70 550 L(R)

X-n 8180-9080∗ 41 48 0.68 210 L/R

X-wL 8180-9080# 41 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(R)

Ka 31700-33700 85 150 0.4 1100 R(L)

Q 42300-44900 180 350 0.3 3500 L(R)

∗ : 8GHz LNA narrow band use. # : 8GHz LNA wide band use.

⋆ : Narrow bandwidth filter, 1405 - 1435 MHz, is used generally to mitigate RFI.

IVS 2010 Annual Report 43
Kashima 34-m Radio Telescope Kashima Space Research Center, NICT

3. Staff

The engineering and technical staff of the Kashima 34-m radio telescope are listed in Table 3.

Dr. Kondo has returned to KSRC in March 2010 and is continuing the development of the K5

system. On the other hand, Dr. Sekido has temporarily moved to a government office.

Table 3. The engineering and technical staff of the Kashima 34-m radio telescope.

Name Main Responsibilities

Eiji Kawai responsible for operations and maintenance

Mamoru Sekido software and reference signals

Kazuhiro Takefuji mechanical and RF related parts

Shingo Hasegawa K5 operation and data transfer

Ryuichi Ichikawa responsible for the project

Yasuhiro Koyama international e-VLBI

Tetsuro Kondo software correlator development and e-VLBI

4. Current Status and Activities

The 34-m radio telescope is an active facility for both geodetic and radio astronomical purposes.

In addition, experimental VLBI measurements for spacecraft tracking and precise time transfer

have been performed over the recent years. Figure 2 shows a pie chart of the annual operation

time for each purpose. The total operation time during 2010 was 1543 hours, which increased as

compared to the previous year’s total of 1246.5 hours. The increase of operation time of the 34-m

Kashima antenna was caused mainly by filling in for the 32-m Tsukuba antenna of Geospatial

Information Authority of Japan (GSI) during a necessary repair caused by a lightning damage.

During this time we performed more than twenty IVS sessions including 1-hour “Intensive” dUT1

sessions.

We repaired and maintained several parts of the antenna (i.e., rustproof painting of reflector

structure) between the end of May and July of 2010 in order to keep all components working.

5. Future Plans

As more than two decades have passed, the Kashima 34-m radio telescope requires continuous

repairs. We are now preparing some countermeasures to maintain the antenna performance in

anticipation of the new project for the next five years. Fortunately NICT headquarters supports

the replacement of the AZ/EL drive units. We are going to install them in the next fiscal year.

References

[1] Kawai, E., M. Sekido, R. Ichikawa, Kashima 34-m Radio Telescope, International VLBI Service for

Geodesy and Astrometry 2008 Annual Report, NASA/TP–2009-214183, D. Behrend and K. D. Baver

(eds.), pp. 114–117, 2008.

[2] Kawai, E., J. Nakajima, H. Takeuchi, H. Kuboki, T. Kondo, M. Suzuki, K. Saito, RFI mitigation at a

44 IVS 2010 Annual Report
Kashima Space Research Center, NICT Kashima 34-m Radio Telescope

2 GHz band by using a wide-band high-temperature superconductor filter, J. Geod. Soc. Jpn., Vol. 54,

No. 1, pp. 31–37, 2008.

Figure 2. Statistical chart of the telescope operation time according to purpose.

IVS 2010 Annual Report 45
Kashima and Koganei 11-m VLBI Stations Kashima Space Research Center, NICT

Kashima and Koganei 11-m VLBI Stations

Hiroshi Takiguchi, Ryuichi Ichikawa

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 brief report

summarizes the status of these antennas, the staff, and the activities during 2010.

1. Introduction

Figure 1. 11-m VLBI antennas at Kashima (left) and Koganei (right).

Two 11-m VLBI antennas at Kashima and Koganei (Figure 1) used to be stations of the Key

Stone Project (KSP) VLBI Network. The network consisted of four VLBI stations at Kashima,

Koganei, Miura, and Tateyama (Figure 2). These 11-m antennas and other VLBI facilities at

Miura and Tateyama stations have been transported to Tomakomai Experimental Forest of the

Hokkaido University and to the campus of Gifu University, respectively. As a consequence, two

11-m stations at Kashima and Koganei are remaining as IVS Network Stations. The KSP was a

research and development project of the National Institute of Information and Communications

Technology (NICT, formerly Communications Research Laboratory) [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 the purposes of technical developments and miscellaneous

observations.

46 IVS 2010 Annual Report
Kashima Space Research Center, NICT Kashima and Koganei 11-m VLBI Stations

Koganei Kashima

Miura

Tateyama

Tomakomai

Gifu

145 E 135 E 140 E

35 N

40 N

Figure 2. Geographic locations of four KSP VLBI stations and two stations at Tomakomai and Gifu.

2. Current Status

The main specifications of the antennas are summarized in Table 1. Both antennas can observe

S and X-band. Originally, the specifications of these antennas were the same. However, the

specifications were changed due to improvement and breakdown of equipment.

Table 1. The specifications of the KSP 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’ 20.13” N 35◦ 42’ 38.01”

Longitude E 140◦ 39’ 26.90” E 139◦ 29’ 17.10”

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 8180 ∼ 8600

S band 3000 3000

Local Frequency (MHz) X Low band 7200 7200

X High band 7680 7600

In 2009, we installed the radio frequency (RF) distribution system using optical fibers at

Koganei to transmit the reference signal to the VLBI back end which is coherent with Universal

Time, Coordinated (NICT). Therefore, the reference signal (10MHz/1PPS) at Koganei station

is coherent with UTC(NICT) [2]. In November 2009, we observed the all-sky Tsys of Kashima

and Koganei antennas to research the influence of radio frequency interference (RFI) signal. In

X-band, we did not see the RFI signal. However, in S-band, we detected interference from the

RFI signal at each station. At Kashima, we introduced a more narrow band-pass filter to reject

the RFI signal in early 2010. In April 2010, we introduced another band-pass filter (2212 ∼ 2360

IVS 2010 Annual Report 47
Kashima and Koganei 11-m VLBI Stations Kashima Space Research Center, NICT

MHz) at both stations. Figure 3 shows the intermediate frequency (IF) spectrum at S-band (left:

Kashima 11m, right: Koganei 11m). In the last annual report, we described that we changed the

phase calibration (P-cal) unit from 5-MHz to 1-MHz signal. However, we changed back the P-cal

unit to 5-MHz signal at both stations, because the 1-MHz P-cal unit was found out to be unstable.

Additionally, we set up a precise temperature control room at the Kashima 11m observation room.

KASHIMA 11m KOGANEI 11m

500 600 700 800 900 1000

MHz

500 600 700 800 900 1000

MHz

Figure 3. The IF spectrum in S-band (left: Kashima 11m, right: Koganei 11m).

3. Activities in 2010

Since 2007, we have been performing special purpose geodetic VLBI experiments between the

Kashima (11-m or 34-m) and Koganei (11-m) stations to evaluate the capability of geodetic VLBI

for precise time and frequency transfer. In 2010 we carried out two inter-comparison experiments

(August and October) on the Kashima 11m - Koganei 11m baseline. Thereby we compared results

from VLBI, GPS, TWSTFT with a DPN code and time comparison equipment (TCE) on the

satellite ETS-8. For both experiments, we used two types of sampling systems named K5/VSSP32

and K5/VSI (ADS1000 and ADS3000+). About the results of these experiments, please see the

NICT “Analysis Center” and “Technology Development Center” reports in this volume.

In order to verify our technical developments, experiments on Kashima-Koganei baselines have

also been conducted for several purposes. These experiments include e-VLBI observations, geodetic

observations using MARBLE (Multiple Antenna Radio-interferometry of Baseline Length Evaluation) system, and many others. In particular, we carried out dedicated experiments such as “RF

direct sampling”, “crystal clock tests for T&F”, and “feeding multiple samplers (K5/VSSP32) to

one PC”.

Apart from the VLBI sessions, the Space Environment Group of NICT started to use the 11-m

antenna at Koganei to download data from the STEREO spacecraft. Two STEREO spacecraft

were launched by NASA in October 2006 to investigate the solar terrestrial environment and to

provide 3D images of the Sun and solar storms. The Koganei 11-m antenna is therefore operated

for this purpose when no VLBI sessions are scheduled.

48 IVS 2010 Annual Report
Kashima Space Research Center, NICT Kashima and Koganei 11-m VLBI Stations

4. Staff Members

The 11-m antenna stations at Kashima and Koganei are operated and maintained by the

Space-Time Standards Group at Kashima Space Research Center, NICT. The staff members of

the group are listed in Table 2. The operation and maintenance of the 11-m VLBI station at

Koganei is also greatly supported by Space-Time Standards Group, Space Environment Group,

and Space Communications Group at Koganei Headquarters of NICT. We are especially thankful

to Jun Amagai and Tadahiro Gotoh for their support.

Table 2. Staff members of Space-Time Standards Group, KSRC, NICT.

Name Main Responsibilities

KAWAI Eiji Antenna Systems

ICHIKAWA Ryuichi Meteorological Sensors, IGS Receivers

AMAGAI Jun Antenna System and Timing Systems at Koganei 11m station

SEKIDO Mamoru Field System, Calibration and Frequency Standard Systems

HASEGAWA Shingo System Engineer

5. Future Plans

In 2011, we plan to continue precise time transfer VLBI experiments and e-VLBI developments.

In addition to the VLBI observations and developments, the data downlink from the two STEREO

spacecraft will be continued. Additionally, we are planning to set up the following things to improve

the antenna’s condition for precise time and frequency transfer VLBI experiments:

• overhaul the Hydrogen maser

• adjust the phase calibration (P-cal) unit

• develop the digital phase calibration unit

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.

IVS 2010 Annual Report 49
Kokee Park Geophysical Observatory USNO and NASA GSFC

Kokee Park Geophysical Observatory

Ron Curtis

Abstract

This report summarizes the technical parameters and the staff of the VLBI system at Kokee Park

on the island of Kauai.

1. KPGO

The Kokee Park Geophysical Observatory (KPGO) is located in the 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.

Table 1. Location and addresses of Kokee Park Geophysical Observatory.

Longitude 159.665◦ W

Latitude 22.126◦ N

Kokee Park Geophysical Observatory

P.O. Box 538 Waimea, Hawaii 96796

USA

2. Technical Parameters of the VLBI System at KPGO

The receiver is of NRAO (Green Bank) design (dual polarization feed using cooled 15 K HEMT

amplifiers). The DAR rack and tape drive were supplied through Green Bank. The antenna is

of the same design and manufacture as those used at Green Bank and Ny- ̊Alesund. We presently

employ a Mark 5A recorder for all of our data recording.

The technical parameters of the radio telescope are summarized in Table 2.

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 of the VLBI System at KPGO

The staff at Kokee Park during calendar year 2010 consisted of five people employed by Honeywell Technology Solutions, Inc. under contract to NASA for the operation and maintenance of the

observatory. Matt Harms, Chris Coughlin, and Ron Curtis conducted VLBI operations and maintenance. Ben Domingo was responsible for antenna maintenance, with Amorita Apilado providing

administrative, logistical, and numerous other support functions. Kelly Kim of Caelum Research

Corporation also supported VLBI operations and maintenance during 24-hour experiments and as

backup support.

50 IVS 2010 Annual Report
USNO and NASA GSFC Kokee Park Geophysical Observatory

Table 2. 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

SSEFD(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

SSEFD(CASA) 665 Jy

G/T 35.15 dB/K

η 0.539

VLBI terminal type VLBA/VLBA4-Mark 5

Field System version 9.7.6

4. Status of KPGO

Kokee Park has participated in many VLBI experiments since 1984. We started observing with

GAPE, continued with NEOS and CORE, and are now in IVS R4 and R1. We also participate

in the RDV experiments. We averaged 1.5 experiments per week during calendar year 2000 and

increased to an average of 2 experiments of 24 hours each week, with daily Intensive experiments,

starting in year 2002 and continuing into 2010.

Kokee Park also hosts other systems, including a 7-m PEACESAT command and receive antenna, a DORIS beacon, a QZSS monitoring station, a TWSTFT relay station, and a Turbo-Rogue

GPS receiver. Kokee Park is an IGS station.

In October of 2007, Japanese interests, along with representatives from NASA, USNO, and the

IVS 2010 Annual Report 51
Kokee Park Geophysical Observatory USNO and NASA GSFC

State Department, held a meeting at KPGO to explore the possible installation of a project called

Quasi-Zenith Satellite System (QZSS). In 2008, further investigation continued towards making

the QZSS project a part of KPGO. NASA sent an engineering team to investigate the support

requirements that would be needed to implement the QZSS project here, and an engineering

team from Japan surveyed the site for the hardware that would be installed. The aging KPGO

infrastructure was upgraded in stages as the project progressed. In October of 2009, the power at

KPGO was upgraded to support the QZSS and Two-Way Satellite Time and Frequency Transfer

(TWSTFT) requirements. In March of 2010 the construction of the antenna base for the project

was completed, and all components were installed and tested. In July of 2010 the TWSTFT for

the project was operationally configured by USNO and NICT.

In June of 2010, the remote control capability for the DORIS beacon was installed at KPGO.

In October of 2010, two members of the Ny- ̊Alesund VLBI team visited KPGO for the sharing

of processes and procedures on operations and maintenance.

Also, in 2008, advances were made for making real-time VLBI data from KPGO a reality.

The agencies that will be responsible for the wideband pipes leading from the site entered into a

service agreement late in 2008. The coordination with the parties involved in the communication

infrastructure upgrades continued through 2010. While work continues towards implementing the

final architecture an interim configuration has permitted some successful testing. Initially, the

daily Intensive experiments are being targeted so correlation back at the Washington Correlator

can happen days earlier than it previously did. 24-hour experiment data flow will hopefully follow

when the final architecture is implemented. The testing of the new communication infrastructure

is expected to continue in 2011.

5. Outlook

Now that we have started flowing real-time data for the daily USNO Intensive experiments in

2010, we hope to build on that start and support 24-hour experiments in (almost) real time as well

in 2011. If the sustained data rate requirements cannot be met, we will need to set up a buffering

system of some sort with the Mark 5 recorder.

In late 2010 work began on running fiber cable up the mountainside so the data rate needs

can be fully met. The local Navy plans to provide the fiber cable when the run is completed and

tested in 2011.

Plans are in progress to upgrade KPGO to Mark 5B mode in 2011.

52 IVS 2010 Annual Report
USNO and NASA GSFC Kokee Park Geophysical Observatory

Figure 1. KPGO VLBI 20-m antenna (right) with

the old NASA USB 9-m antenna in the background.

Figure 2. QZSS antenna.

Figure 3. DORIS remote control (left foreground)

and beacon (right foreground).

Figure 4. QZSS/TWSTFT equipment racks.

IVS 2010 Annual Report 53
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 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

54 IVS 2010 Annual Report
Agenzia Spaziale Italiana Matera CGS VLBI Station

installed in 2002 and replaced the old SLR system. CGS also hosted mobile SLR systems MTLRS

(Holland/Germany) and TLRS-1 (NASA).

In May 1990 the CGS extended its capabilities to Very Long Baseline Interferometry (VLBI),

installing a 20-m radio telescope. Since then, Matera has performed in 869 sessions up through

December 2010.

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.

Figure 2. MLRO in action, photo courtesy of Francesco Ambrico.

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).

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.

IVS 2010 Annual Report 55
Matera CGS VLBI Station Agenzia Spaziale Italiana

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.

In October 2010, the Mark 5A was replaced by a new Mark 5B+. The VSI Sampler kit was

installed in place of the old Mark IV formatter.

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 2 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 2010, 56 sessions were acquired. 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].

In April 2008, due to cracks on the surface, the AZI-1 wheel was replaced by a newly built one.

In April 2009, a second wheel was replaced due to the same kind of problem.

56 IVS 2010 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 the mean time, another goal is to replace the Antenna Control Unit and both Azimuth and

Elevation encoders, because it is not possible to find spare parts for these components anymore.

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 2010 Annual Report 57
Medicina Network Station Istituto di Radioastronomia, Medicina

The Medicina Station Status Report

Alessandro Orfei, Andrea Orlati, Giuseppe Maccaferri, Franco Mantovani

Abstract

General information about the Medicina Radio Astronomy Station, the 32-m antenna status, and

the staff in charge of VLBI observations are provided. In 2010 the data from geodetic VLBI observations

were acquired using the Mark 5A recording system with good results. Updates of the hardware have

been performed and are briefly described.

1. The Medicina 32-m Antenna and 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 about 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, 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 part

of the IGS network, is installed in the vicinity. Another GPS system is installed near the VLBI

telescope (MSEL) and is part of the EUREF network.

2. Antenna Description

The Medicina antenna has Cassegrain optics, consisting of a primary mirror 32-m in diameter,

and a secondary mirror, called the subreflector, of convex shape and about 3-m in diameter. The

subreflector, mounted on a quadrupode, 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; Andrea Orlati, Software

Engineer, takes care of the observing schedules and regularly implements SKED, DRUDG, and

the Field System. At the end of 2010 Giuseppe Maccaferri took a one-year sabbatical period.

Marco Bartolini and Simona Righini have been temporarily included in the staff helping Andrea

Orlati for the VLBI preparation and observation.

58 IVS 2010 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 operating system was updated to Debian Etch and kernel 2.6.18. The sdk 8.3 and StreamStorm driver version 9.20 were also installed. Switching between e-VLBI and vlbi on disk is now

straightforward.

The Mark 5 has been equipped with a new 10-Gbit network card. Our disk pool for geodetic

sessions is still 33 TB. No other purchases are planned by now.

As regards the receivers, the 22-GHz multifeed receiver will be no longer available in Medicina

by spring 2011, when it will be sent to the SRT site. We have under construction a dual feed

system as its substitute.

The S/X receiver cooling system, including the helium pipeline, needs a complete refurbishment. We are preparing the maintenance and substitution of the S/X cooling system; in the

meantime the receiver will be used uncooled. INAF has procured enough money to make heavy

maintenance on the 32-m antenna. It will be a long work, and we foresee we will repair the elevation

wheel, paint the antenna structure, and change the subreflector drives.

The upgrade to 10 Gb/s is still work in progress, as is the creation of a 10 Gb/s POP center at

Bologna Headquarters. The needed devices have been bought but not installed yet. Negotiations

with a local network consortium are still the main issue. Data from EUROPE experiments have

been transferred to the Bonn Correlator through the network on a regular basis since 2009.

5. Geodetic VLBI Observations

In 2010 Medicina took part in 24 (24-hour) routine geodetic sessions (namely two IVS-T2,

eighteen IVS-R4, one IVS-R1, two EUROPE, and one R&D experiments).

IVS 2010 Annual Report 59
National Astronomical Observatory of Japan Mizusawa VLBI Observatory, NAOJ

VERA Geodetic Activities

Takaaki Jike, Seiji Manabe, Yoshiaki Tamura, Makoto Shizugami, VERA group

Abstract

Geodetic activities of VERA in the year 2010 are briefly described. The regular geodetic observations are carried out both in K- and S/X-bands. The frequency of regular observations are three times

a month—twice for the VERA internal observations in K-band and once in S/X-band. The networks

of the S/X sessions are JADE of GSI and IVS-T2. The raw data of the T2 sessions are electronically

transferred to the Bonn and Haystack correlators via Internet by using the Tsunami protocol.

Gravimetric observations are carried out at the VERA stations. The superconducting gravimeter

previously installed at Esashi Earth Tides Station was moved to Mizusawa and placed in the vicinity

of the VERA antenna in order to monitor vertical displacement at the end of 2008, and the observation

continued throughout the year.

1. General Description

VERA is a Japanese domestic VLBI network consisting of Mizusawa, Iriki, Ogasawara, and

Ishigakijima stations. Each station is equipped with a 20-m radio telescope and a VLBI backend.

The Ishigakijima antenna is shown in Figure 1. The VERA array is controlled from the Array

Operation Center at Mizusawa via Internet.

The primary scientific goal of VERA is to reveal structure and dynamics of our Galaxy by

determining 3-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 even 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 north-east sky at Ishigakijima station is blocked by a near-by 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. Iriki

station as well as these stations are frequently hit by strong typhoons. The wind speed sometimes

reaches up to 60–70m/s.

2. Technical Parameters

Parameters of the antennas and 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

observation in K-band with the recording rate of 1 Gbps. The other is the conventional S/X60 IVS 2010 Annual Report
Mizusawa VLBI Observatory, NAOJ National Astronomical Observatory of Japan

Figure 1. VERA Ishigakijima antenna.

120

120

130

130

140

140

150

150

20

20

30

30

40

40

50

50

Mizusawa

Ishigakijima

Iriki

Ogasawara

2272km

1284km

1231km

1336km

1

1831km

000km

Figure 2. Location 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”.199E, 39◦ 08’ 00”.726N, 75.7m(sea level)

Iriki 130◦ 26’ 23”.593E, 31◦ 44’ 52”.437N, 541.6m(sea level)

Ogasawara 142◦ 12’ 59”.809E, 27◦ 05’ 30”.487N, 223.0m(sea level)

Ishigakijima 124◦ 10’ 15”.578E, 24◦ 24’ 43”.834N, 38.5m(sea level)

band observation 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 20m 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. Organizational Change and Staff Members

Mizusawa VERA Observatory of NAOJ was reorganized to Mizusawa VLBI Observatory in

April 2009. VERA and VSOP-2 were integrated into a unified project. Noriyuki Kawaguchi was

inaugurated as Director in April 2010. The geodesy group consists of S. Manabe (chief, scientist),

Y. Tamura (scientist), T. Jike (scientist), and M. Shizugami (software technician).

IVS 2010 Annual Report 61
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 16MHz Digital DIR2000 4 VERA

K5-VSSP 16 4MHz VC HDD Mizusawa

Ishigakijima

4. Current Status and Activities

4.1. VLBI

VERA observes seven days a week except for the maintenance period in the summer. The

nominal frequency of geodetic observations is three days a month. Among these three, VERA

internal geodetic observations in K-band are performed twice 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 the S/X sessions

is to make the VERA coordinates refer to 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. 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 observation 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/Xband is 500 at most. It has been confirmed that the K-band observations are far more precise,

although the ionospheric delay is not corrected for. 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.

The error ellipsoid is fairly elongated in the vertical direction due to the insufficient network size

for separating the vertical displacement from the zenith atmospheric delay variation. There seems

no significant systematic difference in the estimated coordinates between S/X- and K-bands. This

means that the majority of the ionospheric effect can be eliminated in the course of estimating the

tropospheric delay, at least for the VERA network whose typical size is around 2300 km. However,

the number of observations are not enough to derive a definite conclusion.

In order to link the VERA network to the international reference frame, VERA started participation in the IVS-T2 sessions by using Mizusawa and Ishigakijima stations in 2009. The

observations at Ishigakijima were conducted by GSI. In September 2009, we successfully made

62 IVS 2010 Annual Report
Mizusawa VLBI Observatory, NAOJ National Astronomical Observatory of Japan

a test observation and electronic data transfer to the Haystack correlator via Tsunami protocol.

In 2010, we participated in six T2 sessions and in three JADE sessions. VERA internal geodetic

observations were carried out 28 times. The final estimation of the geodetic parameters are derived

by using the software developed by VERA team.

4.2. Other Activities

Continuous GPS observations were carried out at each VERA station throughout the year. The

observation of gravity tide with a LaCoste-Romberg gravimeter at Ogasawara was completed, and

that at Ishigakijima is underway. The provisional result shows that there is no large discrepancy

in the tidal amplitude and phase between the observations and those predicted by ocean models.

The superconducting gravimeter (SCG) was moved from the Esashi Earth Tides Station to

Mizusawa in order to accurately monitor gravity change for the purpose of monitoring height

change at VERA Mizusawa station. Four water table gauges surrounding the SCG were used for

monitoring the water table height. The preliminary results show that gravity variation due to the

variation of the water table can be corrected as accurately as the 1μgal level.

5. Future Plans

The internal K-band VLBI and the participation in the IVS-T2 sessions will be continued.

Continuous GPS and gravimetric observations will also be carried out. Reconfirmation of local

ties between GPS and VLBI has become an urgent task. The possibility of optical fiber links

between Mitaka and the VERA stations is being pursued. Widening of the receiving and recording

bandwidth is planned.

IVS 2010 Annual Report 63
Noto VLBI Station Istituto di Radioastronomia INAF, Stazione VLBI di Noto

Noto Station Status Report

G. Tuccari

Abstract

Noto station was not operational for a large part of 2010 due to a structural damage in the radio

telescope. An expensive maintenance is needed, and INAF found the resources to repair the structure

at the end of the year. The activity at the station is reported.

1. Antenna Status, Receivers, Networks

Noto antenna suffered from very serious damage to the axis of a driving azimuth wheel (see

Figures 1 and 2). This event necessitated stopping all operations and placing the antenna in a

safe state. As the azimuth track grout needs to be remade, new wheels and a new track have been

planned. The entire repair operation has been financed (about 850,000 Euro) by INAF (Istituto

Nazionale di Astrofisica). In the first months of 2011 the selection of the company able to renew

the structure will be made, and then a period of around six months is planned for fully recovering

the antenna functionality. The whole work (wheel replacement, grout and track removal, new

track installation and its anchorage with innovative techniques and telescope alignment) should

be completed by the end of summer 2011.

The maintenance of the receivers (C,Q,K) is currently underway. The SXL receiver developed

in the last years will be renewed in order to reduce its weight, allowing its placement in the primary

focus in a safe way. All the bands will also be converted in a digital implementation to be transfered

with 10G Ethernet optical network technology to the control station and the DBBC environment.

A fiber optics link for e-VLBI activities has been financed by GARR (Italian Academic and

Research Network) and is in the commissioning phase. It is planned to start with the installation

in June 2011.

2. DBBC Backend

The DBBC backend is now regularly used at some stations after a gradual introduction in the

station activities. Here, in summary, we list the main news.

Two operational modes are possible at present—the Digital Down Converter configuration and

the Multichannel Equispaced configuration.

The Digital Down Converter configuration generates 16 x 1-16 MHz wide tunable bands. The

implementation emulates an analog VLBI down-converter system, with independent channels in

bandwidth and tuning base. Each Core2 board is able to produce four BBCs.

The Multichannel Equispaced configuration generates 16 x 32 MHz wide bands. The implementation is realized adopting the intrinsic capability of a highly efficient DFT processor to

down-convert in base band contiguous slices of band. As the single DFT operation shows poor

frequency rejection between adjacent channels, a preliminary filter is adopted to greatly improve

the separation performance.

64 IVS 2010 Annual Report
Istituto di Radioastronomia INAF, Stazione VLBI di Noto Noto VLBI Station

Figure 1. The damaged Noto azimuth wheel. The arrow points towards the damaged area.

Figure 2. The damaged axis in detail; the wheel is off-axis.

IVS 2010 Annual Report 65
Noto VLBI Station Istituto di Radioastronomia INAF, Stazione VLBI di Noto

2.1. Hardware

In the VLBI backend implementation two observing types are mainly required: tunable configuration and fixed contiguous bands. The first is adopted to emulate the present Mark IV terminal

and is required for both geodetic and astronomical observing modes. The second is devoted to

astronomical millimeter observations and the coming VLBI2010 geodetic modes. Both modes are

required in the same terminal to be used depending on the observation to be performed; so some

efforts have been made to accomplish these modes in a unique hardware architecture.

The ADB1 board operates with a 1024 MHz sampling clock, for converting an input signal in

the range 10—2200 MHz, while the ADB2 is operated at 2048 MHz with an input signal of up

to 3500 MHz. The ADB2 is able to operate in ADB1 mode and moreover can adopt as piggyback a FILA10G board, to transfer pure sampled data using optical fibers with a 10G Ethernet

connection. The ADB2 board was widely tested and is available to be inserted in the standard

DBBC2 stack.

The processing unit Core2 board is also fully operative and represents the element adopted

to generate the down-converted channels in both modes: tunable and fixed tuning. The board is

compatible with ADB1 and ADB2 and supports a minimal equivalent of four Core1 functionality.

One Core2 board is able to emulate the complete functionality of four analog BBCs, or to generate

a fixed tuning version of fifteen 32-MHz-wide baseband channels, covering an input receiver band

of 512 MHz.

The new CaT2 board (Clock and Timing) is able to generate a highly flexible number of

synthesized sampling clock (e.g., 2048 MHz, 1024 MHz) values, phase locked with an external 10

MHz. Low phase-noise and very small sensitivity to temperature are the main features. The board

is also producing 1PPS synchronization signals for all the ADB boards and the entire digital chain.

Frequency selection is performed with the use of the DBBC2 internal PC Set.

The FiLa10G can be used as piggy-back board with any ADB2 sampler, giving the possibility

to transmit and receive at the same time a high data rate of 20 Gbps + 20 Gbps. The bi-directional

functionality could be required, for instance, when an RFI mitigation is needed to be realized in

a remote location with respect to the sampling and processing site. With the typical sampling

frequency of 2.048 MHz and the full 10-bit data representation, a double optical fiber set meets

the full data handling requirement. The Fila10G is the interface between the DBBC and Mark 5C

recorder.

2.2. Firmware

The DBBC2 VHDL firmware was completely rewritten in a platform-independent fashion.

This was accomplished with a great simplification that produced a very compact and efficient

code. Performance improvement guarantees a bit-by-bit identical output from a set of BBCs

belonging to the same Core2 board, having of course the same tuning settings and input data.

Some debugging is still underway to check the entire new code.

The fixed tuned (PFB) configuration firmware is also available; it produces a set of 16 (15

usable) contiguous 32 MHz bands from a 512 MHz input range, in any of the Nyquist zones

available from the ADB1/2 boards. This configuration is available for the VLBI2010 mode or for

the millimeter VLBI network.

Firmware under development is covering the following tasks: a) fully tunable 1 GHz input

bandwidth, b) 1 GHz PFB with 31 channels 32 MHz bandwidth, c) 65K points spectrometer.

66 IVS 2010 Annual Report
Istituto di Radioastronomia INAF, Stazione VLBI di Noto Noto VLBI Station

2.3. New Hardware Development

New hardware parts to be integrated in the system are under development. This covers the

interfacing, input bandwidth, and processing capability.

The FILA10G board is the interface between the system and the Mark 5C recorder or the

network. Main connections are two optical fibers operating each at a maximum rate of 10 Gbps.

In VLBI standard this is limited by 8.192 Gbps/fiber, and for the present recording capability

the limitation is 4 Gbps. The data rate is fully bi-directional and compliant with the standard

Ethernet networks, under UDP protocol. At present the development status sees the hardware

defined and available with some prototypes, and the firmware development completed for Mark

5B mode while VDIF modes are underway.

The 10G network FILA10G board is adopting optical fibers. In order to be connected with

one or two Mark 5C recorders, that adopt the copper CX4 standard, it needs to be interfaced with

a commercial 10G switch having both types of ports. As an alternative, a bi-directional interface

that can be used for this purpose was developed. It is named GLAPPER to recall its functionality

to be a transition between GLAss and coPPER.

A kit to expand the backend functionalities to the VLBI2010 has been defined as upgrade

element for a standard DBBC terminal. In such an implementation eight IFs are implemented.

2.4. HAT-Lab

HAT-Lab is a spin-off company supported by INAF for the DBBC production. The company

has agreements with IRA-Noto, where laboratories are placed for a part of the production, and

MPI in Bonn where other phases of the production are realized. A certain number of operations are

realized by external specialized companies to simplify and optimize the production of the complex

boards. Assembly and testing is fully realized at HAT-Lab, IRA, and MPI.

At present eight systems have been deployed by IRA, and in 2010 HAT-Lab has delivered

eight additional systems. Production time is today close to six months while the first batch of

production took a longer time, around nine months, due to the initial settings of the production

lines.

2.5. Fringe Test

Regular observations are underway in the geodetic network. More fringe test observations have

also been performed with the down-converter configuration. A reduction in the fringe amplitude

has initially been seen, around 80%. This has been found due to an additional noise in the

timing communication between ADB1 and Core2 boards. An extensive laboratory testing has

been realized, and the best conditions have been determined making use of a phase calibration.

3. Geodetic Observations in 2010

During 2010, the Noto station participated in three geodetic experiments: EUR103, EUR104,

and T2062.

IVS 2010 Annual Report 67
Ny- ̊Alesund 20-Meter Antenna Geodetic Institute, Norwegian Mapping Cadastre Authority

Ny- ̊Alesund 20-meter Antenna

Carl Petter Nielsen

Abstract

In the year 2010, the 20-meter VLBI antenna at the Geodetic Observatory, Ny- ̊Alesund, participated in VLBI experiments, observing 91 of 91 scheduled 24-hour experiments and 116 of 118 scheduled

Intensives. The reason for the lost experiments was the repair of the cooling system. Several experiments during November had to be run with a warm receiver due to a failure of the cold-head. In 2010,

Ny- ̊Alesund was manned by four employees dividing three positions between them: Carl Petter Nielsen

as base commander and Geir Mathiassen, Moritz Sieber, and Lars Karvonen as engineers, all working

75%. In connection with the application for two new antennas, the Norwegian Mapping Authority

(NMA) carried out an extensive Enviromental Impact Assessment (EIA) and will continue towards

its completion in summer 2011. During spring some holes were drilled to establish the quality of the

ground and to find the best location for the new antennas. In the autumn Geir Mathiassen and Carl

Petter Nielsen visited Kokee Park to learn more about antenna maintenance.

1. General Information

The Geodetic Observatory of the NMA is situated at 78.9◦ N and 11.87◦ W 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 2010, Ny- ̊Alesund was scheduled for 91 24-hour VLBI experiments, including R1,

R4, EURO, RD, T2, and RDV sessions, and 118 Intensives within the Int1/Int3 program, making

a total of 209 experiments. Two Intensives had to be cancelled because of station problems, in

both cases, connected to the cooling system. Of the 207 completed experiments 71 1-hour and four

24-hour experiments were added during the year because of downtime/problems at other stations.

This is an increase of 72.5% since 2009 (measured in number of experiments).

In addition to the 20-meter VLBI antenna, the Geodetic Observatory has two GPS antennas

in the IGS system and a Superconducting Gravimeter in the Global Geodynamics Project (GGP)

installed at the site. There is also a CHAMP GPS and a SATREF (dGPS) installation at the

station. At the French research station in Ny- ̊Alesund, there is a DORIS station. In October

2004, a GISTM (GPS Ionospheric Scintillation and TEC Monitor) receiver was installed at the

Mapping Authority 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).

2. Component Description

The antenna is intended for geodetic use and is designed for receiving in S-band and X-band.

Ny- ̊Alesund is a Mark 5A station. The station configuration file can be found on the IVS Web site:

ftp://ivscc.gsfc.nasa.gov/pub/config/ns/nyales.config. Ny- ̊Alesund is located so far north that the

sun is below the horizon from the 23rd of October until the 22nd of February, and the station

has midnight sun from the 20th of April to the 27th of August. The station is situated under the

auroral circle during daytime giving some extra disturbance in the ionosphere, but generally the

polar atmosphere is calmer than the atmosphere closer to the equator.

68 IVS 2010 Annual Report
Geodetic Institute, Norwegian Mapping Cadastre Authority Ny- ̊Alesund 20-Meter Antenna

3. Staff

Carl Petter Nielsen has a two year contract as base commander, ending 2011.12.31. Geir

Mathiassen, Moritz Sieber, and Lars Karvonen all have two year contracts as engineers ending

2012.09.01, 2011.09.01, and 2012.02.01, respectively. Everybody works 75%, which means that

three full-time positions are covered. When Carl Petter Nielsen is off, one of the others steps in as

base commander.

Table 1. Staff related to VLBI operations at Ny- ̊Alesund.

Hønefoss: Section manager: Line Langkaas

Station responsible at Hønefoss: Line Langkaas

Ny- ̊Alesund: Station commander: Carl Petter Nielsen

Engineer Geir Mathiassen

Engineer Moritz Sieber

Engineer Lars Karvonen since 2010.02.01

Figure 1. Ny- ̊Alesund antenna.

IVS 2010 Annual Report 69
Ny- ̊Alesund 20-Meter Antenna Geodetic Institute, Norwegian Mapping Cadastre Authority

4. Current Status and Activities

Ny- ̊Alesund participated in the scheduled VLBI experiments. During 2010 e-VLBI was extended to the transfer of R4 and Int1 sessions from Ny- ̊Alesund to the Washington Correlator

in addition to transferring R1 and Int3 measurements to the Bonn Correlator. The Ministry of

Education granted funding for a fiber cable between Longyearbyen and Ny- ̊Alesund. The new

cable will enable us to take part in real time correlation as opposed to our present radiolink, which

is 100 Mbit/s.

The Superconducting Gravimeter (SCG) placed on the same foundation as IGS-GPS NYA1

has been running without problems. The yearly service on the system was performed by the staff

in September. There were some problems in transporting the liquid helium (LHe) to Ny- ̊Alesund.

Due to the 2–3 weeks it takes to transport the LHe to Ny- ̊Alesund, most of it might turn into

gas on the journey, especially if the ship experiences bad weather. Therefore we had to have an

extra tank of LHe, but still we only had just enough LHe to last until the first boat in April 2011.

National Astronomical Observatory of Japan, Mizusawa VERA Observatory, which owns the SCG,

lent this equipment to NMA starting 2007.04.01, to continue the scientific measurement series.

NMA plans to take part in VLBI2010 and has applied to the Norwegian government for funding

of two new VLBI antennas and an SLR system. In order to establish the optimal site, some ground

drilling has been done, and on this background a site has been chosen. Ny- ̊Alesund is an Arctic

research village, and the scientific community (organized in Ny-SMAC) would like to keep Ny-

 ̊Alesund and the surroundings as pristine and unaffected by human activity as possible. Therefore

NMA has initiated an extensive Enviromental Impact Assessment (EIA) involving the different

interested parties.

In the autumn Geir Mathiassen and Carl Petter Nielsen visited Kokee Park to learn more

about antenna maintenance. This was a very useful exercise for the staff at Ny- ̊Alesund, who all

are fairly new to VLBI.

5. Future Plans

Ny- ̊Alesund will continue to participate in the 119 regular and 43 Intensive experiments as

well as the CONT11 in September. The station is currently trying to replace the Mark IV with

a Mark 5 formatter. Hopefully we will succeed despite some problems at the moment. In order

to save energy, three heat pumps will be installed, and the plan to insulate the ceiling will finally

be carried out. R ̈udiger Haas and Sten Bergstrand will measure the movement of the surrounding

terrain in late February before the solar heating starts.

If our application for funding is successful, building of the roads and the foundations of the

new antennas will start in 2011.

The SCG has to be refilled with liquid helium each year, and the lift has to be re-certified every

year. A new car will be bought. Depending on the availability of cable ships, the new fiber cable

between Longyearbyen and Ny- ̊Alesund will be laid down during summer 2011 or 2012.

70 IVS 2010 Annual Report
Bundesamt f ̈ur Kartographie und Geod ̈asie (BKG) German Antarctic Receiving Station (GARS) O’Higgins

German Antarctic Receiving Station (GARS) O’Higgins

Christian Pl ̈otz, Reiner Wojdziak, Alexander Neidhardt

Abstract

In 2010 the German Antarctic Receiving Station (GARS) O’Higgins contributed to the IVS observing program with four observation sessions. The remote control tests with the software developed at

Wettzell were continued for VLBI sessions. The antenna of the Global Navigation Satellite Systems

(GNSS) reference point “OHI3” was replaced by a calibrated one for GALILEO satellites.

1. General Information

The German Antarctic Receiving Station (GARS) is jointly operated by the Federal Agency

for Cartography and Geodesy (BKG; as part of the duties of the Geodetic Observatory Wettzell,

GOW) and the German Aerospace Center (DLR). The Institute for Antarctic Research Chile

(INACH) coordinates the activities and logistics. The 9-m radio telescope at O’Higgins is used for

geodetic VLBI and for downloading of remote sensing images from satellites such as ERS-2 and the

TanDEM-X as well as for commanding and monitoring spacecraft telemetry. In 2010 the station

was manned in January and February from BKG and the colleagues of DLR. DLR and BKG jointly

sent engineers and operators for the campaigns together with a team for the infrastructure (e.g.,

power generator). In 2010 the DLR kept the station operational during the year.

Over the last years, special flights with “Hercules C-130” aircrafts and small “Twin Otter

DHC-6” aircrafts 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 the staff, the

technical material, and also the food for the entire campaign from Punta Arenas via Base Frei on

King George Island to O’Higgins on the Antarctic Peninsula. Another route uses transportation

by ship to and from O’Higgins. Due to the fact that the conditions for landing on the glacier

are absolutely weather dependent and require a lot of security precautions, the usage of a ship for

transportation to O’Higgins becomes more and more important. In general, transport of personnel

and cargo is quite challenging. Arrival time and departure time depend strongly on the weather

conditions and on the general logistics.

After the long Antarctic winter usually the equipment at the station has to be initialized.

Damages, which result from the winter period or strong storms, have to be identified and repaired.

Shipment of spare parts or material for upgrades from Germany has to be carefully prepared in

advance.

The 9-m radio telescope for VLBI is co-located with other equipment:

• an H-Maser, an atomic Cs-clock, a GPS time receiver, and a Total Accurate Clock (TAC)

offer time and frequency.

• two GNSS receivers were operational, while the permanent site “OHI3” was used in the frame

of IGS all over the year. The receivers worked without failure in 2010.

• a meteorological station provided pressure, temperature, and humidity and wind information,

as long as the temporarily extreme conditions outside did not disturb the sensors.

IVS 2010 Annual Report 71
German Antarctic Receiving Station (GARS) O’Higgins Bundesamt f ̈ur Kartographie und Geod ̈asie (BKG)

• the installation of a new radar tide gauge was shifted to 2011. The radar sensor itself will

be position-calibrated by a GPS antenna mounted on top of the radar sensor unit.

• defective underwater sea level gauge will be replaced for permanent monitoring of temperature, tide pressure, and salinity of the sea water.

The 9-m radio telescope is designed for dual purpose:

• performing geodetic VLBI and

• receiving the remote sensing data from LEO satellites, mainly from ERS-2 and TanDEM-X.

Figure 1. Photo of GARS O’Higgins taken during transport from the landing zone to the station (on the

right side is the rope bridge which connects the peninsula to O’Higgins).

Figure 2. Sunset behind the penguin colony.

2. Technical Staff

The staff members for operation, maintenance and upgrade of the GARS VLBI components

and the geodetic devices are summarized in Table 1.

72 IVS 2010 Annual Report
Bundesamt f ̈ur Kartographie und Geod ̈asie (BKG) German Antarctic Receiving Station (GARS) O’Higgins

Table 1. Staff members.

Name Affiliation Function Working for

Johannes Ihde BKG interim head of the GOW (until September 2010) GOW

Ullrich Schreiber BKG head of the GOW (since October 2010) GOW

Christian Pl ̈otz BKG electronic engineer O’Higgins (responsible), RTW

Reiner Wojdziak BKG software engineer O’Higgins, IVS Data Center

Leipzig

Thomas Kl ̈ugel BKG geologist administration for O’Higgins

(mainly 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)

3. Observations in 2010

GARS participated in the following sessions of the IVS observing program during the Antarctic

summer campaign (January-February 2010)

• IVS-T2067 February 02-03, 2010

• IVS-OHIG67 February 03-04, 2010

• IVS-OHIG68 February 09-10, 2010

• IVS-OHIG69 February 10-11, 2010

The observations were recorded with Mark 5A. The related data modules were carried from

O’Higgins to Punta Arenas by the staff when they returned home. From Punta Arenas, the disk

units were shipped by regular air transport back to Wettzell and then to the correlator in Bonn,

Germany.

Figure 3. Mostly used for transportation to and from O’Higgins is the FACH “Twin Otter DHC-6”.

IVS 2010 Annual Report 73
German Antarctic Receiving Station (GARS) O’Higgins Bundesamt f ̈ur Kartographie und Geod ̈asie (BKG)

4. Maintenance

The extreme environmental conditions in the Antarctic require special attention to the GARS

telescope and to the infrastructure. Corrosion frequently results in problems with connectors and

capacitors. Therefore defective equipment needs to be detected. The antenna, the S/X-band

receiver, the cooling system, and the data acquisition system have to be activated properly. In

2010 a replacement dewar was planned in Wettzell, but the unit will have to be finished in 2011 in

order to replace the original O’Higgins dewar. The current dewar has to be pumped permanently

by a turbo molecular pump to maintain the required vacuum due to air leakage at the chamber.

Those components, which were damaged during the previous campaign or because of the extreme conditions, were replaced. The meteorological station failed partly during the Antarctic

winter. Therefore a new system will be installed to fulfill again the reliability requirements for

collecting weather data. The intermediate frequency distributor module “ifdcd” failed in February

due to problems on the Monitor and Control Bus (MCB) board, which realizes the communication

to the NASA Field System. The module was transported to Wettzell, repaired, and sent back

to the O’Higgins station. Nevertheless, it is very difficult to maintain and repair this kind of

equipment. Some components as well as technical information are close to unavailable.

5. Technical Improvements

Remote control of complete VLBI sessions was extended. With the newly developed software

from Wettzell, the O’Higgins Field System can be controlled over a secure Internet connection

from Wettzell. This is a key feature for extended operation periods at GARS O’Higgins.

O’Higgins is represented in the GNSS network with the reference point “OHI3”. With the

GALILEO capability upgrade of the GNSS system, the station participates in the COoperative

Network for GIOVE Observation (CONGO) network, by establishing a GALILEO reference station

at O’Higgins.

6. Upgrade Plans for 2011

It is planned to install the radar tide gauge directly on shore. A sea level tide gauge is planned

to be re-installed. Additionally a new communication antenna setup, capable of up to 8 Mbit/s,

is going to extend bandwidth for data transmission as peer-to-peer connection between O’Higgins

and Oberpfaffenhofen, Germany. The GARS station will be manned by DLR continuously in

2011 for a planned period of three years, because of the TanDEM-X-Mission. This may lead to

an extended operation period of IVS VLBI measurements. A new S/X-band dewar will replace

the original dewar of the O’Higgins VLBI system. Furthermore it is planned to realize a second

gravimeter measurement. The first one took place in 1997.

74 IVS 2010 Annual Report
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 2010 the Onsala Space Observatory contributed as an IVS Network Station to 27 VLBI sessions organized by the IVS. We used the majority of these sessions to do ultra-rapid dUT1 observations

together with our colleagues in Tsukuba. Furthermore, we observed several additional one-baseline

ultra-rapid dUT1 sessions. This report briefly summarizes the activities during the year 2010.

1. General Information

The Onsala Space Observatory has a more than 40-year history in VLBI. Onsala was the first

European observatory to be involved in geodetic/astrometric VLBI observations, and the first

trans-atlantic VLBI observations were performed together with Haystack Observatory already in

April 1968. Today Onsala is a fundamental geodetic station with equipment for geodetic VLBI,

GNSS, a superconducting gravimeter, and several radiometers for atmospheric measurements.

Figure 1 shows a recent aerial photo of the area around the 20-m telescope.

Figure 1. Aerial photo taken in December 2010. Shown are: (1) the radome enclosing the 20-m radio

telescope used for geodetic/astrometric VLBI, (2) the IGS antenna, (3) the water vapor radiometer Astrid,

(4) the old gravimeter house, (5) the new gravimeter house, and additional office and laboratory buildings.

2. Staff Associated with the IVS Network Station at Onsala

The staff associated with the IVS Network Station at Onsala remained the same as reported

in last year’s annual report. Contact information is found on the observatory Web page http:

//www.chalmers.se/rss/oso-en/.

IVS 2010 Annual Report 75
Onsala Space Observatory (OSO) Onsala Space Observatory (OSO)

3. Geodetic VLBI Observations for the IVS during 2010

In 2010 the Onsala observatory was involved in four IVS observing series: EUROPE, R1, T2,

and RD10. In total, Onsala participated and acquired useful observations in 27 experiments, see

Table 1. All experiments were recorded on Mark 5 modules. Most of the experiments whose

data were correlated at the Bonn correlator were additionally recorded in parallel on the PCEVNcomputer that is daisy-chained to the Mark 5 computer. The observed data of these experiments

were then e-transferred using the Tsunami protocol, and no Mark 5 modules were actually sent

to Bonn. Radio interference due to UMTS mobile telephone signals continued to be a disturbing

factor for the S-band observations.

Table 1. Geodetic VLBI experiments at the Onsala Space Observatory during 2010.

Exper. Date Remarks Correlated

R1-413 JAN.11 E-transfer to Bonn o.k, but 30 min lost due to Mark 5 module failure

EUR-103 JAN.18 E-transfer to Bonn o.k.

R1-415 JAN.25 E-transfer to Bonn o.k.

R1-417 FEB.08 E-transfer to Bonn o.k.

RD-10.02 FEB.17 module shipment to Haystack o.k.

R1-420 MAR.01 E-transfer to Bonn o.k.

EUR-104 MAR.02 E-transfer to Bonn o.k., but some scans lost due to power failure

R1-425 APR.06 E-transfer to Bonn o.k.

RD-10.03 APR.07 module shipment to Haystack o.k.

R1-426 APR.12 E-transfer to Bonn o.k.

R1-427 APR.19 E-transfer to Bonn o.k.

R1-428 APR.26 E-transfer to Bonn o.k., but some problems with phase-cal

RD-10.04 MAY.04 module shipment to Haystack o.k.

R1-437 JUN.28 E-transfer to Bonn o.k, but 40 min missed due to power failure

RD-1005 JUN.29 module shipment to Haystack o.k.

EUR-106 JUL.05 E-transfer to Bonn o.k.

R1-438 JUL.06 E-transfer to Bonn o.k.

R1-440 JUL.19 E-transfer to Bonn o.k.

R1-445 AUG.23 E-transfer to Bonn o.k.

R1-446 AUG.30 E-transfer to Bonn o.k.

R1-449 SEP.20 E-transfer to Bonn o.k.

T2-071 SEP.21 module shipment to Haystack o.k.

R1-450 SEP.27 E-transfer to Bonn o.k.

T2-072 OCT.05 module shipment to Haystack o.k.

R1-457 NOV.15 E-transfer to Bonn o.k, but 6 scans missed due to Mark 5 problems

R1-461 DEC.13 E-transfer to Bonn o.k.

R1-462 DEC.20 E-transfer to Bonn o.k.

76 IVS 2010 Annual Report
Onsala Space Observatory (OSO) Onsala Space Observatory (OSO)

4. Fennoscandian-Japanese Ultra-rapid dUT1 Measurements

During 2010 we continued our involvement in the successful Fennoscandian-Japanese ultrarapid dUT1 project. We used a number of standard 24-hour IVS sessions where both Onsala and

Tsukuba (or Kashima) were involved to continuously determine dUT1 results during the ongoing

VLBI observations. In total, 15 R1 sessions, three RD sessions, and two T2 sessions were used as

ultra-rapid dUT1 sessions. Even one European session, EUR.104, was performed as an ultra-rapid

experiment. In this case, both Onsala and Mets ̈ahovi sent their data in real-time to the Tsukuba

correlator, where the data were correlated and analyzed. However, the dUT1 results were of low

quality, mainly due to the short baseline Onsala-Mets ̈ahovi. Additionally, we performed a few

dedicated one-baseline ultra-rapid dUT1 sessions. These sessions were observed for several hours

during the European night hours after standard IVS sessions. In both cases the dUT1 results were

determined already during the ongoing VLBI observations using a ‘sliding window’ approach with

approximately 35 scans. Table 2 gives an overview of these additional one-baseline ultra-rapid

dUT1 sessions.

Table 2. Dedicated Fennoscandian-Japanese ultra-rapid dUT1 experiments in 2010.

Exper. Date Duration Baseline Mbps Transfer Correlation Analysis

UR0.271 SEP.28 8 h Onsa-Kash 256 real-time real-time automated

UR0.279 OCT.06 8 h Onsa-Tsuk 256 real-time real-time automated

UR0.348 NOV.16 12.5 h Onsa-Tsuk 256 real-time real-time automated

UR0.355 DEC.21 12.5 h Onsa-Tsuk 256 real-time real-time automated

5. Monitoring Activities in 2010

Monitoring activities were continued as described in previous annual reports.

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 Vaisala instrument was installed at Onsala in late 2002 and has been calibrated

at SMHI main facility in Norrk ̈oping every 1–2 years since then. The agreement between the

Onsala pressure sensor and the SMHI pressure sensor is on the level of ±0.1 hPa.

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. New

temperature sensors were installed and the measurements made available via Internet, see

http://wx.oso.chalmers.se/pisa/.

Microwave radiometry. The water vapor radiometer Astrid was in operation continuously during 2010, mainly observing in a so-called sky-mapping mode. The second water vapor radiometer Konrad is still being upgraded in the electronic lab at the observatory.

Sea-level monitoring. We operated the GNSS-based tide gauge during several months at the

coastline close to the observatory to monitor the local sea-level. The tidal analysis of the

sea-level variations clearly shows the dominant ocean tides in the Kattegatt.

IVS 2010 Annual Report 77
Onsala Space Observatory (OSO) Onsala Space Observatory (OSO)

Superconducting gravimetry. The superconducting gravimeter (SCG) operated continuously

during 2010. It produced a highly precise record of gravity variations, and it recorded

earthquakes and free oscillations of the earth. Further information on the SCG can be

found on the Web page http://froste.oso.chalmers.se/hgs/SCG/. Auxilliary sensors

for bedrock temperature and rock deformation below the gravimeter house were installed in

the spring of 2010. The measurements are available on a Web page, see http://wx.oso.

chalmers.se/gravimeter/.

Seismological observations. A three-axis seismometer has been operated at the observatory

since May 2010. Since the current operating site is slightly disturbed by man-made vibrations,

the instrument has to be moved to a better site within the observatory premises. The actual

location has not yet been identified.

Monitoring of the RFI environment. During 2010 a system to monitor the radio frequency

interference (RFI) environment was developed as part of a master’s thesis. The instrument

will be installed permanently at the Onsala site in 2011.

6. New Contract with the Swedish Research Council

In connection with the international evaluation of the observatory carried out in 2009 by the

Swedish Research Council (VR), a new contract between Chalmers University of Technology, the

host university for the observatory, and VR was signed in late 2010. This contract states that

the observatory has the role as a Swedish national infrastructure for radio astronomy as well as

geodesy.

7. Outlook

The Onsala Space Observatory will continue to operate as an IVS Network Station and to

participate in the IVS observation series. For 2011 a total of 41 experiments is planned, including

the 15-day-long CONT11 campaign. We aim to use e-transfer of as many of the experiments as

possible. We will also continue the Fennoscandian-Japanese ultra-rapid dUT1 project and focus

on 24-h ultra-rapid dUT1 sessions, and additional one-baseline ultra-rapid sessions during the

European night hours.

During 2011 we plan to carry out the following hardware improvements:

• Replacement of the analog VLBI backend by a digital one.

• Installation of the GNSS-based tide gauge at a new location for continuous observations. As

a reference we will add a traditional tide gauge based on pressure sensors.

• A more permanent installation of the seismometer at a place at the observatory with fewer

man-made vibrations.

• Monitoring of the RFI environment.

Encouraged by the positive evaluation of the observatory in 2009, and the new contract with

the Swedish Research Council in 2010, we will start a discussion on a transition of Onsala to

become fully VLBI2010-compliant.

78 IVS 2010 Annual Report
CSIRO Astronomy and Space Science Parkes Network Station

Parkes 2010 IVS Report

John Reynolds, Tasso Tzioumis

Abstract

This report describes the 2010 activities and future plans of the IVS Network Station at Parkes,

Australia.

1. New Status

In February 2010 the Parkes Observatory officially became a network station of IVS, having

participated actively for many years as an “ex officio” member.

2. 2010 Observing

In 2010 Parkes participated in just two IVS sessions (R1416 and CRF61). Planned participation

in several more sessions fell through due to cancellations coming from the delays in commissioning

of the AUSTRAL network. It is hoped the level of participation in 2011 will resume to its typical

levels of six to eight sessions per year.

In addition to these two IVS sessions, Parkes during 2010 also participated in several hybrid

astronomy/geodesy observations in a program led by Leonid Petrov of ADNET Systems/GSFC.

This program has the dual aims of identifying additional calibrator sources in the Southern Hemisphere and refining the locations of several southern hemisphere radio astronomy stations that are

equipped neither with dual S/X receiving systems nor IVS-compatible recording systems.

3. Maintenance

The Parkes station is equipped with a Mark 5B+ recorder and Mark 5 D/A rack, which

replaced the long-serving Mark IIIA recorder in late 2007. (The rack code is MARPOINT, for

those interested in such history). In mid-2010 the Observatory purchased 14 new disk modules

with 8TB capacity for use with both IVS and other sessions. Use of these SATA modules required

an upgrade to the Mark 5B+ to Debian Etch and SDK 8, thereby exposing an unusual fault with

the Streamstor card, which was unable to read back SATA modules. The board was returned to

Conduant who promptly replaced two termination resistors, the values of which had been optimized

since the manufacture of the board. No further problems were experienced.

4. Future Plans

The dual S/X receiver at Parkes currently has limited bandwidth that precludes the use of

the IF3 module. An upgrade to the receiver is planned in 2011 to allow wider bandwidths to be

recorded using an IF3 module or equivalent.

IVS 2010 Annual Report 79
Parkes Network Station CSIRO Astronomy and Space Science

Figure 1. Parkes 64-meter antenna, with the movable 60-foot antenna (now decommissioned) in the distance.

(Credit: John Sarkissian, CSIRO.)

80 IVS 2010 Annual Report
CSIRO Astronomy and Space Science Parkes Network Station

Figure 2. Parkes antenna, with geodetic monument and dual-frequency GPS antenna in the foreground.

(Credit: John Sarkissian, CSIRO.)

IVS 2010 Annual Report 81
Parkes Network Station CSIRO Astronomy and Space Science

Figure 3. Parkes antenna at night. (Credit: John Sarkissian, CSIRO.)

82 IVS 2010 Annual Report
Shanghai Astronomical Observatory, CAS Sheshan

Sheshan VLBI Station Report for 2010

Xiaoyu Hong, Qingyuan Fan, Bo Xia, Tao An

Abstract

This report summarizes the observing activities at the Sheshan station (SESHAN25) in 2010. The

SESHAN25 radio telescope participated in sixteen 24-hour VLBI sessions organized by the IVS and

two VLBI sessions organized by the EVN, as well as in a number of e-VLBI sessions and formatter

tests by the EVN. In October and November 2010, SESHAN25 was involved in the VLBI tracking of

the Chinese Chang’E-2 Lunar satellite. We also report on updates and development of the facilities at

the station.

1. General Information

The Sheshan VLBI station (also named SESHAN25 in the geodetic community) is located

at Sheshan, about 30 km west of Shanghai. 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 member of the IVS and EVN.

The SESHAN25 telescope takes part in international VLBI experiments for astrometric, geodetic,

and astrophysical research. Apart from its international VLBI activities, the telescope spent a

large amount of time on the Chinese Lunar Project, including the testing before the launch of the

Chang’E-2 satellite and the tracking campaign after the launch of Chang’E-2.

2. VLBI Observations in 2010

In 2010, SESHAN25 participated in 16 IVS sessions. SESHAN25 also participated in the EVN

sessions in February and June. There were no known problems during the observations. A new

6.7-GHz receiver with dual-circular polarization has been available since spring 2010. We found

fringes in the EVN February session. Soon it witnessed the first methanol spectral lines from a

massive star-forming region observed with the new receiver. Methanol maser line studies were

started both in single-dish and in VLBI modes after that. In order to participate in the Chinese

Chang’E-2 Lunar Project, SESHAN25 prepared for Chang’E-2 tracking in mid-September, and it

did real-time VLBI tracking after its launch on 1st October. Since December 2010, SESHAN25

has observed the Chang’E-2 satellite with a long term routine VLBI tracking model for two or

three days per week.

3. Development and Maintenance of Sheshan Telescope in 2010

We have upgraded the Mark 5A Firmware Version to 12.06 (API 10.07, SDK 8.2), in order to

use SATA modules. We also performed routine maintenance of our antenna in the middle of 2010.

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.

IVS 2010 Annual Report 83
Sheshan Shanghai Astronomical Observatory, CAS

Table 1. The staff of the Sheshan VLBI Station.

Name Background Position and 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 Operator gouwei@shao.ac.cn

Linfeng YU Electronics Operator lfyu@shao.ac.cn

Yongbin JIANG Electronics Operator jyb@shao.ac.cn

5. Outlook

In 2011 the Sheshan radio telescope will take part in 23 IVS sessions and three EVN sessions.

The telescope will regularly monitor the Chang’E-2 satellite in its lunar orbit for 2–3 days per

week in 2011.

A new telescope with a diameter of 65-m will be built about 6 km west of the current site of

the Sheshan 25-m radio telescope. It is planned to be available for C, L, and S/X bands in 2012.

84 IVS 2010 Annual Report
Radio Astronomy Lab of Crimean Astrophysical Observatory Simeiz Station

Stations of Space Geodesy and Geodynamics of CrAO:

Simeiz VLBI, Simeiz-1873 SLR, CrAO-GPS

A.E. Volvach, A.I. Dmitrotsa, V. Andreatta

Abstract

This report gives an overview about the geodetic VLBI, SLR and GPS activities at CrAO stations.

We summarize briefly the status of the 22-m radio as IVS Radio Network Station Telescope, the laser

Simeiz-1873, and the GPS-CrAO stations.

1. General Information

The fundamental geodynamics area “Simeiz-Katsively” is situated on the coast of the Black

Sea near the village of Simeiz about 20 km west of the city of Yalta in the Ukraine. It consists

of two satellite laser ranging stations, a permanent GPS receiver, a sea level gauge, and the radio

telescope RT-22. All these components are located within 3 km (Figure 1).

Figure 1. The geodynamics area “Simeiz-Katsively”.

The positions of the points in the geodynamics test area “Simeiz-Katsively” have been determined by a special GPS survey campaign. Results are presented in Table 1.

1.1. “Simeiz” (Crimea) VLBI Station

The radio telescope RT-22 has a steering parabolic mirror with diameter 22 m and focal length

9 525 mm (Figure 2). The surface has a root mean square accuracy of 0.25 mm and an effective

area of 210 m2 which does not depend on elevation angle at geodetic frequencies 2.3 and 8.4 GHz.

The antenna has an azimuth-elevation mounting with an axis offset of −1.8±0.2 mm. The working

range in azimuth is [-210◦, 210◦] (zero is to the south) and in elevation is [-1◦, 85◦]. The maximum

IVS 2010 Annual Report 85
Simeiz Station Radio Astronomy Lab of Crimean Astrophysical Observatory

Table 1. Final solution for coordinates of points in the area “Simeiz-Katsively”.

Station X, m RMS, m Y, m RMS, m Z, m RMS, m

KTHI 3785378.6041 0.0004 2551165.3915 0.0003 4439717.4172 0.0004

KTLR 3785923.9017 0.0005 2550781.8054 0.0003 4439471.6117 0.0004

KTRT 3785160.8761 0.0004 2551262.2573 0.0002 4439789.8357 0.0004

SIME 3783746.4067 0.0000 2551362.7445 0.0000 4441445.1801 0.0000

CRAO 3783897.2187 0.0006 2551404.3953 0.0004 4441264.2859 0.0006

SIMI 3783887.4552 0.0004 2551403.5454 0.0003 4441266.8603 0.0005

KTE2 3785236.0690 0.0477 2551188.5462 0.0308 4439784.2244 0.0531

KTE1 3785206.0519 0.0345 2551216.1368 0.0240 4439790.8836 0.0426

slewing rate is 1.5

◦/sec. The control system of the telescope provides accuracy of pointing at the

level of 10′′.

The foundation pit of the telescope is 9 meters deep, and it has three meters of crushed stones

and then six meters of concrete. The height of the elevation axis above the foundation is 14.998

meters. The telescope is located 80 meters from the edge of the Black Sea.

The reference point of the radio telescope has IERS name “CRIMEA”, ITRF name “Simeis”,

IERS DOMES number 12337S008, and CDP number 7332.

The reference point of the antenna is the point of projection of the azimuthal axis on the elevation axis. The coordinates of this point are determined in analysis of the observations. However,

this point may move with respect to the local area where the radio telescope is located.

RT-22 was equipped with modern Mark 5A and Mark 5B+ VLBI recording systems and a

new H-maser. That gives the possibility to continue astrophysical and fundamental geodetic VLBI

observations.

Figure 2. CrAO-GPS, Simeiz-1873 SLR, and Simeiz VLBI stations.

86 IVS 2010 Annual Report
Radio Astronomy Lab of Crimean Astrophysical Observatory Simeiz Station

1.2. Satellite Ranging Station SLR “Simeiz-1873”

Regular satellite laser ranging started in our observatory in 1976 as an INTERKOSMOS station.

In 1988 CrAO installed a new station (near the old station) with name Simeiz-1873 (Figure 2):

Network: ILRS and EUROLAS, Name: Simeiz, Code: SIMI, Plate: Europe, CDP: 1873, IERS

DOMES: 12337S003, Laser SOD: 12337S003. The coordinates of station are presented in Table 2.

Table 2. Coordinates to 01.01.2010 by ITRF2005 of the Simeiz-1873 station.

Latitude 44◦ 24′ 47.31′′

Longitude 33◦ 59′ 27.44′′

Height 364.24 m

X 3783902.127 m

Y 2551405.097 m

Z 4441257.417 m

1.3. GPS Station “GPS-CrAO”

The GPS-CrAO station (Figure 2) was upgraded in 2008. The GPS system includes a receiver

and an antenna. The computer system and Meteorological Survey Equipment were supplied by

NASA/Science Division/UNAVCO (Figure 3).

Figure 3. GGN-CrAO.

IVS 2010 Annual Report 87
Simeiz Station Radio Astronomy Lab of Crimean Astrophysical Observatory

2. Current Status and Activities

In 2010 the Space Geodesy and Geodynamics stations regularly participated in the International

Network programs of IVS, the International GNSS Service (IGS), and the International Laser

Ranging Service (ILRS).

GPS-CrAO

Simeiz-1873 

Figure 4. “GPS-CrAO” and “Simeiz-1873” stations of International Network - IGS and ILRS.

From January 1 through December 31, Simeiz VLBI station participated in twelve 24-hour

geodetic sessions. Simeiz regularly participated in the EUROPE and T2 series of geodetic sessions.

Use of the Simeiz antenna is shared with the “Radioastron” program. The Research program provides for work with highly sensitive radiometers at frequencies of 22 GHz and 36 GHz.

The catalog of sources for flight program “Radioastron” observations of a sample of sources from

the preliminary “Radioastron” catalog were obtained at 22.2 and 36.8 GHz on the RT-22 radio

telescope of the Crimean Astrophysical Observatory [1]. This makes it possible to obtain spectral

characteristics of the sources near 22 GHz the fundamental frequency of the experiment “RadioAstron”. To implement the project prepared by the scientific program, a substantial part of which

is the study of compact structures in extragalactic sources, we conducted ground-based VLBI test

experiments.

3. Future Plans

Our plans for the coming year are the following: put into operation the VLBI Data Acquisition

System DBBC, upgrade the laser of SLR Simeiz-1873 station, and set up new GPS station near

Simeiz VLBI station.

References

[1] A.E. Volvach // Space Science and Technology. 2009. T.15. N.5. P.82–97.

88 IVS 2010 Annual Report
National Institute of Polar Research JARE Syowa Station 11-m antenna

JARE Syowa Station 11-m Antenna, Antarctica

Koichiro Doi, Kazuo Shibuya, Yuichi Aoyama

Abstract

The operation of the 11-m S/X-band antenna at Syowa Station (69.0◦S, 39.6◦E) by the Japanese

Antarctic Research Expeditions (JAREs) started in February 1998 and continues until today (December

2010). A cumulative total of 91 quasi-regular geodetic VLBI experiments were observed by the end of

2010. Syowa Station will participate in six OHIG sessions in 2011.

The data from three OHIG sessions in 2010 were recorded on hard disks through the K5 terminal.

They will be brought back from Syowa Station to Japan in April 2011. The data from the OHIG62

through the OHIG69 sessions observed by JARE48 and JARE49 have been transferred to the Bonn

Correlator directly by way of one of NICT’s servers. Analysis results calculated by the GSFC IVS

Analysis Center from the data until the OHIG69 session indicate that the length of the Syowa-Hobart

baseline is increasing with a rate of 55.3 ± 0.9 mm/yr and that the length of the Syowa-HartRAO

baseline is increasing with a rate of 10.9 ± 0.8 mm/yr. The length of the Syowa-O’Higgins baseline is

slightly increasing with a rate of 2.5 ± 1.5 mm/yr.

1. Overview

Syowa Station has become one of the key observatories in the Southern Hemisphere’s geodetic

network, as reported in [1]. 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].

A K5 recording system was introduced at Syowa Station in September 2004. Syowa’s K4

recording terminal was 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

became possible with the introduction of the K5 system, but huge VLBI data transfers are not

realistic because of the low transfer speed.

2. Notes on System Maintenance

There is no significant problem in the “mechanical system”. After the hydrogen maser set

(Anritsu RH401A; 1002C) had been used for observations from 2004 to 2010, it was turned off

at the end of 2010, because of problems in the 10 MHz output. A backup hydrogen maser set

(Anritsu RH401A; 1001C) replaced the 1002C, and it is operating normally. The hydrogen maser

1002C will be back to Japan in April 2011. It will be overhauled and will be deployed in Syowa in

January 2012 again. The tube in the Cs frequency comparator and local oscillator will have to be

replaced with a new one in the near future.

3. Session Status

Table 1 summarizes the status of processing as of December 2010 for the sessions after 2004.

The OHIG sessions involved Fortaleza (Ft), O’Higgins (Oh), Kokee Park (Kk), Parkes (Pa), TIGO

Concepci ́on (Tc), Syowa (Sy), Hobart (Ho), and HartRAO (Hh). In 2005, Syowa joined the CRD

sessions, but after 2006, Syowa participated only in OHIG sessions. Syowa participated in three

IVS 2010 Annual Report 89
JARE Syowa Station 11-m antenna National Institute of Polar Research

OHIG sessions in 2010.

Until 2004, K4 tapes containing the OHIG sessions’ data from Syowa Station were copied to

Mark IV tapes at GSI, and the Mark IV tapes were sent to the Mark IV Correlator for final

correlation. Since the introduction of the K5 system, K5 hard disk data brought back from Syowa

Station have been transferred by ftp to the MIT Haystack Observatory or the Bonn Correlator

through a NICT server and converted to the Mark 5 format data there.

Figure 1. Syowa VLBI staff for JARE-51 (February 2010 — January 2011).

4. Staff of the JARE Syowa Station 11-m Antenna

• Kazuo Shibuya, Project coordinator at NIPR.

• Koichiro Doi, Yuichi Aoyama, Liaison officer at NIPR.

• Yuichi Aoyama (from National Institute of Polar Research), Chief operator for JARE-49

(February 2008 — January 2009).

• Hideaki Kumagai (from NEC), Antenna engineer for JARE-49.

• Yusuke Murakami (from University of Tokyo), Chief operator for JARE-50 (February 2009

— January 2010).

• Yuji Yamaguchi (from NEC), Antenna engineer for JARE-50.

• Iuko Tsuwa (from University of Tokyo), Chief operator for JARE-51 (February 2010 —

January 2011) (left in Figure 1).

• Yoshinao Kinjyo (from NEC), Antenna engineer for JARE-51 (right in Figure 1).

90 IVS 2010 Annual Report
National Institute of Polar Research JARE Syowa Station 11-m antenna

Table 1. Status of OHIG and CRDS sessions as of December 2010.

Code Date Station Hour Correlation Solution Notes

OHIG37 2005/Feb/02 Ho, Hh, Ft, Oh, Kk 24 h Yes Yes J46

OHIG38 2005/Feb/15 Ho, Hh, Ft, Oh, Kk 24 h Yes Yes

CRDS18 2005/Apr/11 Ho, Hh 24 h Yes Yes

CRDS19 2005/May/10 45, Hh 24 h Yes Yes

OHIG39 2005/Nov/08 Ho, Hh, Ft, Oh, Kk 24 h Yes Yes

OHIG40 2005/Nov/09 Ho, Hh, Ft, Oh, Kk 24 h Yes Yes

OHIG41 2005/Nov/16 Ho, Hh, Ft, Oh, Kk 24 h Yes Yes

OHIG42 2006/Jan/31 Ho, Hh, Ft, Oh, Kk, Tc 24 h Yes Yes

OHIG43 2006/Feb/08 Ho, Hh, Ft, Oh, Kk, Tc 24 h Yes Yes J47

OHIG44 2006/Feb/14 Ho, Hh, Ft, Oh, Kk, Tc 24 h Yes Yes

OHIG45 2006/Nov/07 Ho, Hh, Ft, Oh, Kk, Tc 24 h Yes Yes

OHIG46 2006/Nov/14 Ho, Hh, Oh, Kk, Tc 24 h Yes Yes

OHIG47 2006/Nov/29 Ho, Hh, Ft, Oh, Kk, Tc 24 h Yes Yes

OHIG49 2007/Feb/13 Ho, Hh, Ft, Oh, Kk, Tc 24 h Yes Yes J48

OHIG51 2007/Nov/06 Ho, Ft, Oh, Kk, Tc 24 h Yes Yes

OHIG52 2007/Nov/07 Ho, Ft, Oh, Kk, Tc 24 h Yes Yes

OHIG53 2007/Nov/13 Ho, Hh, Ft, Oh, Kk, Pa, Tc 24 h Yes Yes

OHIG54 2007/Nov/14 Ho, Hh, Ft, Oh, Kk, Pa, Tc 24 h Yes Yes

OHIG55 2008/Feb/06 Hh, Oh, Kk, Tc 24 h Yes Yes J49

OHIG56 2008/Feb/12 Hh, Oh, Kk, Tc 24 h Yes Yes

OHIG57 2008/Feb/13 Hh, Oh, Kk, Tc 24 h Yes Yes

OHIG59 2008/Nov/12 Ho, Ft, Oh, Kk, Tc 24 h Yes Yes

OHIG60 2008/Nov/18 Ho, Ft, Oh, Kk, Pa, Tc, Ts 24 h Yes Yes

OHIG61 2008/Nov/19 Ho, Ft, Oh, Kk, Tc 24 h Yes Yes

OHIG62 2009/Feb/04 Ft, Ho, Kk, Oh, Tc 24 h Yes Yes J50

OHIG63 2009/Feb/10 Ft, Ho, Kk, Oh, Tc 24 h Yes Yes

OHIG64 2009/Feb/11 Ft, Ho, Kk, Oh, Tc 24 h Yes Yes

OHIG65 2009/Nov/10 Ho, Kk, Oh, Tc 24 h Yes Yes

OHIG66 2009/Nov/11 Ho, Kk, Oh, Tc 24 h Yes Yes

OHIG67 2010/Feb/03 Ft, Kk, Oh, Tc 24 h Yes Yes J51

OHIG68 2010/Feb/09 Ft, Ho, Kk, Oh, Tc, Hb 24 h Yes Yes

OHIG69 2010/Feb/10 Ft, Ho, Kk, Oh, Tc, Hb 24 h Yes Yes

45: DSS45, Ts: Tsukuba32

J46: JARE-46, op K. Egawa eng I. Okabayashi J47: JARE-47, op T. Sawagaki eng H. Ishii

J48: JARE-48, op N. Arai eng H. Sugawara J49: JARE-49, op Y. Aoyama eng H. Kumagai

J50: JARE-50, op Y. Murakami eng Y. Yamaguchi J51: JARE-51, op I. Tsuwa eng Y. Kinjyo

IVS 2010 Annual Report 91
JARE Syowa Station 11-m antenna National Institute of Polar Research

5. Analysis Results

As of the end of December 2010, 75 sessions from May 1999 through February 2010 have been

analyzed with the software CALC/SOLVE developed by NASA/GSFC.

According to the result analyzed by the GSFC IVS Analysis Center, the length of the SyowaHobart baseline is increasing with a rate of 55.3 ± 0.9 mm/yr. The Syowa-HartRAO baseline

shows a slight increase with a rate of 10.9 ± 0.8 mm/yr. These results agree approximately with

those of GPS. The Syowa-O’Higgins baseline also shows slight increase, although the rate is only

2.5 ± 1.5 mm/yr. Detailed results from the data until the end of 2003 as well as comparisons with

the results from other space geodetic techniques are reported in [3].

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.

92 IVS 2010 Annual Report
Bundesamt f ̈ur Kartographie und Geod ̈asie - TIGO TIGO

Geodetic Observatory TIGO in Concepci ́on

Sergio Sobarzo, Eric O ̃nate, Cristian Herrera, Pedro Zaror, Felipe Pedreros,

Octavio Zapata, Hayo Hase

Abstract

In 2010, 119 successful VLBI observations were carried out at TIGO. The present report reviews

the 2010 activities, and the forthcoming 2011 tasks are also given.

1. General Information

The operation of TIGO is based on an agreement between the Republic of Chile and the Federal

Republic of Germany. The operation relies on three institutions:

• Universidad de Concepci ́on (Chile),

• Instituto Geogr ́afico Militar (Chile), and

• Bundesamt f ̈ur Kartographie und Geod ̈asie (Germany).

TIGO is located on terrain of the Universidad de Concepci ́on (long. 73.025 degrees West, lat.

36.843 degrees South), in Concepci ́on, Chile.

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 with 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 changed.

3. Staff

The VLBI staff changed in two positions: Miguel Soto and Cristian Duguet left TIGO at the

beginning of the year and were replaced by Felipe Pedreros and Octavio Zapata. The 2010 TIGO

VLBI group consisted of the persons listed in Table 1.

4. Current Status and Activities

During 2010 TIGO was scheduled to participate in 119 IVS experiments (see Table 2) and four

24-hour experiments framed of the TANAMI project [2]. Five additional experiments (TQUAK)

had been initiated as soon as TIGOCONC became operational again after the M8.8 earthquake in

Concepci ́on on February 27, 2010.

IVS 2010 Annual Report 93
TIGO Bundesamt f ̈ur Kartographie und Geod ̈asie - TIGO

Figure 1. Current VLBI Staff: Hase, Herrera, Sobarzo, Zaror, and Zapata. O ̃nate and Pedreros were absent.

Table 1. TIGO-VLBI support staff in 2010.

Staff Function Email

Hayo Hase Head hayo.hase@tigo.cl

Sergio Sobarzo Chief Engineer sergio.sobarzo@tigo.cl

Eric O ̃nate Electronic Engineer eric.onate@tigo.cl

Cristian Herrera Informatic Engineer cristian.herrera@tigo.cl

Pedro Zaror Mechanical Engineer pedro.zaror@tigo.cl

Felipe Pedreros Telecommunications Engineer felipe.pedreros@tigo.cl

Octavio Zapata Telecommunications Engineer octavio.zapata@tigo.cl

any VLBI-operator on duty vlbi@tigo.cl

all VLBI-operators vlbistaff@tigo.cl

Table 2. TIGO’s IVS observation statistics for 2010.

Name # of Exp. OK Failed

R1xxx 47 41 6

R4xxx 50 46 4

R&D 4 4 0

OHIGxx 6 6 0

T20xx 7 7 0

TQAKXX 5 5 0

Tanami 4 4 0

Total IVS 119 109 10

94 IVS 2010 Annual Report
Bundesamt f ̈ur Kartographie und Geod ̈asie - TIGO TIGO

4.1. Post-earthquake Recovery

The M8.8 earthquake destroyed or damaged several instruments and infrastructure of TIGO. All

TIGO containers had been shaken heavily and changed their positions. A horizontal displacement

of more than 3 meters of the TIGO site was measured by GPS/GLONASS and later on confirmed

by independent VLBI and SLR measurements (Fig. 2).

The recovery consisted of a diagnosis plan and damage analysis of the equipment to bring them

back to operation as soon as possible. The TIGO team made tests of all components of the VLBI

systems including racks, wiring, inclinometers, computers, and the radio telescope.

The mechanical functionality was carefully checked to detect possible damages in the cables

chain, motors, and gears, among others by conducting manual movements in azimuth and elevation

to avoid problems later on during real measurements.

Thanks to these successful tests, TIGO was able to participate already two weeks after the

major event from the R1422 experiment onwards—covering still the period of strong post-seismic

motion.

VLBI measurements are shown in Fig. 2 where the earthquake displacement and subsequent

behavior can be appreciated.

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Figure 2. TIGOCONC coordinate time series showing earthquake displacement. a) North component b)

East component c) Height component.

4.2. Mark 5 Upgrade

In September and October 2010, an upgrade of the Data Acquisition System was performed.

This consisted of a complete change of hardware and software of one of the two recording systems,

namely from Mark 5A to Mark 5B, and the replacement of one VSI card in the formatter. For the

IVS 2010 Annual Report 95
TIGO Bundesamt f ̈ur Kartographie und Geod ̈asie - TIGO

development of this project, the MIT Haystack Observatory facilitated a Mark IV formatter as

backup while the necessary tests and adjustments were performed for the implementation of the

new system.

5. Future Plans

The VLBI activities in 2011 will be focused on:

• execution of the IVS observation program for 2011

• continuation of investigations related to e-VLBI

• repetition of the local survey.

(a) (b) (c)

Figure 3. Earthquake damage, photos taken in Concepci ́on a few days after the quake.

References

[1] Vandenberg, N.R.: International VLBI Service for Geodesy and Astrometry 2000 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.

96 IVS 2010 Annual Report
Geospatial Information Authority of Japan Tsukuba 32-m VLBI Station

Tsukuba 32-m VLBI Station

Shinobu Kurihara, Kensuke Kokado, Ryoji Kawabata, Jiro Kuroda, Misao Ishihara,

Daisuke Tanimoto, Yasuko Mukai

Abstract

The Tsukuba 32-m VLBI station is operated by the Geospatial Information Authority of Japan

(GSI). This report summarizes the current status and the future plans of the Tsukuba 32-m VLBI

station and related facilities. Over 200 sessions were observed with Tsukuba 32-m, Kashima 34-m,

and other GSI antennas in accordance with the IVS Master Schedule. Lightning struck the Tsukuba

facility in July, and the antenna and some devices were damaged. Some IVS sessions planned at

Tsukuba were canceled, and Kashima 34-m antenna filled in for Tsukuba 32-m antenna during two

months. In addition, several ultra-rapid dUT1 experiments and compact VLBI system experiments

were conducted.

1. General Information

The Tsukuba 32-m VLBI station (TSUKUB32) is located at GSI in Tsukuba Science City

which is about 50 km to the northeast of the capital Tokyo. GSI has three regional stations

besides TSUKUB32: SINTOTU3, CHICHI10, and AIRA, which form the 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 define the reference frame of Japan and to monitor the plate motions for the

advanced study of crustal deformations. Additionally, Mizusawa (VERAMZSW) and Ishigakijima

(VERAISGK), which are part of the VERA network of the National Astronomical Observatory of

Japan (NAOJ), also participated in the JADE sessions.

Figure 1. Tsukuba 32-m VLBI station and VLBI

team.

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Figure 2. Geodetic VLBI network in Japan.

IVS 2010 Annual Report 97
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 system Az-El

Receiving feed Cassegrain

Diameter of main reflector 32 m

Azimuth range 10 – 710◦

Elevation range 5 – 88◦

Az/El drive velocity 3

◦/sec

Tsys (X/S) 50 K / 75 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 DBBC

In 2010, a hydrogen maser frequency standard (Anritsu Corp., SA0D05A) and the next generation gigabit sampler (Cosmo Research Corp., ADS3000+) were installed at Tsukuba 32-m station.

And as the Field System PC, having been used since 2002, became dated, we replaced it with a

new rack mount type PC.

3. Staff

Table 2 lists the regular operating staff belonging to the GSI VLBI observation group. The

former head of the Space Geodesy Division, Shigeru Matsuzaka, transferred to the Planning Department as the Assistant Director for International Observation, and Misao Ishihara took over

the division head position in April. Ryoji Kawabata newly joined our group as a technical official

in April. Yoshihiro Fukuzaki and Yuji Miura moved to another division in June, and Jiro Kuroda

became the deputy head of our division. Kensuke Kokado had been visiting the Haystack Observatory in the United States as a visiting researcher until January 6, but after that, he came

back to our group. Kazuhiro Takashima had been an IVS Directing Board at-large member, but

he left the post for health reasons. Shinobu Kurihara succeeded to the post in October. Routine

operations were mainly performed under contract with Advanced Engineering Service Co., Ltd.

(AES).

4. Current Status and Activities

4.1. Geodetic VLBI Observations

The regular sessions in the IVS Master Schedule are shown in Table 3. TSUKUB32 participated

in 61 domestic and international 24-hr VLBI sessions and 118 Intensive 1-hr sessions this year.

SINTOTU3, CHICHI10, and AIRA participated not only in domestic sessions but also in some

international sessions.

98 IVS 2010 Annual Report
Geospatial Information Authority of Japan Tsukuba 32-m VLBI Station

Table 2. Staff list of the GSI VLBI group.

Name Position/Company Function

Misao ISHIHARA Head of Space Geodesy Div. Supervisor

Jiro KURODA Deputy head of Space Geodesy Div. Management, Collocation

Shinobu KURIHARA VLBI operation chief Responsible official, IVS DB member

Kensuke KOKADO Analysis chief Correlation, Analysis, Data transfer

Ryoji KAWABATA Technical official VLBI operation, miscellaneous work

Kazuhiro TAKASHIMA Senior researcher Research

Daisuke TANIMOTO AES, Co., Ltd. Observation

Yasuko MUKAI AES, Co., Ltd. Observation and Correlation

Toshio NAKAJIMA I-JUSE System engineer

Table 3. The number of regular sessions in 2010.

Sessions TSUKUB32 KASHIM34 SINTOTU3 CHICHI10 AIRA

IVS-R1 38 6 – – –

IVS-T2 6 1 – 7 7

APSG 2 – 2 2 2

VLBA 4 1 – – –

IVS-R&D 5 – – – –

JADE 6 2 7 4 4

IVS-INT2 80 12 – – –

IVS-INT3 38 7 – – –

Total 179 29 9 13 13

4.2. Lightning Strike at Tsukuba 32-m Antenna

On July 25, Tsukuba 32-m antenna was damaged by a lightning strike. The air conditioner in

the observation room stopped, and the interface port of the ACU and the encoders for the Az drive

& reflector in the waveguide were broken. Since it was expected to require a long time to restore

the antenna, colleagues at NICT KSRC (National Institute of Information and Communications

Technology, Kashima Space Research Center) kindly let us use Kashima 34-m antenna during

repair period. We could operate totally 29 sessions using Kashima 34-m antenna in August and

September as shown in Table 3. The session numbers in the KASHIM34 column only reflect

sessions that were operated by GSI during the period of the Tsukuba 32-m repair. With the

IVS-INT2 on October 2, Tsukuba 32-m resumed operation.

4.3. Ultra-rapid dUT1 Experiments

The ultra-rapid dUT1 experiment is a joint project of Japan (GSI & NICT) and Fennoscandia

(Onsala & Mets ̈ahovi). This year again, we tried to transfer the regular IVS 24-hr data from

the Fennoscandian station to the Tsukuba correlator and to carry out automatic data conversion,

correlation, and data analysis. The experiment was conducted in 22 IVS 24-hr sessions and seven

special schedules. For IVS-R1417 on February 8, we demonstrated the ultra-rapid experiment by

near real-time Internet broadcasting of antenna image, correlation fringe image, and dUT1 time

series plot at the 6th IVS General Meeting. The details of the analysis are reported in the Tsukuba

Analysis Center report.

IVS 2010 Annual Report 99
Tsukuba 32-m VLBI Station Geospatial Information Authority of Japan

4.4. Developing a Compact VLBI System (MARBLE)

GSI and NICT are developing a compact VLBI system with a 1.5-m diameter aperture dish

(MARBLE: Multiple Antenna Radio-interferometry of Baseline Length Evaluation) in order to

provide reference baseline lengths for GPS and EDM calibration. In the report year, eight geodetic experimental observations were carried out between two MARBLEs and two large antennas

(TSUKUB32 or KASHIM34). In particular, the last two experiments were implemented using

ADS3000+ for data acquisition, and we succeeded in IF data sampling and obtaining geodetic

solutions.

5. VLBI2010

GSI started the consideration of VLBI2010 by setting up the VLBI2010 Exploratory internal

Committee in the Geodetic Department in January. So far, eight meetings have been convened,

and the committee decided their policy to construct a new VLBI2010 antenna. After the decision,

GSI included an expense for VLBI2010 in the budget requests for the next fiscal year starting in

April 2011. The expense request is for RFI environment and underground condition surveys. In

the government draft budget for the fiscal year 2011, the request was approved. The budget will

be formally approved, when the bill is passed by the Diet.

6. Future Plans

The gigabit digital sampler “ADS3000+” will be used in routine operation. The anti-aliasing

filters necessary for “ADS3000+” will be delivered by the end of March 2011. First we will try

“ADS3000+” in a JADE session.

7. Other Topics

On December 24, Mr. Hyun-Hee Joo commenced a six-month visit to Japan from NGII (National Geographic Information Institute) of the Republic of Korea. He will stay at GSI until the

middle of June 2011 to acquire VLBI-related technique and management skills necessary to succeed

in their KVG (Korean VLBI for Geodesy) project.

100 IVS 2010 Annual Report
Urumqi Observatory, NAO–CAS Nanshan Station

Nanshan VLBI Station Report for 2010

Aili Yusup, Xiang Liu

Abstract

The Nanshan 25-meter radio telescope is operated by Urumqi Observatory. This report describes

the activities and the status of Nanshan VLBI station as an IVS network station in 2010.

1. Introduction

The Nanshan VLBI station is located 70 km south of Urumqi, the capital city of the Xinjiang

Uygur Autonomous Region of China. The station is affiliated with the Urumqi Observatory of the

National Astronomical Observatories of CAS. In 2010, we participated in a total of 153 domestic

and international VLBI sessions and contributed to IVS in geodetic VLBI observations. Nanshan

VLBI station has participated in domestic VLBI experiments as one of the VLBI ground stations

tracking the Chinese Chang’E satellite. In addition, a GPS station, as a part of the IGS network,

is located near the VLBI telescope.

Figure 1. Urumqi Observatory of the National Astronomical Observatories of CAS is located at the foothills

of the Tianshan mountain range. Within the IVS the site is also known as Nanshan VLBI Station.

IVS 2010 Annual Report 101
Nanshan Station Urumqi Observatory, NAO–CAS

2. Telescope Status

2.1. Antenna

• Diameter: 25 meter

• Antenna type: Modified Cassegrain

• Seat-rack type: Azimuth-pitching ring

• Main surface precision: 0.40 mm (rms)

• Pointing precision: 15′′ (rms)

• Rolling range: Azimuth: −270◦to 270◦; Elevation: 5◦to 88◦

• Maximum rolling speed: Azimuth: 1.0◦/sec; Elevation: 0.5◦/sec

Figure 2. The 25-m, modified Cassegrain radio telescope of Urumqi Observatory was built in 1993.

2.2. Receivers

The basic specifications of the receivers and the antenna sensitivity are given in Table 1. In

2010, the S/X-band feed horn was replaced with a new one.

102 IVS 2010 Annual Report
Urumqi Observatory, NAO–CAS Nanshan Station

Table 1. Specifications of receivers.

Parameters Freq. Range

(MHz)

1.3 cm dual under construction 22100–24000

3.6 cm RCP Tsys= 50K DPFU=0.093 8100–8900

6 cm dual Tsys= 22K DPFU=0.11 4700–5110

13 cm RCP Tsys= 70K DPFU=0.096 2150–2450

18 cm dual Tsys= 24K DPFU=0.088 1400–1720

30 cm LCP Tsys=160K DPFU=0.06 800–1200

49 cm dual under construction 560–660

92 cm dual under construction 305–345

2.3. Recording System

The recording systems available at the Nanshan VLBI station are Mark 5B, Mark IV, Mark

II, and K5. The performance of the observing system was improved in the report year. A new

FS computer was installed, the Field System was upgraded to version 9.10.4, and it works well.

The DBBC System, which was built at Shanghai Observatory (SHAO), was installed at Urumqi

for domestic VLBI observations with the Mark 5B recorder. The analog BBC system is still being

used for international VLBI observations together with the Mark 5B recorder.

2.4. Time and Frequency System

There are three H-masers at Nanshan Station: an MHM2010 imported from Symmetricom

company of the U. S. plus the No. 13 and No. 90 H-masers made in Shanghai. The time and

frequency comparison system operates continuously.

3. IVS Observations in 2010

Nine IVS sessions were scheduled for Nanshan VLBI station in 2010. We participated in six

of these sessions and had to cancel three sessions due to a conflict with tracking the Chinese

Chang’E-2 satellite from September to November 2010; the details for five of these sessions are

listed in Table 2. There is a pretty strong but narrow 3G cellphone signal at S-band, which led to

a total loss of signal in SR2U as documented in the IVS session reports.

Table 2. IVS sessions of Nanshan VLBI station in 2010.

Experiment Date Remarks (problems)

T2067 02.02 Observed, no signal in SR2U

T2068 04.13 Observed, no signal in SR2U

T2069 05.18 Observed, no signal in SR2U

T2070 07.20 Observed, no signal in SR2U

APSG27 12.15 Observed, no known problems

IVS 2010 Annual Report 103
Nanshan Station Urumqi Observatory, NAO–CAS

4. Personnel

The main staff of Nanshan VLBI Station is compiled in Table 3.

Table 3. The main staff of Nanshan VLBI Station.

Name Position Working area e-mail

Na Wang Professor Station chief na.wang@uao.ac.cn

Aili Yusup Professor Chief engineer aliyu@uao.ac.cn

Xiang Liu Professor VLBI friend liux@uao.ac.cn

Maozheng Chen Senior engineer Receiver mzchen@uao.ac.cn

Minghui Shao Senior engineer Time and Freq., Terminal shaomh@uao.ac.cn

Wenjun Yang Engineer Terminal yangwj@uao.ac.cn

Shiqiang Wang Engineer Antenna Wangshq@uao.ac.cn

Hua Zhang Engineer Terminal, Time and Freq. zhangh@uao.ac.cn

Guanghui Li Engineer Network, Computer ligh@uao.ac.cn

Jun Ma Engineer Receiver majun@uao.ac.cn

Chenyu Chen Engineer Antenna chency@uao.ac.cn

Jun Nie Scientist Network, Computer niejun@uao.ac.cn

Ming Zhang Scientist Astronomy zhangming@uao.ac.cn

104 IVS 2010 Annual Report
Institute for Radio Astronomy and Space Research, Auckland University of Technology Warkworth Observatory

Warkworth 12-m VLBI Station: WARK12M

Sergei Gulyaev, Tim Natusch, Stuart Weston, Neville Palmer, David Collett

Abstract

This report summarizes the geodetic VLBI activities in New Zealand in 2010. It provides geographical and technical details of WARK12M—the new IVS network station operated by the Institute

for Radio Astronomy and Space Research (IRASR) of Auckland University of Technology (AUT). The

details of the VLBI system installed in the station are outlined along with those of the co-located GNSS

station. We report on the status of broadband connectivity and on the results of testing data transfer

protocols; we investigate UDP protocols such as ‘tsunami’ and UDT and demonstrate that the UDT

protocol is more efficient than ‘tsunami’ and ‘ftp’. Overall, the station is fully equipped, connected,

and ready to start participating in regular IVS observational sessions from the beginning of 2011.

Figure 1. Warkworth 12-m (right) and Warkworth 30-m (left) antennas. Photo: Jordan Alexander

1. Introduction

The New Zealand 12-m radio telescope is located some 60 km north of the city of Auckland,

near the township of Warkworth (see Figure 1). It was manufactured by Patriot Antenna Systems

(now Cobham Antenna Systems), USA. The antenna specifications are provided in Table 1. The

radio telescope is designed to operate at S and X bands and supplied with an S/X dual-band dualpolarization feed. The antenna is equipped with a digital base band converter (DBBC) developed

by the Italian Institute of Radio Astronomy, a Symmetricom Active Hydrogen Maser MHM-2010

(75001-114), and a Mark 5B+ data recorder developed at MIT Haystack Observatory.

The support foundation for the antenna is a reinforced concrete pad that is 1.22 m thick by

6.7 × 6.7 meters square. The ground that the foundation is laid on consists of weathered sandstone/mudstone, i.e. of sedimentary origin, laid down in the Miocene period some 20 million years

ago. The pedestal is essentially a steel cylinder of 2.5 m diameter. It supports the antenna elevation axis which is at a height of approximately 7.1 m above ground level. Apart from the pedestal,

IVS 2010 Annual Report 105
Warkworth Observatory Institute for Radio Astronomy and Space Research, Auckland University of Technology

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′′

Frequency range 1.4—43 GHz

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

Main dish F/D ratio: 0.375

all other components of the antenna (the reflector and feed support structure) are constructed

of aluminium. The radio telescope is directly connected to the regional network KAREN (Kiwi

Advanced Research and Education Network) [1].

In November 2010 Telecom New Zealand handed over to Auckland University of Technology

its 30-meter Cassegrain wheel-and-track beam-waveguide antenna. It was manufactured in 1984

by Nippon Electric Corp., and since then it was used by Telecom NZ for communication between

New Zealand and various Pacific Islands. The antenna is just 200 meters north of WARK12M

(Figure 1). According to expert opinion, the antenna is in good state, and after conversion to a

radio telescope, it has the potential to contribute to both astronomical and geodetic VLBI.

2. Antenna Position Survey

The reference point of a VLBI site is defined as the intersection of the azimuth and elevation

axes of the telescope. A preliminary survey has been conducted in collaboration with the New

Zealand Institute of Geological and Nuclear Sciences (GNS Science) and Land Information New

Zealand (LINZ) to determine an initial estimate of the reference point of the VLBI site WARK12M

(see details in [2]). A real-time kinematic (RTK) GPS method was used to derive the position

with respect to the co-located GPS station WARK.

A co-located GPS station WARK was established in November 2008 at the radio telescope

site and is one of 39 PositioNZ network stations in New Zealand [3]. All data received from the

PositioNZ stations are processed to produce daily positions for each station in terms of ITRF2000.

The RTK reference receiver was set up in an arbitrary location with clear sky view and was

configured to record raw observations in addition to transmitting real-time corrections. The RTK

station was later post-processed with respect to WARK, and all RTK rover-surveyed positions

were subsequently adjusted relative to the updated reference position.

Several points on the rim of the main reflector were identified, and each point was measured

several times with the RTK rover while the telescope was repositioned in elevation and azimuth

106 IVS 2010 Annual Report
Institute for Radio Astronomy and Space Research, Auckland University of Technology Warkworth Observatory

between each measurement. The rover GPS antenna was mounted on a 0.5 m survey pole and

was hand held for each measurement. For determination of the horizontal axis, the telescope

azimuth axis was held fixed at Az = 0◦. A point near the highest edge of the reflector was

identified and measured with the telescope in four positions of elevation. This was repeated with

a point on the edge of the reflector to one side of the telescope. Five positions of elevation were

measured at this point. For determination of the vertical axis, the telescope elevation axis was

held fixed at El = 80◦. Three points around the edge of the reflector were identified, and three

measurements of each identified point with the fixed telescope elevation and varying azimuths were

conducted. The resulting points from these measurements describe two vertical circles of rotation

which define the movable elevation axis and three horizontal circles of rotation which define the

movable azimuthal axis. The coordinates for all subsequent calculations were retained as geocentric

Cartesian coordinates to avoid any possibility of errors related to transformation of projection.

To determine the axes and their intersection point, the equation of a circle from three points

was used to calculate all possible combinations of three observed points which define a circle of

rotation. Mean values were taken for all horizontal axis definitions and all vertical axis definitions.

The midpoint of the closest point of approach of each axis with the other was used as the final

estimate of the point of intersection. The distance between the axes was calculated to be 24 mm.

Based on the variation of results for different combinations of survey points, we estimate that the

accuracy of the determined intersection point is within 0.1 m.

In summary, the following coordinates of the intersection of the azimuth and elevation axes for

WARK12M were derived in terms of ITRF2000 at the epoch of the survey (March 2010):

X = −5115324.5 ± 0.1 m

Y = 477843.3 ± 0.1 m

Z = −3767193.0 ± 0.1 m

The radio telescope reference point coordinates will subsequently be re-determined to a higher

accuracy with the use of a variety of terrestrial and GNSS survey techniques (e.g. [4]) and a more

rigorous least squares analysis of the observations. Four geodetic survey monuments have been

built within 15–20 m from the antenna pedestal for this purpose.

3. Network Connectivity and Data Transfer Protocols

In April 2010, the regional advanced network KAREN established a GigaPoP at the Warkworth Radio Astronomical Observatory, which provides a 1 Gbps international connectivity for the

WARK12M radio telescope. Soon after the connection of WARK12M to KAREN, connectivity

was achieved with a number of VLBI partners and correlation centers, including Bonn (Germany),

CSIRO (Australia), JIVE (Netherlands), and Mets ̈ahovi (Finland).

Various network protocols were tested, such as ‘ftp’, ‘tsunami’ [5] and UDT [6]. The results of

data transfer tests between the IRASR and the data processing center in Bonn are presented in

Table 2. They were obtained by transferring an actual 16-bit VLBI file produced in observations

with the 12-m radio telescope. It was transferred from IRASR’s IBM Blade server via the KAREN

network using the default settings for each protocol with no tuning. Columns 1 and 2 show the

protocol used and the amount of data sent in bytes, and columns 3 and 4 give the time it took to

transfer the data and an average throughput rate (each test was repeated 5–10 times).

IVS 2010 Annual Report 107
Warkworth Observatory Institute for Radio Astronomy and Space Research, Auckland University of Technology

Table 2. Data transfer statistics: IRASR to Bonn.

Protocol Bytes Time (s) Throughput (Mbps)

Ftp 65 G 8016 65

Tsunami 65 G 3466 151

UDT 65 G 1920 273

Table 2 clearly demonstrates the advantage of the UDT protocol over ‘tsunami’ and ‘ftp’. UDT

is about two times faster than ‘tsunami’ and more than four times faster than the standard ‘ftp’

protocol. Tests were conducted repeatedly over several days and at different times resulting in

slightly different average rates without changing the main conclusion that the UDT protocol is

superior to ‘ftp’ and ‘tsunami’. In addition, UDT has an application programming interface (API)

allowing easy integration with existing or future applications. Also, UDT is a better citizen on the

network leaving bandwidth for TCP and other UDP protocols, a capability which is very important

on a shared network such as KAREN.

A traceroute command from the AUT Blade server to the IP address in Bonn gave a route of

14 hops. Re-issuing this command repeatedly over several months showed that the route appears

stable, without any changes. A high number of hops on the route (14) demonstrates the complexity

of the path and explains why data transfers via protocols such as ‘ftp’ are not efficient.

In June 2010 file transfer tests to the correlator site at Curtin University, Perth were conducted.

Using ‘tsunami’, a rate of 300 Mbps was achieved, while UDT was superior at 400 Mbps sustained

throughput. In December 2010 the first e-VLBI tests from the Mark 5B recorder at the Warkworth

Observatory to a server at CSIRO, Australia using UDP were conducted. The required data rate

of 512 Mbps was achieved sustainably.

It is worth mentioning data transfer sessions conducted between Warkworth and Mets ̈ahovi in

2010. In August WARK12M participated in observations of the ESA’s Mars Express (MEX). First,

data (86 GB) was transmitted to Mets ̈ahovi using ‘tsunami’; the next set of data (187 Gbytes)

was sent to Mets ̈ahovi using UDT. Average rates sustained were 250 and 300 Mbps respectively.

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] Petrov, L. et al. First geodetic observations using new VLBI stations ASKAP-29 and WARK12M,

Publications of the Astronomical Society of Australia, 2011. Preprint arXiv:1012.4243.

[3] Blick, G. and Collett, D. New Zealand geodetic system, Part 4 – PositioNZ GNSS continuously operating network. Survey Quarterly, 63, 20, 2010.

[4] Dawson, J., Johnston, G. and Twilley, B. In Proceedings of the IERS Workshop in site co-location,

IERS Technical Note, No 33. 128, 2004.

[5] Wagner, J. Tsunami UDP Protocol. Available online: http://tsunami-udp.sourceforge.net

[6] Gu, Y. UDT: A High Performance Data Transport Protocol (Unpublished doctoral dissertation). University of Illinois, Chicago, USA, 2005. See also http://udt.sourceforge.net/doc/udt-2009.ppt

108 IVS 2010 Annual Report
MIT Haystack Observatory Westford Antenna

Westford Antenna

Mike Poirier

Abstract

Technical information is provided about the antenna and VLBI equipment at the Westford site of

the Haystack Observatory and about changes to the systems since the IVS 2009 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 in the National Geodetic Survey

Project POLARIS. Westford has continued to perform geodetic VLBI observations on a regular

IVS 2010 Annual Report 109
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 independent timing

information and comparisons between GPS and the maser. 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.

110 IVS 2010 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 VLBI program at Westford and their primary responsibilities

are:

Chris Beaudoin broadband development

Joe Carter antenna controls

Brian Corey VLBI technical support

Kevin Dudevoir pointing system software

Dave Fields technician, observer

Glenn Millson observer

Arthur Niell principal investigator

Michael Poirier site manager

Alan Whitney site director

4. Status of the Westford Antenna

From January 1, 2010 through December 31, 2010, Westford participated in 61 standard 24-

hour and 31 Intensive geodetic sessions. Westford regularly participated in the IVS-R1, IVS-R4,

IVS-R&D, RD-VLBA, TQAK, and Intensive sessions along with fringe tests, e-VLBI sessions, and

VLBI2010 broadband development testing.

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 2010 Annual Report 111
Westford Antenna MIT Haystack Observatory

5. e-VLBI

Westford did not participate in any e-VLBI sessions during 2010 due to network limitations

to the outside world from Haystack. 2011 expects to see this role change with network upgrades

already scheduled and in progress. e-VLBI participation was replaced by the evaluation of the

new Roach Digital Backend (RDBE) and Mark 5C units, a joint program with NRAO. Successful

geodetic trials of the systems between Westford and the 5 meter at GGAO were achieved.

6. VLBI2010

In April 2010, Westford participated in a broadband VLBI experiment with MV3 at GGAO in

which the source 4C39.25 was observed through transit. This experiment provided data to aid in

the development of polarimetric analysis of the geodetic observables.

7. Outlook

Westford is expected to participate in 80 24-hour sessions in 2011. We also plan to have the

flexibility to support occasional fringe tests, e-VLBI experiments, and the continuing VLBI2010

broadband development testing.

112 IVS 2010 Annual Report
Forschungseinrichtung Satellitengeod ̈asie (FESG) Geodetic Observatory Wettzell: RTW and TTW

Geodetic Observatory Wettzell: 20-m Radio Telescope and Twin

Telescope

Alexander Neidhardt, Gerhard Kronschnabl, Raimund Schatz

Abstract

In the year 2010 the 20-m radio telescope at the Geodetic Observatory Wettzell, Germany contributed again very successfully to the IVS observing program. But because of a problem with the

elevation bearing the workload had to be reduced, and a three-month maintenance shutdown from

September to November was necessary. Aside from this, technical changes, developments, improvements, and upgrades have been done to increase the reliability of the entire VLBI observing system.

In parallel the construction of the new Twin radio telescope (TTW) has continued.

1. General Information

The 20-m Radio Telescope 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 Technical University Munich.

In addition to the RTW also an ILRS laser ranging system, several IGS GPS permanent stations, a large laser gyroscope G (ringlaser), and complementary local techniques such as time and

frequency, meteorology, and superconducting gravity meter are operated. Currently also the first

fully VLBI2010 compliant Twin telescope is built up on location of the GOW. It should extend the

observation possibilities according to the technical suggestions of the International VLBI Service

for Geodesy and Astrometry (IVS) Working Group 3 (WG3) and VLBI2010 Committee.

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 separate report about TIGO), and the

German Antarctic Receiving Station (GARS) O’Higgins in Antarctica, operated together with

the German Space Center (DLR) and the Institute for Antarctic Research Chile (INACH) (see

separate report about O’Higgins).

2. Staff

The staff of the GOW consists in total of 32 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 on a position which is funded by the

“Novel EXploration Pushing Robust e-VLBI Services” (NEXPReS) project in cooperation with

the Max-Planck-Institute for Radioastronomy (MPIfR), Bonn. It was also possible to support

student operators to work within development projects and internships.

3. Observations in 2010

The 20-m RTW has supported the geodetic VLBI activities of the IVS and other partners, such

as the EVN, for over 25 years. All successfully observed sessions in the year 2010 are summarized

in Table 2. Because of a severe problem with the elevation bearing, the observation workload had

to be reduced to less than 50% of the normal from March to August. In consultation with the IVS

IVS 2010 Annual Report 113
Geodetic Observatory Wettzell: RTW and TTW Forschungseinrichtung Satellitengeod ̈asie (FESG)

Table 1. Staff members of RTW.

Name Affiliation Function Working for

Johannes Ihde BKG interim head of the GOW (until September 2010) GOW

Ullrich Schreiber BKG head of the GOW (since October 2010) GOW

Alexander Neidhardt FESG head of the RTW group and VLBI station chief RTW, TTW (partly O’Higgins,

laser ranging)

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 (since August 2010) NEXPReS

Alexander Bauer FESG/BKG student (January to May 2010) RTW

Thomas Guggeis FESG/BKG student (January to December 2010) RTW, project work

Martin Riederer FESG/BKG student (March to December 2010) RTW, project work

Johannes Vogl FESG/BKG student (March to December 2010) RTW, project work

Table 2. RTW observations in 2010.

program number of program number of

24h-sessions 1h-sessions

IVS R1 29 INT1(Kokee-RTW) 175

IVS R4 28 INT2/K(Tsukuba-RTW) 68

IVS T2 1 INT3/K(Tsukuba-RTW-NyAl) 33

IVS R&D 5 total (in hours) 276

RDV/VLBA 1

EUROPE 2 special program in hours

total 66 VENUS (4 obs.)/MARS Express (1 obs.) 5

total (in hours) 1584 DBBC tests 1

total (in hours) 8

Coordinating Center, the IVS 2010 Master Schedule was adjusted to optimize the combination of

R1 and R4 with minimal influence on the time series. The main priority was to participate 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 routinely uses the increased Internet

connection capacities of 1 Gbit/sec for the e-transfers to Bonn, Tsukuba, and Haystack. According

to the implementation of a Field System extension for remote control, weekend INTENSIVEs were

done in the new observation modes by remote attendance, remote control from students at the

laser ranging system, or completely unattended (these new modes were suspended in the time of

the bearing problems).

In addition to the standard sessions, RTW was also active for Digital Baseband Converter

(DBBC) tests and for spacecraft tracking. Within these additional one-hour observations the ESA

Venus Express and the Mars express spacecraft were observed at X-band with the Wettzell radio

telescope, using a framework of the assessment study for possible contributions in the European

VLBI network to the upcoming ESA deep space missions. The first goal of these observations

was to develop and test the scheduling, data capture, transfer, processing, and analysis pipeline.

114 IVS 2010 Annual Report
Forschungseinrichtung Satellitengeod ̈asie (FESG) Geodetic Observatory Wettzell: RTW and TTW

The high dynamic range of the detections allowed achievement of a milliHz level of the spectral

resolution accuracy and extraction of the phase of the spacecraft signal carrier line. Apart from

other important results, the measured phase fluctuations of the carrier line at different time scales

can be used to determine the influence of the Solar wind plasma density fluctuations on the accuracy

of the astrometric VLBI observations.

4. Technical Improvements and Maintenance

VLBI observations require high reliability of all participating stations. Therefore careful maintenance of all components is essential to ensure successfully performed VLBI measurements through

the year. Within the maintenance work, the repair of the bearing was one of the big events of

the year. The radio telescope team became aware of emerging elevation bearing problems about

a year ago. In early spring the problem increased, when squeaking noises forced the operators to

stop observing sessions. In March a special inspection done by the Wettzell group and a team

from Vertex Antennentechnik GmbH brought to light that the elevation bearings were severely

damaged. The right side of the elevation axis was lowered by 2 mm and the left side by 0.5

mm in comparison to the original state. In consultation with the Coordinating Center, Wettzell’s

observing load was reduced while technical solutions were investigated. In order to change the

defective bearings, a disassembly of the antenna was unavoidable. Luckily a sufficient amount of

money was put aside by FESG over the past several years so that the repair could be funded by

the FESG. Then the repair itself was scheduled for September to November. A 400-ton crane lifted

the 40-ton main reflector and the counterweights (each 35 tons) off the pedestal. After inspection

the gear wheels and the new elevation bearings were installed a few days later. Following a couple

of photogrammetric surveys the dish surface could be re-adjusted to 0.15 mm RMS. Almost as

planned, the 20-m radio telescope went back into operation on 29 November 2010. Within the

whole maintenance the RTW team, the administration of the TUM (especially FESG), and, of

course, the whole team of Vertex Antennentechnik GmbH did an excellent job.

Figure 1. Repair of the bearings of the 20-m radio telescope.

The Twin Telescope Wettzell (TTW) project has been planned for the period 2008-2011. As

the construction of the tower foundations was finished at the end of 2009, where the main driver

was the high stability requirement of the reflector for several load scenarios (with snow, ice, and

wind), the structures of the main reflectors were assembled from their single parts at the beginning

of 2010. The elevation cabins (40-ton-per-piece steel construction) had to be trucked from Italy

IVS 2010 Annual Report 115
Geodetic Observatory Wettzell: RTW and TTW Forschungseinrichtung Satellitengeod ̈asie (FESG)

to Wettzell on a heavy load transport. As the 400-ton crane was already ordered for the repair

of the 20-m telescope, it was cost-effective to also use it for the mounting of the “Twins”. On 19

October 2010 the lift of the reflectors became a media event with television and reporter teams on

location. The installation worked flawlessly and after the last of the 280 screws at each reflector was

tightened, the silhouettes of the new instruments were visible for the first time. First functionality

tests of the new radio telescopes are scheduled for 2011. Together with the existing 20-m antenna,

the Twin Telescope offers many new possibilities for satisfying future geodetic needs.

Figure 2. The new “skyline” of the observatory with the Twin telescopes in the background.

In July the NEXPReS project started. Wettzell participates in Task 3 of Work Package 5

mainly together with MPIfR. The goal is to support the identification and repair of failures of the

systems during e-VLBI correlations in near real-time. Therefore the software implementations for a

remotely controllable extension to the NASA Field System (FS) will be continued. An appropriate

authentication, a dedicated role management for different user types, different remote access states

to shared telescopes, and sophisticated graphical user interfaces should be developed. In 2010 the

project started with the engagement of Martin Ettl as project engineer and with first preparations

to release the existing software for future FS packages.

Additionally, the 20-m RTW has to be kept on a high technical standard and has to be improved according to technological advancement. In 2010 the following additional developments

and maintenance tasks have been done:

• Test setup of the new Digital Baseband Converter (DBBC), including observations with test

schedules to record data for system evaluations, maintain parts of the controlling code to

run the DBBC via Ethernet.

• Regular tasks and maintenance days (obtaining replacements for the hardware, 8-pack repairs, gear maintenance, FS updates, cryo-system maintenance, servo replacements, improvements by using EVN-PCs for e-VLBI issues).

5. Plans for 2011

For 2011, dedicated plans are:

• Usage of the digital baseband converters (DBBC)

• Continuing NEXPReS

• Continuing construction of and first tests with the Twin telescopes

• Investigations on VLBI2010-conforming radar systems for laser ranging.

116 IVS 2010 Annual Report
Observatorio Astron ́omico Nacional Instituto Geogr ́afico Nacional – Yebes

Instituto Geogr ́afico Nacional of Spain

Francisco Colomer, Jes ́us G ́omez–Gonz ́alez, Jos ́e Antonio L ́opez–Fern ́andez,

Susana Garc ́ıa–Espada, Pablo de Vicente

Abstract

This report updates the description of the Yebes Observatory facilities as an IVS Network Station.

The Yebes 40-m radio telescope 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 well, and the construction of the first three antennas of VLBI2010

specifications has been contracted.

1. General Information: the IGN Facilities at Yebes

The radio telescopes (the new 40-m and the old 14-m which was an IVS Network Station since

2003) are located at the Observatory of Yebes, a department of the Instituto Geogr ́afico Nacional

(IGN, Ministerio de Fomento).

Yebes Observatory is also the reference station for the Spanish GNSS network and holds permanent facilities for gravimetry. The RAEGE project will provide a new VLBI2010-type antenna

in Yebes in 2012. An SLR system in a new control building will also be built in the near future.

2. IGN Staff Working on VLBI Projects

Table 1 lists the IGN staff who are involved in geodetic VLBI studies and operations. The

VLBI activities are also supported by other staff such as receiver engineers, computer managers,

secretaries, and students. The process of hiring dedicated telescope operators has suffered delays,

not being yet available; this limits the amount of observing time that Yebes can offer to the IVS.

Table 1. Staff in the IGN VLBI group (Email: vlbitech@oan.es).

Name Background Role Address∗

Francisco Colomer Astronomer VLBI Project coordinator ROM, IGN

Pablo de Vicente Astronomer VLBI Technical coordinator CAY

Susana Garc ́ıa–Espada Engineer geoVLBI expert CAY

Jes ́us G ́omez–Gonz ́alez Astronomer Deputy Director for IGN

Astronomy, Geodesy and Geophysics

Jos ́e Antonio L ́opez–Fdez Engineer Yebes site manager CAY

Javier L ́opez–Ramasco Geodesist Geodesist CAY

Alvaro Santamar ́ıa Geodesist Geodesist CAY

Addresses:

ROM: Real Observatorio de Madrid. Calle Alfonso XII, 3. E–28014 Madrid, Spain.

CAY: Centro Astron ́omico de Yebes. Apartado 148, E–19080 Guadalajara, Spain.

IGN: Instituto Geogr ́afico Nacional. Calle General Iba ̃nez de Ibero 3, E–28003 Madrid, Spain.

IVS 2010 Annual Report 117
Instituto Geogr ́afico Nacional – Yebes Observatorio Astron ́omico Nacional

Table 2. Characteristics of the Yebes 40-m geodetic VLBI station.

Parameter Value DAR VLBA5 (14) + VSI-C

Diameter 40 meter Recorder Mark 5B

Receivers 2 - 115 GHz H-maser T4-Science iMaser 3000

S/X Tsys 190/50 K GPS TrueTime XL-DC

S/X SEFD 1400/210 Jy Weather station SEAC-EMC

3. Status of Geodetic VLBI Activities at IGN

The 40-m radio telescope has participated in 18 sessions, of the EURO, R4, and T2 types. One

was lost (R4425, bad disk reported).

Yebes has been connected to GEANT at 1 Gbps since April 2009. Ways to increase the capacity  ́

are under consideration.

A new Hydrogen maser has been purchased, to replace the Russian KVART-73 maser which

failed in 2009 after 13 years of successful operation.

An absolute gravimeter is now permanently placed at the new building in Yebes. A GWR

superconducting gravimeter was installed in May 2010 (see Fig. 1).

Figure 1. GWR superconducting gravimeter installed in a dedicated building in Yebes.

Cooperation with the geodesy group at Onsala Space Observatory in Sweden continued by

modeling the tropospheric effect caused by neutral atmosphere using the HIRLAM 3D-VAR numerical weather prediction model, where a direct improved mapping function is calculated using

raytracing. First results were presented at the IVS 2010 General Meeting in Hobart (Australia).

118 IVS 2010 Annual Report
Observatorio Astron ́omico Nacional Instituto Geogr ́afico Nacional – Yebes

4. Project RAEGE

IGN has started the construction in Spain and Portugal of a network of four new Fundamental Geodynamical and Space Stations. The project, named RAEGE (after “Red Atl ́antica de

Estaciones Geodin ́amicas y Espaciales”), consists of the erection in Yebes (1), Canary Islands (1),

and Azores Islands (2), of one radio telescope of VLBI2010 class (i.e. of 13.2-m diameter, high

slew rate, capable of operating in the 2-14 GHz bands but also up to 90 GHz), a permanent GNSS

receiver, a gravimeter, and (at least in Yebes) an SLR station.

Radio frequency interference (RFI) has been monitored at the Yebes station and the chosen

sites at the Santa Mar ́ıa (see Fig. 2) and Flores Island of the Azores, demonstrating that in the

latter cases the spectrum in the band of interest is very clean.

The construction of three antennas, to be installed in Yebes, Azores (Santa Mar ́ıa), and Canary

Islands, has been contracted to MT Mechatronics (Germany). The first antenna (see Fig. 3) will

be erected in Yebes in 2012, shortly followed by the antenna in Santa Mar ́ıa.

A cooperation with the Institute of Seismology (IoS) of the Chinese Academy of Sciences will

allow the loan of a mobile SLR system to Yebes in 2011. This system will operate until the fixed

SLR station is built.

Figure 2. RFI measurement at the RAEGE station in Santa Mar ́ıa, Azores Islands.

References

[1] de Vicente P., Garc ́ıa–Espada S., Barcia A., Bola ̃no R., Barbas L. “Tuning the T4 Science hydrogen maser”. Informe T ́ecnico OAN 2010-1 (see

http://www1.oan.es/informes/archivos/IT-OAN-2010-1.pdf).

[2] Garc ́ıa–Espada S., Haas R., Colomer F. “Application of Raytracing through the High Resolution Numerical Weather Model HIRLAM for the Analysis of European VLBI”. 2010. Proceedings of the IVS

General Meeting. Hobart (Tasmania, Australia). p. 232.

[3] G ́omez-Gonz ́alez J., Colomer F., L ́opez-Fern ́andez J.A., Assis M.C.S. “RAEGE: An Atlantic Network

of Geodynamical Fundamental Stations”. 2010. Proceedings of the IVS General Meeting. Hobart (Tasmania, Australia). p. 101.

[4] G ́omez-Gonz ́alez J., Colomer F., L ́opez-Fern ́andez J.A. (2010), “ An Atlantic Network of Geodynamical

Fundamental Stations (Project RAEGE)”. Eos Trans. AGU, 91(26), Meet. Am. Suppl., Abstract G12A05.

IVS 2010 Annual Report 119
Instituto Geogr ́afico Nacional – Yebes Observatorio Astron ́omico Nacional

Figure 3. Design of the VLBI2010 antennas for RAEGE.

[5] G ́omez-Gonz ́alez J., Colomer F., L ́opez-Fern ́andez J.A., Assis M.C.S. “An Atlantic Network of Geodynamical Fundamental Stations (Project RAEGE)”. Joint European and National Astronomy Meeting

(JENAM), Special Session SPS2 “Radio Astronomy in Iberia”. Lisbon, September 6-10 2010. p.93.

[6] L ́opez-P ́erez J.A., L ́opez-Fern ́andez J.A. “First Radio-Frequency Interference Measurement Campaign at Yebes Observatory”. Informe T ́ecnico OAN 2010-5 (see

http://www1.oan.es/informes/archivos/IT-OAN-2010-5.pdf).

[7] L ́opez-P ́erez J.A., L ́opez-Fern ́andez J.A. “Radio-frequency interference measurements in Santa

Maria island for the selection of the RAEGE antenna site”. Informe T ́ecnico OAN 2010-12 (see

http://www1.oan.es/informes/archivos/IT-OAN-2010-12.pdf).

[8] L ́opez-P ́erez J.A., L ́opez-Fern ́andez J.A. “Radio-frequency interference measurements in Flores

island for the selection of the RAEGE antenna site”. Informe T ́ecnico OAN 2010-17 (see

http://www1.oan.es/informes/archivos/IT-OAN-2010-17.pdf).

[9] Teke K., Boehm J., Nilsson T., Schuh H., Steigenberger P., Dach R., Heinkelmann R., Willis P.,

Haas R., Garc ́ıa–Espada S., Hobiger T., Ichikawa R., Shimizu S. 2010. “Multi-technique comparison of

trophosphere zenith delays and gradients during CONT08”. Journal of Geodesy, DOI:10,1007/s00190-

010-0434-y.

120 IVS 2010 Annual Report
Operation Centers

Operation Centers

Institut f ̈ur Geod ̈asie und Geoinformation der Universit ̈at Bonn IGGB Operation Center

The Bonn Geodetic VLBI Operation Center

A. Nothnagel, A. M ̈uskens

Abstract

The IGGB Operation Center has continued to organize and schedule the IVS-T2, IVS-OHIG, IVSINT3, and EUROPE sessions.

1. Center Activities

The IGGB VLBI Operation Center is located at the Institute of Geodesy und 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 2010 are the same as in 2009.

• 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, Madrid

(DSS65A), 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 (7 sessions in 2010) 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

planned 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, 12 to 15 stations have been scheduled in each session,

requiring multiple passes on the IVS correlators. The scheduling of these sessions has to

take into account that a sufficient number of observations is 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 2010, only three sessions of the Southern Hemisphere and Antarctica Series with

the Antarctic stations Syowa (Japanese) and O’Higgins (German) plus Fortaleza, Hobart,

Kokee, and DSS45 were organized. The (southern) winter O’Higgins burst was canceled for

various reasons. The purpose of these sessions is the maintenance of the VLBI TRF and

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 will be delayed considerably.

IVS 2010 Annual Report 123
IGGB 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 Mb/s from Tsukuba and Wettzell.

Since December, the correlation has been solely carried out with the new DiFX software

correlator because the Mark IV hardware correlator died in mid-December as a result of a

control crash. Although the development of the full data correlation and export process was

not yet complete at that time, the sessions have been processed with a reasonable latency. At

present, several small processing steps still require manual interaction and iterations, causing

small delays to persist.

Since the beginning of 2010, 46 sessions have been observed and transmitted successfully.

90% of the sessions have been correlated and have had their databases delivered within the

first 8 hours after the end of the observations. A further 5% have been completed within 10

hours. The rest took between 10 and 24 hours due to difficulties with networking hardware.

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

124 IVS 2010 Annual Report
NASA Goddard Space Flight Center 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 2010 to

December 2010. The report forecasts activities planned for the year 2011.

1. Changes to the CORE Operation Center’s Program

The Earth orientation parameter goal of the IVS program is to attain precision at least as good

as 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 were 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 2010:

IVS-R1: 52 sessions, scheduled weekly and mainly on Mondays, five to nine station networks

RDV: 6 sessions, scheduled evenly throughout the year, 13 to 16 station networks

IVS-R&D: 5 sessions, scheduled monthly, six to eight station networks

2. IVS Sessions from January 2010 to December 2010

This section displays the purpose of the IVS sessions for which the CORE Operation Center is

responsible.

• IVS-R1: In 2010, the IVS-R1s were scheduled weekly with five to nine station networks.

During the year, 17 different stations participated in the IVS-R1 network, but there were

only seven stations that participated in at least half of the scheduled sessions—Ny- ̊Alesund

(47), Westford (48), Tigo (41), Tsukuba (38), Hobart-26m (34), Kokee (33), and Wettzell

(29). After being down for almost two years, HartRAO started participating in the IVS-R1s

again in mid-August. Also the new Hobart-12m antenna was tagged along to several sessions

during 2010.

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

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 discs to the

correlator as rapidly as possible. 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 8 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 2010 Annual Report 125
CORE Operation Center NASA Goddard Space Flight Center

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 five R&D sessions in 2010, as decided by the IVS Observing

Program Committee, was to improve the scheduling technique of the Intensive sessions.

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 2010.

The R1 sessions’ formal uncertainties are generally at the level of the 2008-2009 averages, but

somewhat better than in 2009. The R4 X-pole uncertainty for 2010 sessions is clearly worse than

for 2008-2009. This must be caused by poorer network geometry due to the loss of several stations

during the year. For example, Fortaleza was down and not available to participate during 2010. In

addition, Svetloe’s and Wettzell’s participation was cut by 50 percent when compared to the two

stations’ participation during 2009. The other EOP parameter uncertainties are at the level of the

2008-2009 average. The R4 uncertainties are clearly significantly worse than the R1 uncertainties,

because the global geometry of the R1s is better. RDV uncertainties are not significantly different

in 2010 than in the preceding two years. Clearly the RDV formal errors are significantly better

than any of the other experiment series. This must be due to the larger number of RDV stations

as well as better global geometry.

Table 2 shows the EOP differences with respect to IGS for the R1, R4, T2, and RDV series.

The WRMS differences were computed after removing a bias, but estimating rates does not affect

the residual WRMS significantly. Of all the series, the RDV series has the best WRMS agreement

of X-pole and Y-pole with IGS in 2010 as well as for all sessions since 2000. Both the R1 and R4

series show worse WRMS agreement of X-pole for 2010 than for the R1 and R4 series since 2000,

but not much difference for Y-pole. This is consistent with the formal error trend for the R4s. It

is not clear why the agreement is worse for the R1s. For all session types, LOD WRMS agreement

with IGS for 2010 is somewhat better than the agreement for each full series since 2000. There

are some significant biases greater than 100 mas between the VLBI and GPS series that should

be investigated. Formal uncertainties of the bias estimates are not shown, but the polar motion

biases are all several sigma.

Table 1. Average EOP Formal Uncertainties for 2010

Session Num X-pole Y-pole UT1 DPSI DEPS

Type (μas) (μas) (μs) (μas) (μas)

R1 51/52 60(61,57) 59(63,52) 2.3(2.4,2.5) 117(129,114) 47(52,44)

R4 51/52 98(73,80) 88(79,90) 3.3(2.9,3.5) 178(192,194) 73(73,79)

RDV 5/6 41(40,43) 45(42,45) 1.9(1.7,2.2) 69(70,79) 29(28,31)

T2 3/7 75(79,56) 72(91,66) 4.3(4.1,2.9) 158(171,139) 65(69,58)

Values in parentheses are for 2009 and then 2008. For the number of sessions in 2010,

both the number of processed sessions as of the end of January 2011 and the number

of sessions observed are given.

126 IVS 2010 Annual Report
NASA Goddard Space Flight Center CORE Operation Center

Table 2. Offset and WRMS Differences (2010) Relative to the IGS Combined Series.

X-pole Y-pole LOD

Session Type Num Offset WRMS Offset WRMS Offset WRMS

(μas) (μas) (μas) (μas) (μs/d) (μs/d)

R1 51(459) -54(-1) 132(98) 166(121) 96(95) 1.9(0.3) 15(17)

R4 51(458) -35(-42) 132(112) 183(120) 117(114) 4.0(1.9) 16(19)

RDV 5(65) 10(45) 77(81) 160(154) 44(90) 6.6(0.3) 14(15)

T2 3(69) -203(-6) 192(145) 423(98) 151(146) 23.8(0.9) 11(20)

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 everyone reading this

report will know whom to contact about their particular question.

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

Irv Diegel Maser maintenance Honeywell

Mark Evangelista Receiver maintenance Honeywell

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

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

5. Planned Activities during 2011

The CORE Operation Center will continue to be responsible for the following IVS sessions

during 2011.

IVS 2010 Annual Report 127
CORE Operation Center NASA Goddard Space Flight Center

• 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.

128 IVS 2010 Annual Report
U.S. Naval Observatory NEOS Operation Center at USNO

NEOS Operation Center

Kerry Kingham, M.S. Carter

Abstract

This report covers the activities of the NEOS Operation Center at USNO for 2010. The Operation

Center schedules 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 2010, the operational

IVS-R4 network included VLBI stations at Kokee Park (Hawaii), Wettzell (Germany), Ny- ̊Alesund

(Norway), TIGO (Chile), Svetloe, Badary and Zelenchukskaya (Russia), Hobart (Australia), Yebes

(Spain), and Matera and Medicina (Italy). A typical R4 consisted of five to eight stations.

The regular stations for the weekday IVS Intensives were Kokee Park and Wettzell. Intensives

including Kokee Park, Wettzell, and Svetloe were observed twice per month in order to characterize

the Kokee Park — Svetloe baseline so that Svetloe can be used as an alternate for Wettzell should

it be needed. This year, Wettzell underwent a major overhaul and Kokee Park — Ny- ̊Alesund

Intensives were scheduled during the period Wettzell was unavailable.

The Operation Center updated the 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 2010.

52 IVS-R4 experiments

220 Intensives (Kk–Wz or Kk–Ny)

2 Kk-Sv-Wz Intensives

3 Kk-Sv-Ny Intensives

2. Staff

K. A. Kingham and M. S. Carter are the only staff members of the NEOS Operation Center.

Kingham is responsible for the overall management, and Carter makes the schedules. M. S. Carter

is located at the USNO Flagstaff Station (NOFS).

IVS 2010 Annual Report 129
NEOS Operation Center at USNO U.S. Naval Observatory

Figure 1. U. S. Naval Observatory Flagstaff Station, location of half of the Operation Center.

130 IVS 2010 Annual Report
Correlators

Correlators

Institut f ̈ur Geod ̈asie und Geoinformation der Universit ̈at Bonn Bonn MPIfR/BKG Correlator

The Bonn Astro/Geo Correlator

Simone Bernhart, Alessandra Bertarini, Arno M ̈uskens, Walter Alef

Abstract

The Bonn VLBI correlator is operated jointly by the MPIfR and the IGG in Bonn and the BKG

in Frankfurt. The hardware Mark IV processor system was switched off in early December 2010 after

a severe hardware failure, and subsequently geodetic correlation was moved over to the DiFX software

correlator. Astronomical production correlation has been done exclusively with the DiFX correlator

since autumn 2009.

1. Introduction

The Bonn correlator is hosted at the Max-Planck-Institut f ̈ur Radioastronomie (MPIfR)1 Bonn,

Germany. It is operated jointly by the MPIfR and the Bundesamt f ̈ur Kartographie und Geod ̈asie

(BKG)2in cooperation with the Institut f ̈ur Geod ̈asie und Geoinformation der Universit ̈at Bonn

(IGG)3. It is a major correlator for geodetic observations and MPIfR’s astronomical projects, for

instance those involving millimeter wavelengths and astrometry. Astronomical experiments have

been correlated with the DiFX software correlator since autumn 2009 while geodetic correlation

was still ongoing on the Mark IV until December 3rd, 2010. The decommissioning of the hardware

correlator, initially scheduled for the end of 2010, was preponed due to a severe hardware failure

which could not be repaired with an acceptable effort.

2. Present Correlator Capabilities

In 2010, the Mark IV and DiFX correlators were operated in parallel in Bonn. The DiFX correlator was mainly used for the correlation of astronomical experiments, while the geodetic use was

initially restricted to testing such as the feasibility of geodetic correlation and the implementation

of the phase-cal signal extraction in the correlator software. The geodesists had to change over to

the DiFX correlator earlier than planned due to an unexpected Mark IV hardware failure in early

December.

2.1. Mark IV Correlator

The Bonn hardware correlator was one of the four Mark IV VLBI data processors in the world.

It was operational from 2000 until early December 2010. It consisted of a standard Mark IV

correlator rack, seven Mark 5A units, four Mark 5B units, and one additional unit dedicated to

e-VLBI. The hardware Mark IV processor system and capabilities have not been changed since the

last report and can be found at http://ivscc.gsfc.nasa.gov/publications/ar2009/cobonn/.

1

http://www.mpifr-bonn.mpg.de/div/vlbicor/

2

http://www.bkg.bund.de/

3

http://www.gib.uni-bonn.de/

IVS 2010 Annual Report 133
Bonn MPIfR/BKG Correlator Institut f ̈ur Geod ̈asie und Geoinformation der Universit ̈at Bonn

2.2. DiFX Correlator

DiFX (Distributed FX correlator) was developed at Swinburne University in Melbourne, Australia by Adam Deller (and collaborators), and adapted to the VLBA operational environment by

Walter Brisken and NRAO staff.

Key parameters of the software correlator cluster are:

• 60 nodes with 8 compute cores each (480 cores total)

• 4 TFlops (floating point operations) in the Linpack benchmark test

• Infiniband 20 Gb interconnect

• two times 1 Gb Ethernet interconnect

• two 20 TB raid systems

• FXmanager control computer which is the control node for the correlator

• Frontend control computer for users who use the cluster for other tasks than correlation

• Appliance control computer for installing and monitoring the cluster

• closed loop rack cooling

• Correlation is done with the pre-release of DiFX version 2.04(DiFX-trunk)

• 14 Mark 5 units are connected to the software correlator. VLBI data can be played into the

cluster from the Mark 5 recorders via 1 Gb Ethernet. If more than 14 playback units are

required and in the case of e-VLBI, data are copied to the raid systems (presently five) prior

to correlation.

• All Mark 5s can play back all kinds of Mark 5 data (A/B/C).

• The fuse-based access to Mark 5 modules on all Mark 5s was changed to the native mode

(implemented by Walter Brisken) making the Mark 5s part of the software cluster.

• The Mark 5A and Domino programs on the Mark 5s have been replaced by NRAO’s

mk5daemon. It enables reading the module directories, i.e., the start and stop time of

each scan; resetting the streamstor card; rebooting the Mark 5s, and module conditioning.

The capabilities of the DiFX software correlator can be found at http://www.mpifr-bonn.

mpg.de/div/vlbicor/correlator\_e.html. Some important features are:

• Phase-cal extraction of all tones in a sub-band simultaneously

• Interface to Mk IV data format which enables the use of geodetic analysis software and

Haystack fringe fitting program.

4

astro-ph/-72141: DiFX: A software correlator for very long baseline interferometry using multi-processor computing environments

134 IVS 2010 Annual Report
Institut f ̈ur Geod ̈asie und Geoinformation der Universit ̈at Bonn Bonn MPIfR/BKG Correlator

3. Staff

The people in the geodetic group at the Bonn correlator are:

Arno M ̈uskens - group leader, scheduling of T2, OHIG, EURO, INT3.

Alessandra Bertarini - experiment setup and evaluation of correlated data, software correlator

development. Digital baseband converter (DBBC) testing. Finished PhD at IGG Bonn in June

2010, subject of the thesis: Effects on the geodetic-VLBI measurables due to polarization leakage

in the receivers.

Simone Bernhart - e-VLBI supervision and operations, experiment setup and evaluation of

correlated data, media shipping. Finished PhD at the MPIfR in March 2010, subject of the thesis:

Flux Density and Kinematic Measurements of the IDV Source 0917+624.

Laura La Porta - experiment setup and evaluation of correlated data, DBBC testing.

Rene B ̈ockelmann - setup and trial correlation of INT3.

Fr ́ed ́eric Jaron - phasecal extraction for software correlator, software support, and Web page

maintenance.

Six student operators for the night shifts and the weekends.

The people in the astronomy group of MPIfR at the Bonn correlator who support IVS correlation are:

Walter Alef - head of the VLBI technical department, correlator software maintenance and upgrades, computer system and cluster administration. Friend of the correlator.

David Graham - technical development, consultant, DBBC development and testing - retired in

July 2010.

Alan Roy - deputy group leader, instrument scientist (water vapor radiometer, technical assistance, development of FPGA firmware for linear to circular polarization conversion, project

manager for equipping APEX for millimeter VLBI).

Helge Rottmann - software correlator development and operation, cluster administration.

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.

Michael Wunderlich - engineer, technical VLBI developments, (Mark IV correlator and) Mark 5

maintenance.

Rolf M ̈artens - technician maintaining correlator hardware and Mark 5 playbacks.

Gino Tuccari - guest scientist from INAF, DBBC development, DBBC project leader.

4. Status

Experiments: In 2010 the Bonn group correlated 51 R1, seven EURO, six T2, eight OHIG, 44

INT3, and about 27 astronomical experiments (including tests and mm observations).

e-VLBI: e-transfers to Bonn are performed on a regular basis from Tsukuba, Ny- ̊Alesund, Onsala,

Mets ̈ahovi, Wettzell, Kashima (including data of the Antarctic Syowa station), Aira, Chichijima,

Japanese VERA stations Ishigakijima (all from Tsukuba) and Mizusawa (from Mitaka), Medicina, Yebes, and Hobart (since autumn 2010). Furthermore, successful tests have been performed

between New Zealand and Bonn and between Fortaleza and Bonn. E-transfer reduces the time

between observation and correlation since no shipment is required. The achieved data rates range

IVS 2010 Annual Report 135
Bonn MPIfR/BKG Correlator Institut f ̈ur Geod ̈asie und Geoinformation der Universit ̈at Bonn

from 100 Mb/s with Ny- ̊Alesund (limited by radio link) to 600 Mb/s with peaks up to 800 Mb/s

(with Mets ̈ahovi). The 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 46 Tbyte. A

Web page has been developed (http://www.mpifr-bonn.mpg.de/cgi-bin/showtransfers.cgi)

which shows currently active (Tsunami) e-transfers. This is not intended as a scheduling tool

for upcoming e-transfers but should rather help to coordinate transfer times and rates on a first

come-first served basis.

Hardware correlator: Six Mark 5A and five Mark 5B units were available for the hardware

correlator. One additional Mark 5 unit was dedicated to e-VLBI. The Mark IV correlator was shut

down at the beginning of December due to a broken control board. A repair would have taken

longer than the initially scheduled replacement by the DiFX correlator at the end of 2010.

DiFX software correlator: The implementation of the phase-cal signal extraction into the DiFX

correlator software was finished and verified for geodetic experiments; the first R1 was correlated

without phase-cal extraction in May. Since September, further R1s and one EURO experiment

were correlated on both the MarkIV and the DiFX correlator, and the results were compared

concerning their compatibility. The abrupt changeover to the DiFX correlator in early December, however, made it necessary to iron out a few bugs in the conversion software from DiFX to

Mark IV format causing delays in the submission of the experiment databases. Nevertheless, the

use of geodetic analysis software and the Haystack fringe fitting program is now working, which

enables the delivery of the databases back on schedule. For the DiFX correlator, no station units

are required anymore. Hence, they have been removed from the Mark 5 racks, and the units are

only used for data playback.

DBBC: The Bonn group is involved in the development of a 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: Wettzell (3), Latvia,

Yebes, and AuScope (Australia), and the functionality of these DBBCs is currently being tested.

Hobart12, one of the AuScope stations, already uses it in their regular observations.

5. Outlook for 2011

DiFX Correlator: There are still some minor bugs in the conversion software from DiFX to

Mark IV format which need to be fixed. Attempts are currently being made to iron out some

minor issues in the export software as well. Furthermore a graphical user interface will be installed

on the DiFX control computer in the near future to simplify the use of the software correlator.

e-VLBI: Stream correlation using e-VLBI transfer will continue, and e-VLBI tests with other antennas are planned/ongoing. An additional 70 TB data raid will be installed at the cluster in midFebruary to increase the storage capacity for correlated geodetic data and future e-transfers, especially with regard to the envisaged higher observing rate of 512 Mbps in the course of VLBI2010.

In order to meet the requirements of the higher observing rate, there are still plans to upgrade our

Internet connection from 1Gbps to 2Gbps. However, the funding and technical implementation

prove to be more than difficult.

DBBC: There is ongoing testing among several EVN stations in order to deploy a fully functional

DBBC and replace the analog BBCs in the field.

136 IVS 2010 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 2010. Highlights include

processing of the very large astrometry session IYA2009, more VLBI2010 experiments, a new tarball

release, DiFX software correlator development, RDBE and Mark 5C testing, and more u-VLBI SgrA*

observations. Non-real-time e-VLBI transfers and engineering support of other correlators continued.

1. Introduction

The Mark IV VLBI correlator of the MIT Haystack Observatory, located in Westford, Massachusetts, is supported by the NASA Space Geodesy Program and the National Science Foundation. The available correlator time is 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 Correlator serves as a development system for testing new

correlation modes, for e-VLBI, for hardware improvements such as the Mark 5C system, and for

diagnosing correlator problems encountered at Haystack, at the identical correlator at the U.S.

Naval Observatory, and, until late 2010, also at the Max Planck Institute for Radioastronomy.

This flexibility is made possible by the presence on-site of the team that designed the correlator

hardware and software.

2. Summary of Activities

2.1. IYA2009 Session

IYA2009 production processing dominated the entire first half of the year, essentially until

June when the final data set was exported to Goddard. In total, twenty-two passes were needed

to process all baselines of the thirty-three stations which participated, and roughly 560 hours

of correlator time were used. This experiment tested all aspects of the processing chain. Many

limitations of the real-time system, other supporting software, and the HOPS software suite were

found and fixed. Examples include total number of files, total number of stations in the real-time

software, and plotting limits within the aedit post-processing software. All these limits were raised

in order to shepherd the experiment through to export.

2.2. Broadband Delay Experiments

Four broadband-delay development experiments using prototype VLBI2010 systems were conducted and correlated in a variety of configurations, including different frequency placements of

the RF bands and different LO frequency offsets. These experiments were designed to explore the

capabilities and potential limitations of the evolving VLBI2010 hardware. All were interferometric

observations between the Westford 18-m and the GGAO 5-m antennas, with the post-receiver

hardware at each site including four digital back ends (DBEs) and Mark 5B+ units. Although

there were fewer broadband experiments this year, each was conducted more effectively due to

lessons learned from previous years’ work. All were re-observations of previous experiment types

IVS 2010 Annual Report 137
Haystack Correlator MIT Haystack Observatory

such as one overlapping bands test, a 3C273B/3C279 source swapping test, and a 4C39.25 transit.

These tests were facilitated by changes to the post-processing software to allow a fit of 64 channels across four bands, extracting phase cal information from all tones within the bands, and by

correcting the phases for ionospheric effects.

2.3. New Tarball Release

A new tarball was released after extensive development and testing. This involved significant

revision to the run-time software system which now incorporates techniques like compilation from

source code on each individual platform in order to improve stability and to maintain compliance

with the growing number of operating systems involved in the hardware correlator system. This

tarball was installed in Bonn and is pending installation at WACO.

2.4. DiFX Software Correlator Development

Extensive DiFX correlator testing is underway, with the intent of transitioning to the new

system by mid-2011. The difx2mark4 application was developed in order to convert the output of

the DiFX correlator into Mark IV format for reading into the HOPS package for post-processing.

Extensive effort was expended on getting the DiFX correlator to handle phase cal tones properly.

In December 2010 the Bonn correlator switched to DiFX for production, a transition made possible

by these developments.

2.5. Independent HOPS Package

An independent HOPS release package was developed so that this package can be made generally available to the geodesy and astronomy communities. Thus, recipients of raw correlator

output can do their own post-correlation analysis.

2.6. Digital Backend Testing

Testing was done on some next generation digital backend systems such as the RDBE and

recording systems such as the Mark 5C. The Conduant SDK9 software package was also tested on

two Mark 5B DOMs.

2.7. WACO Support

In addition to the usual support work, a significant amount of correlator time was used for

testing equipment, such as four Mark 5Bs and several CIBs, prior to their shipment to WACO.

There was also testing of a suspect control board when WACO was having top-crate syncing

problems.

2.8. Bonn Support

Help was provided in converting K5 e-VLBI-transferred data to Mark 5B format; this was

an augmentation of the ability to convert K5 to Mark 5A format. Various disk and correlator

software related processing problems were addressed. Additionally, Haystack re-established the

programmer for FIFO chips in order to replenish stock and provide spares to Bonn and WACO.

138 IVS 2010 Annual Report
MIT Haystack Observatory Haystack Correlator

2.9. Galactic Center Polarization Project

Another u-VLBI project involving observations of the galactic center (SgrA*) was conducted,

this time with dual polarization. This also was an engineering test of a phased-array processor

system to combine the collecting area of interferometer elements on Mauna Kea. This system

will increase the sensitivity of the u-VLBI array and will be adopted at other sites once fully

operational.

2.10. Frequency Standard Test

There was an experiment to compare the stability and performance of a crystal sapphire oscillator to a hydrogen maser and rubidium clock as a frequency standard for the u-VLBI project.

2.11. e-VLBI

Non-real-time transfers have continued. Data from ten experiments were transferred to

Haystack this year from six stations, all in Japan: Kashima, Tsukuba, Chichijima, Ishigakijima,

Aira, and Mizusawa. In addition, this year the Westford station participated in twenty-six Intensive

sessions which were e-transferred to the GSI correlator.

2.12. Experiments Correlated

In 2010, twenty-seven geodetic VLBI experiments were processed at the Haystack Correlator,

consisting of the previously mentioned IYA2009, two R&Ds, four T2s, and twenty test experiments.

The test experiments included broadband development and a wide assortment of other projects,

some of which were touched on in the summary above. As usual, there was also a large number

of smaller tests that are not included in the above count because they were too small to warrant

individual experiment numbers.

2.13. Current/Future Hardware and Capabilities

As of the end of 2010, functioning hardware installed at the correlator included two tape units,

seven Mark 5A units, seven station units, seven Mark 5B units (DOMs) with their associated

correlator interface boards (CIBs), sixteen operational correlator boards, two crates, and miscellaneous other support hardware. We have the capacity to process all baselines for eleven stations

simultaneously in the standard geodetic modes, provided the aggregate recordings match the above

hardware matrix. This configuration reflects the addition of three new 5B units, for a grand total

of fourteen playback units on the Mark IV correlator. This gives us the capability to run larger

experiments in one pass.

In mid-2011, we hope to transition to the software correlator, only keeping the hardware

correlator alive in support of USNO until their transition, expected in 2012.

3. Staff

Staff who participated in aspects of Mark IV, DiFX, Mark 5, and e-VLBI development and

operations include:

IVS 2010 Annual Report 139
Haystack Correlator MIT Haystack Observatory

3.1. Software Development Team

• John Ball - Mark 5A/5B; e-VLBI

• Roger Cappallo - real-time correlator software and troubleshooting; system integration; postprocessing; Mark 5B/5C; Linux conversion; e-VLBI; DiFX correlator development

• Geoff Crew - DiFX correlator development, post-processing software

• Kevin Dudevoir - correlation; maintenance/support; Mark 5A/5B/5C; e-VLBI; Linux

conversion; correlator software and build system development; computer system support/development

• Jason SooHoo - e-VLBI; Mark 5A/5B/5C

• Chester Ruszczyk - e-VLBI; Mark 5A/5B/5C

• Alan Whitney - system architecture; Mark 5A/5B/5C; e-VLBI

3.2. Operations Team:

• Peter Bolis - correlator maintenance

• Brian Corey - experiment correlation oversight; station evaluation; technique development

• Dave Fields - playback drive maintenance; Mark 5 installation and maintenance; general

technical support

• 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 by mid-2011. Testing of a complete

VLBI2010 system is expected to start in early 2011. Testing and implementation of new digital

back end and recording systems will continue.

140 IVS 2010 Annual Report
IAA RAS IAA Correlator Center

IAA Correlator Center

Igor Surkis, Voitsekh Ken, Alexey Melnikov, Vladimir Mishin, Violet Shantyr,

Vladimir Zimovsky

Abstract

The activities of the 6-station IAA RAS correlator includes regular processing of domestic geodetic

VLBI programs Ru-E and Ru-U. Since 2009, the Ru-U sessions have been transferred in e-VLBI mode

for correlation at the IAA Correlator Center.

1. Introduction

The IAA Correlator Center is located and hosted 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 domestic VLBI network Quasar.

2. Summary of Activities

The IAA RAS correlator has the following features:

• 6-station and 15-baselines,

• maximal data range of 1 Gbps from each station,

• 1- or 2-bit quantized input VLBI signals,

• VSI-H input signals format,

• 16 frequency channels per baseline (240 frequency channels in total),

• maximal clock frequency of 32 MHz,

• Mark 5B playback terminals.

The correlator hardware is based on FPGA technology. Data processing and data transfer

boards are placed in the Compact PCI 6U crates. All of the correlator hardware is mounted in

four racks as shown in Figure 1.

The correlator equipment is connected through a local network and consists of crates, playback

terminals, and a control personal computer. The correlator operates using GNU/Linux. Special

software for controlling correlator works on crates and control computer and has a user-friendly

GUI.

3. Experiments in 2010

In 2010 the IAA Correlator Center processed the domestic 2- and 3-station sessions and 4-

station sessions with international participation. 22 Ru-E and 52 Ru-U domestic sessions were

observed and processed.

The 24-hour 3-station Ru-E VLBI sessions are intended for EOP estimation. Signal sampling

is 1-bit, frequency channel bandwidth is 16 MHz, and the total bit rate is 512 Mbps using standard

wide geodetic frequency setup.

IVS 2010 Annual Report 141
IAA Correlator Center IAA RAS

Figure 1. The 6-station IAA RAS correlator.

The 1-hour 2-station Ru-U VLBI sessions are intended for UT1-UTC estimation. Signal sampling is 1-bit, frequency channel bandwidth is 8 MHz, and the total bit rate is 256 Mbps using

standard wide geodetic frequency setup. All of the 1-hour Ru-U sessions were processed in e-VLBI

mode; about 40 GB of data from each station were transferred to the correlator. The first several

scans of the Ru-E sessions were processed in e-VLBI mode for verification of station equipment.

Several test VLBI experiments have been carried out with Shanghai Observatory in China.

142 IVS 2010 Annual Report
IAA RAS IAA Correlator Center

4. Staff

• Artemy Fateev — software developer;

• Voitsekh Ken — hardware developer;

• Alexey Melnikov — software developer, scheduler;

• Vladimir Mishin — software developer, post processing;

• Violet Shantyr — software developer, post processing;

• Igor Surkis — leading investigator, software developer;

• Vladimir Zimovsky — hardware developer.

IVS 2010 Annual Report 143
VLBI Correlators in Kashima National Institute of Information and Communications Technology

VLBI Correlators in Kashima

Ryuichi Ichikawa, Moritaka Kimura, Mamoru Sekido

Abstract

K5 VLBI data acquisition and processing systems developed at the Kashima Space Research Center

have been used for data processing of R&D VLBI experiments. Two major correlation tasks processed in

2010 were the MARBLE project, which aimed at establishing a reference baseline for length calibration,

and a project for time and frequency transfer. The high speed software correlation system for K5/VSI

called “GICO3” has been extended to be used for geodetic VLBI measurements.

1. General Information

Figure 1. Location of NICT/KSRC.

The VLBI group of the Kashima Space Research Center (KSRC) of the National Institute

of Information and Communications Technology

(NICT: Fig.1) has been contributing to the VLBI

community by developing the K5 VLBI data acquisition system (DAS) and correlation systems.

The multi-channel DAS named K5/VSSP32 [1]

has been used for geodetic and radio science observations. A corresponding software correlation

package for the K5/VSSP32 has been developed

and maintained by Dr. T. Kondo. Another DAS

system named K5/VSI [2], which captures the data

stream from a VSI-H interface [4], utilizes a different software correlator called “GICO3” [3].

The former K5/VSSP32 system is a multichannel data acquisition system with four channel

inputs per unit. One unit has the sampling capability in the range of 40 kHz to 64 MHz, with

quantization bits 1, 2, 4, and 8 and the limit for

the output data rate of up to 256 Mbps. A geodetic K5 DAS system is composed of four K5/VSSP32 units. This system has been widely used

for geodesy operationally. e-VLBI experiments for rapid UT1 measurements have been performed

using this system in collaboration with the Onsala, Mets ̈ahovi, Tsukuba, and Kashima stations.

Another K5 system (K5/VSI) was originally developed with the feature of a high sampling rate

for astronomy. Since the K5/VSI DAS is a recording system, it can be used in combination with

any sampler systems with the VSI-H interface. For instance, this system has been regularly used

in a combination with Mark 5B sampler (VSI-H output) in ultra-rapid UT1 measurements on the

Wettzell—Tsukuba baseline.

2. Staff

The names of the staff members who contribute to the Correlation Center at NICT/Kashima

and their tasks are listed below in alphabetical order.

144 IVS 2010 Annual Report
National Institute of Information and Communications Technology VLBI Correlators in Kashima

• HASEGAWA Shingo: maintenance and troubleshooting of K5 system computers, operation

of the 34-m antenna for IVS sessions.

• HOBIGER Thomas: developer of a new VLBI database system that uses NetCDF, research

on atmospheric delay calibration with the ray tracing technique, development of software

receiver for GNSS.

• ICHIKAWA Ryuichi: VLBI Project Manager at Kashima, research on the MARBLE project,

atmospheric delay with ray tracing.

• KAWAI Eiji: maintenance of the 34-m telescope, operation of the telescope for IVS sessions.

• KIMURA Moritaka: developer of the high speed Gigabit software correlator “GICO3” and

the K5/VSI DAS.

• KONDO Tetsuro: development and maintenance of the software correlator package of the

K5/VSSP32.

• KOYAMA Yasuhiro: Group Leader of “Space-Time Application Group”.

• SEKIDO Mamoru: e-VLBI development and observations, maintenance of the 34-m station.

• TSUTSUMI Masanori: maintenance of K5 system computers.

3. Component Description

In 2010 VLBI experiments have been performed for the MARBLE project [5] and for technology

development of the time and frequency transfer between distant pairs of atomic time standards

[6]. Table 1 shows a brief summary of the experiments.

Table 1. Major correlation tasks processed in 2010.

Project Exp code Date Stations baseline x scans Data rate

(Mbps)

MARBLE m10223 11 Aug. Ks34, Mb1, Mb2 3x239 256

MARBLE m10259 16 Sep. Ks34, Mb1, Mb2 3x242 256

MARBLE m10266 23 Sep. Ks34, Mb1, Mb2 3x234 256

MARBLE m10280 7–9 Oct. Ks34, Mb1, Mb2 3x721 256

MARBLE m10316 11 Nov. Ts32, Mb1, Mb2 2x295 2048

MARBLE m10356 22 Dec. Ts32, Mb1, Mb2 2x318 2048

Time Comp. k10116 26 Apr. Ks34, Ks11 ,Kg11 3x987 256

Time Comp. k10130 10 May. Ks34, Ks11 ,Kg11 3x701 256

Time Comp. k10148 28 May. Ks11, Kg11 1x627 256

Time Comp. k10160 9–14 Jun. Ks11, Kg11 1x2968 256

Time Comp. k10189 8–10 Jul. Ks11, Kg11 1x2204 256,2048

Time Comp. k10212 31 Jul.–01 Aug. Ks11, Kg11 1x1388 256

Time Comp. k10216 8 Aug. Ks11, Kg11 1x490 256,2048

Time Comp. k10274 1 Oct. Ks11, Kg11 1x1773 256,2048

Ts32:Tsukuba-32m, Ks34:Kashima-34m, Ks11:Kashima-11m, Kg11:Koganei-11m, Mb1:Marble-1, Mb2:Marble-2

IVS 2010 Annual Report 145
VLBI Correlators in Kashima National Institute of Information and Communications Technology

Ultra-rapid UT1 observations with e-VLBI technology have been performed by the Geospatial

Information Authority of Japan (GSI) on the Onsala—Tsukuba baseline. In addition, the GSI

has started the operational dUT1 observations (i.e., “Intensive” observations) in 2010. We have

supported these e-VLBI experiments, although actual correlation has been performed by GSI.

4. Development and Future Plans

4.1. e-VLBI Development

The high speed sampler ADS3000+, which has the function of a digital base band converter

(DBBC) and sports a VSI-H interface, has been developed together with the K5/VSI DAS. Digital

filtering via FPGA circuit has been tested, and multi-channel observations for geodetic VLBI

applications have been performed for evaluation. Software tools for the data conversion from the

GICO3 high speed software correlation output to conventional Mark3DB have been developed,

and the analysis scheme with the CALC/SOLVE package is being established. This new scheme

of VLBI observation and data processing (ADS3000+ and K5/VSI → GICO3 software correlation

→ Mark3DB → CALC/SOLVE) has been used for the MARBLE and the time and frequency

transfer experiments (Table 1).

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, p.195-199, 2006.

[2] M. Kimura, et al.: The VLBI recording system based on VSI-H with a PC, submitted to Experimental

Astronomy, 2009.

[3] M. Kimura, et al.: High Speed VLBI Software Correlator, Submitted to Pub. Astr. Soc. Pacific, 2010.

[4] Whitney, A. R.: VLBI Standard Hardware Interface Specification -VSI-H Rev. 1.01, 2000.

[5] Ichikawa, R., et al.: Present Status and Outlook of Compact VLBI System Development for Providing

over 10km Baseline Calibration, IVS NICT-TDC News 2, 30, pp. 22-25, 2009.

[6] Takiguchi, H., et al.: Comparison Study of VLBI and GPS Carrier Phase Frequency Transfer -Part II-,

IVS NICT-TDC News2, 30, pp. 26-29, 2009.

[7] Whitney, A. R., et al.: VLBI Data Interchange Format (VDIF), Proceedings of the 8th e-VLBI workshop

at Madrid, PoS(EXPReS09)042 2009.

[8] M. Honma, et al.: Multi-Epoch VERA Observations of H2O Masers in OH 43.9 – 0.1, Publ. Astron.

Soc. Japan, 57, pp. 595-603, 2005.

[9] M. Kimura: Development of the software correlator for the VERA system, IVS NICT-TDC News2,

26, 26-27, 2005.

[10] Deller, A. T., et al.: DiFX: A Software Correlator for Very Long Baseline Interferometry Using Multiprocessor Computing Environments, Pub. Astr. Soc. Pacific, 119, pp. 318-336, 2007.

1http://www.vlbi.org/vsi/

2http://www2.nict.go.jp/w/w114/stsi/ivstdc/news-index.html

146 IVS 2010 Annual Report
Geospatial Information Authority of Japan Tsukuba VLBI Correlator

Tsukuba VLBI Correlator

Kensuke Kokado, Shinobu Kurihara, Ryoji Kawabata, Kentaro Nozawa

Abstract

This report briefly summarizes the activities at the Tsukuba VLBI Correlator in 2010. The Tsukuba

VLBI Correlator processed 96 IVS-INT2 sessions and eight JADE sessions with the K5/VSSP correlation system, which includes the K5/VSSP kernel software. The software correlation system and

high-speed data transfer network enabled us to correlate the data of the IVS-INT2 sessions during

observation. We correlated all of the data of the INT2 sessions with the real-time correlation system

in 2010.

Figure 1. Tsukuba VLBI Correlator

1. Introduction

The Tsukuba VLBI Correlator is part of the VLBI facilities operated by the Geospatial Information Authority of Japan (GSI) as is the Tsukuba 32-m VLBI station (TSUKUB32). A principal

component of our correlation system is the K5/VSSP correlation software package developed by

the National Institute of Communications and Technology (NICT). We can install the software

on commercially-based computers operated by Linux operating system (OS). We processed several

IVS-INT2 sessions and domestic VLBI sessions (JADE sessions) with a number of computers which

IVS 2010 Annual Report 147
Tsukuba VLBI Correlator Geospatial Information Authority of Japan

had the K5/VSSP software package installed. The sessions we processed in 2010 are described in

Section 4.

2. Component Description

The system components of the Tsukuba VLBI correlator are described in Table 1. We have

two systems to process the observed data of international sessions or domestic sessions. System 1

is for JADE sessions and other domestic sessions, which make use of the VLBI stations of Japan

Aerospace Exploration Agency (JAXA) or the compact VLBI system (MARBLE) developed in

a collaboration between GSI and NICT. The system is operated by the management application

“PARNASSUS” (Processing Application in Reference to NICT’s Advanced Set of Software Usable

for Synchronization) designed for distributed correlation processing.

System 2 is for INT2 sessions. We introduced the management application “Cor mgr” in the

system. The application is developed with the Perl programing package. We are able to correlate

the VLBI data automatically using “Cor mgr” and other utility programs. MK3TOOLS is the

program that creates the Mark III database from the output files of the K5/VSSP bandwidth

synthesis program.

The entire hardware is based on commercial products. Although the operating systems of some

data or correlation servers were Redhat Linux release 9, we replaced it with CentOS version 5.4

or 5.5 in 2010. Now, all of the servers work well.

For the INT2 sessions, we have been transferring the data observed at Wettzell or Westford

station via high-speed network. The Tsukuba VLBI Correlator is connected to the high-speed

network “SINET3 (Science Information NETwork3)” operated by the National Institute of Informatics (NII). The network enables us to do real-time data transfer from Wettzell to Tsukuba.

3. Staff

The technical and engineering staff of the Tsukuba VLBI Correlator are as follows. Yuji Miura,

who was a technical staff member in 2009, moved to another department in June 2010. Most of

our staff are subcontracted engineers from either of two private companies: Advanced Engineering

Service Co., Ltd (AES) or The Institute of Japanese Union of Scientists and Engineers (I-JUSE).

Kensuke Kokado: Technical official (GSI)

Correlation Chief, Management of overall activity of Tsukuba VLBI correlator

Maintenance/support of K5 software correlation system and e-VLBI network system

Kentaro Nozawa: Technical Operator (AES)

Main operator of the correlation work

Maintenance of the real-time correlation system (System 2)

Yasuko Mukai: Technical Operator (AES)

Sub-operator of the correlation work

Routine correlation processing, Management of media shipping

Toshio Nakajima: System Engineer (I-JUSE)

System Engineer for maintenance of computers and e-VLBI network system

148 IVS 2010 Annual Report
Geospatial Information Authority of Japan Tsukuba VLBI Correlator

Table 1. Specifications of the K5/VSSP correlation system components

System 1 System 2

Management Server 1 server 1 server

(CPU) (Intel Pentium 4, 3.0GHz) (Intel Xeon 3.4GHz dual CPU)

Correlation Servers 24 servers

(CPU) (Intel Xeon 3.06GHz dual CPU) 8 servers

Data Servers 24 servers (Intel Xeon 3.4GHz dual CPU)

(CPU) (Intel Pentium 4, 3.0GHz)

Data Format K5/VSSP or K5/VSSP32

HDD type Serial ATA Disk

K5/VSSP Archive Version ipvlbi cor 20100723

komb20100811

Main application PARNASSUS 1.3 Cor mgr

MK3TOOLS MK3TOOLS

Operating System CentOS version 5.4, version 5.5

Processing Session JADE IVS-INT2 session

Additional domestic session etc.

4. Current Status and Activities

4.1. Processing of JADE Sessions

JADE is a domestic 24-hour VLBI session type scheduled by GSI. The participating stations

are four GSI stations (TSUKUB32, SINTOTU3, CHICHI10, and AIRA) and two VERA stations

(VERAMZSW and VERAISGK) of the National Astronomical Observatory of Japan (NAOJ).

TSUKUB32 and VERAISGK stations are connected to broad-band network, so we can transfer

the data via network. However, the other stations’ transfer rates are too slow to transfer the data

to the correlator. Therefore, we have to send the data by shipment of the hard disks. These disks

sent by shipment are injected into the disk array of the correlation system. We have more than

100 hard disks for the shipment, because we need more than four disks per station for each JADE

session.

The JADE sessions and the other domestic sessions processed at the Tsukuba correlator in 2010

are described in Table 2. Additional domestic sessions have been observed for the determination

of the positions of USUDA64 and UCHINOUR stations operated by JAXA. GSI commenced the

additional domestic sessions with JAXA in 2006. The participating stations are GSI’s four stations

and USUDA64 or UCHINOUR stations. The session has not been registered yet with the IVS, so

we have not submitted the database.

The processing factor of each JADE session is described in the rightmost column of Table

2. They depend on the number or performance of the correlation servers. We could reduce the

processing time if we had a lot of high-performance servers. The processing factors per baseline

of JADE1009, JADE1010, and JADE1011 were more than 1.00. The cause for the delay was that

we had some trouble with the hard disks or the network file system.

IVS 2010 Annual Report 149
Tsukuba VLBI Correlator Geospatial Information Authority of Japan

Table 2. JADE sessions processed in 2010 (Ts:TSUKUB32, Ai:AIRA, S3:SINTOTU3, Cc:CHICHI10,

Vm:VERAMZSW, Vs:VERAISGK, Uc:UCHINOUR, Kb:KASHIM34).

Session Stations Processed Baseline # Processing Factor

JADE-1001 TsAiCcS3VmVs 11 3.94

JADE-1003 TsAiCcVm 6 2.82

U10073 TsAiCcUc 6 2.38

JADE-1005 TsS3 1 0.43

JADE-1006 TsAiCcS3 6 3.41

JADE-1008 KbAiCcS3Vm 10 8.32

JADE-1009 KbS3 1 1.72

JADE-1010 TsS3 1 1.45

JADE-1011 TsS3 1 1.12

4.2. Processing of IVS-INT2 Session

As the method of data transfer has been improved with the development of the e-VLBI system,

we introduced a real-time data transfer system developed by NICT in 2010. The transfer system

enables us to convert the Mark 5 format data to K5 format data at the same time as the data

transfer. We have adopted the real-time data transfer system on the Ts-Wz baseline only. On

the other baselines, the data is transferred using the UDP-based protocol “TSUNAMI” after the

observing sessions. The data transfer rate reached up to 300 Mbps between Tsukuba and Wettzell.

As the data of the INT2 sessions are processed in real-time, the processing factor of the session is

about 1.00. If we process all of the data with PARNASSUS or Cor mgr after the observing session,

the processing factor will be under 0.4.

Table 3. IVS-INT2 sessions processed in 2010

Session Stations Processed session #

IVS-INT2(K) Ts-Wz 64

IVS-INT2(H) Ts-Wf 16

IVS-INT2(D) Kb-Wz 4

IVS-INT2(F) Kb-Wf 9

Ts:TSUKUB32, Kb:KASHIM34, Wz:WETTZELL, Wf:WESTFORD

5. Plans for 2011

We plan to register the domestic sessions with the JAXA VLBI stations as IVS sessions and

will then submit the databases to the IVS Data Center. The Tsukuba VLBI correlator will process

eight JADE sessions, 101 IVS-INT2 sessions, and two IVS-INT3 sessions. All of the INT2 and the

INT3 sessions will be processed with the real-time correlation system.

150 IVS 2010 Annual Report
U. S. Naval Observatory Washington Correlator

Washington Correlator

Kerry A. Kingham, David M. Hall

Abstract

This report summarizes the activities of the Washington Correlator for the year 2010. 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 2010

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. All of the weekly IVS-R4 sessions, all of the IVS-INT01 Intensives, and the APSG and

CRF sessions were processed at WACO. The facility houses a Mark IV Correlator.

Figure 1. Conversion to Mark 5Bs: five Mark 5Bs (left rack and right bottom) share space with three Mark

5As (upper right) on the right side of the correlator. All of these will be Mark 5B by next year.

IVS 2010 Annual Report 151
Washington Correlator U. S. Naval Observatory

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 sessions 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.

- Prior to April 2010, Intensive observations from Kokee Park Geophysical Observatory

(KPGO) were shipped via FedEx to the Washington area. This required station personnel to travel down the road to the local town to meet the FedEx pickup. The shipping to

the correlator typically took two days. After April 2010, observations from KPGO were sent

directly to the correlator over an Internet 2 connection. This operation saved the two days

of shipping time and allowed processing within 24 hours of the observation.

- A Mark 5B playback unit was added to the correlator complement of Mark 5s, which now

brings the correlator complement to eight Mark 5As and four Mark 5Bs. An additional Mark

5B+ is used for transfers.

- Intensive observations from Kokee Park, Wettzell, and Ny- ̊Alesund were routinely transferred

via e-VLBI during 2010. 24-hour sessions from both Hobart antennas, Ny- ̊Alesund, Tsukuba,

Aira, Kashima, Chichijima, and Sintotu were also transferred by high-speed networks.

- Correlator time was also spent processing test observations connected with the commissioning

of the Hobart 12-m antenna.

- Table 1 lists the experiments processed during 2010.

Table 1. Experiments processed during 2010.

51 IVS-R4 sessions

1 IVS-R1 session

4 CRF (Celestial Reference Frame)

4 R&D sessions

211 Intensives

2 Kk-Sv-Wz Intensives

3 Kk-Sv-Ny Intensives

5 TQUAKE (Tigo Earthquake)

3. Staff

The Washington Correlator is under the management and scientific direction of the Earth

Orientation Department of the U.S. Naval Observatory. USNO personnel continue to be responsible

152 IVS 2010 Annual Report
U. S. Naval Observatory Washington Correlator

for overseeing scheduling and processing. During the period covered by this report, a private

contractor, NVI, Inc., supplied a contract manager and correlator operators. Table 2 lists staff

and their duties.

Table 2. Staff.

Staff Duties

Dr. Kerry Kingham (USNO) Chief VLBI Operations Division and Correlator Project Scientist

David Hall (USNO) VLBI Correlator Project Manager

Bruce Thornton (NVI) Operations Manager

Harvis Macon (NVI) Lead Correlator Operator

Roxanne Inniss (NVI) Media Librarian

Kenneth Potts (NVI) Correlator Operator

4. Outlook

The Washington Correlator plans to upgrade the Mark 5A playbacks to Mark 5B, in coordination with the installation of Mark 5Bs at the Network Stations. e-VLBI operations are expected

to expand, and additional transfer capability and disk space will be added. Intensive processing is

expected to transfer to a software correlator by the end of 2011.

IVS 2010 Annual Report 153

Data Centers

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 2010. Included are 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 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 username and password to get access.

An incoming script is watching the incoming area and checking the syntax of the files sent by

IVS components. If it is o.k., 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.

Public access to the BKG Data Center is available through FTP and HTTP:

IVS 2010 Annual Report 157
BKG Data Center Bundesamt f ̈ur Kartographie und Geod ̈asie

FTP: ftp://ivs.bkg.bund.de/pub/vlbi/

HTTP: http://ivs.bkg.bund.de/vlbi/

Structure of 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

Volkmar Thorandt (coordination, data analysis, data center, volkmar.thorandt@bkg.bund.de)

Reiner Wojdziak (data center, Web design, reiner.wojdziak@bkg.bund.de)

Dieter Ullrich (data analysis, data center, dieter.ullrich@bkg.bund.de)

Gerald Engelhardt (data analysis, gerald.engelhardt@bkg.bund.de)

158 IVS 2010 Annual Report
NASA Goddard Space Flight Center CDDIS Data Center

CDDIS Data Center Summary for the IVS 2010 Annual Report

Carey Noll

Abstract

This report summarizes activities during the year 2010 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 and GLONASS), 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 8

Tbytes of on-line disk storage; at this time, over 100 Gbytes are devoted to VLBI activities. (The

over 1 Tbyte archive of raw correlator output files were moved offline from the CDDIS archive in

2010.) The CDDIS is located at NASA GSFC and is accessible to users 24 hours per day, seven

days per week.

2.2. Staffing

Currently, a staff consisting of one NASA civil service employee and five (one full-time, four

part-time) contractor employees supports all CDDIS activities (see Table 1).

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.

IVS 2010 Annual Report 159
CDDIS Data Center NASA Goddard Space Flight Center

Table 1. CDDIS Staff

Name Position

Ms. Carey Noll CDDIS Manager

Dr. Maurice Dube Head, CDDIS contractor staff and senior programmer

Ms. Ruth Labelle Programmer (part-time)

Mr. Scott Fenton Programmer (part-time)

Ms. Lisa Lee Web developer (part-time)

Ms. Lori Tyahla Programmer (part-time)

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, an incoming data area has

been established on the CDDIS host computer, cddis.gsfc.nasa.gov. Using specified file names,

operation and analysis centers deposit data files and analyzed results to appropriate directories

within this filesystem. 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 primary 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)

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

In June 2010 the CDDIS transitioned operations to a new distributed server environment.

Users continued to access the CDDIS as before; however, suppliers of data and product files were

required to use a new server dedicated to incoming file processing. The structure of the VLBI data

and product archive remained unchanged in this new system configuration.

During 2010, over 550 distinct hosts accessed the CDDIS on a regular basis to retrieve VLBI

related files. These users successfully downloaded over 65 Gbytes of data and products (350,000

files) from the CDDIS VLBI archive last year.

160 IVS 2010 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-pilot2000 IVS Analysis Center pilot project (2000)

vlbi/ivs-pilot2001 IVS Analysis Center pilot project (2001)

vlbi/ivs-pilotbl IVS Analysis Center pilot project (baseline)

vlbi/ivs-pilottro IVS Analysis Center pilot project (troposphere)

vlbi/ivs-special IVS special analysis solutions

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

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 2010 Annual Report 161
Italy INAF Data Center Istituto di Radioastronomia–Bologna

Italy INAF Data Center Report

M. Negusini, P. Sarti, C. Abbondanza

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. We also report some changes to the hardware facilities devoted to IVS

activities.

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 2007 a new server with a storage capacity of 1 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.

162 IVS 2010 Annual Report
Kashima Space Research Center, NICT Data Center at NICT

Data Center at NICT

Ryuichi Ichikawa, Hiroshi Takiguchi, Mamoru Sekido, Yasuhiro Koyama

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 Correlation Center 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 Correlation

Center 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. Since 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. In 2009, a series of geodetic VLBI sessions were carried out by using the Kashima 34-m,

Kashima 11-m, and Koganei 11-m stations to demonstrate precise time comparison. Another

series of astronomical VLBI sessions were carried out between the Kashima 34-m and Koganei 11-

m stations to monitor the flux densities of radio variable stars using real-time e-VLBI data transfer

and processing. In addition, seven geodetic experiments using the two compact VLBI systems with

a 1.6-m antenna were also carried out [2]. The analysis results in SINEX (Solution INdependent

EXchange) format as well as in other formats are available on the Web server. Database files of

non-KSP sessions, i.e., other domestic and international geodetic VLBI sessions, are also available

on the Web server. Table 1 lists the Web 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 Web server was prepared to provide large size data files.

Table 1. URL of the Web server systems.

Service URL

KSP Web pages http://ksp.nict.go.jp/

IVS Web mirror pages http://ivs.nict.go.jp/mirror/

Database files http://www3.nict.go.jp/w/w114/stsi/database/

e-VLBI Sessions http://www.nict.go.jp/w/w114/stsi/research/e-VLBI/UT1/

Hayabusa Sessions http://www.nict.go.jp/w/w114/stsi/research/Navi/HAYABUSA/

The responsibilities for the maintenance of these server machines were moved from the VLBI

research group of NICT to the common division for the institutional network service of the laboratory in 2001 to improve the network security of these systems.

IVS 2010 Annual Report 163
Data Center at NICT Kashima Space Research Center, NICT

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 daily or bi-daily (every two days) 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 real-time,

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 tape-based 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 to 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 addition to the KSP regular VLBI sessions, 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 (NAO), and other organizations. These sessions are listed in Table 2. The recent observed data of these sessions were mainly

processed by using the K5 software correlator at NICT either at Koganei or at Kashima or by

using a real-time hardware correlator developed by NAO.

In 2010, 38 IVS geodetic VLBI sessions (442 hours in total) including 1 hour “Intensive”

dUT1 sessions were carried out as shown in Table 2. The increase of IVS sessions is mainly due

to the temporary replacement of the 32-m Tsukuba antenna operated by the GSI by the 34-m

Kashima antenna during the repair of the lightning damage. Seven MARBLE experiments using

the compact VLBI system were also performed together with the GSI Tsukuba 32-m antenna. In

addition, nine time transfer sessions were performed. The purpose of the sessions is to evaluate

the capability of geodetic VLBI experiments for precise and accurate time transfer between Time

and Frequency laboratories located worldwide.

164 IVS 2010 Annual Report
Kashima Space Research Center, NICT Data Center at NICT

Table 2. Geodetic VLBI sessions conducted by NICT (since 2005).

Year exp. names sessions

2005 Geodetic c0505 (CONT05, partial participation),

GEX13

Hayabusa 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

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.

Table 3. Staff members of the Space-Time Standards Group, KSRC, NICT.

Name Main Responsibilities

KOYAMA Yasuhiro Administration of Data Servers

ICHIKAWA Ryuichi Development of compact VLBI system

SEKIDO Mamoru Responsible for e-VLBI sessions

TAKIGUCHI Hiroshi Time Transfer

HASEGAWA Shingo System Engineer

IVS 2010 Annual Report 165
Data Center at NICT Kashima Space Research Center, NICT

4. Future Plans

The IVS Data Center at NICT will continue its service and will archive and release the analysis

results accumulated by the Correlation Center 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.

[2] Hobiger T., Takiguchi H., Ichikawa R., Sekido M., Koyama Y., and Kondo T., Analysis Center at

NICT, IVS 2010 Annual Report, this volume, 2011.

[3] Koyama, Y., T. Kondo, M. Kimura, and H. Takeuchi, IVS NICT TDC News, No. 26, Sep. 2005, pp.

9-12.

166 IVS 2010 Annual Report
Observatoire de Paris, SYRTE/UMR 8630 Paris Observatory (OPAR) Data Center

Paris Observatory (OPAR) Data Center

Christophe Barache, S ́ebastien B. Lambert

Abstract

This report summarizes the OPAR Data Center activities in 2010. Included is information about

functions, architecture, status, and future plans 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 is one of the three IVS Primary

Data Centers together with CDDIS and BKG. 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, documents),

• mirrors the other ones every three hours,

• gives free FTP access to the files.

Figure 1. Mirroring among the primary Data Centers.

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Paris Observatory (OPAR) Data Center Observatoire de Paris, SYRTE/UMR 8630

This protocol gives the IVS community a 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, Operation 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:

ivscontrol/ : provides the control files needed by the data center

(session code, station code, solution code...)

ivscontrol_new/ : temporary test directory

ivscontrol_old/ : temporary test directory

ivsdocuments/ : provides documents and descriptions about IVS products

ivsdata/ : provides files related to the observations:

aux/ : auxiliary files (schedule, log...)

db/ : observation files in data-base CALC format

ngs/ : observation files in NGS format

sinex/ : observation files in SINEX format

ivsproducts/ : provides results from Analysis Centers:

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 solutions in SINEX format, mainly

designed for combination

trop/ : Tropospheric time series (starting July 2003)

ivs-iers/ : provides products for IERS Annual Report

ivs-pilot2000/ : provides products of 2000 for special investigations

ivs-pilot2001/ : provides products of 2001 for special investigations

ivs-pilottro/ : provides tropospheric time series for Pilot Project

(until June 2003)

ivs-pilotbl/ : provides baselines files

ivs-special/ : specific studies

raw/ : original data (not writable at OPAR Data Center)

3. Current Status

The OPAR Data Center is operated on a PC Server (PowerEdge 2800 - Xeron 3.0 GHz) at

Paris Observatory running the Fedora Linux operating system.

168 IVS 2010 Annual Report
Observatoire de Paris, SYRTE/UMR 8630 Paris Observatory (OPAR) Data Center

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 connection with 2 Mbit/s rate. Users can get the IVS products by using the FTP protocol. Access to

this server is free for users.

FTP access:

ivsopar.obspm.fr

username : anonymous

password : your e-mail

cd vlbi (IVS directory)

This year, 25 distinct users regularly put/got data on/from the FTP OPAR ivsincoming. There

were also 3273 distinct users of the Web OPAR server. We provide more statistical information

about the OPAR Data Center access in Figure 2.

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 2010 Annual Report 169
Paris Observatory (OPAR) Data Center Observatoire de Paris, SYRTE/UMR 8630

Figure 2. Monthly access of the Data Center during 2010. For each month in column 1, columns 2 through

6 show, in order, the number of different visitors, the total number of visits, the number of pages viewed,

the number of accesses of the Web site, and the downloaded bandwidth in megabytes (Mo) or gigabytes

(Go).

170 IVS 2010 Annual Report
Analysis Centers

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 2010. Changes which happened 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 1-hour

observational sessions for obtaining Earth Orientation Parameters (EOP) and rapid UT1-UTC

values, respectively. Due to staff changes in 2007 we had a gap in our submissions for IVS. In

2008 we resumed submitting results of 24-hour session processing. During 2010 the activities of

the SPU AC continued unchanged.

2. Staff

The lecturer in astronomy 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 Prof. Veniamin Vityazev.

3. Activities in 2010

• In 2010 we continued the work resumed in 2008. The routine estimation of the five Earth

Orientation Parameters was performed. The OCCAM package software (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, and R4 observing programs, and it

covers 23 years of observations (from January 2, 1989 until the end of 2010). The total

number of processed experiments is about 1640, of which 100 VLBI sessions were processed

in 2010. Our experience and the equipment of the Analysis Center was used for giving

lectures and practical work on the basics of radio interferometry for the university students.

In 2010, the work of the SPU AC was supported by the project “Kinematic and Dynamic

Astronomy” (a grant of the President of the Russian Federation for leading scientific schools)

as well as by the project “Acquisition and analysis of time-series in astronomy and the study

of astronomical catalogs” (an SPU grant for fundamental research).

• All parameters have been 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 2010 Annual Report 173
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: 1989.01–2010.12

– CRF: fixed to ICRF-Ext.2

– TRF: VTRF2005 was used as an a priori TRF

– Estimated parameters:

1. EOP: x, y, UT1 − UTC, 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 2011 we are going to continue our regular processing of the results of the VLBI sessions as well

as giving lectures and the practical work for the students within a special course on radio astrometry

which is included in 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.

174 IVS 2010 Annual Report
Geoscience Australia Geoscience Australia Analysis Center

Geoscience Australia Analysis Center

Oleg Titov

Abstract

This report gives an overview about the activities of the Geoscience Australia IVS Analysis Center

during 2010.

1. General Information

The Geoscience Australia (GA) IVS Analysis Center is located in Canberra. The Geodesy

Group operates as a part of the Geospatial and Earth Monitoring Division (GEMD).

2. Component Description

Currently the GA IVS Analysis Center contributes nutation offsets, EOP, and EOP rates on a

regular basis for IVS-R1 and IVS-R4 networks and their predecessors (IRIS-A and NEOS-A). The

EOP time series are available for 1983 to 2010. The CRF catalogs using a global set of VLBI data

since 1979 are regularly submitted.

3. Staff

• Dr. Oleg Titov - project manager

4. Current Status and Activities

Several CRF solutions have been prepared using the OCCAM 6.2 software. The last solution

has been uploaded in January 2011. VLBI data comprising 4,005 daily sessions from 25-Nov-1979

to 02-Oct-2010 have been used to compute several global solutions with different sets of reference

radio sources. This includes 5,017,615 observational delays from 2,848 radio sources observed by

60 VLBI stations. [1].

Station coordinates were also estimated using NNR and NNT constraints. The long-term time

series of the station coordinates have been established 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 [2]. The tectonic motion of the TIGOCONC VLBI site

after a strong earthquake on 27 February 2010 is under study (Figure 1).

The adjustment has been done by least squares collocation [3], which considers the clock offsets,

wet troposphere delays, and troposphere gradients as stochastic parameters with a priori covariance

functions. The gradient covariance functions were estimated from GPS hourly values [4].

5. Geodetic Activity of the Australian Radio Telescopes

During 2010 three Australian radio telescopes – Hobart26, Hobart12 operated by the University

of Tasmania (UTAS), and Parkes operated by the Australia Telescope National Facility (ATNF),

– were involved in geodetic VLBI observations. GA’s Geodesy Group supported the observations

IVS 2010 Annual Report 175
Geoscience Australia Analysis Center Geoscience Australia

Figure 1. Height, latitude, and longitude variations of the TIGOCONC geodetic positions in 2010 following

the 27 February 2010 earthquake.

in different ways including assistance with campaign scheduling.

The Parkes 64-meter telescope participated in two geodetic VLBI sessions in 2009 (R1416 and

CRF-61) for improvement of the ITRF and the ICRF in the Southern Hemisphere. This program

is undertaken in cooperation with ATNF and UTAS.

In August 2010 a group of scientists from Australia and Germany undertook a run of spectroscopic observations of the reference radio sources. They used the New Technology Telescope

(NTT) optical facility (3.58-meter telescope in La Silla, Chile) operated by the European Southern

Observatory (ESO). The goal of this work is to identify the radio sources regularly observed for

the geodetic and astrometric VLBI programs. New red shifts of 31 radio sources in the southern

176 IVS 2010 Annual Report
Geoscience Australia Geoscience Australia Analysis Center

hemisphere have been found. Five radio sources (1659-621, 1758-651, 1815-553, 2236-572, and

2344-514) belong to the list of the ICRF2 defining sources. Two observers (Oleg Titov and David

Jauncey (ATNF)) were supported by a travel grant of the Access to Major Research Facilities Program (AMRFP) to travel to La Silla. A paper reporting the results is under preparation. Figure 2

shows a sky field around the 1758-651 source made at NTT. Two stellar objects are close to each

other; therefore the slit of the spectrograph was directed to cover both objects. Figure 3 shows

the dirty spectrum of the two objects. While the brighter object does not show any features, the

fainter companion has two strong emission lines. The clean spectrum after processing shown in

Figure 4 reveals two strong emission lines identified as CIII] and MgII. A set of less prominent

lines was also found.

Figure 2. The NTT image of the sky field around the quasar 1758-651 (shown by arrow). Closeness of the

quasar to the bright star probably caused an identification failure in the past.

Figure 3. The spectra of the two optical objects of Figure 2. The spectrum of the star has no features while

the less powerful spectrum of 1758-651 highlights two emission lines shown by arrows.

IVS 2010 Annual Report 177
Geoscience Australia Analysis Center Geoscience Australia

Figure 4. The clean spectrum of 1758-651 after processing. Two main lines CIII] and Mg II are followed by

a set of less prominent lines. The red shift was estimated as equal to 1.2.

6. New Geodetic VLBI Network

Geoscience Australia supported the installation work of the new Australian geodetic VLBI

network during 2010. Antenna Hobart12 started operations in October 2010. Two other antennas,

Katherine and Yarragadee, will start operations in 2011.

Acknowledgements

This report has been published with permission of the Geoscience Australia CEO. Copyright

Commonwealth of Australia (Geoscience Australia) 2011.

References

[1] Titov, O., Systematic effects in the radio source proper motion, In: Proceedings of the 19th European

VLBI for Geodesy and Astrometry Meeting, Bordeaux, G. Bourda, P. Charlot, and A. Collioud (eds.),

14–18, 2009.

[2] Titov, O., P. Tregoning, Post-seismic motion of the 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.

[3] 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.

[4] Haas, R., private communication.

178 IVS 2010 Annual Report
Laboratoire d’Astrophysique de Bordeaux Bordeaux IVS Analysis Center

Report for 2010 from the Bordeaux IVS Analysis Center

Patrick Charlot, Antoine Bellanger, G ́eraldine Bourda, Arnaud Collioud, Ming Zhang,

Alain Baudry

Abstract

This report summarizes the activities of the Bordeaux IVS Analysis Center during the year 2010.

The work was 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) testing of a pipeline to model-fit VLBI structures in an

automatic way; 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 implementation

of the IVS Live Web site which allows one to monitor IVS sessions in real time and to view source

images.

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, DORIS) at the

observation level. This effort also involves space geodesy groups in Toulouse, Grasse, and Paris.

2. Description of 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 2009

and 2010 (with 6-hour EOP resolution) have been produced and integrated in the multi-technique

solutions derived by the GRGS within the framework of the “Combination at the Observation

Level” (COL) Working Group. Additional work was dedicated to implementing operational procedures for automating the data processing with GINS and for assisting in evaluating the results.

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 as for the ICRF2 [2] or the future Gaia link.

IVS 2010 Annual Report 179
Bordeaux IVS Analysis Center Laboratoire d’Astrophysique de Bordeaux

3. Scientific Staff

During the past year, several changes occurred with IVS staff. The most significant event is

that G ́eraldine Bourda obtained a permanent position at the LAB, starting on 1 September 2010;

this position comprises research, teaching duties, and IVS service activity. With two researchers

and two engineers on permanent positions, the IVS group can now build on solid ground. Also

Ming Zhang’s CNRS post-doctoral fellowship ended on 30 September 2010; he then went back

to China and obtained a permanent position at Urumqi Astronomical Observatory. Yet another

change is Alain Baudry’s retirement on 1 September 2010; now with a part-time ESO contract to

accomplish ALMA duties, he still spends time at the LAB and keeps contact with VLBI and IVS.

In all, six individuals contributed to IVS analysis and research activities during 2010. A description

of what each person worked on, along with the time spent on these activities, 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.

• G ́eraldine Bourda (50%): now with a permanent position at the LAB. She is tasked with developing the VLBI part of GINS and is 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 process the RDV sessions with AIPS and DIFMAP to image the sources, to

maintain the Bordeaux VLBI Image Database (BVID), and to develop VLBI2010 simulations.

• Ming Zhang (50%): post-doc fellow funded by the CNRS (until 30 September 2010). His work

has been targeted towards finding automatic ways to model-fit VLBI structures and extract

physical information with the aim of studying the evolution of the sources from the BVID.

• Alain Baudry (10%): radioastronomy expert with specific interest in radio source imaging

and astrometric VLBI. Retired since 1 September 2010.

4. Analysis and Research Activities during 2010

As noted above, a major activity of the Bordeaux group consists in imaging the sources observed

during the RDV sessions on a systematic basis. During 2010, two such sessions were processed

(RDV76 and RDV78), resulting in 370 VLBI images at either X or S band for 156 different sources.

The imaging work load has been shared between the USNO and Bordeaux groups since 2007

(starting with RDV61): the USNO group processes the odd-numbered RDV sessions while the

Bordeaux group processes the even-numbered 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 [3, 4] 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 2108 VLBI images (with links to an additional

1The BVID may be accessed at http://www.obs.u-bordeaux1.fr/BVID

180 IVS 2010 Annual Report
Laboratoire d’Astrophysique de Bordeaux Bordeaux IVS Analysis Center

7124 VLBI images from the Radio Reference Frame Image Database of the USNO at either S, X,

K, or Q band) along with 9232 structure correction maps and as many visibility maps.

Plans to take advantage of this wealth of VLBI images for astrophysics have also been initiated. For this purpose, a pipeline that automatically fits Gaussian components to the observed

VLBI structures and subsequently estimates jet proper motions and flux density variability has

been developed [5]. Comparison with results obtained manually for a few sources shows excellent

agreement in the case of structures with strong and well-separated VLBI components, whereas

results sometimes disagree for structures that comprise weak and/or blended VLBI components.

A comparison for a large data set (50 to 100 sources) is now underway to assess the potential use

of this pipeline to study source structural variability in a systematic way from the BVID data.

The other major activity in the group is an observational program to identify and characterize

appropriate radio sources to align the ICRF and the future Gaia optical frame. To this end, dedicated VLBI observations of a sample of 398 optically-bright radio sources have been undertaken [6].

From this sample, an initial 105 sources have already been imaged, half of which show the required

properties in terms of astrometric suitability [7]. During the past year, a total of 106 hours of

observing time was allocated to image an additional 215 sources. These observations were carried

out in March and November 2010 with a 15-station network combining the European VLBI Network and the Very Long Baseline Array. Observations of the remaining sources are planned for

March 2011 to complete the imaging work. Next will come dedicated astrometric observations of

the most compact sources identified though such imaging to accurately measure their positions.

5. Dissemination and Outreach

As reported in [5], the Bordeaux group set up a dynamic Web site displaying VLBI images of

the observed radio sources in real time for the particular IVS session dedicated to the International

Year of Astronomy 2009 (IYA2009) which took place on 18 November 2009. Following this event –

which drew quite a lot of interest – the IVS Directing Board suggested that the IYA09 Web site be

extended in order to make it run for every IVS session. The work was carried out during 2010, and

a final product, IVS Live, was presented for approval to the IVS Directing Board in October 2010.

The IVS Live Web site may be reached from the IVS home page or directly at the following address:

http://ivslive.obs.u-bordeaux1.fr/

IVS Live is meant both as an outreach and a scientific tool. The main reason for its existence

is to monitor IVS sessions in real time and to view source images (Fig. 1). But it can also be used

to navigate through IVS sessions and to search for specific information about sources and stations.

It will be regularly updated and extended in order to increase its value to the IVS community.

The most recent enhancement is a display of the projected source direction on the terrestrial map.

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. We will also continue imaging the

RDV sessions in cooperation with USNO as well as evaluating the source astrometric suitability

based on structure index and source compactness indicators. In addition, we expect to develop

astrophysical interpretation of the BVID data by using the pipeline that we have developed to

IVS 2010 Annual Report 181
Bordeaux IVS Analysis Center Laboratoire d’Astrophysique de Bordeaux

Figure 1. A snapshot of the IVS Live Web site while observing the source 0552+398 in the course of

the IVS session R1459 on 30 November 2010. See the December 2010 IVS newsletter for details on the

functionalities.

model-fit VLBI structures in an automatic way. Regarding the Gaia link, our goal is to complete

the VLBI imaging of the 398 optically-bright radio sources selected for this purpose, to assess their

astrometric suitability, and to engage in astrometric observations on the most compact of these

sources. Simulations of the VLBI2010 system’s imaging capabilities will also be started again with

focus on the assessment of the accuracy of the structural corrections derived from such images.

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] IERS Technical Note 35: 2009, The Second Realization of the International Celestial Reference Frame

by Very Long Baseline Interferometry, Eds. A. L. Fey, D. Gordon and C. S. Jacobs, Frankfurt am Main:

Verlag des Bundesamts f ̈ur Kartographie und Geod ̈asie, 204 pages.

[3] Fey, A. L., Charlot, P.: 1997, VLBA Observations of Radio Reference Frame Sources. II. Astrometric

Suitability Based on Observed Structure, ApJS, 111, 95–142.

[4] 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.

[5] Charlot, P., Bellanger, A., Bourda, G., Collioud, A., Zhang, M., Baudry, A.: 2010, Report for 2009

from the Bordeaux IVS Analysis Center, IVS 2009 Annual Report, Eds. D. Behrend and K.Baver,

NASA/TP-2010-215860, p 213–216.

[6] Bourda, G., Charlot, P., Porcas, R., Garrington, S.: 2010, VLBI observations of optically-bright extragalactic radio sources for the alignment of the radio frame with the future Gaia frame. I. Source

detection, A&A, 520, A113.

[7] Bourda, G., Collioud, A., Charlot, P., Porcas, R., Garrington, S.: 2011, VLBI observations of opticallybright extragalactic radio sources for the alignment of the radio frame with the future Gaia frame.

II. Imaging candidate sources, A&A, 526, A102.

182 IVS 2010 Annual Report
BKG and DGFI BKG/DGFI Combination Center

BKG/DGFI Combination Center Annual Report 2010

Sabine Bachmann, Robert Heinkelmann, Michael Gerstl

Abstract

This report summarizes the activities of the BKG/DGFI Combination Center in 2010 and outlines

the planned activities for the year 2011. The main goal in 2010 was to perform the operational combination of the IVS Rapid EOP series (R1 and R4 sessions). Since October 1, 2009 these combinations have

been performed at the BKG/DGFI Combination Center. In 2011 the responsibility for the operation

of the IVS quarterly solutions should also be taken over from the IVS Analysis Coordinator.

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 will be 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 should be 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 has been adopted

from the combination process developed and performed by the IVS Analysis Coordinator (cf. [3],

[4]). In 2009 the responsibility for the combination of the two IVS EOP series (rapid and quarterly

solutions) on the basis of datum-free normal equations in SINEX format was taken over by the

Combination Center.

At BKG Combination Center (BKG CC) 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 will be available at the

BKG/DGFI IVS Combination Center Web page [6]. If requested by the Analysis Centers,

the results will be provided by e-mail, too.

• Creating high quality combination products and performing timely archiving and distribution: Combination products will be created using the DGFI DOGS software package [7].

• Submitting official IVS combination products to the IERS: The produced official IVS combination products will be submitted to the responsible IERS components as requested by the

IERS. This will be supported by the staff of the IERS Central Bureau at BKG.

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BKG/DGFI Combination Center BKG and DGFI

• Placing final results in IVS Data Centers: Final results will be placed in the BKG Data

Center. This will be assisted by the staff of the BKG Data Center in Leipzig.

• Generating official IVS input to the ITRF: Official IVS input to the ITRF will be created as

combined weekly solutions in SINEX format.

DGFI is in charge of the following Combination Center functions:

• Developing state-of-the-art combination procedures: State-of-the-art combination procedures

will be developed mainly at DGFI. This work, as well as the following item, is also related

to DGFI’s efforts within the IERS WG on the Combination on Observation Level (COL).

• Performing software development and documentation: At DGFI the DOGS software package

will be continuously updated by implementing the developed state-of-the-art combination

procedures.

• Adhering to IERS Conventions: The DGFI DOGS software package is continuously updated

to be in accordance with the IERS Conventions.

3. Staff

At the end of March 2010 Wolfgang Schwegmann, responsible for the BKG CC, left BKG and

thus the Combination Center after several years of collaboration with the IVS. At BKG, without

interruption, Sabine Bachmann took over the combination procedure. The list of the staff members

of the BKG/DGFI Combination Center in 2010 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

Alexander Lothhammer BKG Hardware alexander.lothhammer@bkg.bund.de

maintenance

4. Current Status and Activities

The combination of the IVS Rapid EOP series (R1 and R4 sessions), started in 2009 at BKG,

has been continued routinely in 2010. In 2010, six IVS Analysis Centers (BKG, DGFI, GSFC,

IAA, OPA, and USNO) contributed to the IVS combined product (see [4]). 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. The results of the combination process

are placed in 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 at the BKG/DGFI

184 IVS 2010 Annual Report
BKG and DGFI BKG/DGFI Combination Center

Combination Center Web page [6]. The main update of the combination procedure was the change

of the nutation parameter from dψ and dǫ (referring to the IAU2000A precession-nutation model)

to dX and dY (referring to the IAU2006 precession-nutation model), the latter being used by four

out of the six Analysis Centers.

The completion of the IVS quarterly solution has been intensively continued. Within the

quarterly combination, every three months all available sessions from 1979 up to the present

are combined. Presently several tests have been performed with good intra-technique results.

Comparisons with external time series from IERS and IGS are under way.

5. Plans for 2011

The inter-technique combinations for IVS activities are currently performed by accumulating

either normal equations or solution equations. Since the observations analyzed by the various Analysis Centers are initially identical, combinations on the observation equation level are pointless.

Compared to the combination of solution equations, the normal equation level is advantageous because it still enables correlations among the parameters and allows the addition of a unique set of

datum (condition) equations. The functional models of the inter-technique combination methods

for normal equations and solutions are trivial, while the stochastic models are not. The current

algorithm applied for routine combinations on the normal equation level includes individual scaling

of the Analysis Centers’ contributions through variance component estimation. The scaling is in

particular valuable, because different parameter estimation techniques (e.g. least-squares adjustment, Kalman filter, Square Root Information Filter (SRIF), or least squares collocation) may

be applied. Besides the scaling among the Analysis Centers the combination algorithm should

consider the fact that the same original observations are used by the Analysis Centers. The ‘reapplication of observations’ requires the stochastic model to contain off-diagonal elements. The

framework of a combination theory considering this fact was introduced by [2] and labeled the

Operator Software Impact (OSI). As a first step for improving the IVS combination strategy, the

OSI model has been applied to the combination of troposphere parameters during CONT08 [1].

In 2011 it is planned to test the OSI model on the normal equation level and to make it available

for IVS routine combinations.

In 2011 the work of the BKG/DGFI Combination Center will focus on the following:

• Performing the IVS quarterly solution combination on an operational basis.

• Performing quality control of improved Analysis Center solutions and using these solutions

in the routine combination.

• Including two 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, and the other based on the OCCAM software and provided by

Oleg Titov from Geoscience Australia (AUS), Canberra, Australia.

• Entire transition of the combination software to the actual nutation parameter dX and dY

as soon as every AC contributes these parameters in their SINEX files.

• Extending the combination analysis by including source parameters.

IVS 2010 Annual Report 185
BKG/DGFI Combination Center BKG and DGFI

• Maintaining and extending available information on the combination procedure and combination results available at the Combination Center Web page [6].

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.

[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.

[6] http://vlbi.geod.uni-bonn.de/IVS-AC/index.html

BKG/DGFI Combination Center results at Analysis Coordinator’s Web page.

[7] http://ilrs.dgfi.badw.de/fileadmin/dogs/cs manual.ps

DOGS CS software manual (German version only).

186 IVS 2010 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 2010 through December 2010 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 cgs2009a

The main VLBI data analysis activities at the CGS in the year 2010 were directed towards

the realization of a global VLBI solution, named cgs2009a, using the CALC/SOLVE software

(developed at GSFC). The solution activities, started at the end of 2009, ended in March 2010,

when the solution sections (CRF, TRF, and EOP) were published in the IVS archives. The main,

final characteristics of this solution are:

• Data span:

1979.08.03 - 2009.12.22 (3680 sessions)

• Estimated Parameters:

– Celestial Frame:

Right ascension and declination as global parameters for 1678 sources

– Terrestrial Frame:

Coordinates and velocities for 88 stations as global parameters

– Earth Orientation:

Unconstrained X pole, Y pole, UT1, Xp rate, Yp rate, UT1 rate, dpsi, and deps.

IVS 2010 Annual Report 187
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 2010. At present 957 sessions have been analyzed and submitted, covering the

period from 2002 to 2010. The results are available at the IVS Data Centers.

3.3. IVS Product “Time Series of Baseline Lengths”

Regular submission of station coordinate estimates, in SINEX files, continued during 2010 for

the IVS product “Time Series of Baseline Lengths”. This is composed of 4306 sessions, from 1979

to 2010.

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 and 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.

188 IVS 2010 Annual Report
DGFI, Deutsches Geod ̈atisches Forschungsinstitut DGFI Analysis Center

DGFI Analysis Center Annual Report 2010

Robert Heinkelmann, Manuela Seitz, Michael Gerstl, Hermann Drewes

Abstract

This report summarizes the activities of the DGFI Analysis Center in 2010 and outlines the planned

activities for 2011.

1. General Information and Component Description

The German Geodetic Research Institute (Deutsches Geod ̈atisches Forschungsinstitut, DGFI)

is an autonomous and independent research institute hosted at the Bavarian Academy of Sciences

(BADW) located in Munich. It is run by the Free State of Bavaria, and it is evaluated every

four years by a scientific advisory board consisting of four international experts nominated by the

International Association of Geodesy (IAG) and of three professors working at German universities

nominated by the German Geodetic Commission (Deutsche Geod ̈atische Kommission, DGK). The

research covers all fields of geodesy and includes the participation in national and international

projects as well as functions in international bodies (see also http://www.dgfi.badw.de).

In November 2010 the research activities of DGFI were reviewed by the scientific advisory

board for the first time. In their expertise the scientific board pointed out positively the proposed work in the context of IVS enabling the IVS AC at DGFI to carry on its work for another

four-year period (2011-2014). On the 28th of October 2010 the scientific geodetic institutions in

Munich and Bavaria—namely the Institute of Astronomical and Physical Geodesy (IAPG) and

the Forschungseinrichtung Satellitengeod ̈asie (FESG) including the personnel at the Geodetic Observatory Wettzell (both at Technical University Munich (TUM)), the Bayerische Kommission f ̈ur

die internationale Erdmessung and the Deutsches Geod ̈atisches Forschungsinsitut of the Deutsche

Geod ̈atische Kommission (both at the Bavarian Academy of Sciences)—have signed a cooperation

agreement to establish the Center for Geodetic Earth system Research (Centrum f ̈ur Geod ̈atische

Erdsystemforschung), CGE1. The CGE’s mission is the research of global change through the measurement of changes in the solid Earth, the oceans, the ice caps, and the atmosphere, as well as

the analysis of these changes with regards to the triggering physical processes.

2. Staff

The DGFI IVS AC2is operated by Robert Heinkelmann and Manuela Seitz. The recent

developments and numerical optimizations of our VLBI analysis software were almost completely

carried out by Michael Gerstl. Our activities are managed by Hermann Drewes, who retired at the

end of 2010. We regret to lose Hermann’s expertise; but, nevertheless, we wish Hermann a joyful

retirement.

3. Current Status and Activities

• IVS Operational Analysis Center at DGFI

1http://www.badw.de/aktuell/pressemitteilungen/archiv/2010/PM 28 2010/index.html

2http://www.dgfi.badw.de/index.php?id=126&L=2

IVS 2010 Annual Report 189
DGFI Analysis Center DGFI, Deutsches Geod ̈atisches Forschungsinstitut

DGFI routinely processes the standard IVS sessions (currently the two IVS rapid turnaround

networks IVS-R1 and IVS-R4) and additional sessions of the geodetic and astrometric program run by IVS and delivers datum free normal equations in SINEX format. The duty

to process and submit sessions within 24 hours after the availability of the database (DB)

version 4 (or higher) demands the full automation of the analysis. A small but important

step towards decreasing the product latency could be achieved with the help of the Institute

of Applied Astronomy (IAA), St. Petersburg, that provided a routine enabling the output

of correlator information from DB in ASCII format. In this context, we want to thank Igor

Surkis and colleagues from IAA for the preparation of FORTRAN routines.

• Automation of the VLBI analysis

The main task during 2010 was the automation of VLBI analysis at the ‘post-post-processing’

level, i.e., starting with DB version 4 (or higher). IVS folders containing DB files are routinely

checked for new files. In case of a new file, the highest DB version available is downloaded

onto a local Linux PC and transformed to NGS format. Applying the routines provided by

IAA an ASCII text file is then created in addition to the transformation from DB to NGS

format. The ASCII text file contains the correlator comments including those on real clock

breaks. The clock breaks mentioned by the correlator are then automatically detected and

removed by an algorithm developed at DGFI. After a first least-squares adjustment, clock

breaks and offsets are considered, and a second robust adjustment is performed, eliminating

possible outliers. The outlier-free group delays corrected for clock breaks and for offsets are

then transformed into normal equations and written to SINEX format via the DOGS-CS

software.

• Re-arrangement of the VLBI software used and developed at DGFI

The VLBI software used at DGFI got completely rearranged and is now part of the DGFI

Orbit and Geodetic Parameter Estimation Software DOGS (Gerstl et al., 2000; Heinkelmann

and Gerstl, 2010).

– The new code enables running on 32bit and 64bit operating systems.

– The explicit declaration of all variables increases the reliability.

– ‘8byte real’ instead of ‘DOUBLE PRECISION’ types of variables allow machine independence.

– ‘COMMON’ blocks are replaced by modules, increasing the reliability.

– Arrays are allocated dynamically, saving memory space.

– Avoidance of ‘EQUIVALENCE’ statements allows optimization.

– Binary files were shortened or completely removed.

The program body is modular, and thus modules which are in common in VLBI and SLR

analyses are now identical for both techniques. The software migration thus increases the

consistency between the VLBI and SLR solutions provided by DGFI and reduces the time

and effort for maintenance. The program language is FORTRAN2003, compatible with

FORTRAN95.

190 IVS 2010 Annual Report
DGFI, Deutsches Geod ̈atisches Forschungsinstitut DGFI Analysis Center

4. Future Plans

At DGFI IVS AC we want to continue and deepen our investigations concerning the atmosphere,

i.e., the neutral atmosphere and the ionosphere. Besides, the inclusion of the DOGS VLBI software

into routine processes will be one of our main goals in 2011. For the operational VLBI analysis

we want to further automate the analysis procedure and to extend our product portfolio. The

Linux PC, which currently runs the automated procedures, is located at the Institute of Geodesy

and Geophysics, TU Vienna, Austria so far. In 2011 we want to migrate those processes to a PC

maintained at our institute.

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] Heinkelmann R. and M. Gerstl: OCCAM - LSM for LINUX: new developments at DGFI (poster). 6th

International VLBI Service for Geodesy and Astrometry General Meeting, 7-13 February 2010, Hobart,

Australia, 2010.

IVS 2010 Annual Report 191
FFI Analysis Center Forsvarets forskningsinstitutt (FFI) (Norwegian Defence Research Establishment)

FFI Analysis Center

Per Helge Andersen

Abstract

FFI’s contribution to the IVS as an Analysis Center focuses primarily on a combined analysis at the

observation level of data from VLBI, GPS (ground-based and LEO), SLR, altimetry and gradiometry

using the GEOSAT software. This report briefly summarizes the current status of analyses performed

with the GEOSAT software. FFI is currently an Analysis Center for IVS and ILRS and a Technology

Development Center for IVS.

1. Introduction

A number of co-located 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

site. 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 antennas is estimated using constraints

in accordance with a priori information given by 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 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.

2. The GEOSAT Software and Analysis Activities in 2010

The analysis activities in 2010 have been concentrated on testing and validating the newly

implemented modules for accelerometry and altimetry. The GEOSAT orbit model has been validated against external LEO orbit. The RMS difference between JPL GRACE orbits and internal

GEOSAT orbits is typically 4 mm in each cartesian direction. The corresponding RMS difference between external GOCE orbits (ESA official, approximately 250 km altitude) and internal

GEOSAT orbits is typically 11 mm.

The Norwegian Mapping Authority (NMA) and FFI have started a close cooperation in analysis

of space geodetic data using the GEOSAT software. NMA has recently been given the status of

an Associate Analysis Center of IVS. The GEOSAT software is to be used in the analysis of VLBI

data. We are right now trying to get our GEOSAT-generated SINEX files accepted by the IVS

combination software. There are options in GEOSAT so that the VLBI model is in compliance

with the other analysis software packages.

192 IVS 2010 Annual Report
Forsvarets forskningsinstitutt (FFI) (Norwegian Defence Research Establishment) FFI Analysis Center

3. Staff

Dr. Per Helge Andersen - Research Professor of Forsvarets forskningsinstitutt (FFI).

IVS 2010 Annual Report 193
BKG/IGGB Analysis Center Bundesamt f ̈ur Kartographie und Geod ̈asie

The BKG/IGGB VLBI Analysis Center

Volkmar Thorandt, Axel Nothnagel, Gerald Engelhardt, Dieter Ullrich, Thomas Artz,

S. Tesmer n ́ee B ̈ockmann, Judith Pietzner

Abstract

In 2010, 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. 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 1-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. The software is

now able to use the IAU2006 Nutation/Precession model. 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 pre- and 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 the MPIfR/BKG Mark 5 Astro/Geo Correlator at Bonn (e.g., EURO, OHIG, and T2)

and submitted them to the IVS Data Centers.

194 IVS 2010 Annual Report
Bundesamt f ̈ur Kartographie und Geod ̈asie BKG/IGGB Analysis Center

• Scheduling

BKG continued scheduling the INT2 Intensive sessions, which are observed on the baselines

TSUKUBA-WETTZELL, KASHIMA-WETTZELL, KASHIMA-WESTFORD, and TSUKUBAWESTFORD. Altogether 92 schedule files were created in 2010.

• BKG EOP time series

The old BKG EOP time series bkg00012 was replaced by the new bkg00013. One main

difference to the former solution is the new a priori set of coordinates of the second realization

of the International Celestial Reference Frame (ICRF2) [2]. Further the estimation of the

nutation parameters in this series is based on partial derivatives of X,Y-nutation components

with respect to IAU2000A/2006 precession and nutation models. Because of a big earthquake

in the region of the VLBI station TIGOCONC in Chile with station displacements of about 3

meters, the modeling of this station was changed from globally estimated station coordinates

to locally estimated coordinates in all post-quake sessions.

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 4097 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 nonet-rotation and no-net-translation conditions for 26 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), PT REYES (USA),

SEST (Chile), SINTOTU3 (Japan), TIGOCONC (Chile), WIDE85 3 (USA), VERAISGK

(Japan), VERAMZSW (Japan), and YEBES40M (Spain) were estimated as local parameters

in each session.

The UT1-UTC Intensive time series bkgint08 was replaced by bkgint09. The series bkgint09

was generated with fixed TRF (VTRF2008a) and fixed ICRF2. The estimated parameter types were only UT1-TAI, station clock, and zenith troposphere. Observations of the

two baselines KOKEE-WETTZELL and TSUKUBA-WETTZELL and also of the networks

KOKEE-SVETLOE-WETTZELL and NYALES20-TSUKUBA-WETTZELL were processed

regularly. The analysis of the e-VLBI experiments each week on Mondays could be finished

almost always on the same day. Delays of maximal one day appeared because of problems in

data transfer. The lack of observations due to maintenance and repair work at WETTZELL

could be compensated by observations with WESTFORD and Ny- ̊Alesund. A total of 3476

UT1 Intensive sessions were analyzed for the period from 1999.01.01 to 2010.12.31.

• Quarterly updated solutions for submission to IVS

In 2010, one quarterly updated solution was computed for the IVS products TRF and CRF.

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

IVS 2010 Annual Report 195
BKG/IGGB Analysis Center Bundesamt f ̈ur Kartographie und Geod ̈asie

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 with

the new models mentioned above were computed for the station coordinates, radio source

coordinates, and EOP parameters including the X,Y-nutation parameters. The a priori

datum for TRF is defined by the VTRF2008a, and ICRF2 is 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 combination with other space geodetic techniques.

3. Research Topics at IGGB

• Correlations within the IVS combination process

As the contributions of each Analysis Center (AC) to the official IVS combined products

are derived from virtually the same set of original observations, correlations between the

contributions are expected. So far, this topic has been completely neglected in any intratechnique combination approach. In a study [3], the observation equations of two ACs (BKG

and IGGB) have been used directly for the combination (in contrast to using normal equation

systems, NEQs). With this approach, the level of correlations has been determined, and the

influence of neglecting the correlations on the estimated combined parameters as well as their

formal errors have been investigated. Based on CONT02 observations, it turned out that a

realistic level of correlations between the two contributions lies between 0.5 and 0.7, which

is much less than expected.

• Determination of sub-daily tidal ERP models

The IERS model for tidal Earth Rotation Parameter (ERP) variations with periods around

one day and below as given in the IERS Conventions [4] does not describe all effects that

are measured by VLBI. An empirical model has been estimated from VLBI observations

applying a new approach based on the transformation of NEQs [5]. Furthermore, the general

reliability and stability of VLBI-derived sub-daily ERP has been investigated [6].

Furthermore, the approach of estimating a sub-daily tidal ERP model applying the transformation of NEQs has been used to determine a combined model based on homogeneously

reprocessed GPS and VLBI NEQs. This combination also allows to determine long term time

series of hourly spaced ERPs. It turned out that the combined time series can be estimated

almost without any constraints as geometric instabilities of the techniques are cross-wise

compensated and the stochastic noise is reduced which is the very purpose of combinations.

• Gravitational deformation of the Effelsberg radio telescope

Radio telescopes are subject to varying gravitational effects when tilted in different ele196 IVS 2010 Annual Report
Bundesamt f ̈ur Kartographie und Geod ̈asie BKG/IGGB Analysis Center

vation angles for observations of extra-terrestrial objects. The Effelsberg radio telescope’s

paraboloid was subject to a novel type of survey being carried out with a total station. It was

mounted head-down close to the sub-reflector of the telescope to determine the paraboloid

deformations through coordination of discrete points on the surface. The main reflector of

the telescope is subject to displacements of individual points of up to 54 mm, while the focal

length changes by about 13 mm when the telescope is tilted from 90◦to 7◦ pointing elevation.

4. Personnel

Table 1. Personnel at BKG/IGGB Analysis Center

Thomas Artz IGGB +49-228-733563 thomas.artz@uni-bonn.de

Gerald Engelhardt BKG +49-341-5634438 gerald.engelhardt@bkg.bund.de

Axel Nothnagel IGGB +49-228-733574 nothnagel@uni-bonn.de

Judith Pietzner IGGB +49-228-733565 judith.pietzner@igg.uni-bonn.de

Sarah Tesmer IGGB +49-228-733563 boeckmann@uni-bonn.de (until Dec. 15, 2010)

n ́ee B ̈ockmann

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] Ma, C. et al. (2009) IERS Technical Note No. 35: The Second Realization of the International Celestial

Reference Frame by Very Long Baseline Interferometry; Presented on behalf of the IERS/IVS Working

Group, edited by Alan L. Fey, David Gordon, Christopher S. Jacobs.

[3] B ̈ockmann, S., T. Artz and A. Nothnagel (2010) Correlations between the contributions of individual

IVS analysis centers, In: Behrend, D. and K. D. Baver (Eds.), IVS 2010 General Meeting Proceedings,

NASA/CP-2010-215864, 222-226, 2010.

[4] McCarthy, D. and G. Petit (2004) IERS Conventions (2003), IERS Technical Note 32, Verlag

des Bundesamtes f ̈ur Kartographie und Geod ̈asie, Frankfurt am Main, (available electronically at

http://www.iers.org/IERS/EN/Publications/TechnicalNotes/tn32.html).

[5] Artz, T., S. B ̈ockmann and A. Nothnagel (2011) Assessment of Periodic Sub-diurnal Earth Orientation

Parameter Variations at Tidal Frequencies via Transformation of VLBI Normal Equation Systems,

submitted to J Geod.

[6] Artz, T., L. Bernhard, A. Nothnagel, P. Steigenberger and S. Tesmer (2011) A Rigorously Combined

Sub-daily Earth Rotation Model from GPS and VLBI Observations, submitted to J Geophys Res.

[7] Artz, T., S. B ̈ockmann, L. Jensen, A. Nothnagel and P. Steigenberger (2010) Reliability and Stability

of VLBI-derived Sub-Daily EOP Models, In: Behrend, D. and K. D. Baver (Eds.), IVS 2010 General

Meeting Proceedings, NASA/CP-2010-215864, 355-359, 2010.

IVS 2010 Annual Report 197
GSFC Analysis Center NASA Goddard Space Flight Center

GSFC VLBI Analysis Center

David Gordon, Chopo Ma, Dan MacMillan, John Gipson, Karen Baver, Sergei Bolotin,

Karine Le Bail

Abstract

This report presents the activities of the GSFC VLBI Analysis Center during 2010. The GSFC

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.

2. Activities

2.1. Analysis Activities

The GSFC Analysis Center analyzes all IVS sessions, using the Calc/Solve system, and performs the AIPS 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, INT01, and INT03

sessions. During 2010, GSFC analyzed 149 24-hour (53 R1, 53 R4, 5 RDV, 6 R&D, 5 EURO, 7 T2,

1 APSG, 8 OHIG, 4 CRF, and 7 JADE) sessions, five 3-hour (TQuak) sessions, and 366 1-hour

UT1 (229 INT01, 92 INT02, and 45 INT03) sessions, and we submitted updated EOP and daily

Sinex files to IVS immediately following analysis. As part of the RDV program, we also observed

51 requested sources for the astronomy community and determined precise positions for most.

2.2. Research Activities

• R&D Intensives: We continued studying an alternative scheduling strategy for the INT01

Intensives, begun in 2009, by running 5 additional R&D Intensive sessions. In these sessions,

Kokee and Wettzell observed a series of 1-hour pseudo-Intensives that alternated between

the current strategy (using a small list of strong sources) and an alternative strategy (using

all mutually visible geodetic sources). As a result of preliminary analysis, the USNO began

using the alternative strategy on alternating days beginnning in July 2010.

• IYA2009 Session: For the celebration of the International Year of Astronomy in 2009, GSFC

scheduled the largest astrometric VLBI session ever attempted. This involved 34 globally

distributed stations and used 243 of the 295 ICRF2 defining sources. Correlation was done

at Haystack in 2010. Thirty-two stations performed adequately and were made into X and

S databases. We analyzed these using a test version of Solve which was updated to handle

32 stations, and the analyzed databases were submitted to IVS.

198 IVS 2010 Annual Report
NASA Goddard Space Flight Center GSFC Analysis Center

• ITRF2008: GSFC participated in studying and evaluating the two versions of ITRF2008,

provided by IGN (France) and DGFI (Germany). The IGN TRF shows a scale difference of

-0.39 ppb compared to a GSFC Calc/Solve solution. This is due to a scale difference of -1.05

between SLR and VLBI solutions. Removing rotation and translation differences, the WRMS

position and velocity differences between the IGN or DGFI solutions and a GSFC solution

were 2-3 mm and 0.3-0.4 mm/yr for the 40 most frequently used stations. When the TRF

was fixed to the IGN or DGFI TRF’s, the resulting X-pole and Y-pole estimates were not

significantly different from a standard Calc/Solve solution in which positions and velocities

were estimated. We also studied the Allan variances of the EOPs differenced from IGS EOPs.

The two ITRF2008 solutions and the GSFC solution show the same level and type of noise,

with no significant differences. Our results were reported at the IAG Symposium “Reference

Frames for Applications in Geosciences”.

• High Frequency EOP: We generated a new empirical high frequency EOP tidal model. Comparisons with other empirical models derived from VLBI and GPS data show good agreement. We also compared the new model and other HF-EOP empirical models against models

derived using satellite altimetry data and found small but significant differences.

• Comparisons of Wet Zenith Delays: We compared tropospheric parameters derived from

three independent radio techniques (VLBI, GPS and WVR) for the CONT05 campaign.

These comparisons showed very good agreement, with path length WRMS residual differences

at the level of 5-10 mm.

• VLBA HW/SW Correlator Comparison: A detailed comparison was made of the RDV77 session, as correlated on both the VLBA hardware correlator and the new VLBA-DiFX software

correlator. Group delay differences agreed at an average WRMS of 4.2 psec, with a noise

floor of ∼2.5 psec on the shortest baselines. These results compare well to other correlator

comparisons and essentially validate the VLBA-DiFX correlator for geodetic processing.

• Chilean Earthquake: We studied the motion of the VLBI station TIGOCONC in Concepci ́on,

Chile, near the epicenter of the 8.8 magnitude earthquake of February 27, 2010. We found

coseismic offsets of -45, -3040, and -678 mm in the Up, East, and North directions. Also,

post-seismic transient motion was seen in the East component during the months following,

but after 10 months, the East rate has nearly returned to its previous value. We presented

our results at the Fall AGU Meeting.

• VLBI2010 Simulations: We investigated the geodetic performance of the future VLBI2010

network, focusing on expected accuracy and possible systematic effects. We performed simulations of several different error contributions: 1) troposphere mapping function error, 2)

antenna gravitational deformation, 3) site pressure error, and 4) latitude-dependent tropospheric turbulence. Biases at the 1-2 mm level in site positions can result from the first three

error sources. Vertical uncertainty due to tropospheric turbulence has latitude dependence,

but no significant bias. These results were reported at the Fall AGU Meeting.

• ICRF2 Effects: A study was made of the effects of the switchover to ICRF2. Only small

differences are seen in the TRF, CRF, and EOPs from VLBI solutions. The most obvious

effect is an ∼40 μasec rotation of the CRF, mostly about the Y-axis. This is primarily

a result of the small overlap of the ICRF and ICRF2 defining sources and the subsequent

IVS 2010 Annual Report 199
GSFC Analysis Center NASA Goddard Space Flight Center

difficulty of aligning them. We compared EOPs from an ICRF and an ICRF2 solution to

IGS EOPs, using Allan variances, and found no significant differences.

• Source Monitoring: We continued our successful source monitoring program using the R1

and RDV sessions. In May we switched over from monitoring the ICRF defining sources to

the ICRF2 defining sources. In July USNO joined this program with the R4 sessions.

• Astronomical Source Catalog: An astronomical source catalog in the ICRF2 frame was

compiled. This catalog contains positions of 3658 total sources, of which 3468 are X/S global

sources, 39 are X/S arc sources, 125 are X/GPS-ionosphere sources, and 26 are X-only

sources. It is available at http://lupus.gsfc.nasa.gov/dataresults main.htm.

• Source Position Time Series Studies: We continued our analysis of source position time series.

We analyzed and compared the VLBI data from the last 20 years (1989.5–2009.5) and from

the last 10 years (1999.5–2009.5). Data over the last 10 years shows greater stability, pointing

to network improvements. The selection of a set of stable sources is not unique: compared

with an OPA solution, the overlap is at 85% of the sources. The analysis of various sources

showed that the time series noise is not a stationary process. We compared time series of ten

different analysis centers using five different software packages, for data through mid-2008.

We found that the correlation in source stabilities depends somewhat on the analysis strategy

and the software package used.

• Regularization of VLBI Time Series: VLBI sessions are typically not spaced at regular intervals, making analysis difficult with basic statistical tools. We developed a tool to construct

a regular data span using Singular Spectrum Analysis (SSA). For source time series, prediction using this tool has been studied and has shown efficiency in the short-term (one to

two years). The SSA method has permitted us to decompose the UT1-TAI time series into

tendencies, periodic signals, and white noise.

• Geodetic Catalog: We analyzed the sources in the geodetic catalog, and some show different

behavior over the last ten years than over the entire VLBI period. A signal can be detected

easily for such sources as an apparent proper motion (local drift, jump, and/or periodic

signal). The sources identified have since been removed from the geodetic catalog.

• Meteorological Data: We have looked for discrepancies in the meteorological data in CONT08

and all 2008 R1 and R4 sessions. Station pressures in the databases can differ by up to 10

hPa from ECMWF data, which can produce vertical differences of up to 1 mm. Also, some

stations have no met data, requiring Calc/Solve to use constant default values. Replacing

these constant values with ECMWF values resulted in better performance. However, a

consequence of the use of ECMWF values is loss of the diurnal variations of the met signals

(due to the 6-hr smoothing), which can increase the RMS of fit.

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. A new version of Calc/Solve

was released in May 2010. Among other changes, it uses X/Y nutation partials and allows the use

of the 2006 IAU nutation model as an  ́a priori. We also continued work on a new software system.

A replacement for the interactive part of Calc/Solve, νSolve, is being developed using C++. We

expect first public release of this software in 2011.

200 IVS 2010 Annual Report
NASA Goddard Space Flight Center GSFC Analysis Center

3. Staff

The Analysis Center staff consists of one GSFC civil servant, Dr. Chopo Ma, and six NVI, Inc.

employees who work under contract to GSFC. Dr. Ma oversees the GSFC VLBI project for GSFC

and is also the IVS 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 seven 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.

Dr. Sergei Bolotin Database analysis, next generation software 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 updates.

Dr. Karine Le Bail Time series statistical analysis (EOPs, 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, apparent

proper motion, VLBI2010 simulations, VLBI+SLR combination.

4. Future Plans

Plans for the next year include: ICRF2 maintenance, astronomical catalog expansion, participation in VLBI2010 development, continued development of the new VLBI data structure and the

new analysis software, K/Q observations and high frequency reference frame development, further

analysis of the meteorological data and replacement of missing and bad data, continued study

of various VLBI time series (such as LOD) with the SSA and other statistical tools, and further

research aimed at improving the VLBI technique.

References

[1] “The Celestial Reference Frame at 24 and 43 GHz. I. Astrometry”, G. Lanyi, D. Boboltz, P. Charlot,

A. Fey, E. Fomalont, B. Geldzahler, D. Gordon, C. Jacobs, C. Ma, C. Naudet, J. Romney, O. Sovers,

and L. Zhang; Astronomical Journal, 2010, 139, pp. 1695-1712, doi 10.1088/0004-6256/139/5/1695.

[2] “The Celestial Reference Frame at 24 and 43 GHz. II. Imaging”, P. Charlot, D. Boboltz, A. Fey, E.

Fomalont, B. Geldzahler, D. Gordon, C. Jacobs, G. Lanyi, C. Ma, C. Naudet, J. Romney, O. Sovers,

and L. Zhang; Astronomical Journal, 2010, 139, pp. 1713-1770, doi 10.1088/0004-6256/139/5/1713.

[3] Monte Carlo Simulations of the Impact of Troposphere, Clock and Measurement Errors on the Repeatability of VLBI Positions, A. Pany, J. Bohm, D. MacMillan, H. Schuh, T. Nilsson, and J. Wresnik,

J. Geod., 2010, 85, pp. 39-50, doi 10.1007/s00190-010-0415-1.

IVS 2010 Annual Report 201
Haystack Analysis Center MIT Haystack Observatory

Haystack Observatory Analysis Center

Arthur Niell

Abstract

Analysis activities at Haystack Observatory are directed at improving the accuracy of geodetic measurements, whether from VLBI, GNSS, SLR, or any other technique. In this article the analysis done

in 2010 that contributes to technique improvement as a result of improved geophysical measurements,

modeling, and analysis is reported. The focus was on reduction of the error produced by inaccurate

correction of atmosphere effects. Analysis activities that were related to technology development are

reported elsewhere in this volume.

1. Introduction

The research at Haystack Observatory that directly affects geophysical and geodetic results

has historically been related to atmosphere effects, and that was the case in 2010. The thrust of

that activity during the past year was to define a framework for meteorological data systems that

will enable access to more accurate meteorological data for the individual geodetic techniques and

will, at the same time, facilitate common meteorological calibration of the techniques.

While this framework, as currently conceived, is not dependent on significant new technology

development, it will rely on implementation of the Monitor and Control Infrastructure that is an

integral part of the VLBI2010 system.

2. The Role of the Meteorological Data System

The Earth’s atmosphere affects geodetic results both through integrated effects, such as the

additional delay due to water vapor, and by in situ effects, such as the response to temperature

changes of the VLBI, SLR, or GNSS supporting structure. In addition to the importance of using

the most accurate meteorological data for determining these effects for each geodetic technique,

the accuracy of the overall geodetic system, as constituted in the GGOS project, will be enhanced

by the use of consistent meteorological data. In the simplest case, for example for closely located

systems, the same well-calibrated pressure sensor would be used for all of VLBI, SLR, and GNSS.

In other cases, where different sensors must be used, for example when the temperature needed is

inside a radome for one technique but outside for another co-located system, the relative calibration

should be readily verifiable by easy access to both sets of measurements. Yet another requirement is

for the measurements to be taken continuously in order to be available for performance monitoring

and for calibrating effects that might have significant latency, such as structural deformation which

may have a time lag of hours.

At the center of this framework is adoption of the concept that the meteorological data are observables with the same value as the delay observations themselves and with the same requirements

for understanding the uncertainties and calibration.

In order to facilitate these objectives, the data from each meteorological (“met”) sensor must

be available remotely along with the position of the sensor in global coordinates. The data should

include time, value, and sufficient information to assign an uncertainty that can be related to the

uncertainties of the geodetic observables.

202 IVS 2010 Annual Report
MIT Haystack Observatory Haystack Analysis Center

3. Model for the Met Sensor Data System

Because there may be several sensors of each meteorological quantity at a site, the data from

each sensor should be accessible individually. One way to do this is to have the information for each

sensor stored in a file with a descriptive name. One possibility is ‘station sensortype index.txt’.

The index would allow for multiple sensors at a site. An example would be westford pressure 1.txt.

An example of the need for multiple sensors of the same type is the situation at VLBI sites

with a radome. One (or more) temperatures inside the radome or embedded in the antenna

support structure is needed for thermal deformation, while an outside temperature is needed for

deformation of a co-located GPS structure. In the analysis process the appropriate sensor for

each technique would be selected (and could be easily changed if necessary) by specifying it in a

wrapper.

The data in the file might be:

First line:

% Name yr mm dd hh mm value sig cal corrn uncert X Y Z

Then for each measurement:

w p1 2009 12 11 23 05 1004.5 0.2 9.9 0.5 6378000 4577000 1200000

By providing the location of the sensor in geocentric coordinates each technique can make the

correction to its antenna/telescope location since that is also well known in geocentric coordinates.

Although this particular format would be highly redundant and inefficient in having quantities

such as position and calibration repeated for each measurement, it serves to visualize the minimum

information needed.

The data files should be stored both locally (at least for some period of time) and on a globally

accessible server, such as cddis. Local access during and between observing sessions is necessary for

station health and safety, such as remote monitoring of wind speed or temperature for unattended

operation, while global longterm availability is needed for the data analysis.

4. Implementation

As an example of the value of complementary data sources, a comparison was made in 2005 of

the meterological data at Westford obtained using the GSOS sensors, the Suominet met data, and

a third set of instruments, called yoda, which were located 1.2 km away at the Haystack antenna.

The GSOS instruments were the primary met sensors for the Westford site at the time. After

adjusting the Suominet and yoda data to the height of the GSOS pressure sensor, it was clear that

the GSOS data time tags were off by -1.5 hours. After correction the GSOS and Suominet data

agreed to 0.1 hPa in mean with an RMS difference of 0.2 hPa. The results are shown in Figure 1.

Currently two sets of met sensors are operating at Westford: the Suominet sensors are still

recording data from the site less than 1 km from the Westford antenna, and recently a new set

of met sensors was installed near the Westford GPS and VLBI antennas. The Suominet data

from the site designated SA01 are available almost continuously from 2001doy200 to the present.

The Met3 data sequence began only last year but is continuous. The metadata for each site are

not complete in the current data records since calibration and sensor position information are not

included, but such information can be added after-the-fact.

As is true for many sites, Westford has a poor record of maintaining met sensors. Fortunately

the availability of the Suominet data may help overcome that shortcoming at Westford. The use of

IVS 2010 Annual Report 203
Haystack Analysis Center MIT Haystack Observatory

alternative sources of met data is being implemented by the Goddard analysis group using only a

simple height difference correction for the pressure. Hopefully the new way of storing and applying

met data proposed here will become more widespread.

5. Outlook

Westford and the new VLBI2010 site at the Goddard Space Flight Center should serve as

testbeds for the meteorological data system. In the next year the goal is to fill out the data fields

for calibration and location and to develop, in cooperation with the analysts of all techniques, a

better format.

Figure 1. Data from three pressure sensors near the Westford antenna: a) before correction for height

difference and for a time offset of 1.5 hours in the GSOS data and b) after correction.

204 IVS 2010 Annual Report
Institute of Applied Astronomy of Russian Academy of Sciences (IAA) IAA Analysis Center

IAA VLBI Analysis Center Report 2010

Elena Skurikhina, Sergey Kurdubov, Vadim Gubanov

Abstract

This report presents an overview of IAA VLBI Analysis Center activities during 2010 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. IAA AC contributes to IVS products,

such as daily SINEX files, TRF, CRF, rapid and long-term series of EOP, baseline length, 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 (2003). 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, scientific researcher: development of the QUASAR software, global solution, and DSNX files 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 being developed to provide contributions to IVS products. The

software is capable of calculating all types of IVS products. A scale problem was fixed in the

QUASAR software in 2009.

• Routine analysis

IVS 2010 Annual Report 205
IAA Analysis Center Institute of Applied Astronomy of Russian Academy of Sciences (IAA)

During 2010 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.

The routine data processing was performed with the OCCAM/GROSS software using a

Kalman Filter. 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, 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

The regular determinations of Earth’s orientation parameters with the QUASAR VLBI Network Svetloe-Zelenchukskaya-Badary and single baseline 1-hour observations for UT1 with

e-VLBI transfer were performed weekly. Correlation is performed at the IAA correlator. For

2010 the mean RMS EOP deviations from the IERS 05C04 series in the Ru-E program were

1.1 mas for Pole position, 35 s for UT1-UTC, and 0.37 mas for Celestial Pole position for 20

sessions. The RMS deviation of the Universal Time values from the IERS C04 series for 49

sessions of the Ru-U program was 59 μs. Station positions were specified in the ITRF2008

reference frames for both domestic and IVS observations.

• Antenna Axis Offset Estimation from VLBI observations

We performed a study of the stability of the axis offset value after repairs [1] and estimated

how its value affects EOP estimations. The antenna axis offsets were estimated from global

solutions and single sessions. We have built a set of global solutions from R1 and R4 sessions

from the sets of sessions before and after the SVETLOE repair. We compared our estimates

with local survey data for the stations of the QUASAR network. The Svetloe station axis

offset values have changed in the repairs. For non-global networks, the axis offset value of a

single station can significantly affect the EOP estimations. The main task of this study is

to check the stablility of the axis offset after repairs. The axis offset estimations from single

sessions are very unstable; therefore we used global solutions over several time intervals. For

the estimation of the SVETLOE axis offset we used the R1 and R4 sessions divided into four

intervals:

– 2003.03.06-2005.05.26: 55 sessions, from start of operation until test rail repair

– 2005.07.21-2006.05.04: 40 sessions, from test rail repair until full rail repair and removing of large equipment cabin

– 2006.08.03-2007.06.21: 55 sessions, from full rail repair until repair of the bearings

– 2007.08.30-2009.06.25: 141 sessions, from bearings repair until now

We performed three on-site measurements of the SVETLOE axis offset: in 2005 and 2006 by

Igor Shahnabiev and in 2009 by “Yustas Ltd”. A comparison between our estimated values

(designated as “VLBI”) and on-site Local Geodetic Surveying measurements (designated as

“On-site”) are presented in Table 1.

206 IVS 2010 Annual Report
Institute of Applied Astronomy of Russian Academy of Sciences (IAA) IAA Analysis Center

Table 1. Values of SVETLOE axis offset from VLBI and on-site measurements (in mm).

2003.03.06-

2005.05.26

2005.07.21-

2006.05.04

2006.08.03-

2007.06.21

2007.08.30-

2009.06.25

VLBI −15.5 ± 3.2 −15.9 ± 3.6 −10.0 ± 2.8 +1 ± 2

On-site −12.5±?? −7.5 ± 0.5 −3.0 ± 1.5

In order to determine how the difference in axis offset can affect our EOP estimations from

local network observations, we have processed 41 sessions of our domestic Ru-E [1] program.

These are 24-hour sessions with the network “Quasar” [1] consisting of three observatories

Svetloe, Zelenchukskaya, and Badary and scheduled for the EOP estimation. The biases and

RMS (after removing bias) between obtained EOP and IERS 05C04 series are presented in

Tables 2 and 3. For the results presented in Table 2 a single axis offset value for SVETLOE

was used for all sessions. For the results in Table 3 the estimated and measured values were

taken in their corresponding time intervals.

Table 2. Biases and RMS w.r.t. IERS EOP 05 C04 in EOP estimates with a single SVETLOE offset value.

offset value -75mm -3mm -125mm

EOP bias rms bias rms bias rms

Xp, mas −0.114 ± 0.165 0.952 -0.109 ± 0.166 0.959 -0.101 ± 0.157 0.908

Yp, mas 0.588 ± 0.212 1.225 0.790 ± 0.211 1.221 0.342 ± 0.210 1.216

UT, ms 0.009 ± 0.008 0.046 0.005 ± 0.008 0.046 0.012 ± 0.008 0.046

Xc, mas −0.608 ± 0.120 0.695 -0.596 ± 0.118 0.684 -0.619 ± 0.118 0.679

Yc, mas −0.093 ± 0.114 0.660 -0.094 ± 0.113 0.652 -0.104 ± 0.109 0.631

One can see from the comparison of the bias values of Table 2 that a difference of 1 cm in

the axis offset can result in a difference of up to 0.5 mas in the Y-pole coordinate for our

network configuration. The differences in axis offset did not have much impact on the RMS,

but it can introduce systematic biases in the EOP.

Table 3. Biases and RMS w.r.t. IERS EOP 05 C04 in EOP estimates using estimated (SVETLOE offsets

= -16 mm, -10 mm, 1 mm) and measured (SVETLOE offsets = -12.5 mm, -7.5 mm, -3 mm) values for the

corresponding intervals.

offset value estimated measured

EOP bias rms bias rms

Xp, mas -0.111±0.161 0.956 -0.090 ± 0.161 0.932

Yp, mas 0.690 ±0.210 1.213 0.590 ± 0.210 1.210

UT, ms 0.006±0.008 0.046 0.008 ± 0.008 0.046

Xc, mas -0.615±0.116 0.667 -0.602 ± 0.120 0.693

Yc, mas -0.087±0.111 0.641 -0.110 ± 0.115 0.644

IVS 2010 Annual Report 207
IAA Analysis Center Institute of Applied Astronomy of Russian Academy of Sciences (IAA)

The value of the antenna axis offset can significantly affect the parameters estimated from

VLBI data. Offsets can change through repair work at the stations. In order to improve the

accuracy of VLBI results it is necessary to estimate the axis offset after the repair at the

the stations by on-site measurement or from reprocessing of observations. The differences

between estimated and measured values need to be investigated.

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 improvement of algorithms and software for processing VLBI observations.

References

[1] A. Finkelstein, E. Skurikhina, I. Surkis, A. Ipatov, I. Rahimov, S. Smolentsev, “QUASAR National

Programs of EOP Determinations”, Measuring the future, Proceedings of the Fifth IVS General Meeting,

ed. A. Finkelstein, D. Behrend, St-Petersburg, “Nauka”, 2008, p. 319–323.

[2] S. Kurdubov et al.: Antenna Axis Offset Estimation from VLBI, IVS 2010 General Meeting Proceedings

“VLBI2010: From Vision to Reality”, Edited by Dirk Behrend and Karen D. Baver NASA/CP-2010-

215864 December 2010, p. 247–250.

208 IVS 2010 Annual Report
Institute of Geodesy and Geophysics/University of Technology, Vienna IGG Analysis Center

Vienna IGG Special Analysis Center Annual Report 2010

Harald Schuh, Johannes B ̈ohm, Sigrid B ̈ohm, Vahab Nafisi, Tobias Nilsson, Andrea Pany,

Lucia Plank, Hana Spicakova, Jing Sun, Kamil Teke, Claudia Tierno Ros

Abstract

The main activities of the VLBI group at the Institute of Geodesy and Geophysics (IGG) of the

Vienna University of Technology in 2010 were related to the development of the Vienna VLBI Software

VieVS (http://vievs.hg.tuwien.ac.at/). In particular, tools for the simulation of VLBI observations

and for VLBI global solutions were added to the latest release, and investigations on scheduling and

spacecraft tracking have been started. Furthermore, studies on VLBI2010 simulations, Earth rotation,

and geodynamical parameters from VLBI have been continued. One highlight was the first VieVS User

Workshop held at our institute in September 2010.

1. General Information

The Institute of Geodesy and Geophysics (IGG) is part of the Faculty of Mathematics and

Geoinformation of the Vienna University of Technology. It is divided into three 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. Members of the VLBI group and participants at the first VieVS User Workshop from 7-9 September

2010. Dudy Wijaya, Minttu Uunila, Nataliya Zubko, Emine Tanir, Tobias Nilsson, Jing Sun, Kamil Teke,

Lucia Plank, Veikko Saaranen, Sigrid B ̈ohm, Hana Spicakova, Andrea Pany, Johannes B ̈ohm, Harald Schuh,

Vincenza Tornatore, Matthias Madzak, Joel Botai, Vahab Nafisi.

IVS 2010 Annual Report 209
IGG Analysis Center Institute of Geodesy and Geophysics/University of Technology, Vienna

2. Staff

Personnel at IGG associated with the IVS Special Analysis Center in Vienna are Harald Schuh

(Head of IGG, Chair of the IVS Directing Board), and nine scientific staff members. Their main

research fields are summarized in Table 1.

Table 1. Staff members ordered by the main focus of research.

Johannes B ̈ohm VLBI2010, Vienna VLBI Software (VieVS)

Andrea Pany VLBI2010, troposphere, turbulence theory

Jing Sun (from 04/2010) VLBI2010, scheduling

Sigrid B ̈ohm Earth orientation, tidal influences

Tobias Nilsson VieVS, turbulence, Earth orientation

Lucia Plank VieVS, spacecraft tracking

Hana Spicakova VieVS, global solution

Kamil Teke VieVS, least squares adjustment

Vahab Nafisi troposphere, ray-tracing

Claudia Tierno Ros (from 10/2010) ionosphere

3. Current Status and Activities

• Vienna VLBI Software VieVS

Most of the activities were related to the development of the Vienna VLBI Software VieVS

(http://vievs.hg.tuwien.ac.at/). In particular, tools for the simulation of VLBI observations

and for VLBI global solutions were added to the latest release (Version 1c), and investigations

on scheduling and spacecraft tracking have been started. Furthermore, studies on VLBI2010

simulations, Earth rotation, and geodynamical parameters from VLBI have been continued.

One highlight was the first VieVS User Workshop held at our institute in September 2010.

• Universal Time from IVS Intensive Sessions

We investigated the impact of tropospheric gradients on Universal Time (UT1) estimated

from Intensive sessions. Due to the small number of observations, gradients are normally

not estimated in the analysis of Intensive sessions. Thus the presence of gradients may lead

to errors in the estimated UT1. We did these investigations using both the actual Intensive

sessions (B ̈ohm et al., 2011, [1]) as well as simulated Intensives created by extracting singlebaseline observations from the CONT08 data set (Nilsson et al., 2011, [2]). The results show

that gradients can be a significant error source for the Intensive sessions, especially for the

INT2 and INT3 sessions. We also showed that the results can be improved if gradients are

estimated in the analysis of the Intensive data.

• Global Solutions with VieVS

The module vie glob is the part of VieVS which enables the estimation of reference frames in

global adjustments. It was tested by using artificial observation files (created with vie sim)

following the schedule of IVS R1 and R4 sessions from the years 2002-2010. For example, we

investigated the impact of a priori horizontal gradients on declination of the sources.

210 IVS 2010 Annual Report
Institute of Geodesy and Geophysics/University of Technology, Vienna IGG Analysis Center

• Earth Orientation Parameters from VieVS

A re-processing of all geodetic VLBI sessions from 1984 to 2010, suitable for EOP determination, was conducted with VieVS. In a first step a database with special processing options

for individual (problematic) sessions was created or completed, respectively. Based on this

information several EOP time series for different purposes were calculated:

– A dUT1 time series with 6-hour resolution was computed in order to investigate zonal

tidal signals with periods from 5 to 35 days and to estimate the so-called zonal response

coefficient κ defined by Agnew and Farrell (1978, [3]).

– A series of daily celestial pole offsets was generated for re-introduction in further Earth

rotation parameter (ERP) computations.

– High resolution (hourly) ERP, i.e. polar motion and dUT1, were derived for the whole

time span. The high frequency variations of the ERP were examined for tidal excitation,

and a set of diurnal and semi-diurnal tidal constituents was estimated and compared to

previous estimates from the Occam software and to the terms of the IERS conventional

model (Petit and Luzum, 2010, [4]). Figure 2 displays the resulting amplitudes from

VLBI (Occam, VieVS) for polar motion with respect to the amplitudes of the IERS

model for ERP variations due to ocean tides. The “zero terms” reflect the noise level

of the time series, as the amplitudes are estimated for periods where no tidal signal is

expected.

−15

−10

−5

0

5

10

15

20

25

P1 

K1 

N2 

K2 

N2 

M2 

S2 

Q1 

O1 

M2 

S2 

K2 

Polar motion: residual amplitudes w.r.t. IERS δPM

[μas]

OCCAM

VieVS

σ VieVS

3σ VieVS

zero

terms

Semi−diurnal

retrograde

Semi−diurnal

prograde

zero

terms

Diurnal prograde

Figure 2. Hourly ERP: Amplitudes from VLBI (Occam, VieVS) for polar motion with respect to the

amplitudes of the IERS model for ERP variations due to ocean tides. The “zero terms” reflect the noise

level of the time series, as the amplitudes are estimated for periods where no tidal signal is expected.

IVS 2010 Annual Report 211
IGG Analysis Center Institute of Geodesy and Geophysics/University of Technology, Vienna

• Space VLBI with VieVS

VieVS was prepared to enable the processing of space VLBI data. Actual work has been

done for two mission scenarios so far: on the one hand differential VLBI (D-VLBI) data from

the two sub-satellites of the Japanese lunar mission Selene were processed, and on the other

hand VLBI observations of GNSS satellites were modelled in VieVS. Main parts of research

in this topic are the treatment of fast moving targets in VieVS, the implementation of a

delay model for radio emitters at finite distances, and the adequate mathematical model and

adjustment of the particular unknowns.

• IVS Comparison Campaign

The IVS Comparison Campaign was started with the goal to compare different VLBI analysis

software packages on the basis of the computed delay and its partial derivatives. First

contributions of theoretical delays by six analysis groups indicate that presently an accuracy

of 1 ps agreement cannot be achieved consistently when applying various correction models

during analysis (Plank et al., 2010, [5]).

4. Future Plans

In 2011 we will continue the development of the Vienna VLBI Software VieVS, with special

focus on spacecraft tracking and scheduling. Additionally, we will contribute to the ongoing activities within VLBI2010, and Earth orientation and reference system studies will be carried out.

Other goals are to become an operational IVS Analysis Center, to organize a second VieVS User

Workshop, to use external ray-traced delays, and to equip VieVS with a Kalman filter solution.

Acknowledgements

We are very grateful to the Austrian Science Fund (FWF) for supporting our work by the

research projects P21049-N14 (‘SCHED2010’) and P23143-N21 (‘Integrated VLBI’). We also acknowledge the Austrian Academy of Sciences for funding project 22353 and the German Research

foundation (DFG) for funding project SPEED2 (SCHU 1103/3-2).

References

[1] B ̈ohm, J., Nilsson, T., Schuh, H., Prospects for UT1 measurements from Intensive sessions, in

D. Behrend and K. D. Baver, editors, Proc. 6th IVS General Meeting, Hobart, Tasmania, Australia,

NASA/CP-2010-215864, pp. 251-255, 2010.

[2] Nilsson, T., B ̈ohm, J., Schuh, H., Universal time from VLBI single-baseline observations during

CONT08, J. Geodesy, doi: 10.1007/s00190-010-0436-9, in press 2011.

[3] Agnew, D.C., Farrell, W.E., Self-consistent equilibrium ocean tides, Geophys. J. R. astr. Soc. (1978)

55, pp. 171-181, 1978.

[4] Petit, G., Luzum, B. (eds.), IERS Conventions (2010), IERS Technical Note 36, Frankfurt am Main:

Verlag des Bundesamts f ̈ur Kartographie und Geod ̈asie, 2010.

[5] Plank, L., B ̈ohm, J., Schuh, H., Comparison Campaign of VLBI Data Analysis Software - First Results,

IVS 2010 General Meeting Proceedings, edited by D. Behrend and K.D. Baver, NASA/CP-2010-215864,

pp. 217-221, 2010.

212 IVS 2010 Annual Report
Istituto di Radioastronomia–Bologna Italy INAF Analysis Center

Italy INAF Analysis Center Report

M. Negusini, P. Sarti, C. Abbondanza

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 briefly

outlines the investigations carried out at Medicina and Noto concerning gravitational deformations of

the VLBI telescopes.

1. Current Status and Activity

Investigations on VLBI local tie surveying and antenna deformations continued in 2010. The

deformation patterns of the structure were determined in previous years, and a complete signal

path variation (SPV) model could be defined for the Medicina telescope [1, 2]. The same procedure

adopted for Medicina was applied successfully to Noto. Particular attention was paid to accurate

computation of the coefficients of the linear combinations that determine the SPVs [3]. The two

models were used to correct the VLBI delay in routine geodetic VLBI data analysis. Results clearly

show that the reference point height depends on elevation-dependent signal path variations, these

latter being induced by gravitational deformations [4]. The height shift of the antenna reference

point in Medicina is 8.9 mm, and it is 6.7 mm at Noto, much larger than the VLBI formal errors on

positions. This bias cannot be determined by relying on VLBI data alone as its effect propagates

directly into the estimated station height and antenna axis offset [4].

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 2010, we stored all the 1999-2010 databases available on the IVS Data

Centers. All the databases were processed and saved with the best selection of parameters for the

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 [5].

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 the form of SINEX files. In 2010 we regularly submitted our results to IVS. We have also

computed and submitted 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.

IVS 2010 Annual Report 213
Italy INAF Analysis Center Istituto di Radioastronomia–Bologna

3. Outlook

For the time being, our catalog finally contains all available experiments. In 2011, using our

new Linux workstation and the up-to-date Mark 5 Calc/Solve software, we plan to analyze all

available databases, thus completing the catalog. 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.

References

[1] Sarti, P., C. Abbondanza, L. Vittuari (2009). Gravity dependent signal path variation in a large VLBI

telescope modelled with a combination of surveying methods. J Geodesy 83(11):1115-1126.

[2] Sarti, P., L. Vittuari, C. Abbondanza (2009). Laser scanner and terrestrial surveying applied to gravitational deformation monitoring of large VLBI telescope’s primary reflectors, J Surv Eng 135(4):136-148.

[3] Abbondanza, C., P. Sarti (2010). Effects of illumination functions on the computation of gravitydependent signal path variation models in Cassegrainian VLBI telescopes. J Geodesy 84(8):515-525.

[4] Sarti, P., C. Abbondanza, L. Petrov, M. Negusini (2011). Height bias and scale effect induced by

antenna gravity deformations in geodetic VLBI data analysis. J Geodesy 85(1):1-8.

[5] 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.

214 IVS 2010 Annual Report
Jet Propulsion Laboratory, California Institute of Technology JPL Analysis Center

JPL VLBI Analysis Center Report for 2010

Chris Jacobs

Abstract

This report describes the activities of the JPL VLBI Analysis Center for the year 2010. We continue

to do celestial reference frame, terrestrial reference frame, earth orientation, and spacecraft navigation

work using the VLBI technique. In 2010 we doubled our default reference frame data rate to 448

Mbps. Our international collaboration to build celestial frames at K- (24 GHz) and Q-bands (43 GHz)

matured to roughly part-per-billion (ppb) accuracy. Our in-house work to build a reference at X/Kabands (8.4/32 GHz) is also close to ppb accuracy. We supported several missions with VLBI navigation

measurements. We continue to study ways to improve spacecraft tracking using VLBI techniques.

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.

4. ∆VLBI phase referencing uses the VLBA to measure spacecraft positions.

2. Technical Capabilities

The JPL Analysis Center acquires its own data and supplements it with data from other

centers. The data we acquire is 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 (see Figure

1) which has been the most often used set of 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,

IVS 2010 Annual Report 215
JPL Analysis Center Jet Propulsion Laboratory, California Institute of Technology

DSS 43, and DSS 63). Typical X-band system temperatures are 35K on the HEF antennas.

The 70-m and BWGs are about 20K. Antenna efficiencies are typically well above 50% at

X-band.

Figure 1. The three ‘high-efficiency’ DSN antennas: Goldstone (center); Robledo, Spain (lower left); and

Tidbinbilla, Australia (lower right). These antennas have an optimum efficiency at X-band (8.4 GHz)—

the standard frequency for solar-system exploration. These antennas were completed before 1986 for the

Voyager Uranus encounter. In the 1990s, Ka-band (32 GHz) BWG antennas (not shown) were added.

2. Data acquisition: We use the Mark 5A VLBI data acquisition systems. 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

is later transferred via network to JPL for processing with our software correlator.

3. Correlators: The JPL VLBI Correlator has been exclusively based on the SOFTC software

which handles the ∆DOR, TEMPO, and CRF correlations. The software correlator has also

been used for connected element interferometry 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.

216 IVS 2010 Annual Report
Jet Propulsion Laboratory, California Institute of Technology JPL Analysis Center

• Durgadas Bagri: VLBI instrumental calibrations and TEMPO.

• Jim Border: ∆DOR spacecraft tracking.

• Mike Heflin: ∆DOR, CRF and TRF. Maintains MODEST analysis code.

• Chris Jacobs: S/X, K, Q, X/Ka CRFs, and TRF.

• Peter Kroger: ∆DOR spacecraft tracking.

• Gabor Lanyi: VLBA phase referencing, ∆DOR, WVR, K-Q CRF, and TRF.

• Steve Lowe: Software correlator, fringe fitting software, ∆DOR.

• Walid Majid: ∆DOR, VLBA phase referencing.

• Chuck Naudet: WVR, Mark 5A support, and K-Q CRF.

• Lyle Skjerve: Field support of VLBI experiments at Goldstone.

• Ojars Sovers: S/X, K, Q, and X/Ka CRFs and TRF. Maintains MODEST analysis code.

• Alan Steppe: TEMPO and TRF.

4. Current Status and Activities

In order to support the DSN’s move to Ka-band (32 GHz), JPL is leading a collaboration

(Lanyi et al., Charlot et al.) with Goddard, the U.S.N.O., NRAO, and the Bordeaux Observatory

to extend the ICRF to K-band (24 GHz) and Q-band (43 GHz).

JPL’s X/Ka-band (8.4/32 GHz) CRF was presented in two papers by Jacobs et al. The X/Ka

to Gaia optical frame tie potential was discussed by Bourda, Charlot, and Jacobs.

During 2010 our default Mark 5A rate was increased to 448 Mbps yielding a very high sensitivity

VLBI system when combined with the DSN’s large apertures and low system temperatures.

VLBI spacecraft tracking continues to provide measurements of angular position in support of

mission navigation and planetary ephemeris development (Border, 2009). Jones et al. report on

work done with Cassini to improve the Saturn ephemeris. Measurements of Mars Reconnaissance

Orbiter and Odyssey were obtained to improve the Mars ephemeris, while ESA provided measurements of Venus Express to improve the Venus ephemeris. Measurements were taken during

interplanetary cruise to support navigation for Messenger, New Horizons, Deep Impact, Dawn,

and Akatsuki. Finally, measurements were obtained of Hayabusa during its return trip to Earth

to ensure successful targeting for landing the sample capsule in central Australia.

5. Future Plans

In 2011, we hope to improve TEMPO and reference frame VLBI by increasing data rates to 896

Mbps. Operational Ka-band phase calibrators have been built and are planned for deployment in

2011. Work on the Digital Back End (DBE) continues. Our next generation fringe fitting program

is also expected to come online. We anticipate refereed publications on our X/Ka celestial reference

frame work. On the spacecraft front, we plan to continue supporting a number of operational

missions while further improving techniques for using VLBI for spacecraft tracking.

IVS 2010 Annual Report 217
JPL Analysis Center Jet Propulsion Laboratory, California Institute of Technology

Acknowledgements

The work described here was in part performed at the Jet Propulsion Laboratory, California

Institute of Technology, under contract with the National Aeronautics and Space Administration.

Copyright 2011 California Institute of Technology. Government sponsorship acknowledged.

References

[1] Border, J.S., ‘Innovations in Delta Differential One-way Range: From Viking to Mars Science Laboratory,’ Proc. 21st Int. Sym. Space Flight Dynamics, Toulouse, France, 28 Sep–02 Oct, 2009.

http://www.mediatec-dif.com/issfd/OrbitdI/Border.pdf

[2] Bourda, G., P. Charlot, and C.S. Jacobs, ‘Future Radio Reference Frames and Implications for the

Gaia Link,’ Proc. ELSA Conf.: Gaia at the Frontiers of Astrometry, Sevres, France, 7–11 June 2010.

http://ftphip.obspm.fr/gaia2010/IMG/pdf/Poster Bourda.pdf

[3] Charlot, P., D.A. Boboltz, A.L. Fey, E.B. Fomalont, B.J. Geldzahler, D. Gordon, C.S. Jacobs, G.E.

Lanyi, C. Ma, C.J. Naudet, J.D. Romney, O.J. Sovers, and L. D. Zhang, ‘The Celestial Reference

Frame at 24 and 43 GHz II. Imaging,’ AJ, 139, 5, 1713, 2010. doi: 10.1088/0004-6256/139/5/1713

[4] Heflin, M.B., C.S. Jacobs, O. J. Sovers, A. Moore, and S. Owen, ‘Use of Reference Frames for Interplanetary Navigation at JPL,’ REFAG-2010 Conference, Marne-La-Vallee, France 8–10 Oct 2010.

http://iag.ign.fr/abstract/pdf/Heflin REFAG2010.pdf

[5] Jacobs, Bagri, Britcliffe, Clark, Franco, Garcia-Miro, Goodhart, Horiuchi, Lowe, Moll, Navarro,

Rogstad, Proctor, Sigman, Skjerve, Soriano, Sovers, Tucker, Wang, and White, ‘X/Ka Celestial Reference Frame Improvements: Vision to Reality,’ Proc. IVS GM-2010, eds. D. Behrend & K. D. Baver,

Ses. 4-T03, Hobart, 2010. http://ivscc.gsfc.nasa.gov/publications/gm2010/jacobs1.pdf

[6] Jacobs, C., M. Heflin, O. Sovers, & J. Steppe, ‘Rotational Alignment Altered by Source Position Correlations,’ Proc. IVS GM-2010, Hobart, 2010. ivscc.gsfc.nasa.gov/publications/gm2010/jacobs2.pdf

[7] Jacobs, C.S., J.E. Clark, C. Garcia-Miro, M.B. Heflin, S. Horiuchi, V.E. Moll, L.J. Skjerve, and O.J.

Sovers, ‘The Celestial Reference Frame at X/Ka-Band,’ REFAG-2010 Conference, Marne-La-Vallee,

France 4–8 Oct 2010. http://iag.ign.fr/abstract/pdf/Jacobs REFAG2010.pdf

[8] Jones, D., E. Fomalont, V. Dhawan, J. Romney, W. Folkner, G. Lanyi, J. Border, & R. Jacobson,

‘Astrometric Observations of Cassini with the VLBA: First Eight Epochs,’ BAAS, 42, p. 456, 2010.

http://adsabs.harvard.edu//abs/2010AAS...21544813J

[9] Lanyi, G. E., D. Boboltz, P. Charlot, A. Fey, E. Fomalont, B. Geldzahler, D. Gordon, C.S. Jacobs, C.

Ma, C.J. Naudet, J. Romney, O.J. Sovers, and L.D. Zhang, ‘The Celestial Reference Frame at 24 and

43 GHz I. Astrometry,’ AJ, 139, 5, 1695, 2010. doi: 10.1088/0004-6256/139/5/1695

[10] Ma, Arias, Bianco, Boboltz, Bolotin, Charlot, Engelhardt, Fey, Gaume, Gontier, Heinkelmann,

Kudubov, Lambert, Malkin, Nothnagel, Jacobs, et al, ‘The ICRF2,’ Proc. IVS GM-2010, Session

4-T01, Hobart, 2010. http://ivscc.gsfc.nasa.gov/publications/gm2010/ma.pdf

[11] Majid, W., ‘Monitoring of Active Blazars Using Short Baseline Interferometer,’ BAAS, 42, 379, 2010.

http://adsabs.harvard.edu/abs/2010AAS...21543425M

[12] Navarro, R., Rogstad, Goodhart, Sigman, Soriano, Wang, White, & Jacobs, ‘Updated Deep Space

Communications Complex VLBI Processor,’ Proc. IVS GM-2010, Session 5-P03, Hobart, 2010.

[13] Rogstad, S., C. Goodhart, J. E. Clark, S. Finley, G. Lanyi, L. White, & C. Jacobs, ‘Modernizing the

JPL VLBI Correlator,’ Proc. IVS GM-2010, Session 2-P13, Hobart, 2010.

218 IVS 2010 Annual Report
Korea Astronomy and Space Science Institute / Ajou University KASI Combination Center

KASI Combination Center Report

Younghee Kwak, Jungho Cho

Abstract

This report introduces the activities of the Korea Astronomy and Space Science Institute (KASI)

as an IVS Combination Center and shows the current status of the combination work. It also outlines

the intended tasks for 2011.

1. General Information

KASI was accepted as an IVS Combination Center on October 21, 2008. The KASI Headquarters is located in the Daeduk Research and Development Complex, Daejeon. Currently, the KASI

Space Geodesy Research Group mainly works on the application and the combination of space

geodetic techniques.

2. Component Description

The mission of the KASI Combination Center is:

• to create high quality combination products

• to control the quality of the Analysis Centers’ results

• to provide feedback to the Analysis Centers

• to adhere to the IERS Conventions

3. Staff

Table 1. Personnel at the KASI Combination Center.

Jungho Cho +82-42-865-3234 jojh@kasi.re.kr

Younghee Kwak +82-42-865-2031 bgirl02@kasi.re.kr

4. Current Status and Activities

(1) The Bernese S/W for IVS combination:

For combination analysis, we use the Bernese S/W 5.0 which is a GPS data processing program.

The Bernese S/W provides the functions of stacking normal equations and estimating parameters.

The input to the Bernese S/W is the Normal Equation (N.E.) Matrix and the N.E. vector from

the daily SINEX files of the individual ACs, which is the same input that the BKG/DGFI Combination Center uses. The output are daily SINEX files with combined station coordinates and

IVS 2010 Annual Report 219
KASI Combination Center Korea Astronomy and Space Science Institute / Ajou University

Earth Orientation Parameters (EOP).

(2) Validation of Bernese S/W:

We presented the preliminary combination results at the IVS General Meeting. While TRF

accuracy was within general IVS accuracy [1], some of the EOP looked biased [2]. The Analysis

Coordinator advised us to reanalyze the individual solutions to validate the S/W. We reanalyzed

the CONT08 solutions of BKG, GSFC, and OPA for X-pole, Y-pole, UT1-UTC, and their rates.

Since the EOP series were not provided from USNO for this period, USNO was excluded. IAA

and DGFI were also excluded, because their SINEX format file could not be processed in Bernese

S/W. Figure 1 shows the reanalyzed BKG EOP minus the original EOP from BKG, the original

EOP from BKG minus the three AC combined EOP, and the reanalyzed BKG EOP minus the

three AC combined EOP, respectively. Figure 2 shows the differences between each AC’s solution

and the combined solution.

5. Future Plans

After completing verification of the Bernese S/W, we will produce NQ0 format files (input

format files Bernese S/W handles) for DGFI and IAA to combine all of the ACs’ products. We

will also establish the automated combination processing with the Bernese Processing Engine

(BPE). This automated processing will produce an IVS combination solution for the whole period

(1984 to present) easily and rapidly.

References

[1] Harald Schuh, Patrick Charlot, Hayo Hase, Ed Himwich, Kerry Kingham, Calvin Klatt, Chopo Ma,

Zinovy Malkin, Arthur Niell, Axel Nothnagel, Wolfgang Schl ̈uter, Kazuhiro Takashima, Nancy Vandenberg, Final Report of IVS Working Group 2 for Product Specification and Observing Programs,

2001.

[2] Younghee Kwak, Jungho Cho, in International VLBI Service for Geodesy and Astrometry 2009 Annual

Report, edited by D. Behrend and K.Baver, NASA/TP-2010-215860, 2010.

220 IVS 2010 Annual Report
Korea Astronomy and Space Science Institute / Ajou University KASI Combination Center

Figure 1. The differences between the reanalyzed BKG EOP (KASBKG) and the original EOP from

BKG (BKG), the differences between the original EOP from BKG (BKG) and the three AC combined

EOP (KAScombi), and the differences between the reanalyzed BKG EOP (KASBKG) and the three AC

combined EOP (KAScombi).

IVS 2010 Annual Report 221
KASI Combination Center Korea Astronomy and Space Science Institute / Ajou University

Figure 2. The residuals of each AC’s reanlyzed EOP solution with respect to the three AC combined EOP

(KAScombi). Here, KASBKG, KASGSF, and KASOPA mean the reanalyzed BKG EOP, GSF EOP, and

OPA EOP, respectively.

222 IVS 2010 Annual Report
Karadeniz Technical University, Department of Geomatics Engineering KTU-GEOD IVS Analysis Center

KTU-GEOD IVS Analysis Center Annual Report 2010

Emine Tanır, Kamil Teke

Abstract

This report summarizes the activities of the KTU-GEOD IVS Analysis Center (AC) in 2010 and

outlines the planned activities for the year 2011. Analysis of the IVS EUROPE sessions is one of our

specific interests.

1. General Information

KTU-GEOD IVS Analysis Center (AC) is located at the Department of Geomatics Engineering,

Karadeniz Technical Univesity, Trabzon, Turkey.

2. Staff

Members who have contributed to the research work at the KTU-GEOD IVS Analysis Center

(AC) from the establishment of the AC up to the present are listed in Table 1.

Figure 1. Members of the KTU-GEOD IVS Analysis Center (AC) at the 15th General Assembly of WEGENER, which was held in Istanbul. From right: Emine Tanır and Kamil Teke.

3. Current Status and Activities

Since 23rd of June 1989 every year several (6-12) IVS EUROPE sessions have been carried

out. The last complete solution of IVS EUROPE sessions was done about 10 years ago [1]. In

2010 we analyzed the IVS EUROPE sessions from 1990 to 2010. We determined horizontal and

vertical crustal motion in Europe. We compared our results with the previous findings derived

from VLBI and GNSS data analyses. We considered six VLBI stations: Matera and Medicina

IVS 2010 Annual Report 223
KTU-GEOD IVS Analysis Center Karadeniz Technical University, Department of Geomatics Engineering

Table 1. Staff of the KTU-GEOD Analysis Center.

Name Working Location Main Focus of Research

Emine Tanır Karadeniz Technical University, Responsible for

Department of Geomatics Engineering, KTU-GEOD IVS AC

Trabzon, Turkey. and data processing.

Kamil Teke 1 Vienna University of Technology, Least-squares adjustment.

Institute of Geodesy and Geophysics,

Vienna, Austria.

2 Hacettepe University, Department of Data processing.

Geodesy and Photogrammetry Engineering,

Ankara, Turkey.

in Italy; Wettzell in Germany; Svetloe in Russia; Onsala in Sweden; and Ny- ̊Alesund in Norway.

We analyzed the IVS EUROPE sessions with VieVS (Vienna VLBI Software) developed at the

Institute of Geodesy and Geophysics (IGG), Vienna University of Technology (TU Wien). We

estimated horizontal and vertical velocities for each VLBI station by fitting a linear function to

the coordinate time series. We compared these velocities with those of ITRF2005, VTRF2008,

and a EUREF GNSS solution (see Table 2). According to our results, the VLBI sites of Onsala

and Ny- ̊Alesund are rising at rates of 4 mm/year and 8 mm/year, respectively (see Table 2).

Table 2. Velocity vectors (cm/year) in north, east, and radial directions from the analysis of IVS EUROPE

sessions, from ITRF2005 and VTRF2008 TRF solutions, and from the analysis of EUREF GNSS sessions

(all velocities are at epoch 2000.0).

Stations IVS EUROPE ITRF 2005 VTRF 2008 EUREF GNSS

vn ve vr vn ve vr vn ve vr vn ve vr

MATERA (MATE) 1.9 2.4 0.0 1.9 2.4 0.0 1.9 2.3 0.1 2.0 2.3 0.2

MEDICINA (MEDI) 1.8 2.2 -0.2 1.8 2.2 -0.2 1.8 2.2 -0.2 2.1 2.2 -0.1

WETTZELL (WTZR) 1.5 2.0 0.0 1.6 2.0 0.0 1.6 2.0 0.0 1.7 2.0 0.1

ONSALA60 (ONSA) 1.5 1.7 0.4 1.5 1.7 0.3 1.5 1.7 0.4 1.6 1.7 0.3

SVETLOE 1.3 2.1 0.0 1.6 1.9 0.2 1.1 2.1 0.4 - - -

NYALES20 1.4 1.0 0.8 1.4 1.1 0.8 1.4 1.0 0.8 - - -

Figure 2 shows the radial velocities of the GNSS sites of which coordinate time series are

available approximately longer than four years without any gap. Although the other European

VLBI sites show uplift, the Medicina VLBI site is subsiding about 2 mm/year. The IVS EUROPE

radial velocities estimated by VieVS are in good agreement with the EUREF GNSS solution at

co-located sites in direction and in reasonable agreement in magnitude [2, 3]. The horizontal

and radial velocity estimates of IVS and EUREF solutions agree at co-located sites within a few

mm/year. In general the radial components of the antenna positions do not agree as well as

the horizontal components. For the case of our study, i.e. analyzing IVS EUROPE VLBI data,

estimating EOP or fixing to a priori models did not cause significant differences in the horizontal

224 IVS 2010 Annual Report
Karadeniz Technical University, Department of Geomatics Engineering KTU-GEOD IVS Analysis Center

velocity estimates, contrary to radial velocities. After de-trending the coordinate time series, at

some VLBI sites (e.g., Wettzell) clear annual spectra were detected [3].

Figure 2. Radial velocity vectors from the EUREF GNSS solution.

Figure 3. Relative horizontal velocity vectors from the EUREF GNSS solution when the European plate is

fixed (Europe intra-plate motions).

IVS 2010 Annual Report 225
KTU-GEOD IVS Analysis Center Karadeniz Technical University, Department of Geomatics Engineering

4. Future Plans

We will continue to analyze VLBI sessions with different parameterizations, focusing on the

IVS EUROPE series by using VieVS. In 2011, we plan to study different stochastic models in the

analysis of VLBI sessions.

Acknowledgements

We are thankful to IVS and to the members of the VLBI group at the Institute of Geodesy and

Geophysics (IGG), Vienna University of Technology (TU Wien). We are grateful to Karadeniz

Technical University for its financial support to KTU-GEOD IVS AC research activities.

References

[1] Campbell, J., R. Haas, A. Nothnagel, Measurement of Vertical Crustal Motion in Europe by VLBI,

Science Research Development, European Commission, Geodetic Institute, University of Bonn, 110–

125, 2002.

[2] Tanır, E., K. Teke, H. Schuh, VLBI Estimates of vertical crustal motion in Europe, 15th General

Assembly of WEGENER, Geodesy Department of Kandilli Observatory and Earthquake Research

Institute of Bogazici University, 14-17 September 2010, Istanbul, Turkey.

[3] Teke, K., J. B ̈ohm, T. Nilsson, H. Spicakova, H. Schuh, Intra-Eurasia plate motions based on EUREF,

IVS-Europe, and IVS-combined solutions, 15th General Assembly of WEGENER, Geodesy Department

of Kandilli Observatory and Earthquake Research Institute of Bogazici University, 14-17 September

2010, Istanbul, Turkey.

226 IVS 2010 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

Svitlana Lytvyn, 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 2010.

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 at the center 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]).

During 2010 we ported SteelBreeze to use the Qt3 library. Now there is no need to compile.

Qt2 library and SteelBreeze can be linked with the Qt3 library which is provided with any

Linux distribution.

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.

3. Staff

The VLBI Analysis Center at Main Astronomical Observatory consists of three members:

Yaroslav Yatskiv: Head of the Department of Space Geodynamics; general coordination and

support of activity of the Center.

Svitlana Lytvyn: Junior research scientist of the Department of Space Geodynamics; investigates the stability of VLBI-derived celestial and terrestrial systems.

Sergei Bolotin: Scientific consultant on VLBI software development.

IVS 2010 Annual Report 227
Analysis Center at MAO Main Astronomical Observatory, National Academy of Sciences of Ukraine

4. Current Status and Activities in 2010

In 2010 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 2011

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. We also plan to port SteelBreeze to use the Qt4 widgets library.

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), IERS Technical Note 32, eds. D.D. McCarthy and G. Petit, Bundesamt f ̈ur

Kartographie und Geod ̈asie, Frankfurt am Main.

228 IVS 2010 Annual Report
Kashima Space Research Center, NICT NICT Analysis Center

Analysis Center at National Institute of Information and

Communications Technology

Thomas Hobiger, Hiroshi Takiguchi, Ryuichi Ichikawa, Mamoru Sekido, Yasuhiro Koyama,

Tetsuro Kondo

Abstract

This report summarizes the activities of the Analysis Center at National Institute of Information

and Communications Technology (NICT) for the year 2010.

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. Analysis

of VLBI experiments and related study fields at NICT are mainly concentrated on experimental

campaigns for developing new techniques such as time and frequency transfer, e-VLBI for real-time

EOP determination, prototyping of a compact VLBI system, analysis software development, and

atmospheric path delay studies.

2. Staff

Members who are contributing to the Analysis Center at the NICT are listed below (in alphabetical order, working locations in parentheses):

• HOBIGER Thomas (Koganei, Tokyo), Atmospheric research, analysis software development

• ICHIKAWA Ryuichi (Kashima), Compact VLBI system and atmospheric modeling

• KONDO Tetsuro (Kashima), Software correlator

• KOYAMA Yasuhiro (Koganei, Tokyo), e-VLBI

• SEKIDO Mamoru (Kashima), International e-VLBI and VLBI for spacecraft navigation

• TAKIGUCHI Hiroshi (Kashima), Time-transfer experiments, e-VLBI and loading effects

3. Current Status and Activities

3.1. Ultra-rapid UT1 Experiments

In cooperation with Geospatial Information Authority of Japan (GSI), Onsala Space Observatory, and Mets ̈ahovi Radio Observatory it has become possible [6] to obtain UT1 estimates—which

have been proven to be as accurate as the IERS Bulletin-A results—a few minutes after the last

observation has been made. This operation mode, called ultra-rapid UT1 determination, has been

developed further and extended by a fully automated analysis procedure based on c5++ (Section

3.3). Additionally, results from these low-latency experiments were used by the IERS for test

purposes to check the impact of such near-real-time information for their EOP products.

IVS 2010 Annual Report 229
NICT Analysis Center Kashima Space Research Center, NICT

3.2. Time and Frequency Transfer via VLBI

217.5 218 218.5 219 219.5 220

−800

−600

−400

−200

0

200

400

600

800

1000

ps

K5/VSSP32

K5/VSI

GPS CP

TW(DPN)

ETS8(TCE)

Time Difference Kashima11−Koganei11

DOY

Figure 1. T&F by VLBI using two sampling

modes K5/VSSP32 (S/X multi channel) and

K5/VSI (S/X broadband) (see TDC report in

this issue).

As a new frequency transfer technique which enables the comparison of highly stable frequency standards, we proposed the geodetic VLBI technique using our MARBLE system. NICT is currently developing several T&F transfer techniques besides VLBI

such as GPS and two-way satellite time and frequency

transfer (TWSTFT). In 2010 we carried out two intercomparison experiments (August and October) on the

Kashima 11 m to Koganei 11 m baseline. Thereby we

compared results from VLBI, GPS, TWSTFT with a

DPN code [7], and time comparison equipment (TCE)

on the satellite ETS-8 [8]. Figure 1 shows the result

of the August experiment. The October experiment,

which aimed at checking if these techniques are able

to measure the correct time difference, was conducted

by introducing an artificial delay using a coaxial phase

shifter which was inserted into the path of the reference signal from the Hydrogen maser to the Kashima

11-m antenna. We are analyzing data in detail now.

3.3. Development of a Multi-technique Space-geodetic Analysis Software Package

Otsubo et al. (1994, [4]) have developed an analysis software package based on Java named

CONCERTO4 which enables the user to consistently process SLR, GPS, and other satellite tracking

data. Driven by the need to update the software and to replace the existing Java code, VLBI was

added as an additional module to this analysis package, and it was renamed c5++. The software

provides state-of-the-art modules for a variety of geodetic, mathematical, and geophysical tasks

that can be combined into a stand-alone VLBI application. Although many of these modules can be

used for any of the space geodetic techniques, a couple of technique-specific solutions (like relativity,

antenna deformation) had to be coded exclusively for VLBI. Thanks to the efforts of the Vienna

VLBI group we were able to validate (see Figure 1) our software within the “Comparison Campaign

of VLBI Data Analysis Software” [5] before using it for analysis purposes. As our software has

the capability to carry out unattended ambiguity resolution of single baseline experiments, the

automated analysis procedure of the real-time UT1 experiments has been realized with c5++

[2]. The software is currently under revision to be in agreement with the IERS Conventions 2010

and to become a complete package for multi-baseline experiments. Moreover, further applications

including time and frequency transfer and space-craft navigation are being implemented in order

to support the research activities of NICT’s VLBI project.

3.4. MARBLE

We have developed two prototypes of a compact VLBI system with a 1.6 m diameter aperture dish in order to provide reference baseline lengths for calibration purposes. The reference

230 IVS 2010 Annual Report
Kashima Space Research Center, NICT NICT Analysis Center

Figure 2. Differences of total theoretical delay for the baseline Westford-Wettzell between c5++ and VieVS

as obtained within the “Comparison Campaign of VLBI Data Analysis Software” [5].

baseline is maintained by GSI. We named the system “Multiple Antenna Radio-interferometry for

Baseline Length Evaluation (MARBLE)” [3]. We have carried out six geodetic VLBI experiments

between Kashima and Tsukuba (about 54 km) during the fiscal year of 2010. The baseline length

repeatability is 2.4 mm. Baseline Length (mm)

54184840

54184850

54184860

54184870

54184880

54184890

54184900

54184910

2010/8/1 2010/8/31 2010/9/30 2010/10/30 2010/11/29 2010/12/29

VLBI

GPS

TIME

Figure 3. Baseline lengths between Kashima and Tsukuba as obtained by MARBLE and GPS.

3.5. Ray-traced Troposphere Slant Delay Correction for Space Geodesy

A software package, called Kashima Ray-tracing Tools (KARAT), has been developed which 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.

IVS 2010 Annual Report 231
NICT Analysis Center Kashima Space Research Center, NICT

Besides other space-geodetic techniques like GPS or InSAR, the impact of such corrections on

UT1 estimates from VLBI has been investigated by B ̈ohm et al. [1]. A thorough comparison of

ray-traced troposphere delays with results from other space-geodetic techniques during CONT08

has been made by Teke et al. (2011, [9]). Moreover, the usage of such corrections for other VLBI

applications is currently under investigation.

4. Future Plans

For the year 2011 the plans of the Analysis Center at NICT include:

• Time and frequency transfer experiments by VLBI

• Further improvement of the multi-technique space-geodetic analysis software c5++

• Extension of the concept of ultra-rapid UT1 experiments to a multi-baseline network which

allows the determination of all three EOPs

• Improvement of processing speed and efficiency for the VLBI data correlation using multiprocessors/multi-cores and high-speed networks

• VLBI experiments for spacecraft tracking and its analysis

References

[1] Boehm J., T. Hobiger, R. Ichikawa, T. Kondo, Y. Koyama, A. Pany, H. Schuh and K. Teke, Asymmetric

tropospheric delays from numerical weather models for UT1 determination from VLBI Intensive sessions

on the baseline Wettzell-Tsukuba, Journal of Geodesy, 84(5), 319-325, 2010.

[2] 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, in press, 2011.

[3] Ichikawa R., A. Ishii, H. Takiguchi, H. Kuboki, M. Kimura, J. Nakajima, Y. Koyama, T. Kondo, M.

Machida, S. Kurihara, K. Kokado, and S. Matsuzaka, Development of a Compact VLBI System for

Providing over 10-km Baseline Calibration, “Measuring The Future”, Proc. of the Fifth IVS General

Meeting, 400-404, 2008.

[4] Otsubo T., H. Kunimori, B. Engelkemier, and F. Takahashi, Error control of numerical integration in

SLR analysis software CONCERTO, Journal of the Geodetic Society of Japan, 40, 4, 347-355, 1994.

[5] Plank L., J. Boehm and H. Schuh, Comparison Campaign of VLBI Data Analysis Software - First

Results, Proceedings of the IVS 2010 General Meeting, NASA-CP-2010-215864, 217-221, 2010.

[6] Sekido M., H. Takiguchi, Y. Koyama, T. Kondo, R. Haas, J. Wagner, J. Ritakari, S. Kurihara and K.

Kokado, Ultra-rapid UT1 measurements by e-VLBI, Earth, Planets and Space, 60(8), 865-870, 2008

[7] Amagai J., T. Gotoh, Current Status of Two-way Satellite Time and Frequency Transfer Using a Pair

of Pseudo Random Noises, APTF 2008 Proceedings, 2008.

[8] Takahashi Y., F. Nakagawa, H. Kunimori, J. Amagai, S. Tsuchiya, R. Tabuchi, S. Hama, H. Noda,

Precise Time Transfer and Ranging Experiment Result between Ground and ETS-VIII, International

Symposium on GPS/GNSS 2008 Proceedings, 2008.

[9] Teke K., J. Boehm, T. Nilsson, H. Schuh, P. Steigenberger, R. Dach, R. Heinkelmann, P. Willis,

R. Haas, S. Garcia-Espada, T. Hobiger, R. Ichikawa and S. Shimizu, Multi-technique comparison of

troposphere zenith delays and gradients during CONT08, Journal of Geodesy, in print, 2011.

232 IVS 2010 Annual Report
Norwegian Mapping Authority (NMA) NMA Analysis Center

NMA Analysis Center

Halfdan Pascal Kierulf

Abstract

This report summarizes the activities of the NMA Analysis Center in 2010 and outlines the planned

activities for 2011. The NMA had in 2010 two main goals. The first goal was to adapt the multitechnique geodetic software GEOSAT to deliver to the IVS Combination Center unconstrained SINEX

solutions compatible with the solutions from the other IVS Analysis Centers. The other was to be

accepted as an IVS Associate Analysis Center. NMA was accepted as an IVS Associate Analysis

Center on 28 October 2010. NMA has performed lots of activity during 2010 to modify the software

to be as compatible as possible with the other VLBI software used to deliver results to the IVS. The

overall agreement between the GEOSAT solution and results from the other IVS Analysis Centers are

satisfactory. However, some discrepancies still exist and have to be adressed.

1. Introduction

During recent years the Norwegian Mapping Authority (NMA) has started a close collaboration

with Forsvarets forskningsinstitutt (FFI, Norwegian Defense Research Establishment) to use and

further develop the geodetic multi-technique software GEOSAT ([1, 2]). One of the main goals of

this project has been to use the VLBI module of GEOSAT to establish NMA as an IVS Analysis

Center and to deliver unconstrained Solution Independent Exchange format (SINEX) solutions for

the IVS combined solutions ([3]).

To produce VLBI solutions for IVS is the first part of a larger strategic plan from NMA. The

next step is to include other geometric geodetic techniques (GNSS and SLR) in a common solution,

in which 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 satellite

altimetry.

2. NMA Analysis Activities in 2010

The NMA has in collaboration with FFI made a large effort to make the GEOSAT software

compatible with other VLBI analysis software.

One of the first challenges that had to be solved was how to extract an unconstrained SINEX

solution from the Square-Root Information Filter (SRIF) matrix given by GEOSAT. A first test

solution was sent to the IVS Combination Center in autumn 2009. During 2010 several solutions

covering all VLBI sessions with at least four stations from 1994 to present were submitted to the

IVS Combination Center. The first solution was presented at the 6th IVS General Meeting, Hobart,

Australia [5]. The overall agreement between the NMA-GEOSAT solution and the solutions from

the other ACs is satisfactory for this first comparison. However, some discrepancies have been

found (see [5] for details). This revealed some issues that have to be investigated. The NMA is in

an iterative process with the IVS Combination Center to sort out these issues.

The discrepancies between results from GEOSAT and results from other IVS Analysis Centers

may have several reasons. Differences in the underlying models are one possible explanation. For

a short description of the main features of the software, see Section 4. The use of 3D-raytracing

instead of VMF1 ([4]) is likely to produce some systematic differences. GEOSAT was therefore

IVS 2010 Annual Report 233
NMA Analysis Center Norwegian Mapping Authority (NMA)

extended with the option to use the VMF1 mapping function. The first results using VMF1 have

been compared to the other solutions. This has reduced the discrepancies. During the iterative

process with the IVS Combination Center some other discrepancies in the software were also

revealed, and the software was updated. To what extent the use of a Kalman filter approach

instead of a Least Square Adjustment may introduce differences is unknown, but it is not likely

that it would give long-term systematic differences.

3. NMA Planned Analysis Activities in 2011

The NMA will in 2011 continue the iterative process with the IVS Combination Center to

make the GEOSAT solution as compatible as possible with the other software. As soon as the

GEOSAT solution is in satisfactory agreement with the other solutions, NMA will start to deliver

unconstrained normal equations in SINEX format to the IVS-EOP combination on a routine basis.

Tests of different models are also planned, for instance a comparison of results using VMF1 and

3D-raytracing.

4. The GEOSAT Software

During the last 28 years FFI has developed a software package called GEOSAT for the combined

analysis of VLBI, GNSS (GPS, Galileo, GLONASS), SLR and other types of satellite tracking data

(DORIS, PRARE, altimetry, gravity, radar, direction, Deep Space Network, etc.) The observations

are combined at the observation level with a consistent analysis strategy and consistent models.

With this procedure, the time-evolution of the common multi-technique parameters (for example

EOP, geocenter, troposphere, or clock parameters) is treated consistently across the techniques.

GEOSAT is based on an upper diagonal factorized Kalman filter which allows the estimation

of time variable parameters, such as the troposphere and clocks, as stochastic parameters. The

tropospheric delays in various directions are mapped to tropospheric zenith delay using ray-tracing.

Meteorological data from ECMWF with a resolution of six hours is used to perform this ray-tracing.

The ray-tracing depends both on elevation and azimuth angle. Atmospheric pressure corrections

are applied ([7]). Other models are following the IERS and IVS conventions [6].

5. Staff

Dr. Halfdan Pascal Kierulf - Research geodesist of Norwegian Mapping Authority (NMA)

Dr. Per Helge Andersen - Research Professor of Forsvarets forskningsinstitutt (FFI and 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., and 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., and Schuh, H. 2006, Troposphere mapping functions for GPS and very long base234 IVS 2010 Annual Report
Norwegian Mapping Authority (NMA) NMA Analysis Center

line 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., and Kristiansen, O. 2010, VLBI analysis with the

multi-technique software GEOSAT. IVS 2010 General Meeting Proceedings, edited by Dirk Behrend

and Karen D. Baver (NASA/CP-2010-215864)

[6] Petit, G., and Luzum, B. (eds.), 2010. IERS Conventions (2010). (IERS Technical Note; 36) Frankfurt

am Main: Verlag des Bundesamts f ̈ur Kartographie und Geod ̈asie. 179 pp., paperback, in print

[7] Petrov, L., and Boy, J.-P. 2004. Study of the atmospheric pressure loading signal in VLBI observations,Journal of Geophysical Research, (doi: 10.1029/2003JB002500)

IVS 2010 Annual Report 235
Paris Observatory Analysis Center (OPAR) Observatoire de Paris, SYRTE, CNRS/UMR8630

Paris Observatory Analysis Center OPAR: Report on Activities,

January—December 2010

S ́ebastien B. Lambert, Christophe Barache

Abstract

We report on activities of the Paris Observatory VLBI Analysis Center (OPAR) for calendar year

2010 concerning the development of operational tasks and our Web site.

1. Operational Status

1.1. Reanalyses

Four reanalyses of diurnal sessions were done (2010a, b, c, and d), and the resulting EOP series

and radio source catalogs were sent to the IVS. The latest solution processed 5,070 sessions since

1979. Each of these solutions estimated EOP and rates as session parameters, station coordinates

and velocities as global parameters, and ∼1,400 sources’ coordinates as global parameters, while

the remaining sources’ coordinates (about 1,000) were treated as session parameters. Troposphere

and clock parameters were estimated every 20 minutes and 60 minutes, respectively, and gradients

were estimated every six hours except for a list of 110 stations. Axis offsets were estimated as global

parameters for a list of 66 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). We used the latest version

of the Calc/Solve geodetic VLBI analysis software package. More details can be found on the

Analysis Center Web site at http://ivsopar.obspm.fr/earth/glo.

1.2. Coordinate Time Series

Station and radio source coordinate time series were also produced and updated regularly

(approximately every three months). Figures 1 and 2 show the Web pages relevant to the radio

source coordinate time series. For each source, a page displays plots of original and smoothed

time series and provides links to source information at various external databases (e.g., the French

Virtual Observatory software package Aladin that permits to get the optical counterpart of the

VLBI quasars, or the Bordeaux VLBI Image Database that gives the VLBI structure).

1.3. Operational Solutions

OPAR personnel have routinely analyzed diurnal sessions since 1979. The solution is aligned

to the 2010c global solutions. All session types were analyzed, but only unconstrained normal

equations relevant to the IVS rapid turn-around sessions (R1 and R4) were sent to the IVS in

SINEX format for combination in the framework of the IVS Analysis Coordinator’s task.

The operational solution 2010i analyzing Intensive sessions after 2006 was also submitted to

the IVS together with corresponding SINEX files.

An important step was the automation of the treatment of diurnal and Intensive sessions, in

order to match the IERS requirements in terms of latency. We built up homemade scripts, based

236 IVS 2010 Annual Report
Observatoire de Paris, SYRTE, CNRS/UMR8630 Paris Observatory Analysis Center (OPAR)

Figure 1. The Web page listing the sources for which coordinate time series are available. The color

code indicates the number of observations: highlighted source names stand for sources having the longest

observational history.

Figure 2. The Web page relevant to 2145+067 with the time series plots and the links to external databases.

on the UNIX cron command, to regularly check the local OPAR Data Center within 30 minutes

after the mirroring between the three primary IVS Data Centers. If new sessions are available, a

IVS 2010 Annual Report 237
Paris Observatory Analysis Center (OPAR) Observatoire de Paris, SYRTE, CNRS/UMR8630

bash script launches the solutions and sends the SINEX and EOP files back to the Data Center as

IVS products. The main numerical results of the analysis are sent out by e-mail to the analyst so

that he/she can check whether the solution is acceptable or needs special care. The Web site is also

updated automatically by a crontab file located on a different machine. We therefore guarantee

that newly arrived IVS databases are processed within less than 24 hours after submission.

Operational analysis of both diurnal and Intensive sessions will be continued in 2011. All the

above products, except SINEX files, were also published on the OPAR Web site. SINEX files were

only sent to the Data Centers.

2. Follow-up of Various Phenomena

2.1. 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

atmospheric and oceanic circulation modeling at diurnal and subdiurnal frequencies. At OPAR,

we maintain a FCN model directly fitted to routinely estimated nutation offsets (Fig. 3). More

explanations and material can be found at http://ivsopar.obspm.fr/earth/geo.

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 3. The free core nutation fitted to opa2010d nutation offsets with respect to the IAU 2006 nutation

and precession models.

238 IVS 2010 Annual Report
Observatoire de Paris, SYRTE, CNRS/UMR8630 Paris Observatory Analysis Center (OPAR)

2.2. Displacement of TIGO at Concepci ́on

Still using the routinely analyzed diurnal sessions, we monitored the displacement of the station

of TIGO at Concepci ́on after the 27 February 2010 (2010.15) earthquake. Figure 4 displays the

UEN coordinates of TIGO with respect to the mean position estimated in the 2010d solution. The

monitoring is continued at http://ivsopar.obspm.fr/earth/tigo.

2010.2 2010.3 2010.4 2010.5 2010.6 2010.7 2010.8 2010.9 2011 2011.1

−200

0

200

Up (mm)

2010.2 2010.3 2010.4 2010.5 2010.6 2010.7 2010.8 2010.9 2011 2011.1

−2400

−2300

−2200

−2100

East (mm)

2010.2 2010.3 2010.4 2010.5 2010.6 2010.7 2010.8 2010.9 2011 2011.1

−600

−500

−400

−300

North (mm)

Figure 4. The UEN coordinates of TIGO with respect to the mean position estimated in the 2010d solution.

3. Staff Members

Staff members who contributed to the OPAR Analysis and Data Centers in 2010 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,

• Anne-Marie Gontier, who headed OPAR since its inception in 1998, passed away on September 24th 2010.

IVS 2010 Annual Report 239
Onsala Space Observatory (OSO) Analysis Center Onsala Space Observatory (OSO)

Onsala Space Observatory – IVS Analysis Center

R ̈udiger Haas, Hans-Georg Scherneck

Abstract

We briefly summarize the activities of the IVS Analysis Center at the Onsala Space Observatory

during 2010 and give examples of results of ongoing work.

1. Introduction

We concentrate on a number of research topics that are relevant for space geodesy and geosciences. These research topics are addressed in connection to data observed with geodetic VLBI

and complementing techniques.

2. Calibration of VLBI Atmospheric Delays with External Information

We used the CONT05 campaign to study whether VLBI atmospheric delays can be calibrated

using external information. As external information we used atmospheric parameters derived from

GPS data analysis and water vapor radiometers (WVR).

All eleven stations that participated in CONT05 are equipped with GPS. The GPS data were

analyzed by the precise point positioning (PPP) technique [1] with the Gipsy-Oasis software [2],

and zenith wet delays (ZWD) and atmospheric gradients were estimated with five minute temporal

resolution. Six of the CONT05 stations also had at least one WVR operating during the campaign.

For three of these stations, Kokee, HartRAO and Wettzell, both ZWD and gradients could be

derived from the WVR, while for the remaining three stations, Algopark, Onsala and Tsukuba,

only ZWD could be derived from the WVR observations. The temporal resolution was 30 minutes.

In a first step, the time series of ZWD and gradients from GPS and WVR were compared to

those that result from the analysis of the CONT05 VLBI data. The VLBI results were derived

with the Calc/Solve software [3] with a temporal resolution of 1 hour for ZWD and 6 hours for

gradients.

As an example, Figure 1 shows the time series of ZWD and gradients for Wettzell and Algopark.

Wettzell turns out to be an extreme case in the sense that the east gradient (EGR) bias between

VLBI and WVR is as large as 2.5 mm. In general the gradient biases are smaller than 0.3 mm.

The gradient RMS is in general on the order of 1–1.5 mm, with the exception of Kokee which is an

extreme case with a value of 10 mm for the comparison of VLBI and WVR derived north gradient

(NGR). The biases for ZWD are in general on the order of 2–4 mm but can reach in extreme cases

up to 20 mm for the comparison of Algopark and Tsukuba VLBI and WVR results. The ZWD

RMS are in general on the order of 6–10 mm but can reach in extreme cases up to 20 mm for the

comparison of Algopark VLBI and WVR results.

In a second step, slant delays were constructed based on the GPS and WVR results for the

atmospheric parameters. The NMF mapping function [4] was used to map the zenith delays

into the line of sight of each observation. Also a set of slant delays was generated that was

derived from the VLBI results for atmospheric parameters themselves. Then three ‘calibration’

solutions were produced with Solve—i.e., the three different sets of slant delays were introduced

as calibrations. The parameterization was identical to the reference solution—i.e., ZWD and

240 IVS 2010 Annual Report
Onsala Space Observatory (OSO) Onsala Space Observatory (OSO) Analysis Center

12 14 16 18 20 22 24 26 28

0

50

100

150

200

ZWD

Day in Sep. 2005

mm

WETT

GPS

WVR

VLBI

12 14 16 18 20 22 24 26 28

−15

−10

−5

0

5

Day in Sep. 2005

mm

EGR

12 14 16 18 20 22 24 26 28

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0

5

10

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mm

NGR

12 14 16 18 20 22 24 26

0

100

200

300

Day in Sep. 2005

mm

ZWD

ALGO

GPS

WVR

VLBI

12 14 16 18 20 22 24 26

−2

0

2

Day in Sep. 2005

mm

EGR

12 14 16 18 20 22 24 26

−2

0

2

Day in Sep. 2005

mm

NGR

Figure 1. Time series of zenith wet delays (ZWD), east gradients (EGR), and north gradients (NGR) for

Wettzell (left) and Algopark (right) during CONT05.

gradients were estimated with 1-hour and 6-hour temporal resolution, respectively. Figure 2 shows

the resulting WRMS of the four solutions for all fifteen CONT05 sessions. There is no significant

improvement in the WRMS when using GPS- or VLBI-calibration with respect to the uncalibrated

reference solution (called NMF-solution in Figure 2). The WRMS fit even deteriorates when the

WVR-based slant delays are used as calibration.

Figure 3 presents a comparison of estimated ZWD for Onsala (left), HartRAO (middle), and

Tsukuba (right). The ZWD in general reduce to values near zero when slant delays are used as

calibration in the analysis. This can be expected if the slant delays were really representing the

true atmospheric conditions. However, there are still signatures left in the ZWD time series. At

HartRAO there are signatures of up to 20 mm visible when GPS- or WVR-derived slant delays are

used as calibration, and at Tsukuba the WVR-calibration even produces a bias of about 40 mm.

This indicates strongly that the slant delays used for the calibration are not good enough and for

some stations introduce noise and biases.

3. Raytracing through the High Resolution Numerical Weather Model HIRLAM

We used data from the High Resolution Numerical Weather Model HIRLAM to derive slant

delays and apply these in the analysis of Europe VLBI data [5]. The slant delays were calculated

by 1-dimensional raytracing using the Davis-Herring-Niell raytracing software [6]. European VLBI

sessions from March 2005 to September 2007 were analyzed and the results from the HIRLAMcalibration were compared to results from a standard analysis. If ZWD are estimated from both

approaches, a clear reduction in the estimated ZWD and their variation is visible when using

the HIRLAM-calibration. If ZWD are not estimated in the HIRLAM-calibration approach, the

baseline repeatabilities improve with respect to a standard solution only if an elevation cutoff angle

of 19 degrees or larger is used. Below this value, the standard approach of estimating ZWD still

gives superior baseline repeatabilities.

IVS 2010 Annual Report 241
Onsala Space Observatory (OSO) Analysis Center Onsala Space Observatory (OSO)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

20

25

30

35

40

45

C05−session

wrms (ps)

NMF

GPS−cal

WVR−cal

VLBI−cal

Figure 2. Resulting WRMS for four different analyses: NMF – a standard solution without calibrating

atmospheric delays; GPS-cal – a solution using GPS-derived slant delays for the calibration; WVR-cal – a

solution using WVR-derived slant delays for the calibration; and VLBI-cal – a solution using VLBI-derived

slant delays for the calibration.

12 14 16 18 20 22 24 26

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−50

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50

100

150

200

250

ZWD (mm)

Day in Sep. 2005

ONSA

NMF

GPS−cal

WVR−cal

VLBI−cal

12 14 16 18 20 22 24 26

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20

40

60

80

100

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140

ZWD (mm)

Day in Sep. 2005

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WVR−cal

VLBI−cal

12 14 16 18 20 22 24 26

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−50

0

50

100

150

200

250

300

350

400

ZWD (mm)

Day in Sep. 2005

TSUK

NMF

GPS−cal

WVR−cal

VLBI−cal

Figure 3. Estimated ZWD for Onsala (left), HartRAO (middle), and Tsukuba (right) when either no

calibration is applied (NMF) or a calibration is applied based on GPS results (GPS-cal), WVR results

(WVR-cal), or VLBI results (VLBI-cal).

4. Time and Frequency Transfer with VLBI and GPS

We used the CONT08 data to evaluate time and frequency transfer with VLBI and GPS [7].

Those VLBI stations that use the same H-maser for their VLBI and GPS equipment are of major

interest. The Onsala-Wettzell baseline shows the best results in CONT08. The VLBI-derived

frequency link stability was 1.2E-15 for one day, while the corresponding GPS-derived frequency

link stability was between 1.9E-14 and 6.2E-16, depending on which GPS-receiver at Wettzell was

included in the analysis. The significant relative frequency offset of about at least 5E-16 can be

242 IVS 2010 Annual Report
Onsala Space Observatory (OSO) Onsala Space Observatory (OSO) Analysis Center

attributed to either technique, e.g., the absence of integer ambiguity resolution in the GPS-analysis

and possible biases introduced by day-boundary problems in the VLBI solutions.

5. Ocean Tide Loading

The automatic ocean tide loading provider [8] was maintained during 2010.

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. During 2011 we plan to intensify our

activities.

References

[1] Zumberge J.F., Heflin M.B., Jefferson D.C., Watkins M.M., Webb F.H. (1997) Precise point positioning

for the efficient and robust analysis of GPS data from large networks. J. Geophys. Res., 102 (B3),

5005–5017.

[2] Webb F.H., Zumberge J.F. (1993) An introduction to GIPSY/OASIS-II precision software for the analysis of data from the Global Positioning System. JPL Publ. No. D-11088, Jet Propulsion Laboratory,

Pasadena, California.

[3] Ma C., Sauber J.M., Bell L.J., Clark T.A., Gordon D., Himwich W.E., Ryan J.W. (1990) Measurement

of horizontal motions in alaska using very long baseline interferometry. Journal of Geophysical Research,

95(B13), 21,991–22,011, doi:10.1029/JB095iB13p21991.

[4] Niell A.E. (1996) Global mapping functions for the atmosphere delay at radio wavelengths. J. Geophys. Res., 101, B2, 3227–3246

[5] Garcia-Espada S. Haas R., Colomer F. (2010) Application of Raytracing through the High Resolution

Numerical Weather Model. In:IVS 2010 General Meeting Proceedings, D. Behrend and K.D. Baver

(eds.), NASA/CP. 2010 215864, 232–236, http://ivscc.gsfc.nasa.gov/publications/gm2010/

garcia-espada.pdf.

[6] Davis J.L, Herring T.A.E., Niell A.E. (1987–1989) The Davis/Herring/Niell Raytrace program.

[7] Carsten R., Haas R., Jaldehag K., Johnasson J. (2010) VLBI and GPS-based Time-transfer Using CONT08 Data, In: IVS 2010 General Meeting Proceedings, D. Behrend and K.D. Baver (eds.),

NASA/CP 2010215864, 365–369, http://ivscc.gsfc.nasa.gov/publications/gm2010/rieck.

pdf.

[8] Scherneck H.-G., Bos M. (2002) Ocean Tide and Atmospheric Loading. In: IVS 2002 General Meeting

Proceedings, N.R. Vandenberg and K.D. Baver (eds.), NASA/CP-2002-210002, 205–214.

IVS 2010 Annual Report 243
PMD Analysis Center Politecnico di Milano, DIIAR

New Associate Analysis Center Established at PMD

Vincenza Tornatore

Abstract

In this report a new Associate Analysis Center is presented to the scientific community: the Politecnico di Milano DIIAR (PMD) Analysis Center (AC). The IVS Directing Board approved the proposal

for such a new AC at its 24th meeting in Shanghai on October 23, 2010. An introduction of the

group collaborating in the AC, location of PMD, its equipment, and the foreseen scientific activities

are briefly presented in this report. We will make all efforts to develop the AC towards the scientific

main purposes of the IVS.

1. Principal Characteristics

The proposal of DIIAR (Dipartimento di Ingegneria Idraulica, Ambientale, Infrastrutture

viarie, Rilevamento) of Milano Politecnico to become an International VLBI Service for Geodesy

and Astrometry Analysis Center (IVS AC) [1] was accepted at the 24th Directing Board meeting,

which was held in correspondence with the Joint GGOS/IAU Science Workshop “Observing and

Understanding Earth Rotation”, in Shanghai, China on October 25-28, 2010.

All office supplies, hardware, and personnel are supported and maintained by DIIAR, Politecnico di Milano, the host institution of the PMD AC (see Figure 1).

Figure 1. Head office of Politecnico di Milano University where PMD is hosted.

The hardware equipment consists of a server, a personal computer, a notebook, two printers

(one black-and-white and one color laser jet), a fax, and a scanner. All the equipment together

with the MATLAB compiler are provided by DIIAR.

The software we are going to use in the Analysis Center is VieVs (Vienna VLBI Software) [3],

which is developed by the members of the VLBI group of the Institute of Geodesy and Geophysics

244 IVS 2010 Annual Report
Politecnico di Milano, DIIAR PMD Analysis Center

(IGG), Vienna University of Technology (TU Wien). VieVs uses the programming language Matlab. Matlab is a very well known tool for university students. In many courses of their curriculum

the students of Politecnico di Milano use Matlab. The use of Matlab will ease the implementation

of new ideas and models also in the VieVs software.

2. Group at DIIAR Contributing to the PMD IVS Analysis Center

The following personnel will support the work of the new Analysis Center:

• Dr. Vincenza Tornatore: responsible for PMD (primary scientific/technical contact).

• Dr. Letizia Cannizzaro: expert in time series evolution and GPS data processing.

• Mrs. Cinzia Vajani: with secretary’s and hardware maintenance tasks.

• PhD student: with primary interest in the geodetic VLBI technique; still to be engaged.

3. Main Interests and Future Plans

The principal interests of PMD IVS AC concern the study of the European baseline evolution.

The first objective of the Analysis Center is to start to analyze all EUROPE sessions under

the same modeling conditions and analogous parametrization using the VieVs software. We would

like first to compare our results with those of other ACs that have similar interest in the study of

EUROPE sessions and preferably use the same VieVS software in order to have some degree of

validation, e.g., with the KTU-GEOD (Karadeniz Technical University, Department of Geomatics

Engineering) IVS AC that has also interest in EUROPE sessions [2]. The main purpose of PMD

is to estimate European site coordinates and baseline lengths with respective variance-covariance

matrices and to study their temporal evolution.

Another purpose of the Analysis Center is to compare VLBI results with GPS (Global Positioning System) results obtained for stations where the two techniques are present. We would like

to apply the same statistical studies to both techniques to reveal possible differences in estimated

deformations of the European plate. Comparisons with geophysical models in the area should also

be performed.

Since the software VieVS is fully compatible with the Windows and Linux Operating Systems

and it is distributed with its open source code based on Matlab, it would be very compelling to

also involve students in the implementation of particular models compatible with those from other

space geodetic techniques like GPS. The presence in the same Department of expertise in studies

of GPS time series evolution will represent a good opportunity for direct comparisons of VLBI

results obtained under the same processing strategies.

Acknowledgements

We are thankful to the Directing Board of the IVS, to DIIAR “Politecnico di Milano”, and to

all colleagues collaborating for supplying the necessary means to obtain fruitful results.

IVS 2010 Annual Report 245
PMD Analysis Center Politecnico di Milano, DIIAR

References

[1] Schl ̈uter, W., D. Behrend, The International VLBI Service for Geodesy and Astrometry (IVS): current

capabilities and future prospects, Journal of Geodesy, Vol. 81, Nos. 6–8, pp. 379–387, June 2007. DOI

10.1007/s00190-006-0131-z.

[2] Tanır, E., K. Teke, J. B ̈ohm, and H. Schuh, Contribution of Geodetic VLBI Studies to IERS Products

and Functions of KTU GEOD IVS Analysis Center, In: 4th National Engineering Surveying Symposium

Proceedings Book, Karadeniz Technical University, 134–164, 14–16 October 2009 (in Turkish).

[3] B ̈ohm, J., H. Spicakova, L. Plank, K. Teke, A. Pany, J. Wresnik, S. Englich, T. Nilsson, H. Schuh,

T. Hobiger, R. Ichikawa, Y. Koyama, T. Gotoh, T. Kubooka, and T. Otsubo, Plans for the Vienna VLBI

Software VieVS, In: Proceedings of the 19th European VLBI for Geodesy and Astrometry Working

Meeting, G. Bourda, P. Charlot and A. Collioud (eds.), 24–25 March, 2009.

246 IVS 2010 Annual Report
Pulkovo Observatory PUL Analysis Center

Pulkovo IVS Analysis Center (PUL) 2010 Annual Report

Zinovy Malkin

Abstract

This report briefly presents the PUL IVS Analysis Center activities during 2010 and plans for the

coming year. The main topics of the investigations of PUL staff in the report 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 activities are:

• Improvement of the International Celestial Reference Frame (ICRF).

• Computation and analysis of the Earth rotation parameters (EOP).

• Modeling of the celestial pole offset (CPO) and free core nutation (FCN).

• Comparison of VLBI products with other space geodesy techniques.

• Computation and analysis of observation statistics.

The PUL AC’s Web page http://www.gao.spb.ru/english/as/ac vlbi/ is supported. The

homepage contains the following sections:

• General Information on the PUL AC: brief history, activity overview, staff.

• VLBI data analysis: CPO/FCN series, UT1 Intensives series, mean Pole coordinates. Data

are updated daily.

• Data files used in analysis: station information adapted to the SINEX SITE/ID format,

a database name/experiment code cross-reference table including the number and list of

actually observed stations based on the IVS master file, average meteorological parameters

for stations based on information from databases.

• OCARS catalog: The latest version of the catalog of optical characteristics of astrometric

radio sources (OCARS) [2].

• Approaches and occultations: forthcoming mutual events of planets and astrometric radio

sources [3, 4].

• Publications and presentations.

• Links to the VLBI World.

• Contact information.

IVS 2010 Annual Report 247
PUL Analysis Center Pulkovo Observatory

2. Scientific Staff

The PUL team in 2010 included:

1. Zinovy Malkin (70%) — team coordinator, EOP and CRF computation and analysis;

2. Natalia Miller (5%) — EOP analysis;

3. Elena Popova (100%) — CPO analysis (until July).

3. Activities

The main activities of the PUL IVS Analysis Center during 2010 included:

• Regular processing of the Intensive sessions and submission of results to IVS was started in

October 2010.

• ICRF related research was continued, mainly in the framework of the IAG Working Group

1.4.1 “Theoretical Aspects of the Celestial Reference System and Systematic Effects in the

CRF Determination”. The main directions of this activity were comparison and combination

of radio source catalogs, as well as investigation of their stochastic and systematic errors.

• The work on the OCARS catalog was continued. The catalog is updated several times per

year. The latest version is available at the PUL Web page.

• A catalog of the occultations of astrometric radio sources by planets through the year 2050

was computed [4].

• Investigations of CPO modeling and its impact on data processing were continued. The main

results obtained in 2010 were the following:

– PUL CPO and FCN series were computed and updated daily.

– Comparison of CPO models was performed, and recommendations on the choice of an

optimal model for VLBI data processing were developed [5].

– The CPO prediction accuracy for different models was investigated [6], and its impact

on UT1 Intensive results was studied [7].

• PUL archive of VLBI data and products was supported. At present, all available databases

and NGS cards have been stored along with the main IVS and IERS products. These archives

are updated daily.

• Development of algorithms and software for data processing and analysis was 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:

• Continuing VLBI related studies.

• Continuing UT1 Intensives processing.

248 IVS 2010 Annual Report
Pulkovo Observatory PUL Analysis Center

• Continuing development of algorithms and software for data processing.

• Continuing support of the PUL archives of data and products.

References

[1] http://www.gao.spb.ru/english/as/persac/index.htm

[2] Titov O., Malkin Z. Effect of asymmetry of the radio source distribution on the apparent proper motion

kinematic analysis. Astron. Astrophys., 2009, v. 506, No. 3, 1477–1485.

[3] Malkin Z. M., L’vov V. N., Tsekmejster S. D. Forthcoming Close Angular Approaches of Planets to

Radio Sources and Possibilities to Use Them as GR Tests. Solar System Research, 2009, v. 43, No. 4,

pp. 313–318.

[4] L’vov V., Malkin Z., Tsekmeister S. Forthcoming Occultations of Astrometric Radio Sources by Planets.

In: D. Behrend, K. D. Baver (Eds.), IVS 2010 General Meeting Proc., NASA/CP-2010-215864, 2010,

320–324.

[5] Malkin Z. Comparison of CPO and FCN empirical models. In: Proceedings of the Journ ́ees 2010: New

challenges for reference systems and numerical standards in astronomy”, Paris, France, 20–22 Sep, 2010,

in press.

[6] Malkin Z. M. Analysis of the Accuracy of Prediction of the Celestial Pole Motion. Astronomy Reports,

2010, v. 54, No. 11, 1053-1061.

[7] Malkin Z. CPO Prediction: Accuracy Assessment and Impact on UT1 Intensive Results. In: D. Behrend,

K. D. Baver (Eds.), IVS 2010 General Meeting Proc., NASA/CP-2010-215864, 2010, 261–265.

IVS 2010 Annual Report 249
SAI Analysis Center Sternberg State Astronomical Institute (SAI) of Moscow State University

SAI VLBI Analysis Center Report 2010

Vladimir Zharov, Mark Kaufman

Abstract

This report presents an overview of the SAI VLBI Analysis Center activities during 2010 and

the plans for 2011. The SAI AC analyzes all IVS sessions for computation of the Earth orientation

parameters (EOP), investigates time series of source positions within the context of new realizations

of the ICRF, makes submissions of data and analysis products, 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.

2. Component Description

The 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. All reductions are performed

in agreement with IERS Conventions (2003).

The package uses files in NGS format as input data.

The latest version is installed on the correlator of the AstroSpace Center in support of the

Radioastron mission.

3. Staff

• Vladimir Zharov, Prof.: development of the ARIADNA software, development of the methods

of parameter estimation

• Mark Kaufman, scientific researcher: development of the ARIADNA software, solution and

analysis

• Dmitry Duev, post-graduate student: VLBI data processing, troposphere modeling

• Nikolay Voronkov, scientific researcher: global solution

• Svetlana Nosova, 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.

The latest version of software can be used for the solution of many tasks during the Radioastron mission: calculation of delay and delay rate for the space-ground interferometer, orbit

250 IVS 2010 Annual Report
Sternberg State Astronomical Institute (SAI) of Moscow State University SAI Analysis Center

determination of the space telescope by numerical integration of the differential equations of

motion, and use of Doppler tracking, laser ranging, and VLBI observations for improvement

of the Radioastron orbit based on the Kalman filter.

• Routine analysis

During 2010 the routine data processing was performed with the ARIADNA software using

the least-squares method with rigid constraints. SINEX files for both IVS 24-hour and

Intensive sessions were generated. But an attempt to use these files for estimation of the

EOP was unsuccessful due to the rigid constraints. In 2011 a new approach with non-rigid

constraints will be developed for the generation of SINEX files.

The SAI AC operationally processed the 24-hour and Intensive VLBI sessions. VLBI

database creation and processing of all sessions is fully automated. The EOP series

sai2010a.eops and sai2010a.eopi were calculated. These series were computed with the

ITRF2005 catalog of station positions and velocities.

Experimental series sai2010c.eops and sai2010c.eopi were calculated for the experimental

catalog of the radio sources whose positions and velocities were estimated in 2009. Analysis

of these series is being performed.

• Global solution

N. Voronkov re-wrote software for the supercomputer of the Moscow State University to

obtain a global solution. The radio source coordinates and velocities, and the station coordinates and velocities were estimated as global parameters. EOP, troposphere wet zenith

delay (approximated as a polynomial function), troposphere gradients, and station clocks

(approximated as a polynomial function) were estimated as arc parameters for each session.

• Troposphere modeling

At the stations with missing meteorological data we used surface data files (temporal coverage: 4-times daily, spatial coverage: 2.5 degree latitude x 2.5 degree 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 observation.

5. Future Plans

• Continue investigations of VLBI estimation of EOP, station coordinates, and troposphere

parameters and continue comparison with satellite techniques.

• Continue studies concerning the Third Realization of the ICRF.

• Further improve algorithms and software for processing VLBI (ground and space-ground)

observations.

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Shanghai Astronomical Observatory VLBI Analysis Center SHAO, Chinese Academy of Sciences

SHAO Analysis Center 2010 Annual Report

Guangli Wang, Jinling Li, Minghui Xu, Li Guo, Fengchun Shu, Zhihan Qian, Bo Zhang

Abstract

This report gives an introduction to the astrometric/geodetic activities of Shanghai Astronomical

Observatory (SHAO) in 2010. The main activities were the the observation and processing of the VLBI

experiments with the Chinese VLBI network (CVN) and the research activities towards VLBI2010.

1. General Information

We use the CALC/SOLVE system for routine VLBI data analysis. The members involved in

the IVS analysis activities are Guangli Wang, Jinling Li, Minghui Xu, Bo Zhang, Li Guo, Fengchun

Shu, and Zhihan Qian.

2. Activities in 2010

In 2010 we spent most of our time supporting the Chinese Lunar mission. We conducted six

geodetic VLBI experiments using four domestic VLBI stations, the main purpose being to determine the station coordinates, especially of the two new stations, for the Chinese space exploration

projects, as well as for the Project of Monitoring Network of the Chinese Mainland Geological Environment. We carried out three 2-hour experiments to measure UT1 using the two VLBI stations

at Seshan and Urumqi, getting the UT1 solutions within half an hour after the experiment was

completed.

Now we are preparing to restart our routine data analysis and submit to the IVS.

3. Plans for 2011

We will enhance the IVS analysis work, return to our normal contribution of solutions to IVS,

and make more active efforts to be involved in the activities of the VLBI community.

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Geospatial Information Authority of Japan Tsukuna VLBI Analysis Center

Tsukuba VLBI Analysis Center

Kensuke Kokado, Shinobu Kurihara, Ryoji Kawabata, Kentaro Nozawa

Abstract

The Geospatial Information Authority of Japan (GSI) became an IVS operational Analysis Center

on April 7th, 2010. Our role is to submit dUT1 results from the IVS-INT2 session as soon as possible

after the end of the session. GSI has been developing the real-time data processing and analysis system

in cooperation with NICT. This report summarizes the progress and status of the ultra-rapid dUT1

measurement system.

1. Introduction

GSI has implemented the ultra-rapid dUT1 experiment in cooperation with the National Institute of Communications and Technology (NICT), Onsala station of the Onsala Space Observatory

(OSO) in Sweden, and the Mets ̈ahovi station of the Mets ̈ahovi Radio Observatory in Finland since

2007. The purpose of this experiment is to obtain dUT1 results within the shortest possible time.

After some experiments in 2007, we succeeded in obtaining the dUT1 results within 3 minutes

45 seconds of the end of the observing sessions on Feb. 21, 2008, on the Tsukuba—Onsala baseline. The system of the experiments was introduced into an IVS regular session “IVS-INT2” in

2008, and we have been carrying out the ultra-rapid dUT1 experiment in all of the INT2 sessions.

Additionally, we have also implemented the ultra-rapid dUT1 experiment in 24-hour IVS regular

sessions, such as “IVS-R1”and “IVS-T2”, in which the Tsukuba and Onsala stations participated.

Although the system is almost completed, we have not completed the quality check of the dUT1

results yet. After we confirm that the results are consistent with the results of the other Analysis

Centers, we will start to submit the results within a few minutes after the end of the observing

session for IVS-INT2 sessions.

2. Current Analysis Center Activities

Tsukuba VLBI Analysis Center has implemented the ultra-rapid dUT1 measurement to obtain the dUT1 results within a few minutes after the observing sessions. The ultra-rapid dUT1

measurement of IVS-INT2 sessions is implemented automatically, because there is no staff in the

office during the INT2 session scheduled on the weekend. The detail of the automatic data processing system is described in this section. Figure 1 shows the process of the ultra-rapid dUT1

measurement system.

2.1. Automatic Data Transfer Program

For the IVS-INT2 sessions, we must transfer data from the Wettzell or Westford station to

the Tsukuba correlator as soon as possible. Therefore, we introduced a real-time data transfer

system developed by NICT into the sessions. The system adopts VLBI Data Interchange Format

(VDIF) and Simple UDP (SUDP) protocol in the data transfer process. As the VDIF format

data is converted to K5/VSSP format at the time of recording on the receiving server (Tsukuba’s

transfer server), it is not necessary to convert the data after the data transfer. It enables us to

reduce the latency of VLBI sessions. This system requires the K5/VSI board in the station which

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Tsukuna VLBI Analysis Center Geospatial Information Authority of Japan

Figure 1. Ultra-rapid dUT1 measurement system

transfers the data to the correlator. NICT installed the K5/VSI board in the Wettzell station and

succeeded in real-time data transfer from Wettzell to Tsukuba or Kashima station. The Onsala

and Mets ̈ahovi stations have another real-time data transfer system which consists of the Tsunami

protocol and PC-EVN. However, the other stations have not installed a real-time data transfer

system yet, so we implemented the data transfer from the stations after the end of the session.

2.2. Automatic Data Conversion Program

For the INT2 sessions’ Tsukuba—Wettzell baseline, we do not have to convert the data any

more because we have adopted the real-time data transfer system. However, it is necessary to

convert the data from Mark 5 format to K5 format for the INT2 sessions’ Tsukuba—Westford

baseline. As the data transfer is executed immediately after the Mark 5 data is put on the transfer

server at Haystack, we will convert the transferred data after all data is transferred. The data

conversion is also executed automatically using a perl script. It takes about 1.5 hours to convert

all the data. We are considering how to reduce the delay caused by data conversion.

2.3. Automatic Correlation Program

The correlation work for the ultra-rapid dUT1 sessions is implemented by the “Cor mgr”

program developed by NICT. We created some scripts to execute the Cor mgr automatically. The

script confirms if the K5 data of both stations is ready in the data server, and it distributes the

correlation to the correlation servers if the data is available. We use about eight correlation servers

for the correlation work. The processing factor of the correlation system will be less than 0.30 if

all of the data are already available before we start the correlation program.

2.4. Automatic Data Analysis Program

We adopt mainly two kinds of analysis software for the ultra-rapid dUT1 measurement. The

software is OCCAM developed by Vienna University of Technology and C5++ developed by NICT.

We can analyze the VLBI data with the software automatically. The analysis time is less than

254 IVS 2010 Annual Report
Geospatial Information Authority of Japan Tsukuna VLBI Analysis Center

one minute. Therefore, we can obtain the dUT1 results within a few minutes if we complete the

correlation work immediately after the end of the observing session.

3. Results of Our Activities

The Tsukuba Analysis Center analyzes the data of three kinds of ultra-rapid dUT1 sessions.

This section shows the results of the experiments and the assignment for next one.

3.1. Ultra-rapid dUT1 Measurements in INT2 Sessions

We have analyzed the data of INT2 sessions for ultra-rapid dUT1 measurements using

CALC/SOLVE, C5++, and OCCAM. The differences between solutions from pairs of analysis

software are shown in Figure 2. The C5++ solution looks consistent with the CALC/SOLVE

solutions. The differences are less than 40 microseconds. However, some of the OCCAM solutions

have over 40 microseconds difference compared with the CALC/SOLVE solutions. We have to

figure out whether the solution is right or not.

Figure 2. Comparisons of solutions estimated by each software.

3.2. Ultra-rapid dUT1 Measurements during 24-Hour VLBI Sessions

In 2010, we also implemented the ultra-rapid dUT1 measurements for 21 IVS 24-hour sessions

(R1, RDV, T2 etc.) in which Tsukuba, Onsala, or Mets ̈ahovi stations participated. In the case

of 24-hour sessions, we can obtain a number of dUT1 value during the observing session because

the data analysis is done every 35 scans. Although we failed to transfer data of some scans due

to overload of transfer server on some of the sessions, we could obtain dUT1 values at more than

80 points on each session. After IVS 24-hour sessions, Tsukuba and Onsala stations implemented

an additional ultra-rapid dUT1 experiment, which is optimized for dUT1 measurement. We could

observe about 430 scans in 11 hours and obtain dUT1 at more than 330 points during the observing

session. Figure 3 shows the UT1-UTC values obtained by C5++ or OCCAM software on the

“UR0355” session on Dec. 22, 2010. The results of the C5++ analysis fluctuates more than the

OCCAM results. We have to investigate whether the results are reliable or not.

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Tsukuna VLBI Analysis Center Geospatial Information Authority of Japan

Figure 3. Top: OCCAM solutions on additional ultra-rapid dUT1 session. Bottom: C5++ solutions on

additional ultra-rapid dUT1 session.

4. Staff

Kensuke Kokado: Technical Official (GSI)

Management of overall activity of Tsukuba Analysis Center.

Maintenance and support of real-time data transfer system

Maintenance/support of K5 software correlation system and e-VLBI system

Kentaro Nozawa: Technical Operator (AES)

Main operator of the analysis work

Maintenance of the real-time correlation and analysis system

Toshio Nakajima: System Engineer (I-JUSE)

System Engineer for maintenance of computers and e-VLBI network

5. Plan for 2011

Although our Analysis Center has tried ultra-rapid dUT1 measurements on INT2 sessions,

we have not submitted the results officially to the IVS Data Centers yet. As we stabilize the

data processing system, we will start to submit the C5++ results from the end of February 2011.

We plan to implement ultra-rapid dUT1 measurements with the Auckland 12-m antenna in New

Zealand (WARK12M). If we succeed for a North-South baseline, we will be able to obtain X/Y

polar motion parameters immediately after the observing session. We would like to implement two

baseline ultra-rapid dUT1 experiments including West-East and North-South baselines in 2011.

256 IVS 2010 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, Kerry A. Kingham, David M. Hall

Abstract

This report summarizes the activities of the VLBI Analysis Center at the United States Naval

Observatory for calendar year 2010. 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 2010

calendar year, the USNO VLBI Analysis Center produced one periodic global Terrestrial Reference

Frame (TRF) solution for internal use only. Earth orientation parameters (EOP), 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 2010 calendar year, Analysis Center personnel focused much of their efforts on both the

DiFX software correlator implementation at USNO and on establishing a program of daily Intensive

experiments to measure UT1–UTC using two stations of the Very Long Baseline Array (VLBA).

Analysis Center personnel also continued research into future high-frequency celestial reference frames

based upon the VLBA K/Q-band experiments.

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, the production of periodic global Terrestrial Reference

Frame (TRF) and Celestial Reference Frame (CRF) solutions, and the submission to the IVS

of Intensive (EOP-I) and session-based (EOP-S) Earth orientation parameters based on USNO

global TRF 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 2010 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. Due to a decrease in staffing,

the Analysis Center has suspended in-house analysis of the IVS-R1 experiments in favor of using

the databases submitted by NASA-GSFC. Analysis Center personnel continue to be responsible

for the analysis and database submission for the periodic IVS-CRF experiments. In 2010, USNO

scheduled and analyzed four CRF related experiments including IVS-CRF58 through IVS-CRF61.

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.

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2.2. Global TRF Solutions, EOP, and Sinex Submission

USNO VLBI Analysis Center personnel continued to produce periodic global EOP/TRF solutions over the course of the 2010 calendar year. This year a single solution (2010a) was produced

and submitted to the IVS. Analysis Center personnel continued to submit the USN-EOPS series,

which are now based upon the 2010a solution and are updated with new IVS-R1/R4 experiments.

The updated EOPS series was 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. Celestial Reference Frame (CRF)

On January 1, 2010 the Second Realization of the International Celestial Reference Frame

(ICRF2) was adopted by the International Astronomical Union (IAU) as the fundamental reference

frame for all astronomy. USNO VLBI Analysis Center personnel made significant contributions to

the IERS Technical Note No. 35, which provides a complete description of ICRF2.

During the 2010 calendar year, Analysis Center personnel continued work on the production of

global CRF solutions for dissemination by the IVS including crf2010a. The global CRF solutions

produced are routinely compared to the current ICRF (now ICRF2). Also in 2010, Analysis Center

personnel continued to collaborate with colleagues from Bordeaux Observatory, NASA-GSFC,

NASA-HQ, NASA-JPL, and NRAO on a program of high-frequency reference frame observations

made with the VLBA. This project aims to investigate the feasibility of a CRF at frequencies

between 24 and 43 GHz. Recently, two articles were published summarizing the astrometric results

(Lanyi et al., 2010, AJ, 139, 1695) and the imaging results (Charlot et al., 2010, 139, 1713) from

the program. No new K/Q-band sessions were observed in 2010; however a previous session that

was accepted but never scheduled was observed in January 2011. In addition, a proposal for new

observations was submitted.

2.4. Software Correlator

Over the course of the 2010 calendar year, Analysis Center personnel were heavily involved

in the implementation, testing, and evaluation of the DiFX software correlator. It is vital to

the future of VLBI at USNO that a smooth transition takes place from the current Mark IV

hardware correlator to the new DiFX software correlator. In late 2010 the software correlator

implementation was transferred to a single 12-core machine. In addition, two Mark 5 units were

purchased and connected to the correlator via a 1 Gbps ethernet switch. Geodetic data from several

experiments have been successfully correlated on this latest edition of the DiFX software. Postcorrelation fringe-fitting and calibration were performed within the Astronomical Image Processing

System (AIPS), but testing is underway on a new difx2mark4 package that will allow the correlator

output to be read into the more traditional Haystack Observatory Post-processing System (HOPS).

Analysis Center personnel continue to interface with colleagues from various institutions that are

collaborating on DiFX and attended the DiFX meeting in Socorro, NM in October of 2010.

258 IVS 2010 Annual Report
United States Naval Observatory USNO VLBI Analysis Center

2.5. VLBA Intensive Experiments

To test the feasibility of using the VLBA for the purpose of measuring UT1–UTC, two series of

test observations (TB014 and TC015) were conducted in the 2009–2010 time frame. The TC015

series included five VLBA stations and was optimized for the Mauna Kea, HI to St. Croix,

USVI baseline. The TB014 series included only three stations and was optimized for the shorter

Mauna Kea (MK) to Pie Town, NM (PT) baseline. The data were correlated on the USNO

implementation of the software correlator, were fringe-fitted within NRAO’s AIPS package, and

were further analyzed within the GSFC SOLVE package. Figure 1 shows the differences between

the VLBA MK-PT baseline UT1–UTC results and IERS C04-05. Differences between IERS C04-05

and the USN-EOPI and USN-EOPS series are also shown.

Figure 1. Differences in UT1-UTC between IERS C04-05 and data from VLBA test experiments TB014 and

TC015 for the MK-PT baseline. Also shown are differences between IERS C04-05 and both the USN-EOPI

and USN-EOPS standard series for comparison.

Based upon the tests conducted, the USNO signed a memorandum of understanding (MOU)

with NRAO and the National Science Foundation (NSF) to begin using two stations of the VLBA

to measure UT1–UTC. The plan is for a 1.5-hour daily Intensive between the MK and PT stations

to be observed and for the data to be electronically transferred over high-speed network links

to USNO for correlation. This new Intensive series is scheduled to begin in October 2011. To

connect the two stations to the network, USNO has contracted with NRAO for the Pie Town (PT)

station and with the University of Hawaii for the Mauna Kea (MK) station. These contracts will

provide for 1 Gbps links to nearby 10 Gbps POPs on National Lambda Rail and Internet2 for

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PT and MK, respectively. The data from this baseline will be correlated on the DiFX software

correlator, fringed using FOURFIT and HOPS, analyzed within SOLVE, and submitted to the

IVS for distribution to the community.

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:

Name Responsibilities

David Boboltz Periodic global TRF solutions and comparisons; VLBA Intensive program; software correlator implementation; VLBI data analysis.

Alan Fey Periodic global CRF 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.

Kerry Kingham Hardware correlator interface; software correlator implementation;

VLBI data analysis.

David Hall Hardware correlator interface; software correlator implementation;

VLBI data analysis.

4. Future Activities

For the upcoming year January 2011–December 2011, USNO VLBI Analysis Center personnel

plan to accomplish the following activities:

• Continue testing and evaluation of the USNO implementation of the DiFX software

correlator. Streamline pre- and post-correlation processing.

• Begin testing the electronic transfer of VLBI Intensive data from the MK and PT VLBA

stations with regular operations beginning in October 2011.

• Continue analysis and submission of IVS-R4 experiments for dissemination by the IVS.

• Continue the production of periodic global TRF 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 Intensive experiments and submission of EOP-I estimates to

the IVS.

• Continue the scheduling, analysis, and database submission for all IVS-CRF experiments.

• Continue the production of periodic global CRF solutions.

• Continue research into the development of high-frequency reference frames based upon

VLBA K- and Q-band sessions.

260 IVS 2010 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, Roopesh Ojha, Ralph A. Gaume, Kerry A. Kingham

Abstract

This report summarizes the activities of the United States Naval Observatory Analysis Center for

Source Structure for calendar year 2010. VLBA RDV experiments RDV75, RDV77, and RDV79 were

calibrated and imaged. Images from these three experiments were added to the USNO Radio Reference Frame Image Database. VLBA high frequency (K/Q-band) experiment BL151b was calibrated

and imaged. A Southern Hemisphere imaging and astrometry program for maintenance of the ICRF

continued. Activities planned for the year 2011 include continued imaging of ICRF sources at standard

and higher frequencies and continued analysis of source structure and its variation.

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 (a 7.9% increase over the previous year)

of 782 sources (a 10% increase over the previous year) at radio frequencies of 2.3 GHz and 8.4 GHz.

Additionally, the RRFID contains 1,706 images (a 12% percent increase over the previous year) of

282 sources (a 0.7% increase over the previous year) 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

2.1. VLBA Imaging

Very Long Baseline Array (VLBA) observations for maintenance of the celestial and terrestrial

reference frames have been carried out since about 1994. Since 1997, these VLBA RDV (Research and Development with VLBA) observations have been part of a joint program between the

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USNO, the Goddard Space Flight Center (GSFC), and the National Radio Astronomy Observatory (NRAO). During each 24-hour VLBA RDV session, about 100 ICRF sources are observed at

S/X-band (2.3/8.4 GHz) using the VLBA together with up to 10 additional geodetic antennas.

Images are produced from these observations and made available through the RRFID.

VLBA experiment RDV77 (2009OCT07) was calibrated and imaged, adding 180 (90 S-band;

90 X-band) images to the RRFID including images of 21 sources (0110-361, 0332-403, 0521-403,

0627+814, 0705-412, 0714+457, 0717-393, 0855+143, 0857-329, 1015+057, 1149-084, 1232-338,

1327+504, 1406-297, 1456+044, 1817+157, 2005+372, 2039+037, 2215+150, 2311-373, 2348-432)

not previously imaged.

VLBA experiment RDV75 (2009MAY13) was calibrated and imaged, adding 179 (90 S-band;

89 X-band) images to the RRFID including images of 27 sources (0007-325, 0114-211, 0115-214,

0227-369, 0347-211, 0422-380, 0422-389, 0436-129, 0843-336, 1027-186, 1255-177, 1302-208, 1339-

287, 1346-306, 1550-242, 1613-350, 1622-310, 1647+744, 1749+701, 1751+288, 1759-396, 1906-217,

2000+472, 2120-309, 2122-238, 2307+106, 2357-318) not previously imaged.

VLBA experiment RDV73 (2009JAN21) was calibrated and imaged, adding 175 (87 S-band;

88 X-band) images to the RRFID including images of 23 sources (0035-252, 0043-268, 0055-059,

0420+022, 0502-152, 0515+208, 0529+483, 0532-378, 0632-235, 0741-444, 0847-120, 0915-118,

1059-438, 1133-032, 1243-160, 1428+370, 1602-115, 1633-409, 1650-157, 1711-209, 1913-272, 2157-

255, 2220-318) not previously imaged.

Collaborations continue with Glenn Piner at Whittier College and Patrick Charlot of the Laboratoire d’Astrophysique de Bordeaux to calibrate and image several of the VLBA RDV experiments.

2.2. VLBA High Frequency Imaging

A program to extend the ICRF to 24 and 43 GHz continued in 2010. These observations are

part of a joint program between the National Aeronautics and Space Administration, the USNO,

the National Radio Astronomy Observatory (NRAO), and the Laboratoire d’Astrophysique de

Bordeaux. During the calender year 2010 two papers were published in the Astronomical Journal:,

1) “The Celestial Reference Frame at 24 and 43 GHz. I. Astrometry” by Lanyi et al. and 2) “The

Celestial Reference Frame at 24 and 43 GHz. II. Imaging” by Charlot et al. (see § 5).

VLBA high frequency experiment BL151b (2008DEC18) was calibrated and imaged adding

187 (K-band only) images to the RRFID including two sources not previously imaged.

2.3. ICRF Maintenance in the Southern Hemisphere

The USNO and the Australia Telescope National Facility (ATNF) continue a collaborative

program of VLBI research on Southern Hemisphere source imaging and astrometry using USNO,

ATNF, and ATNF-accessible facilities. These observations are aimed specifically toward improvement of the ICRF in the Southern Hemisphere.

A program to monitor the structure of quasars south of declination −30◦that are either known

to be gamma-ray loud or are expected to be gamma-ray loud continued. The program, called

TANAMI (Tracking Active galactic Nuclei with Australia Milliarcsecond Interferometry), is observing a sample of quasars at 8 GHz and 24 GHz bands (see § 5).

262 IVS 2010 Annual Report
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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, Roopesh Ojha, Ralph A. Gaume, and Kerry A. Kingham.

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 2011 are planned:

• Continue imaging and analysis of VLBA 2.3/8.4/24/43 GHz experiments

• Make additional astrometric and imaging observations in the Southern Hemisphere in collaboration with ATNF partners and the TANAMI program team.

5. Relevant Publications

Publications of relevance to Analysis Center activities:

• “TANAMI: tracking active galactic nuclei with austral milliarcsecond interferometry. I. Firstepoch 8.4 GHz images,” Ojha, R., Kadler, M., B ̈ock, M., Booth, R., Dutka, M. S., Edwards,

P. G., Fey, A. L., Fuhrmann, L., Gaume, R. A., Hase, H., Horiuchi, S., Jauncey, D. L.,

Johnston, K. J., Katz, U., Lister, M., Lovell, J. E. J., M ̈uller, C., Pl ̈otz, C., Quick, J. F. H.,

Ros, E., Taylor, G. B., Thompson, D. J., Tingay, S. J., Tosti, G., Tzioumis, A. K., Wilms,

J. & Zensus, J. A. 2010, A&A, 519, 45

• “The Celestial Reference Frame at 24 and 43 GHz. I. Astrometry,” Lanyi, G. E., Boboltz,

D. A., Charlot, P., Fey, A. L., Fomalont, E. B., Geldzahler, B. J., Gordon, D., Jacobs, C. S.,

Ma, C., Naudet, C. J., Romney, J. D., Sovers, O. J. & Zhang, L. D. 2010, AJ, 139, 1695

• “The Celestial Reference Frame at 24 and 43 GHz. II. Imaging,” Charlot, P., Boboltz, D.

A., Fey, A. L., Fomalont, E. B., Geldzahler, B. J., Gordon, D., Jacobs, C. S., Lanyi, G. E.,

Ma, C., Naudet, C. J., Romney, J. D., Sovers, O. J. & Zhang, L. D. 2010, AJ, 139, 1713

IVS 2010 Annual Report 263

Technology Development Centers

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 VLBI2010.

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 Herzberg Institute for Astrophysics of the National Research Council of Canada (DRAO/HIA/NRC).

2. VLBI2010 Committee (V2C)

The Canadian TDC is primarily focused on encouraging the realization of VLBI2010. This is

done by Bill Petrachenko, chairman of the V2C, and Toni Searle, both of NRCan. In collaboration

with others, this year’s activity focused on the following areas:

• Development of algorithms for processing broadband data,

• Application of those algorithms to the processing of broadband data produced by the NASA

broadband delay proof-of-concept effort,

• Development of a specification for VLBI2010 total power detection,

• Execution of studies into the nature, impact, and mitigation of Radio Frequency Interference

(RFI),

• Execution of studies into the impact on the VLBI2010 broadband system of RFI generated

at co-location sites that include the DORIS beacon and SLR aircraft avoidance radar,

• Participation in the VLBI2010 Project Executive Group.

3. DRAO Activities

Two prototype 10-m composite antennas that are light, stiff, and cost effective have been

developed and tested. Under the leadership of Gordon Lacy, design studies for more efficient

designs continue.

Under the leadership of Brent Carlson and Dave Fort, DRAO completed the production of the

correlator for the EVLA project. It is one of the most ambitious radio interferometry correlators

ever designed. Correlator expertise at DRAO is now being directed toward novel designs for the

SKA.

IVS 2010 Annual Report 267
FFI TD Center Forsvarets forskningsinstitutt (FFI) (Norwegian Defence Research Establishment)

FFI Technology Development Center—Software Development

Per Helge Andersen

Abstract

FFI’s contribution to the IVS as a Technology Development Center focuses primarily on the development and validation of the GEOSAT software for a combined analysis at the observation level of

data from VLBI, GPS (ground-based and LEO), SLR, altimetry, and gradiometry. This report shortly

summarizes the latest improvements of the GEOSAT software. FFI is currently an Analysis Center for

IVS and ILRS, and a Technology Development Center for IVS.

1. The GEOSAT Software and Activities in 2010

FFI’s contribution to the IVS as a Technology Development Center focuses primarily on the development and validation of the GEOSAT software for a combined analysis at the observation level

of data from VLBI, GPS (ground-based and LEO), SLR, altimetry, accelerometry, and GRACE

KBR. The advantages of the combination of independent and complementary space geodetic data

at the observation level is discussed in Andersen [1].

Space borne accelerometry has been implemented, and a small set of data has been tested

(GOCE and GRACE). A complete production line for altimetry (Topex, ENVISAT, JASON 1

& 2) has been implemented and tested. The IERS 2010 Conventions have been implemented

and tested. The GEOSAT orbit model has been validated against external LEO orbits. The

RMS difference between JPL GRACE orbits and internal GEOSAT orbits is typically 4 mm in

each cartesian direction. The corresponding RMS difference between external GOCE orbits (ESA

official, approximately 250 km altitude) and internal GEOSAT orbits is typically 11 mm. This

work will continue in 2011.

The Norwegian Mapping Authority (NMA) and FFI have started a close cooperation in analysis

of space geodetic data using the GEOSAT software. NMA has recently been given the status of

an Associate Analysis Center of IVS. The GEOSAT software is to be used in the analysis of VLBI

data. We are right now trying to get our GEOSAT-generated SINEX files accepted by the IVS

combination software. There are options in GEOSAT so that the VLBI model is in compliance

with the other analysis software packages.

2. Staff

Dr. Per Helge Andersen—Research Professor of Forsvarets forskningsinstitutt (FFI). Dr. Eirik

Mysen—Scientist at the Norwegian Mapping Authority (NMA). Dr. Kristian Breili—Scientist

at the Norwegian Mapping Authority (NMA). Dr. Halfdan Kierulf—Scientist at the Norwegian

Mapping Authority (NMA).

References

[1] Andersen, P. H. Multi-level arc combination with stochastic parameters. Journal of Geodesy (2000) 74:

531-551.

268 IVS 2010 Annual Report
NASA Goddard Space Flight Center GSFC Technology Development Center

GSFC Technology Development Center Report

Ed Himwich, John Gipson

Abstract

This report summarizes the activities of the GSFC Technology Development Center (TDC) for 2010

and forecasts planned activities for 2011. The GSFC TDC develops station software including the Field

System, 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

and Ed Himwich, both 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 all the IVS

network stations (i.e., more than 30) 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 started:

• Patriot 12-m Interface. A preliminary interface to Patriot 12-m antennas was developed.

This was implemented using the position and velocity tracking mode in the Patriot antenna

controller. All aspects of this appear to work, but final testing is delayed until next year

when a receiver will be available.

• Satellite Tracking. A satellite tracking capability was developed for the FS. This will allow

an antenna to be pointed at a satellite in one of three modes: (1) Ephemeris, (2) Az-El, or

(3) RA-Dec. The Ephemeris tracking mode is the most flexible and precise. A one second

ephemeris for several hours is built in memory, which the antcn antenna interface can use

to guide the antenna. However, this requires special programming of the antenna interface,

and some antennas may not be able to support this mode. The Az-El mode is useful for

geo-synchronous or possibly slowly moving satellites, if the antenna being used supports

commanding with fixed Az-El coordinates. The RA-Dec mode is the most universal since all

antennas support RA-Dec pointing, but it may have limited usefulness if the satellite is not

IVS 2010 Annual Report 269
GSFC Technology Development Center NASA Goddard Space Flight Center

moving at a nearly sidereal rate. It is expected that the Az-El and RA-Dec modes will be

enhanced to allow periodic recommanding of the position. This may help with tracking slow

moving objects. However, depending on the behavior of the antenna, this may introduce

unacceptable jumps in the antenna tracking. The open source predict program is used to

calculate the pointing angles from the orbital elements.

• Holography. A new SNAP command holog was developed to support holographic measurements of antennas. In it simplest form, this command will move an antenna in a boustrophedon pattern around a grid centered on either an Az-El or RA-Dec commanded position.

A user-defined SNAP procedure is run to collect data at each grid point. Various options

are available including specifying a “return to center” interval for recalibration, changing the

order in which the grid points are visited, and allowing single “cuts” to be made on each

axis.

These new capabilities will be included in FS releases next year. Several other improvements

are expected in future releases, including:

• Support for DBBC and RDBE racks

• Support for Mark 5C 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

• Conversion of the FORTRAN source to use the gfortran compiler; this will enable use of the

source level debugger, gdb, for development and field debugging

• Chekr support for Mark 5A and Mark 5B systems

• Use of the Mark IV Decoder for phase-cal extraction in the field

• FS Linux 9 (based on Debian squeeze) distribution

• Support for periodic firing of the noise diode during observations

• Distribution of the new gnplt.

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 2010 and

plans for 2011.

270 IVS 2010 Annual Report
NASA Goddard Space Flight Center GSFC Technology Development Center

3.1. SKED

The following changes were made to SKED:

• A station is no longer scheduled in tag-along mode if the station is “down” (not available for

observing).

• StatWt was made its own command and given more flexibility. The user can now give

independent weights to each of the stations to try to increase the number of observations

that are scheduled.

• The command SrcWt was introduced. This is analogous to StatWt in that the user instructs SKED to preferentially select scans involving certain stations.

• A new command Coverage was introduced which calculates and reports sky coverage at the

stations.

• Previously the user needed to specify the full path for use in the master command. This

meant, for example, that the user had to change the directory specified in skedf.ctl in order

to use this command for Intensives or if the year changed. Now all the user needs to do is

specify the directory where the master-files are kept, and SKED will search all of master-files.

• Many internal references to tape were removed. The motivation was that many calculations

were no longer necessary since it is no longer necessary to worry about rewinding tapes and

ensuring that there is enough space left at the end of a tape. Some of these calculations

actually led to incorrect schedules or resulted in increased idle time.

• All reported bugs were fixed. For the most part these occurred in unusual circumstances.

• The formatting of some error messages was improved to aid the user in understanding exactly

what the problem was.

In addition we worked on updating the SKED documentation. The last time this was completely updated was in the 1990s.

Plans for the next year include: (1) releasing the updated documentation, (2) making VEX

format native, and (3) modifying SKED as necessary to support VLBI2010.

3.2. DRUDG

The only changes made to DRUDG were in the calculation of BBC frequencies. In some unusual

cases the printed results were incorrect because of round-off errors. This was fixed by making the

intermediate calculations in double precision.

Plans for the next year include: (1) a documentation update and (2) support for VLBI2010.

IVS 2010 Annual Report 271
Haystack Technology Development Center MIT Haystack Observatory

Haystack Observatory Technology Development Center

Chris Beaudoin, Brian Corey, Arthur Niell, Alan Whitney

Abstract

Technology development at MIT Haystack Observatory focused on four areas in 2010:

• Digital backend recorder development

• Development of VLBI2010 receiver hardware

• RFI compatibility at GGOS stations

• Monitor and control infrastructure

1. Digital Backend Recorder Development

In 2010, the Haystack-NRAO collaboration continued to develop the RDBE subsystem (see

Figure 1). In its current state, the RDBE is functional as a polyphase filter bank (PFB) processing

eight user-selectable 32-MHz channels from a choice of sixteen uniformly-spaced channels in the

512-MHz IF bandwidth. A PFB personality with 8-MHz frequency channels is also planned, to

provide compatibility with older data acquisition systems and to allow joint observations with

the operational S/X geodetic network. A digital downconverter (DDC) personality is currently

under development and will support flexible tuning of LO frequency and bandwidth for multiple

baseband frequency channels.

Currently the RDBE produces data in Mark 5B formatted packets at 2 Gbps over its 10 Gigabit

Ethernet interface; a VDIF output data-formatting module is currently under development for the

RDBE and will provide more flexibility in the data output format. The RDBE also possesses a

timing module which can be programmed to start and stop data packet transmission. This feature

allows the RDBE to control the data observation start and stop times, hence shifting the time

keeping responsibility from the Mark 5 data recorder to the digital backend. The Mark 5C 10Gbps

data packet recorder was also demonstrated to reliably record ethernet data packets produced by

the RDBE at a data rate of 2 Gbps; 4 Gbps operation is expected in the near future.

In July 2010 a VLBI fringe test was conducted between the Westford 18-m and GGAO 5-

m antennas. In this experiment both sites used an RDBE programmed with the 32-MHz PFB

personality and a Mark 5C data packet recorder. A 10-minute recording was made on the source

3C84, and fringes were successfully detected.

2. Development of VLBI2010 Receiver Hardware

Haystack Observatory is engaged in the development of a receiver front-end for the new GGAO

Patriot 12-m antenna (see GGAO 2010 network station report). This hardware (see Figure 2a) is

based on the cryogenic 2-14 GHz Eleven antenna developed at Chalmers University of Technology.

In January 2010, noise temperatures were measured at 2-10 GHz with the new feed [1] and a set

of Caltech 1-12 GHz LNAs [2]; the measured values were ∼20 K over 3-10 GHz, with somewhat

higher values expected above 10 GHz due to higher LNA noise temperatures.

The feed, shown in Figure 2a, is expected to be installed on the Patriot 12-m antenna in early

2011.

272 IVS 2010 Annual Report
MIT Haystack Observatory Haystack Technology Development Center

Figure 1. System Block Diagram of RDBE.

In late 2010 Sandy Weinreb and Ahmed Akgiray [3] introduced a new unbalanced broadband

QRFH design (see Figure 2b). This feed was designed specifically for the Patriot 12-m antenna and

requires only one LNA per polarization. At Caltech a prototype QRFH was constructed, and its

radiation patterns were measured; the measurements indicate performance is near the theoretical

expectation. This feed is also expected to be evaluated on the Patriot 12-m antenna in 2011.

Figure 2. Broadband microwave feeds to be evaluated on the Patriot 12-m antenna at GGAO. (a) Chalmers

Eleven Feed, with associated hybrids and LNAs, (b) Caltech QRFH.

A broadband noise-adding radiometer (NAR) system was developed at Haystack to provide

VLBI2010 receiver noise temperature diagnostics. The system is based on a MiniCircuits broadband log-detector, which performs an RF power to DC voltage transducer function, and an Arduino

IVS 2010 Annual Report 273
Haystack Technology Development Center MIT Haystack Observatory

microcontroller, which coherently integrates the receiver noise power during on and off states of

the calibrated noise source. A block diagram of the NAR system is shown in Figure 3.

Figure 3. System block diagram of the Arduino-based Noise Adding Radiometer.

3. RFI Compatibility at GGOS Stations

Haystack staff studied the compatibility between a VLBI2010 receiver and both a DORIS

ground transmitter and an SLR aircraft radar. The latter two systems have the potential to

degrade VLBI data quality and, in the worst case, damage the front-end of the receiver. For a

VLBI2010 receiver incorporating LNAs similar to the Caltech LNAs [2], studies [4] concluded that

the power received at the feed from a DORIS beacon should be below -80 dBW, and below -70

dBW as received from the SLR radar. Options for inserting an RF barrier between a transmitter

and a VLBI antenna are being investigated. The goal is to satisfy these power level restrictions

without significantly degrading the DORIS and SLR data products.

274 IVS 2010 Annual Report
MIT Haystack Observatory Haystack Technology Development Center

4. Monitor and Control Infrastructure (MCI)

MCI collaboration between Wettzell station, NVI, and Haystack continued in 2010. In July

2010, a face-to-face meeting of the VLBI2010 MCI team took place at Wettzell. The main outcome

pertinent to the VLBI community was the team sanction of a generalized MCI interface which can

be adapted to accommodate arbitrary MCI system architectures. This was deemed necessary in

order to accommodate MCI system architectural situations that extend beyond the specific cases

encountered at Wettzell, GGAO, and Westford/Haystack. MCI self-identification will be a key

feature of this generalization.

Haystack has also outlined a detailed description of the MCI needed for the newly installed Patriot 12-m radio telescope at GGAO. Hardware currently under development jointly by HoneywellTSI and Haystack will meet the MCI requirements set forth for this system. The SysMon scheduler

and IDL2RPC communications interface developed at Wettzell will be incorporated to provide the

software backbone for this system.

References

[1] J. Yang, et.al., “Cryogenic 2-13 GHz Eleven feed for reflector antennas in future wideband radio

telescopes,” IEEE Trans. on Antennas Propag. Special Issue on Antennas for Next Generation Radio

Telescopes, vol. 59, no. 3, March 2011

[2] N. Wadefalk and S. Weinreb, “Data sheet on CITCRYO1-12A, 1-12 GHz Cryogenic HEMT Low Noise

Amplifier,” California Institute of Technology

[3] A. Akgiray and S. Weinreb, “Wideband Near-Constant Beamwidth Flared Quad-Ridge Horn Feed

for Reflector Antennas in Radio Astronomy.” Presented at the 2011 National Radio Science Meeting,

Boulder, Colorado

[4] C. Beaudoin, B.E. Corey, and B. Petrachenko, “Radio frequency compatibility of VLBI, SLR, and

DORIS at GGOS stations.” Poster G11B-0638 presented at the 2010 American Geophysical Union Fall

meeting, San Francisco, CA

IVS 2010 Annual Report 275
Technology Development Center at NICT Kashima Space Research Center, NICT

Technology Development Center at NICT

Kazuhiro Takefuji, Tetsuro Kondo, Hiroshi Takiguchi

Abstract

The National Institute of Information and Communications Technology (NICT) leads the development of the VLBI technique and is highly active in both observations and technical developments.

This report gives a review of the Technology Development Center (TDC) at NICT and summarizes

recent activities.

1. TDC at NICT

NICT’s IVS Technology Development Center publishes the newsletter “IVS NICT-TDC News

(former IVS CRL-TDC News)” at least once a year in order to inform about the development

of VLBI related technology . The newsletter is available through the Internet from the following

URL http://www2.nict.go.jp/w/w114/stsi/ivstdc/news-index.html.

2. Staff Members of NICT TDC

Table 1 lists the staff members of NICT who are involved in the VLBI Technology Development

Center.

Table 1. Staff Members of NICT TDC as of January 2011 (alphabetical).

Name Works

AMAGAI, Jun QZSS1, GPS analysis, TWSTFT2

HASEGAWA, Shingo K5/VSSP32, K5/VSI

HOBIGER, Thomas QZSS1, e-VLBI, GPS, GNSS analysis

ICHIKAWA, Ryuichi MARBLE3system, VLBI analysis

ISHII, Atsutoshi MARBLE3system

KAWAI, Eiji 34-m and 11-m antenna system

KIMURA, Moritaka Giga-bit system, K5/VSI, Software correlator, e-VLBI

KONDO, Tetsuro K5/VSSP32, Software correlator, e-VLBI

KOYAMA, Yasuhiro e-VLBI, Group reader

MIYAUCHI, Yuka Software correlator

SEKIDO, Mamoru e-VLBI, Delta-VLBI, VLBI analysis

TAKEFUJI, Kazuhiro ADS3000+ system

TAKIGUCHI, Hiroshi VLBI analysis, e-VLBI, GPS analysis

TSUTSUMI, Masanori K5 system, ADS3000+ system

1 QZSS: Quasi-Zenith Satellite System

2 TWSTFT: Two-Way Satellite Time and Frequency Transfer

3 MARBLE: Multiple Antenna Radio-interferometry of Baseline Length Evaluation

276 IVS 2010 Annual Report
Kashima Space Research Center, NICT Technology Development Center at NICT

3. Current Status and Activities

3.1. RF Direct Sampling

We have successfully carried out a test VLBI experiment with the so-called “RF direct sampling” technique. In a conventional VLBI system, RF signals are converted to IF band and

thereafter converted further to baseband using an analog baseband converter. Finally the signals

are sampled and converted to digital signals. With recent technology it became possible to sample

IF signals directly due to the performance improvement of sampling devices, which led to the

development of our digital baseband converter, named ADS3000. Recently a few sampling devices

support a wide frequency bandwidth of up to or more than 10 GHz. If RF signals such as those

in the 8 GHz band signals can be sampled directly, an IF converter becomes obsolete within the

receiving system. This will reduce the costs of the system and increase the reliability of the system. ADX-830 developed by the ELECS INDUSTRY CO. LTD., is a sampler that has an input

bandwidth of 30 GHz. We have carried out a test VLBI observation between the 34-m and 11-m

antennas at Kashima by using the ADX-830 to evaluate the feasibility of RF direct sampling. Figure 1 shows the corresponding system block diagram. RF direct sampling with sampling modes of

2bit-1024Msps, 1bit-2048Msps, and 1bit-4096Msps were performed at the Kashima 11-m antenna.

At the Kashima 34-m antenna, IF signals were sampled by using the ADS-1000 system with a

sampling mode of 2bit-1024Msps. We could successfully get fringes except for the 1bit-4096Msps

mode (Figure 2).

SAMPLER

ADS1000

PLO

KASHIMA 34m

PLO

KASHIMA 11m

SAMPLER

ADX-830

PC

CLOCK GEN

ELECS

5MHz 10MHz 1PPS

LNA

AMP

AMP LNA

AMP

BPF

LPF

ANTENNA ANTENNA

SAMPLER

ADS1000

PLO

KASHIMA 34m

PLO

KASHIMA 11m

SAMPLER

ADX-830

PC

CLOCK GEN

ELECS

5MHz 10MHz 1PPS

LNA

AMP

AMP LNA

AMP

BPF

LPF

ANTENNA ANTENNA

Figure 1. System block diagram for RF direct sampling at the Kashima 11-m antenna.

IVS 2010 Annual Report 277
Technology Development Center at NICT Kashima Space Research Center, NICT

Figure 2. First fringe from RF direct sampling using a 2bit-1024Msps sampling mode of the ADX-830. See

the on-line Annual Report for a colored version of the upper right figure.

3.2. Geodetic VLBI using the K5/VSI System

MK3TOOLs

Calc/Solve

K5

cout

komb

komb

K5/VSSP32

GICO3

K5/VSI

gco

gico2komb

cout

software

correlator

Figure 3. Data flow from

the K5 sampling system to

the baseline analysis program.

NICT is currently developing two types of sampling systems named

K5/VSSP32 and K5/VSI (ADS1000 and ADS3000+). Also, we are developing software correlators corresponding to each system. The K5

software correlator handles data from K5/VSSP32 and is mainly used

for geodetic VLBI experiments of Japanese stations as well as for international experiments conducted by GSI. The K5/VSI and GICO3 software

correlator forms the other suite of tools, which are mainly used for astronomical purposes. In 2010, we developed new data conversion programs

(Figure 3) which enable us to use the K5/VSI system for geodetic VLBI

experiments. In order to evaluate the results based on data which was

sampled by the K5/VSI system, we carried out a comparison experiment between K5/VSSP32 and K5/VSI system on the Kashima11m—

Koganei11m baseline. Table 2 shows the baseline length calculated from

the two types of K5 system. Results from two experiments show good

agreement. Thus it is concluded that the K5/VSI and GICO3 software

correlator can be used for geodetic VLBI experiments without loss of

precision.

278 IVS 2010 Annual Report
Kashima Space Research Center, NICT Technology Development Center at NICT

Table 2. The baseline length calculated from the data which was sampled either with K5/VSSP32 or

K5/VSI.

Exp. date System Baseline Length 1σ

2010/08/04 K5/VSSP32 109099639.00 mm 0.53 mm

2010/08/04 K5/VSI 109099639.00 mm 0.57 mm

2010/10/01 K5/VSSP32 109099635.43 mm 0.58 mm

2010/10/01 K5/VSI 109099635.58 mm 0.66 mm

3.3. ADS3000+ — First DBBC Fringe Detected

Figure 4. First DBBC fringes between

the Kashima 11-m antenna and the Koganei 11-m antenna.

NICT has developed a next-generation ADC called

ADS3000+ which supports up to 4-GHz sampling and which

is equipped with FPGA chips to realize a digital baseband

converter (DBBC) and real-time RFI(CW) suppression.

There are 16ch DBBCs inside the ADS3000+ [1]. The

specifications of the DBBC are shown in Table 3. Analog baseband spectra (band character) which are frequencyconverted by an image-rejection mixer have a downside

shape. The overall band-character of the DBBC shows a flat

and symmetric shape. The flat band-character of DBBC is

anticipated to increase the SNR. A first DBBC VLBI experiment was carried out in June 2010. The K5/VSSP32 system

was deployed at the Koganei 11-m antenna, and ADS3000+

(DBBC) was installed in the Kashima 11-m antenna leading to a baseline of about 140 km. After correlation of the

recorded data, first DBBC fringes could be successfully detected. The results are shown in Figure 4.

Table 3. Specification of ADS3000+ DBBC mode. One VSI-H outputs 16ch x 2bit or 8ch x 4bit of DBBC,

and the VSI clock speed is adjustable. 1024Msps x 4ch is supported by the DBBC for broadband purposes.

Sample speed Quantization VSI clock

8Msps 4bit Fix: 64MHz, Variable 8MHz

16Msps 4bit Fix: 64MHz, Variable 16MHz

32Msps 4bit Fix: 64MHz, Variable 32MHz

64Msps 4bit Fix: 64MHz, Variable 64MHz

1024Msps 2bit Fix: 64MHz

References

[1] Takefuji K., Tsutsumi M., Takeuchi H., and Koyama Y., Current Status of Next-Generation A/D

Sampler ADS3000+, IVS TDC News, No. 31, pp.6-9, 2010.

IVS 2010 Annual Report 279
Onsala Space Observatory (OSO), TDC Onsala Space Observatory (OSO)

Onsala Space Observatory – IVS Technology Development Center

Miroslav Pantaleev, R ̈udiger Haas, Leif Helldner, Lars Pettersson, Karl- ̊Ake Johansson,

Benjamin Klein1

Abstract

This report briefly describes the technical development relevant for geodetic/astrometric VLBI done

during 2010 at the Onsala Space Observatory.

1. A Cryogenic Receiver for VLBI2010 with the Eleven Feed

We have continued our collaboration with the Antenna Group at the Department of Signals

and Systems at Chalmers University of Technology concerning the improvement of the Eleven feed

design [1]. The activities related to the integration of the Eleven feed in a cryogenic receiver for

VLBI2010 are summarized as follows:

• Cryogenic tests to verify the expected system noise performance.

• Design and prototype tests aiming to decrease the size of the feed.

• Design and tests of different descrambling alternatives.

• Development of a model for the system noise temperature.

One Eleven feed was integrated in a test cryostat to measure reflection coefficients and system noise

temperatures. Figure 1 shows the construction drawing of the test cryostat and the measured S11

reflection coefficients of the Eleven feed at room temperature and at cryogenic conditions. The

reflection coefficient does not change when the feed is cooled to cryogenic temperature. This

proves that the mechanical and cryogenic designs are good and that the feed can be used at

cryogenic temperatures. The small variations can be explained by the change of the permittivity

with temperature. The fact that S11 at cryogenic and at room temperatures are similar confirms

that there are no significant deformations of the petals or the twin lead line.

For the noise temperature tests presented already in last year’s report we used single ended

cryogenic LNAs for the 4–8 GHz band from the Group for Advanced Receiver Development at

the department [2], [3]. During 2010 we replaced these with cryogenic differential amplifiers from

Sander Weinreb’s group at the California Institute of Technology and started tests with these.

Two alternative descrambling solutions allowing a reduction of the number of ports from eight

to four were designed, fabricated, and tested. The first alternative is based on an ultra wide-band

balun designed as a continuously scaled, gradually curved, end-fire traveling wave structure [5],

realized on microstrip, similar to the concept of the Vivaldi antenna. The measured result showed

acceptable performance in the operated bandwidth, but generally the performance degraded around

5 GHz. The second alternative aims to resolve these issues. It is based on tapered transitions from

symmetrical to single ended ports on microstrip, and a prototype development started.

A model for the system noise temperature was developed [4], based on the multiport network

method. Figure 2 shows the predicted system noise temperature over the frequency band from

2 to 13 GHz. However, work is continuing to derive more accurate noise models. There is also

ongoing work to verify these simulated results experimentally.

1PhD student at Hartebeeshoek Radio Observatory (HartRAO), South Africa

280 IVS 2010 Annual Report
Onsala Space Observatory (OSO) Onsala Space Observatory (OSO), TDC

Figure 1. Left: Construction drawing of the test cryostat. Right: Measured S11 reflection coefficients at

room temperature without and inside the cryostat, and at cryogenic temperatures inside the cryostat.

Figure 2. Measured (solid blue line) and predicted (dashed blue line) system noise temperatures Tsys

when the cryostat with the Eleven feed is pointing at the zenith, including different contributions to Tsys.

The measurements were done at the Haystack Observatory.

IVS 2010 Annual Report 281
Onsala Space Observatory (OSO), TDC Onsala Space Observatory (OSO)

2. RFI Monitoring and Mitigation

A MSc thesis project developed a radio frequency interference (RFI) monitoring system [6].

A software application was developed that communicates with different types of digital receivers

(spectrum analyzers) and a control unit for omnidirectional and steerable antennas (Fig. 3). The

detection of interference signals uses the generalized spectral kurtosis (GSK) estimator [7]. A file

containing frequencies, power levels, and the indication of any interference is saved, and corresponding plots are generated (see Fig. 3).

Another MSc thesis project had the goal of developing a software application which can be used

to identify RFI. This work was based on the Interconnect Break-out-Board (iBOB) providing realtime power spectrum density (PSD) estimates with 2048 frequency channels [8]. The PSD estimates

are fed into a Spectral Kurtosis (SK) algorithm implemented in MatLab for the calculation and

flagging of RFI.

Figure 3. Left: The main antenna control unit. Right: The Web-based interface for RFI monitoring.

3. Further Technical Development

A number of additional technical projects were carried out in 2010. The upgrade and repair of the microwave radiometer Konrad continued. The system to monitor the vertical height

changes of the 20-m radio telescope was upgraded. New temperature sensors were installed and

the measurements made available on a Web page, see http://wx.oso.chalmers.se/pisa/.

282 IVS 2010 Annual Report
Onsala Space Observatory (OSO) Onsala Space Observatory (OSO), TDC

4. Outlook and Future Plans

We will continue to develop the cryogenic receiver for VLBI2010 using the Eleven feed. New prototypes will be produced in 2011. We plan to install an RFI monitoring station at Onsala and will

include RFI mitigation in the telescope control system.

References

[1] Yang J, Pantaleev M, Kildal P-S, Klein B, Karandikar Y, Helldner L, Wadefalk N, Beaudoin C: Cryogenic 2-13 GHz Eleven Feed for Reflector Antennas in Future Wideband Radio Telescopes. Submitted

to: IEEE TAP Special Issue on Antennas for Next Generation Radio Telescopes, 2010.

[2] Pantaleev M, Yang J, Kildal P-S, Karandikar Y, Helldner L, Klein B, Wadefalk N, Haas R, Zamani M,

Zaman A U: Cryogenic 2–14 GHz low noise receiver for radio astronomy using Eleven feed. In: Proc.

of the Gigahertz Symposium 2010, Lund University, 9-10 March 2010.

[3] Risacher C, Sundin E, Perez Robles V, Pantaleev M, Belitsky V: Low Noise and Low Power Consumption Cryogenic Amplifiers for Onsala and APEX Telescopes. In: Proc. of GaAs Conference, ISBN

1-58053-994-7, pp. 375–377, Amsterdam, The Netherlands, 11-12 October 2004.

[4] Klein B, Kildal P-S, Yang J, Pantaleev M, Helldner L, Beaudoin C: System noise calculations over the

decade bandwidth of the Eleven feed. International Workshop on Phased Array Antenna Systems for

Radio Astronomy, Brigham Young University, Provo, UT USA, May 3–5, 2010.

[5] Fekri M Z: Design of power dividers and 180 deg hybrids for use with the Eleven antenna for VLBI2010

and SKA applications. MSc thesis, Chalmers University of Technology, May 2010.

[6] Gillani S A A: RF Interference Monitoring for the Onsala Space Observatory. MSc thesis, Chalmers

University of Technology, May 2010.

[7] Nita GM, Gary DE: The generalized spectral kurtosis estimator Mon. Not. R. Astron. Soc.,

doi:10.1111/j.1745-3933.2010.00882.x, 2010.

[8] Qureshi R A: FFTS Based RFI Monitoring for Onsala Space Observatory. MSc thesis, Chalmers University of Technology, May 2010.

IVS 2010 Annual Report 283

Bibliography

Bibliography

Bibliography

Bibliography

1. Introduction

The following bibliography compiles papers that were published in the field of geodetic and

astrometric VLBI during the year 2010. 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 2010

C. Abbondanza, P. Sarti: “Effects of Illumination Functions on the Computation of Gravitydependent Signal Path Variation Models in Cassegrainian VLBI Telescopes”. Journal of

Geodesy, 84(8), doi:10.1007/s00190-010-0389-z, 515–525, 2010.

P.H. Andersen: “FFI Analysis Center”. In: International VLBI Service for Geodesy and Astrometry 2009 Annual Report, edited by D. Behrend and K. Baver, NASA/TP-2010-215860,

226, 2010.

P.H. Andersen: “FFI Technology Development Center Software Development”. In: International VLBI Service for Geodesy and Astrometry 2009 Annual Report, edited by D. Behrend

and K. Baver, NASA/TP-2010-215860, 292, 2010.

T. Artz, S. Bockmann, A. Nothnagel, P. Steigenberger:  ̈ “Sub-diurnal Variations in

the Earth’s Rotation from Continuous VLBI Campaigns”. Journal of Geophysical Research,

115(B05404), doi:10.1029/2009JB006834, American Geophysical Union, Washington DC, ISSN

0148-0227, 2010.

C. Barache: “Paris Observatory (OPAR) Data Center”. In: International VLBI Service for

Geodesy and Astrometry 2009 Annual Report, edited by D. Behrend and K. Baver, NASA/TP2010-215860, 203–206, 2010.

K. Baver, J. Gipson: “Strategies for Improving the IVS-INT01 UT1 Estimates”. In: International VLBI Service for Geodesy and Astrometry 2010 General Meeting Proceedings, edited by

D. Behrend and K. Baver, NASA/CP-2010-215864, 256–260, 2010.

C. Beaudoin, B. Corey, A. Niell, A. Whitney: “Haystack Observatory Technology Development Center”. In: International VLBI Service for Geodesy and Astrometry 2009 Annual

Report, edited by D. Behrend and K. Baver, NASA/TP-2010-215860, 296-299, 2010.

C. Beaudoin, P. Kildal, J. Yang, M. Pantaleev: “Development of a Compact Eleven Feed

Cryostat for the Patriot 12-m Antenna System”. In: International VLBI Service for Geodesy and

Astrometry 2010 General Meeting Proceedings, edited by D. Behrend and K. Baver, NASA/CP2010-215864, 420–424, 2010.

C. Beaudoin, A. Niell: “Post-correlation Processing for the VLBI2010 Proof-of-concept System”. In: International VLBI Service for Geodesy and Astrometry 2010 General Meeting Proceedings, edited by D. Behrend and K. Baver, NASA/CP-2010-215864, 35–45, 2010.

D. Behrend: “Coordinating Center Report”. In: International VLBI Service for Geodesy and

Astrometry 2009 Annual Report, edited by D. Behrend and K. Baver, NASA/TP-2010-215860,

39–44, 2010.

IVS 2010 Annual Report 287
Bibliography

S. Bernhart, A. Bertarini, A. Muskens, W. Alef:  ̈ “The Bonn Astro/Geo Mark IV Correlator”. In: International VLBI Service for Geodesy and Astrometry 2009 Annual Report, edited

by D. Behrend and K. Baver, NASA/TP-2010-215860, 169–172, 2010.

G. Bianco, G. Colucci, F. Schiavone: “Matera CGS VLBI Station”. In: International VLBI

Service for Geodesy and Astrometry 2009 Annual Report, edited by D. Behrend and K. Baver,

NASA/TP-2010-215860, 93–96, 2010.

H. Bignall, D. Jauncey, J. Lovell, R. Ojha, C. Reynolds: “Finding Extremely Compact

Sources Using the ASKAP VAST Survey”. In: International VLBI Service for Geodesy and

Astrometry 2010 General Meeting Proceedings, edited by D. Behrend and K. Baver, NASA/CP2010-215864, 325–329, 2010.

D. Boboltz, A. Fey, N. Geiger, R. Ojha, Z. Dugan, K. Kingham, D. Hall: “U.S.

Naval Observatory VLBI Analysis Center”. In: International VLBI Service for Geodesy and

Astrometry 2009 Annual Report, edited by D. Behrend and K. Baver, NASA/TP-2010-215860,

280–283, 2010.

S. Bockmann, T. Artz, A. Nothnagel:  ̈ “VLBI Terrestrial Reference Frame Contributions

to ITRF2008”. Journal of Geodesy, 84(3), 201–219, doi:10.1007/s00190-009-0357-7, ISSN 0949-

7714, Springer Verlag, Berlin, 2010.

S. Bockmann, T. Artz, A. Nothnagel:  ̈ “Correlation Between the Contributions of Individuals IVS Analysis Centers”. In: International VLBI Service for Geodesy and Astrometry 2010

General Meeting Proceedings, edited by D. Behrend and K. Baver, NASA/CP-2010-215864,

222–226, 2010.

S. Bockmann, T. Artz, V. Tesmer:  ̈ “International VLBI Service for Geodesy and Astrometry:

EOP Combination and Quality of the Combined Products”. Journal of Geophysical Research,

115(BO4404), doi:10.29/2009JB006465, ISSN 0148-0227, American Geophysical Union, Washington DC, 2010.

J. Bohm, T. Hobiger, R. Ichikawa, T. Kondo, Y. Koyama, A. Pany, H. Schuh, K. Teke:  ̈

“Asymmetric Tropospheric Delays from Numerical Weather Models for UT1 Determination from

VLBI Intensive Sessions on the Baseline Wettzell–Tsukuba”. Journal of Geodesy, 84, 319–325,

doi:10.1007/s00190-10-0370-x, 2010.

J. Bohm, T. Nilsson, H. Schuh:  ̈ “Prospects for UT1 Measurements from VLBI Intensive

Sessions”. In: International VLBI Service for Geodesy and Astrometry 2010 General Meeting

Proceedings, edited by D. Behrend and K. Baver, NASA/CP-2010-215864, 251–255, 2010.

S. Bolotin, J. Gipson, D. MacMillan: “Development of a New VLBI Data Analysis Software”. In: International VLBI Service for Geodesy and Astrometry 2010 General Meeting

Proceedings, edited by D. Behrend and K. Baver, NASA/CP-2010-215864, 197–201, 2010.

S. Bolotin, S. Lytvyn: “Comparison of the Combined Catalogues RSC(GAOUA)05 C 03 and

RSC(PUL)06 C 02 with the Current Realization of the International Celestial Reference Frame

(ICRF)”. Kinematics and Physics of Celestial Bodies, Vol. 26, No. 1, 2010 (in Ukrainian).

O.J. Botai, L. Combrinck, V. Sivakumar, H. Schuh, J. Bohm:  ̈ “Extracting Independent

Local Oscillatory Geophysical Signals by Geodetic Tropospheric Delay”. In: International VLBI

Service for Geodesy and Astrometry 2010 General Meeting Proceedings, edited by D. Behrend

and K. Baver, NASA/CP-2010-215864, 345–353, 2010.

G. Bourda, A. Collioud, P. Charlot, R. Porcas: “Global VLBI Observations of Weak

288 IVS 2010 Annual Report
Bibliography

Extragalactic Radio Sources: Imaging Candidates to Align the VLBI and Gaia Frames”. In:

International VLBI Service for Geodesy and Astrometry 2010 General Meeting Proceedings,

edited by D. Behrend and K. Baver, NASA/CP-2010-215864, 310–314, 2010.

J. Campbell, A. Nothnagel: “Intra-plate Deformation in West-central Europe”. Journal of

Geodynamics, 49, 130–140, doi:10.1016/j.jog.2009.10.004, ISSN 0264-3707, Elsevier Science Ltd.,

2010.

P. Charlot, A. Bellanger, G. Bourda, A. Collioud, M. Zhang, A. Baudry: “Report for

2009 from the Bordeaux IVS Analysis Center”. In: International VLBI Service for Geodesy and

Astrometry 2009 Annual Report, edited by D. Behrend and K. Baver, NASA/TP-2010-215860,

213–216, 2010.

A. Collioud, P. Charlot: “VLBI2010 Imaging and Structure Corrections”. In: International

VLBI Service for Geodesy and Astrometry 2010 General Meeting Proceedings, edited by D.

Behrend and K. Baver, NASA/CP-2010-215864, 45–49, 2010.

F. Colomer, P. de Vicente, J. Gomez-Gonz  ́ alez, J. L  ́ opez-Fern  ́ andez, S. Garc  ́  ́ıa Espada: “Instituto Geografico Nacional of Spain”. In: International VLBI Service for Geodesy and

Astrometry 2009 Annual Report, edited by D. Behrend and K. Baver, NASA/TP-2010-215860,

150–153, 2010.

L. Combrinck, M. Gaylard, J. Quick, M. Nickola: “Hartebeesthoek Radio Astronomy

Observatory (HartRao)”. In: International VLBI Service for Geodesy and Astrometry 2009

Annual Report, edited by D. Behrend and K. Baver, NASA/TP-2010-215860, 74–80, 2010.

B. Corey: “Differences Between VLBI2010 and S/X Hardware”. In: International VLBI Service

for Geodesy and Astrometry 2010 General Meeting Proceedings, edited by D. Behrend and K.

Baver, NASA/CP-2010-215864, 18–22, 2010.

R. Curtis: “Kokee Park Geophysical Observatory”. In: International VLBI Service for Geodesy

and Astrometry 2009 Annual Report, edited by D. Behrend and K. Baver, NASA/TP-2010-

215860, 89–92, 2010.

J.M. Dickey: “How and Why to Do VLBI on GPS”. In: International VLBI Service for

Geodesy and Astrometry 2010 General Meeting Proceedings, edited by D. Behrend and K.

Baver, NASA/CP-2010-215864, 65–69, 2010.

K. Doi, K. Shibuya, Y. Aoyama: “JARE Syowa Station 11-m Antenna Antarctica”. In: International VLBI Service for Geodesy and Astrometry 2009 Annual Report, edited by D. Behrend

and K. Baver, NASA/TP-2010-215860, 126–129, 2010.

A. Dyakov, S. Smolentsev: “Zelenchukskaya Radio Astronomical Observatory”. In: International VLBI Service for Geodesy and Astrometry 2009 Annual Report, edited by D. Behrend

and K. Baver, NASA/TP-2010-215860, 154–156, 2010.

G. Engelhardt, V. Thorandt: “Long-term Stability of Radio Sources in VLBI Analysis”. In:

International VLBI Service for Geodesy and Astrometry 2010 General Meeting Proceedings,

edited by D. Behrend and K. Baver, NASA/CP-2010-215864, 295–299, 2010.

M. Ettl, A. Neidhardt, M. Muhlbauer, C. Pl  ̈ otz, C. Beaudoin:  ̈ “The Wettzell System

Monitoring Concept and First Realizations”. In: International VLBI Service for Geodesy and

Astrometry 2010 General Meeting Proceedings, edited by D. Behrend and K. Baver, NASA/CP2010-215864, 444–449, 2010.

IVS 2010 Annual Report 289
Bibliography

L. Fedotov, E. Nosov, S. Grenkov, D. Marshalov: “The Digital Data Acquisition System for the Russian VLBI Network of New Generation”. In: International VLBI Service for

Geodesy and Astrometry 2010 General Meeting Proceedings, edited by D. Behrend and K.

Baver, NASA/CP-2010-215864, 400–404, 2010.

A. Fey, D. Boboltz, R. Ojha, A. Gaume, K. Kingham: “USNO Analysis Center for Source

Structure Report”. In: International VLBI Service for Geodesy and Astrometry 2009 Annual

Report, edited by D. Behrend and K. Baver, NASA/TP-2010-215860, 284–287, 2010.

A. Fey, R. Ojha, D. Boboltz, N. Geiger, K. Kingham, D. Hall, R. Gaume, K. Johnston: “Implementation and Testing of VLBI Software Correlation at the USNO”. In: International VLBI Service for Geodesy and Astrometry 2010 General Meeting Proceedings, edited by

D. Behrend and K. Baver, NASA/CP-2010-215864, 153–156, 2010.

A. Finkelstein, A. Ipatov, M. Kaidanovsky, I. Bezrukov, A. Mikhailov, A. Salnikov,

I. Surkis, E. Skurikhina: “The Quasar Network Observations in e-VLBI Mode Within the

Russian Domestic VLBI Programs”. In: International VLBI Service for Geodesy and Astrometry

2010 General Meeting Proceedings, edited by D. Behrend and K. Baver, NASA/CP-2010-215864,

148–152, 2010.

E. Fomalont, K. Johnston, A. Fey, D. Boboltz, T. Oyama, M. Honma: “The Position/Structure Stability of Four ICRF2 Sources”. In: International VLBI Service for Geodesy

and Astrometry 2010 General Meeting Proceedings, edited by D. Behrend and K. Baver,

NASA/CP-2010-215864, 300–304, 2010.

S. Garc ́ıa-Espada, R. Haas, F. Colomer: “Application of Raytracing through the High

Resolution Numerical Weather Model HIRLAM for the Analysis of European VLBI”. In: International VLBI Service for Geodesy and Astrometry 2010 General Meeting Proceedings, edited

by D. Behrend and K. Baver, NASA/CP-2010-215864, 232–236, 2010.

J. Gipson: “An Introduction to Sked”. In: International VLBI Service for Geodesy and Astrometry 2010 General Meeting Proceedings, edited by D. Behrend and K. Baver, NASA/CP-2010-

215864, 77–84, 2010.

J. Gipson: “IVS Working Group 4: VLBI Data Structures”. In: International VLBI Service

for Geodesy and Astrometry 2010 General Meeting Proceedings, edited by D. Behrend and K.

Baver, NASA/CP-2010-215864, 187–191, 2010.

J. Gomez Gonz  ́ alez, F. Colomer, J. L  ́ opez Fern  ́ andez, M. Assis:  ́ “RAEGE: An Atlantic Network of Geodynamical Fundamental Stations”. In: International VLBI Service for

Geodesy and Astrometry 2010 General Meeting Proceedings, edited by D. Behrend and K.

Baver, NASA/CP-2010-215864, 101–110, 2010.

A. Gontier, S. Lambert, C. Barache: “Paris Observatory Analysis Center OPAR: Report on

Activities January-December 2009”. In: International VLBI Service for Geodesy and Astrometry 2009 Annual Report, edited by D. Behrend and K. Baver, NASA/TP-2010-215860, 265–266,

2010.

D. Gordon: “RDV77 VLBA Hardware/Software Correlator Comparisons”. In: International

VLBI Service for Geodesy and Astrometry 2010 General Meeting Proceedings, edited by D.

Behrend and K. Baver, NASA/CP-2010-215864, 162–166, 2010.

D. Gordon: “Use of GPS TEC Maps for Calibrating Single Band VLBI Sessions”. In: International VLBI Service for Geodesy and Astrometry 2010 General Meeting Proceedings, edited by

290 IVS 2010 Annual Report
Bibliography

D. Behrend and K. Baver, NASA/CP-2010-215864, 242–246, 2010.

S. Gulyaev, T. Natusch: “New Zealand 12-m VLBI Station”. In: International VLBI Service for Geodesy and Astrometry 2009 Annual Report, edited by D. Behrend and K. Baver,

NASA/TP-2010-215860, 138–141, 2010.

S. Gulyaev, T. Natusch, D. Wilson: “Characterization and Calibration of the 12-m Antenna

in Warkworth, New Zealand”. In: International VLBI Service for Geodesy and Astrometry 2010

General Meeting Proceedings, edited by D. Behrend and K. Baver, NASA/CP-2010-215864,

113–117, 2010.

L. Guo, F.C. Shu, W.M. Zheng, T. Kondo, R. Ichikawa, S. Hasegawa, M. Sekido:

“Ionospheric Response to the Total Solar Eclipse of 22 July 2009 as Deduced from VLBI and

GSP Data”. In: International VLBI Service for Geodesy and Astrometry 2010 General Meeting

Proceedings, edited by D. Behrend and K. Baver, NASA/CP-2010-215864, 335–339, 2010.

R. Haas, S. Bergstrand: “COLD MAGICS Continuous Local Deformation Monitoring of

an Artic Geodetic Fundamental Station”. In: International VLBI Service for Geodesy and

Astrometry 2010 General Meeting Proceedings, edited by D. Behrend and K. Baver, NASA/CP2010-215864, 118–122, 2010.

R. Haas, G. Elgered, J. Lofgren, H. Scherneck: “Onsala Space Observatory - IVS Network

Station”. In: International VLBI Service for Geodesy and Astrometry 2009 Annual Report,

edited by D. Behrend and K. Baver, NASA/TP-2010-215860, 113–116, 2010.

R. Haas, G. Elgered, H. Scherneck, T. Nilsson: “Onsala Space Observatory - IVS Analysis

Center”. In: International VLBI Service for Geodesy and Astrometry 2009 Annual Report,

edited by D. Behrend and K. Baver, NASA/TP-2010-215860, 267–270, 2010.

R. Haas, M. Pantaleev, L. Helldner, L. Pettersson, H. Scherneck, G. Elgered:

“Onsala Space Observatory - IVS Technology Development Center”. In: International VLBI

Service for Geodesy and Astrometry 2009 Annual Report, edited by D. Behrend and K. Baver,

NASA/TP-2010-215860, 304-307, 2010.

H. Hase, E. Himwich, A. Neidhardt: “Differences Between S/X and VLBI2010 Operation”.

In: International VLBI Service for Geodesy and Astrometry 2010 General Meeting Proceedings,

edited by D. Behrend and K. Baver, NASA/CP-2010-215864, 31–34, 2010.

R. Heinkelmann, M. Gerstl, M. Seitz, H. Drewes: “DGFI Analysis Center Annual Report

2009”. In: International VLBI Service for Geodesy and Astrometry 2009 Annual Report, edited

by D. Behrend and K. Baver, NASA/TP-2010-215860, 222–225, 2010.

R. Heinkelmann, C. Schwatke: “The Tropospheric Products of the International VLBI Service

for Geodesy and Astrometry”. In: International VLBI Service for Geodesy and Astrometry 2010

General Meeting Proceedings, edited by D. Behrend and K. Baver, NASA/CP-2010-215864,

340–344, 2010.

E. Himwich: “Network Coordinator Report”. In: International VLBI Service for Geodesy and

Astrometry 2009 Annual Report, edited by D. Behrend and K. Baver, NASA/TP-2010-215860,

48–54, 2010.

E. Himwich, J. Gipson: “GSFC Technology Development Center Report”. In: International

VLBI Service for Geodesy and Astrometry 2009 Annual Report, edited by D. Behrend and K.

Baver, NASA/TP-2010-215860, 293–295, 2010.

IVS 2010 Annual Report 291
Bibliography

T. Hobiger, T. Gotoh, J. Amagai, T. Kondo, Y. Koyama: “GPU based GNSS software

receivers - status quo and plans”. IVS NICT Technology Development Center News, No. 31,

ISSN 1882-3432, 10–13, September 2010.

T. Hobiger, T. Gotoh, T. Otsubo, T. Kubooka, M. Sekido, H. Takiguchi, H. Takeuchi:

“c5++ – Multi-technique Analysis Software for Next Generation Geodetic Instruments”. In:

International VLBI Service for Geodesy and Astrometry 2010 General Meeting Proceedings,

edited by D. Behrend and K. Baver, NASA/CP-2010-215864, 212–216, 2010.

T. Hobiger, T. Gotoh, T. Otsubo, T. Kubooka, M. Sekido, H. Takiguchi, H. Takeuchi:

“Automated processing of VLBI experiments with c5++”. IVS NICT Technology Development

Center News, No. 31, ISSN 1882-3432, 14–16, September 2010.

T. Hobiger, H. Takiguchi, R. Ichikawa, M. Sekido, Y. Koyama, T. Kondo: “Analysis

Center at National Institute of Information and Communication Technology”. In: International

VLBI Service for Geodesy and Astrometry 2009 Annual Report, edited by D. Behrend and K.

Baver, NASA/TP-2010-215860, 261–264, 2010.

X. Hong, Q. Fan, T. An, B. Xia: “Sheshan VLBI Station Report for 2009”. In: International

VLBI Service for Geodesy and Astrometry 2009 Annual Report, edited by D. Behrend and K.

Baver, NASA/TP-2010-215860, 117–118, 2010.

R. Ichikawa: “The 9th NICT IVS-TDC Symposium”. IVS NICT Technology Development

Center News, No. 31, ISSN 1882-3432, 1, September 2010.

R. Ichikawa, T. Hobiger, S. Hasegawa, M. Tsutsumi, Y. Koyama, T. Kondo: “Kashima

RAy-Tracing Service: KARATS” IVS NICT Technology Development Center News, No. 31,

ISSN 1882-3432, 25–28, September 2010.

R. Ichikawa, T. Hobiger, Y. Koyama, T. Kondo: “Atmospheric Delay Reduction Using

KARAT for GPS Analysis and Implications for VLBI”. In: International VLBI Service for

Geodesy and Astrometry 2010 General Meeting Proceedings, edited by D. Behrend and K.

Baver, NASA/CP-2010-215864, 237–241, 2010.

R. Ichikawa, H. Takiguchi, M. Sekido, Y. Koyama: “Data Center at NICT”. In: International VLBI Service for Geodesy and Astrometry 2009 Annual Report, edited by D. Behrend

and K. Baver, NASA/TP-2010-215860, 199–202, 2010.

G. Il’in, S. Smolentsev, R. Sergeev: “About the Compatibility of DORIS and VLBI Observations”. In: International VLBI Service for Geodesy and Astrometry 2010 General Meeting

Proceedings, edited by D. Behrend and K. Baver, NASA/CP-2010-215864, 180–183, 2010.

A. Ipatov, V. Mardyshkin, A. Cherepanov, V. Chernov, D. Diky, E. Khvostov, A.

Yevstigneyev: “Radio Telescope Focal Container for the Russian VLBI Network of New

Generation”. In: International VLBI Service for Geodesy and Astrometry 2010 General Meeting

Proceedings, edited by D. Behrend and K. Baver, NASA/CP-2010-215864, 425–429, 2010.

A. Ishii, R. Ichikawa, H. Takiguchi, K. Takefuji, H. Ujihara, Y. Koyama, T. Kondo, S.

Kurihara, Y. Miura, S. Matsuzaka, D. Tanimoto: “Current Status of the Development

of a Transportable and Compact VLBI System by NICT and GSI”. In: International VLBI

Service for Geodesy and Astrometry 2010 General Meeting Proceedings, edited by D. Behrend

and K. Baver, NASA/CP-2010-215864, 53–59, 2010.

A. Ishii, R. Ichikawa, H. Takiguchi, K. Takefuji, H. Ujihara, Y. Koyama, T. Kondo, S.

Kurihara, Y. Miura, S. Matsuzaka, and D. Tanimoto: “Current status of development

292 IVS 2010 Annual Report
Bibliography

of a transportable and compact VLBI system by NICT and GSI”. IVS NICT Technology

Development Center News, No. 31, ISSN 1882-3432, 2–4, September 2010.

D. Ivanov, A. Maslenikov, A. Vytnov: “Experiment of Injecting Phase Cal Ahead of the

Feed: Fist Results”. In: International VLBI Service for Geodesy and Astrometry 2010 General

Meeting Proceedings, edited by D. Behrend and K. Baver, NASA/CP-2010-215864, 429–433,

2010.

C. Jacobs: “JPL VLBI Analysis Center Report for 2009”. In: International VLBI Service for

Geodesy and Astrometry 2009 Annual Report, edited by D. Behrend and K. Baver, NASA/TP2010-215860, 249–252, 2010.

C. Jacobs, D. Bagri, M. Britcliffe, J. Clark, M. Franco, C. Garcia-Miro, C. Goodhart, S. Horuchi, S. Lowe, V. Moll, R. Navarro, S. Rogstag, R. Proctor, E.

Sigman, L. J. Skjerve, M. Soriano, O. Sovers, B. Tucker, D. Wang, L. White:

“X/Ka Celestial Frame Improvements: Vision to Reality”. In: International VLBI Service for

Geodesy and Astrometry 2010 General Meeting Proceedings, edited by D. Behrend and K.

Baver, NASA/CP-2010-215864, 285–289, 2010.

C. Jacobs, M. Heflin, G. Lanyi, O. Sovers, J. Steppe: “Rotational Alignment Altered

by Source Position Correlations”. In: International VLBI Service for Geodesy and Astrometry

2010 General Meeting Proceedings, edited by D. Behrend and K. Baver, NASA/CP-2010-215864,

305–309, 2010.

H. Ju, M. Kim, S. Kim, J. Park, T. Kondo, T. Kim, H. Oh, S. Yi: “The State and

Development Direction of the Geodetic VLBI Station in Korea”. In: International VLBI Service

for Geodesy and Astrometry 2010 General Meeting Proceedings, edited by D. Behrend and K.

Baver, NASA/CP-2010-215864, 95–100, 2010.

U. Kallio, M. Poutanen: “Simulation of Local Tie Accuracy on VLBI Antennas”. In: International VLBI Service for Geodesy and Astrometry 2010 General Meeting Proceedings, edited

by D. Behrend and K. Baver, NASA/CP-2010-215864, 360–364, 2010.

E. Kawai, M. Sekido, R. Ichikawa: “Kashima 34-m Radio Telescope”. In: International VLBI

Service for Geodesy and Astrometry 2009 Annual Report, edited by D. Behrend and K. Baver,

NASA/TP-2010-215860, 81–84, 2010.

H. Kierulf, P. Andersen, S. Bockmann, O. Kristiansen:  ̈ “VLBI Analysis with the Multitechnique Software GEOSAT”. In: International VLBI Service for Geodesy and Astrometry

2010 General Meeting Proceedings, edited by D. Behrend and K. Baver, NASA/CP-2010-215864,

207–211, 2010.

M. Kijima: “Application of Geodetic VLBI Data to Obtaining Long-term Light Curves for Astrophysics”. In: International VLBI Service for Geodesy and Astrometry 2010 General Meeting

Proceedings, edited by D. Behrend and K. Baver, NASA/CP-2010-215864, 265–270, 2010.

K. Kingham, M.S. Carter: “NEOS Operation Center”. In: International VLBI Service for

Geodesy and Astrometry 2009 Annual Report, edited by D. Behrend and K. Baver, NASA/TP2010-215860, 164–165, 2010.

K. Kingham, D. Hall: “Washington Correlator”. In: International VLBI Service for Geodesy

and Astrometry 2009 Annual Report, edited by D. Behrend and K. Baver, NASA/TP-2010-

215860, 188–190, 2010.

S. Kurdubov, E. Skurikhina: “Antenna Axis Offset Estimation from VLBI”. In: International

IVS 2010 Annual Report 293
Bibliography

VLBI Service for Geodesy and Astrometry 2010 General Meeting Proceedings, edited by D.

Behrend and K. Baver, NASA/CP-2010-215864, 247–250, 2010.

S. Kurihara, S. Matsuzaka: “Tsukuba 32-m VLBI Station”. In: International VLBI Service for Geodesy and Astrometry 2009 Annual Report, edited by D. Behrend and K. Baver,

NASA/TP-2010-215860, 134–137, 2010.

Y. Kwak, J. Cho: “KASI Combination Center Report”. In: International VLBI Service for

Geodesy and Astrometry 2009 Annual Report, edited by D. Behrend and K. Baver, NASA/TP2010-215860, 253–257, 2010.

Y. Kwak, T. Kondo, T. Gotoh, J. Amagai, H. Takiguchi, M. Sekido, R. Ichikawa,

T. Sasao, J. Cho, T. Kim: “The First Experiment with VLBI-GPS Hybrid System”. In:

International VLBI Service for Geodesy and Astrometry 2010 General Meeting Proceedings,

edited by D. Behrend and K. Baver, NASA/CP-2010-215864, 330–334, 2010.

Y. Kwak, T. Kondo, T. Gotoh, J. Amagai, H. Takiguchi, M. Sekido, R. Ichikawa,

T. Sasao, J. Cho, T. Kim: “VLBI Type Experimental Observation of GPS”. Journal of

Astronomy and Space Science, 27, 173–180, 2010.

L. Langkaas, T. Dahlen, P. Opseth: “New Fundamental Station in Ny- ̊Alesund”. In: International VLBI Service for Geodesy and Astrometry 2010 General Meeting Proceedings, edited

by D. Behrend and K. Baver, NASA/CP-2010-215864, 111–112, 2010.

R. Lanotte, G. Bianco: “Matera CGS VLBI Analysis Center”. In: International VLBI Service for Geodesy and Astrometry 2009 Annual Report, edited by D. Behrend and K. Baver,

NASA/TP-2010-215860, 220–221, 2010.

K. Le Bail, D. Gordon: “Time-dependent Selection of an Optimal Set of Sources to Define a

Stable Celestial Reference Frame”. In: International VLBI Service for Geodesy and Astrometry

2010 General Meeting Proceedings, edited by D. Behrend and K. Baver, NASA/CP-2010-215864,

280–284, 2010.

L. Liu, Z. Cheng, J. Li: “Analysis of the GPS Observation of the Site Survey at Sheshan 25-m

Radio Telecope in August 2008”. In: International VLBI Service for Geodesy and Astrometry

2010 General Meeting Proceedings, edited by D. Behrend and K. Baver, NASA/CP-2010-215864,

128–132, 2010.

J. Lovell, J. Dickey, S. Gulyaev, T. Natusch, O. Titov, S. Tingay: “The AuScope

Project and Trans-Tasman VLBI”. In: International VLBI Service for Geodesy and Astrometry

2010 General Meeting Proceedings, edited by D. Behrend and K. Baver, NASA/CP-2010-215864,

50–54, 2010.

B. Luzum, A. Nothnagel: “Improved UT1 Predictions through Low-latency VLBI Observations”. Journal of Geodesy, 84(6), 399–402, doi:10.1007/s00190-010-0372-8, ISSN 0949-7714,

Springer Verlag, Berlin, 2010.

S. Lytvyn, Y. Yatskiv: “IVS Analysis Center at Main Astronomical Observatory of National

Academy of Sciences of Ukraine”. In: International VLBI Service for Geodesy and Astrometry

2009 Annual Report, edited by D. Behrend and K. Baver, NASA/TP-2010-215860, 259–260,

2010.

V. L’vov, Z. Malkin, S. Tsekmeister: “Forthcoming Occultations of Astrometric Radio

Sources by Planets”. In: International VLBI Service for Geodesy and Astrometry 2010 General

Meeting Proceedings, edited by D. Behrend and K. Baver, NASA/CP-2010-215864, 320–324,

294 IVS 2010 Annual Report
Bibliography

2010.

C. Ma: “The Second International Celestial Reference Frame (ICRF2)”. In: International VLBI

Service for Geodesy and Astrometry 2010 General Meeting Proceedings, edited by D. Behrend

and K. Baver, NASA/CP-2010-215864, 273–279, 2010.

D. MacMillan, D. Pavlis, F. Lemoine, D. Chinn, D. Rowlands: “VLBI-SLR Combination

Solution Using GEODYN”. In: International VLBI Service for Geodesy and Astrometry 2010

General Meeting Proceedings, edited by D. Behrend and K. Baver, NASA/CP-2010-215864,

227–231, 2010.

Z. Malkin: “Analysis of the Accuracy of Prediction of the Celestial Pole Motion”. Astronomy

Reports, 54(11), doi:10.1134/S1063772910110119, 1053–1061, 2010.

Z. Malkin: “CPO Prediction: Accuracy Assessment and Impact on UT1 Intensive Results”. In:

International VLBI Service for Geodesy and Astrometry 2010 General Meeting Proceedings,

edited by D. Behrend and K. Baver, NASA/CP-2010-215864, 261–264, 2010.

Z. Malkin, N. Miller, E. Popova: “Pulkovo IVS Analysis Center (PUL) 2009 Annual Report”.

In: International VLBI Service for Geodesy and Astrometry 2009 Annual Report, edited by D.

Behrend and K. Baver, NASA/TP-2010-215860, 271–273, 2010.

S. Manabe, T. Jike, Y. Tamura, M. Shizugami, Vera group: “VERA Geodetic Activities”.

In: International VLBI Service for Geodesy and Astrometry 2009 Annual Report, edited by D.

Behrend and K. Baver, NASA/TP-2010-215860, 99–102, 2010.

K.L. Maslennikov, A.V. Boldycheva, Z.M. Malkin, O.A. Titov: “Determination of the

Red Shifts of Selected IVS Program Objects. I”. Astrophysics, 53(2), doi:10.1007/s10511-010-

9107-z, 147–153, 2010.

S. Matsuzaka, S. Kurihara, M. Sekido, T. Hobiger, R. Haas, J. Ritakari, J. Wagner:

“Ultra-rapid dUT1 Measurement on Japan-Fennoscandian Baseline Application to 24-hour

Sessions”. In: International VLBI Service for Geodesy and Astrometry 2010 General Meeting

Proceedings, edited by D. Behrend and K. Baver, NASA/CP-2010-215864, 143–147, 2010.

Y. Miura, K. Kokado, S. Kurihara: “Tsukuba VLBI Correlator”. In: International VLBI

Service for Geodesy and Astrometry 2009 Annual Report, edited by D. Behrend and K. Baver,

NASA/TP-2010-215860, 184–187, 2010.

G. Molera Calves, J. Wagner, A. Neidhardt, G. Kronschnabl, M. Per  ́ ez Ay  ́ ucar,  ́

G. Cimo, S. Pogrebenko:  ́ “First Results of Venus Express Spacecraft Observations with

Wettzell”. In: International VLBI Service for Geodesy and Astrometry 2010 General Meeting

Proceedings, edited by D. Behrend and K. Baver, NASA/CP-2010-215864, 171–175, 2010.

A. Neidhardt, M. Ettl, H. Rottman, C. Plotz, M. M  ̈ uhlbauer, H. Hase, W. Alef,  ̈

S. Sobarzo, C. Herrera, E. Himwich: “E-control: First Public Release of Remote Control

Software for VLBI Telescopes”. In: International VLBI Service for Geodesy and Astrometry

2010 General Meeting Proceedings, edited by D. Behrend and K. Baver, NASA/CP-2010-215864,

439–443, 2010.

A. Neidhardt, G. Kronschnabl, R. Schatz: “Geodetic Observatory Wettzell - 20 m Radiotelescope”. In: International VLBI Service for Geodesy and Astrometry 2009 Annual Report,

edited by D. Behrend and K. Baver, NASA/TP-2010-215860, 146–149, 2010.

A. Neidhardt, M. Losler, C. Eschelbach, A. Schenk:  ̈ “Permanent Monitoring of the

IVS 2010 Annual Report 295
Bibliography

Reference Point of the 20m Radio Telescope Wettzell”. In: International VLBI Service for

Geodesy and Astrometry 2010 General Meeting Proceedings, edited by D. Behrend and K.

Baver, NASA/CP-2010-215864, 133–137, 2010.

A. Niell and the Broadband Development Team: “The NASA VLBI2010 Proof-of-concept

Demonstration and Future Plans”. In: International VLBI Service for Geodesy and Astrometry

2010 General Meeting Proceedings, edited by D. Behrend and K. Baver, NASA/CP-2010-215864,

23–27, 2010.

A. Niell, M. Bark, C. Beaudoin, W. Brisken, H. Frej, S. Doeleman, S. Durand, M.

Guerra, A. Hinton, M. Luce, R. McWhirter, K. Morris, G. Peck, M. Revnell, A.

Rogers, J. Romney, C. Ruszczyk, M. Taveniku, R. Walker, A. Whitney: “RDBE

Development and Progress”. In: International VLBI Service for Geodesy and Astrometry 2010

General Meeting Proceedings, edited by D. Behrend and K. Baver, NASA/CP-2010-215864,

396–399, 2010.

A. Niell, C. Beaudoin, B. Corey: “Haystack Observatory Analysis Center”. In: International

VLBI Service for Geodesy and Astrometry 2009 Annual Report, edited by D. Behrend and K.

Baver, NASA/TP-2010-215860, 235–238, 2010.

T. Nilsson, J. Bohm, H. Schuh:  ̈ “Sub-diurnal Earth Rotation Variations Observed by VLBI”.

Artificial Satellites, 45(2), 49–55, doi: 10.2478/v10018-010-0005-8, 2010.

T. Nilsson, R. Haas: “Impact of Atmospheric Turbulence on Geodetic Very Long Baseline

Interferometry”. Journal of Geophysical Research, 115(B03407), doi:10.1029/2009JB006579,

2010.

C. Noll: “CDDIS Data Center Summary for the IVS 2009 Annual Report”. In: International

VLBI Service for Geodesy and Astrometry 2009 Annual Report, edited by D. Behrend and K.

Baver, NASA/TP-2010-215860, 195–197, 2010.

A. Nothnagel, D. Angermann, K. Borger, R. Dietrich, H. Drewes, B. G  ̈ orres,  ̈

U. Hugentobler, J. Ihde, J. Muller, J. Oberst, M. P  ̈ atzold, B. Richter, M.  ̈

Rothacher, U. Schreiber, H. Schuh, M. Soffel: “Space-Time Reference Systems for

Monitoring Global Change and for Precise Navigation”. Mitteilungen des Bundesamtes f ̈ur

Kartographie und Geod ̈asie, Band 44, Frankfurt am Main, 2010.

A. Nothnagel, S. Bockmann, T. Artz:  ̈ “Analysis Coordination Report”. In: International

VLBI Service for Geodesy and Astrometry 2009 Annual Report, edited by D. Behrend and K.

Baver, NASA/TP-2010-215860, 45–47, 2010.

A. Nothnagel, A. Muskens:  ̈ “The Bonn Geodetic VLBI Operation Center”. In: International

VLBI Service for Geodesy and Astrometry 2009 Annual Report, edited by D. Behrend and K.

Baver, NASA/TP-2010-215860, 159–160, 2010.

M. Negusini, P. Sarti, C. Abbondanza: “Italy INAF Data Center Report”. In: International

VLBI Service for Geodesy and Astrometry 2009 Annual Report, edited by D. Behrend and K.

Baver, NASA/TP-2010-215860, 198, 2010.

M. Negusini, P. Sarti, C. Abbondanza: “Italy INAF Analysis Center Report”. In: International VLBI Service for Geodesy and Astrometry 2009 Annual Report, edited by D. Behrend

and K. Baver, NASA/TP-2010-215860, 247–248, 2010.

H. Oh, T. Kondo, J. Lee, T. Kim, M. Kim, S. Kim, J. Park, H. Ju: “Round-trip System

Available to Measure Path Length Variation in Korea VLBI System for Geodesy”. In: Interna296 IVS 2010 Annual Report
Bibliography

tional VLBI Service for Geodesy and Astrometry 2010 General Meeting Proceedings, edited by

D. Behrend and K. Baver, NASA/CP-2010-215864, 449–453, 2010.

S. Oh, D. Roh, J. Yeom, H. Kobayashi, N. Kawaguchi: “First Phase Development of

Korea-Japan Joint VLBI Correlator and Its Current Progress”. In: International VLBI Service

for Geodesy and Astrometry 2010 General Meeting Proceedings, edited by D. Behrend and K.

Baver, NASA/CP-2010-215864, 405–409, 2010.

A. Orfei, A. Orlati, G. Maccaferri, F. Mantovani: “The Medicina Station Status Report”.

In: International VLBI Service for Geodesy and Astrometry 2009 Annual Report, edited by D.

Behrend and K. Baver, NASA/TP-2010-215860, 97–98, 2010.

M. Pantaleev, J. Jang, Y. Karadikar, L. Helldner, B. Klein, R. Haas, A. Zaman,

M. Zamani, P. Kildal: “Cryogenic Integration of the 2-14 GHz Eleven Feed in a Wideband

Receiver for VLBI2010”. In: International VLBI Service for Geodesy and Astrometry 2010

General Meeting Proceedings, edited by D. Behrend and K. Baver, NASA/CP-2010-215864,

415–419, 2010.

B. Petrachenko: “Canadian VLBI Technology Development Center”. In: International VLBI

Service for Geodesy and Astrometry 2009 Annual Report, edited by D. Behrend and K. Baver,

NASA/TP-2010-215860, 291, 2010.

B. Petrachenko: “VLBI2010: An Overview”. In: International VLBI Service for Geodesy and

Astrometry 2010 General Meeting Proceedings, edited by D. Behrend and K. Baver, NASA/CP2010-215864, 1–7, 2010.

B. Petrachenko: “The Impact of Radio Frequency Interference (RFI) on VLBI2010”. In:

International VLBI Service for Geodesy and Astrometry 2010 General Meeting Proceedings,

edited by D. Behrend and K. Baver, NASA/CP-2010-215864, 434–438, 2010.

L. Plank, J. Bohm, H. Schuh:  ̈ “Comparison Campaign of VLBI Data Analysis Software - First

Results”. In: International VLBI Service for Geodesy and Astrometry 2010 General Meeting

Proceedings, edited by D. Behrend and K. Baver, NASA/CP-2010-215864, 217–221, 2010.

C. Plotz, R. Wojdziak, R. Kilger, A. Neidhardt:  ̈ “German Antarctic Receiving Station

(GARS) O’Higgins”. In: International VLBI Service for Geodesy and Astrometry 2009 Annual

Report, edited by D. Behrend and K. Baver, NASA/TP-2010-215860, 109–112, 2010.

M. Poirier: “Westford Antenna”. In: International VLBI Service for Geodesy and Astrometry

2009 Annual Report, edited by D. Behrend and K. Baver, NASA/TP-2010-215860, 142–145,

2010.

R. Porcas: “VLBI2010: The Astro-Geo Connection”. In: International VLBI Service for

Geodesy and Astrometry 2010 General Meeting Proceedings, edited by D. Behrend and K.

Baver, NASA/CP-2010-215864, 8–17, 2010.

C. Rieck, R. Haas, K. Jaldehag, J. Johansson: “VLBI and GPS-based Time-transfer Using

CONT08 Data”. In: International VLBI Service for Geodesy and Astrometry 2010 General

Meeting Proceedings, edited by D. Behrend and K. Baver, NASA/CP-2010-215864, 365–369,

2010.

M. Rioja, R. Dodson: “Astrometric Core-shifts at the Highest Frequencies”. In: International

VLBI Service for Geodesy and Astrometry 2010 General Meeting Proceedings, edited by D.

Behrend and K. Baver, NASA/CP-2010-215864, 315–319, 2010.

IVS 2010 Annual Report 297
Bibliography

P. Sarti, C. Abbondanza, L. Petrov, M. Negusini: “Height Bias and Scale Effect Induced

by Antenna Gravity Deformations in Geodetic VLBI data analysis”. Journal of Geodesy, 85(1),

doi:0.1007/s00190-010-0410-6, 1–8, 2010.

P. Sarti, M. Negusini, C. Abbondanza: “Improved Geodetic European Very-Long-Baseline

Interferometry Solution using Models of Antenna Gravitational Deformation”. Annals of Geophysics, 53(5-6), doi:10.4401/ag-4739, 2010.

B. Schmeing, D. Behrend, J. Gipson, A. Nothnagel: “Proof-of-Concept Studies for a Local

Tie Monitoring System”. In: International VLBI Service for Geodesy and Astrometry 2010

General Meeting Proceedings, edited by D. Behrend and K. Baver, NASA/CP-2010-215864,

138–143, 2010.

H. Schuh, J. Bohm, S. B  ̈ ohm, T. Nilsson, A. Pany, L. Plank, H. Spicakova, K. Teke,  ̈

J. Wresnik: “Vienna IGG Special Analysis Center Annual Report 2009”. In: International

VLBI Service for Geodesy and Astrometry 2009 Annual Report, edited by D. Behrend and K.

Baver, NASA/TP-2010-215860, 243–246, 2010.

H. Schuh, B. Petrachenko, A. Niell, D. Behrend, B. Corey, J. Wresnik: “The IVS on

its Way to the Next Generation VLBI System”. Annual of the University of Architecture, Civil

Engineering and Geodesy, Vol. XLIV, ISSN 1310-814X, 45–50, 2010.

W. Schwegmann, R. Heinkelmann, M. Gerstl: “BKG/DGFI Combination Center Annual

Report 2009”. In: International VLBI Service for Geodesy and Astrometry 2009 Annual Report,

edited by D. Behrend and K. Baver, NASA/TP-2010-215860, 217–219, 2010.

M. Sekido, M. Kimura: “VLBI Correlators in Kashima”. In: International VLBI Service for

Geodesy and Astrometry 2009 Annual Report, edited by D. Behrend and K. Baver, NASA/TP2010-215860, 180–183, 2010.

M. Sekido, K. Takefuji, M. Kimura, T. Hobiger, K. Kokado, K. Nozawa, S. Kurihara,

T. Shinno, F. Takahashi: “Development of an e-VLBI Data Transport Software Suite with

VDIF”. In: International VLBI Service for Geodesy and Astrometry 2010 General Meeting

Proceedings, edited by D. Behrend and K. Baver, NASA/CP-2010-215864, 410–414, 2010.

E. Skurikhina, S. Kurdubov, V. Gubanov: “IAA VLBI Analysis Center Report 2009”. In:

International VLBI Service for Geodesy and Astrometry 2009 Annual Report, edited by D.

Behrend and K. Baver, NASA/TP-2010-215860, 239–242, 2010.

S. Smolentsev, I. Rahimov: “Svetloe Radio Astronomical Observatory”. In: International

VLBI Service for Geodesy and Astrometry 2009 Annual Report, edited by D. Behrend and K.

Baver, NASA/TP-2010-215860, 123–125, 2010.

S. Smolentsev, R. Sergeev: “Badary Radio Astronomical Observatory”. In: International

VLBI Service for Geodesy and Astrometry 2009 Annual Report, edited by D. Behrend and K.

Baver, NASA/TP-2010-215860, 63–73, 2010.

S. Sobarzo, E. Onate, C. Herrera, P. Zaror, C. Duguet, M. Soto, H. Hase, T. Blum:  ̃

“Geodetic Observatory TIGO in Concepci ́on”. In: International VLBI Service for Geodesy and

Astrometry 2009 Annual Report, edited by D. Behrend and K. Baver, NASA/TP-2010-215860,

130–133, 2010.

H. Spicakova, J. Bohm, S. B  ̈ ohm, T. Nilsson, A. Pany, L. Plank, K. Teke, H. Schuh:  ̈

“Estimation of Geodetic and Geodynamical Parameters with VieVS”. In: International VLBI

Service for Geodesy and Astrometry 2010 General Meeting Proceedings, edited by D. Behrend

298 IVS 2010 Annual Report
Bibliography

and K. Baver, NASA/CP-2010-215864, 202–204, 2010.

I. Surkis, A. Fateev, V. Ken, A. Melnikov, V. Mishin, V. Shantyr, V. Zimovsky: “IAA

Correlator Center”. In: International VLBI Service for Geodesy and Astrometry 2009 Annual

Report, edited by D. Behrend and K. Baver, NASA/TP-2010-215860, 177–179, 2010.

I. Surkis, A. Melnikov, V. Shantyr, V. Zimovsky: “The IAA RAS Correlator First Results”.

In: International VLBI Service for Geodesy and Astrometry 2010 General Meeting Proceedings,

edited by D. Behrend and K. Baver, NASA/CP-2010-215864, 167–170, 2010.

H. Takiguchi, Y. Koyama, R. Ichikawa, T. Gotoh, A. Ishii, T. Hobiger, M. Hosokawa:

“VLBI Measurements for Frequency Transfer”. IVS NICT Technology Development Center

News, No. 31, ISSN 1882-3432, 21–24, September 2010.

K. Takefuji, R. Ichikawa, M. Sekido: “Technology Development Center at NICT”. In:

International VLBI Service for Geodesy and Astrometry 2009 Annual Report, edited by D.

Behrend and K. Baver, NASA/TP-2010-215860, 300–303, 2010.

K. Takefuji, H. Takeuchi, M. Tsutsumi, Y. Koyama: “Next-generation A/D Sampler

ADS3000+ for VLBI2010”. In: International VLBI Service for Geodesy and Astrometry 2010

General Meeting Proceedings, edited by D. Behrend and K. Baver, NASA/CP-2010-215864,

378–382, 2010.

K. Takefuji, M. Tsutsumi, H. Takeuchi, Y. Koyama: “Current Status of Next Generation

A/D Sampler ADS3000+”. IVS NICT Technology Development Center News, No. 31, ISSN

1882-3432, 6–9, September 2010.

H. Takiguchi, M. Sekido, E. Kawai, Y. Koyama: “Kashima and Koganei 11-m VLBI Stations”. In: International VLBI Service for Geodesy and Astrometry 2009 Annual Report, edited

by D. Behrend and K. Baver, NASA/TP-2010-215860, 85–88, 2010.

E. Tanir: “KTU-GEOD IVS Analysis Center Annual Report 2009”. In: International VLBI

Service for Geodesy and Astrometry 2009 Annual Report, edited by D. Behrend and K. Baver,

NASA/TP-2010-215860, 257–258, 2010.

C. Thomas, D. Behrend, D. MacMillan: “The Composition of the Master Schedule”. In:

International VLBI Service for Geodesy and Astrometry 2010 General Meeting Proceedings,

edited by D. Behrend and K. Baver, NASA/CP-2010-215864, 85–94, 2010.

C. Thomas, D. MacMillan: “CORE Operations Center Report”. In: International VLBI

Service for Geodesy and Astrometry 2009 Annual Report, edited by D. Behrend and K. Baver,

NASA/TP-2010-215860, 161–163, 2010.

V. Thorandt, A. Nothnagel, G. Engelhardt, D. Ullrich, T. Artz, S. Bockmann,  ̈

J. Pietzner: “The BKG/IGGB VLBI Analysis Center”. In: International VLBI Service for

Geodesy and Astrometry 2009 Annual Report, edited by D. Behrend and K. Baver, NASA/TP2010-215860, 226–234, 2010.

V. Thorandt, R. Wojdziak: “BKG Data Center”. In: International VLBI Service for Geodesy

and Astrometry 2009 Annual Report, edited by D. Behrend and K. Baver, NASA/TP-2010-

215860, 193–194, 2010.

O. Titov: “Geoscience Australia Analysis Center”. In: International VLBI Service for Geodesy

and Astrometry 2009 Annual Report, edited by D. Behrend and K. Baver, NASA/TP-2010-

215860, 211–212, 2010.

IVS 2010 Annual Report 299
Bibliography

O. Titov: “VLBI2020: From Reality to Vision”. In: International VLBI Service for Geodesy and

Astrometry 2010 General Meeting Proceedings, edited by D. Behrend and K. Baver, NASA/CP2010-215864, 60–64, 2010.

O. Titov, D. Behrend, F. Shu, D. MacMillan, A. Fey: “CRF Network Simulations for

the South”. In: International VLBI Service for Geodesy and Astrometry 2010 General Meeting

Proceedings, edited by D. Behrend and K. Baver, NASA/CP-2010-215864, 176–183, 2010.

M. Titus, R. Cappallo, B. Corey, K. Dudevoir, A. Niell, A. Whitney: “Haystack

Observatory VLBI Correlator”. In: International VLBI Service for Geodesy and Astrometry

2009 Annual Report, edited by D. Behrend and K. Baver, NASA/TP-2010-215860, 173–176,

2010.

V. Tornatore, R. Haas, G. Molera, S. Pogrebenko: “Planning of an Experiment for VLBI

Tracking of GNSS Satellites”. In: International VLBI Service for Geodesy and Astrometry 2010

General Meeting Proceedings, edited by D. Behrend and K. Baver, NASA/CP-2010-215864,

70–74, 2010.

D. Trofimov, V. Vityazev: “Analysis Center of Saint Petersburg University”. In: International

VLBI Service for Geodesy and Astrometry 2009 Annual Report, edited by D. Behrend and K.

Baver, NASA/TP-2010-215860, 209–210, 2010.

G. Tuccari: “NOTO Station Status Report”. In: International VLBI Service for Geodesy and

Astrometry 2009 Annual Report, edited by D. Behrend and K. Baver, NASA/TP-2010-215860,

103–108, 2010.

G. Tuccari, W. Alef, A. Bertarini, S. Buttaccio, G. Comoretto, D. Graham, A.

Neidhardt, P. Platania, A. Russo, A. Roy, M. Wunderlich, R. Zeitlhofler, Y.  ̈

Xiang : “DBBC VLBI2010”. In: International VLBI Service for Geodesy and Astrometry

2010 General Meeting Proceedings, edited by D. Behrend and K. Baver, NASA/CP-2010-215864,

28–30, 2010.

G. Tuccari, W. Alef, A. Bertarini, S. Buttaccio, G. Comoretto, D. Graham, A.

Neidhardt, P. Platania, A. Russo, A. Roy, M. Wunderlich, R. Zeitlhofler, Y.

Xiang: “DBBC2 Backend: Status and Development Plan”. In: International VLBI Service

for Geodesy and Astrometry 2010 General Meeting Proceedings, edited by D. Behrend and K.

Baver, NASA/CP-2010-215864, 392–395, 2010.

VDIF Task Force: “VLBI Data Interchange Format (VDIF) Specification”. In: International

VLBI Service for Geodesy and Astrometry 2009 Annual Report, edited by D. Behrend and K.

Baver, NASA/TP-2010-215860, 21–35, 2010.

A.E. Volvach: “15 Years of Geodetic Experiments at the Simeiz VLBI Station”. In: International

VLBI Service for Geodesy and Astrometry 2009 Annual Report, edited by D. Behrend and K.

Baver, NASA/TP-2010-215860, 119–122, 2010.

G. Wang, J. Li, B. Zhang, L. Guo, F. Shu, Z. Qian: “SHAO Analysis Center 2009 Annual

Report”. In: International VLBI Service for Geodesy and Astrometry 2009 Annual Report,

edited by D. Behrend and K. Baver, NASA/TP-2010-215860, 278–279, 2010.

A. Whitney: “IVS Technology Coordination Report”. In: International VLBI Service for

Geodesy and Astrometry 2009 Annual Report, edited by D. Behrend and K. Baver, NASA/TP2010-215860, 55–59, 2010.

A. Whitney, M. Kettenis, C. Phillips, M. Sekido: “VLBI Data Interchange Format - An

300 IVS 2010 Annual Report
Bibliography

Overview”. In: International VLBI Service for Geodesy and Astrometry 2009 Annual Report,

edited by D. Behrend and K. Baver, NASA/TP-2010-215860, 15–20, 2010.

A. Whitney, M. Kettenis, C. Phillips, M. Sekido: “VLBI Data Interchange Format

(VDIF)”. In: International VLBI Service for Geodesy and Astrometry 2010 General Meeting

Proceedings, edited by D. Behrend and K. Baver, NASA/CP-2010-215864, 192–196, 2010.

A. Whitney, C. Ruszczyk, J. Romney, K. Owens: “The Mark 5C VLBI Data System”. In:

International VLBI Service for Geodesy and Astrometry 2010 General Meeting Proceedings,

edited by D. Behrend and K. Baver, NASA/CP-2010-215864, 373–377, 2010.

X. Zhang, F. Shu, Y. Xiang, R. Zhu, Z. Xu, Z. Chen, W. Zheng, J. Luo, Y. Wu:

“VLBI Technology Development at SHAO”. In: International VLBI Service for Geodesy and

Astrometry 2010 General Meeting Proceedings, edited by D. Behrend and K. Baver, NASA/CP2010-215864, 383–387, 2010.

V. Zharov, M. Kaufman: “SAI VLBI Analysis Center Report 2009”. In: International VLBI

Service for Geodesy and Astrometry 2009 Annual Report, edited by D. Behrend and K. Baver,

NASA/TP-2010-215860, 274–277, 2010.

V. Zharov, M. Sazhin, V. Sementsov, O. Sazhina: “Long-term Variations of the EOP and

ICRF2”. In: International VLBI Service for Geodesy and Astrometry 2010 General Meeting

Proceedings, edited by D. Behrend and K. Baver, NASA/CP-2010-215864, 290–294, 2010.

W. Zheng, Y. Quan, F. Shu, Z. Chen, S. Chen, W. Wang, G. Wang: “The Software

Correlator of the Chinese VLBI Network”. In: International VLBI Service for Geodesy and

Astrometry 2010 General Meeting Proceedings, edited by D. Behrend and K. Baver, NASA/CP2010-215864, 157–161, 2010.

R. Zhu, X. Zhang, W. Wei, Y. Xiang, B. Li, Y. Wu, F. Shu, J. Luo, J. Wang, Z. Xue,

R. Zhao, L. Chen: “The Progress of CDAS”. In: International VLBI Service for Geodesy and

Astrometry 2010 General Meeting Proceedings, edited by D. Behrend and K. Baver, NASA/CP2010-215864, 388–391, 2010.

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IVS Information

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 an official Service of the International Association of Geodesy (IAG).

1.2. Objectives

IVS fulfills its charter through the following objectives. The primary objective of IVS is to

foster VLBI programs as a joint service. This is accomplished through close coordination to

provide high-quality VLBI data and products.

The second objective of IVS is to promote research and development activities in all aspects

of the geodetic and astrometric VLBI technique. This objective also supports the integration of

new components into IVS. The further education and training of VLBI participants is supported

through workshops, reports, electronic network connections, and other means.

The third objective of IVS is to interact with the community of users of VLBI products and to

integrate VLBI into a global Earth observing system. IVS interacts closely with the International

Earth Rotation Service (IERS) which is tasked by the IAU and IUGG with maintaining the

international celestial and terrestrial reference frames and with monitoring Earth rotation.

To meet 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 closely coordinates its activities with the astronomical community because of

the dual use of many VLBI facilities and technologies for both astronomy and astrometry/geodesy.

IVS accepts observing proposals for research and operational programs that conform to the

IVS objectives.

1.3. Data Products

VLBI data products contribute uniquely to these important determinations:

• definition and maintenance of the celestial reference frame

• monitoring universal time (UT1) and length of day (LOD)

• 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 inertial reference frame, such as high-precision navigation and positioning. IVS

provides, through the collaborative efforts of its components, a variety of significant VLBI data

products with differing applications, timeliness, detail, and temporal resolution, such as:

IVS 2010 Annual Report 305
Terms of Reference

• all components of Earth orientation parameters at regular intervals

• terrestrial reference frame

• VLBI data in appropriate formats

• VLBI results in appropriate formats

• local site ties to reference points

• high-accuracy station timing data

• surface meteorology, tropospheric and ionospheric measurements

All VLBI data products are archived in IVS Data Centers and are publicly available.

1.4. Research

The VLBI data products are used for research in many related areas of geodesy, geophysics,

and astrometry, such as:

• UT1 and polar motion excitation (over periods of hours to decades)

• solid Earth interior research (mantle rheology, anelasticity, libration, core modes, nutation/precession)

• 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 vertical (scale) component

• climate studies

To support these activities, there are ongoing research efforts whose purpose is to improve and

extend the VLBI technique in such areas as:

• improvements in data acquisition and correlation

• refined data analysis techniques

• spacecraft tracking (Earth-orbiting and interplanetary)

• combination of VLBI data and results with other techniques

2. Permanent Components

IVS acquires VLBI data, correlates the data, analyzes the data to produce geodetic, astrometric,

and other results, and archives and publicizes data products. IVS accomplishes its goals through

the types of permanent components described in this section. IVS will accept proposals at any

time for a permanent component. Such proposals will be reviewed by the Directing Board. The

seven types of IVS permanent components are:

• Network Stations

• Operation Centers

• Correlators

306 IVS 2010 Annual Report
Terms of Reference

• Analysis Centers

• Data Centers

• Technology Development Centers

• Coordinating Center

IVS acquires VLBI data, correlates the data, analyzes the data to produce geodetic and astrometric results, and archives and publicizes data products. IVS accomplishes its goals through the

operational components described below.

2.1. Network Stations

The IVS observing network consists of high performance VLBI stations.

• Stations can 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 set

up by the Directing Board.

• VLBI data acquisition sessions are conducted by groups of Network Stations that are distributed either globally or over a geographical region.

2.2. Operation Centers

The IVS Operation Centers coordinate the routine operations of one or more networks. Operation Center activities include:

• planning network observing programs,

• establishing operating plans and procedures for the stations in the network,

• supporting the network stations in improving their performance,

• making correlator time available at an IVS Correlator,

• generating the detailed observing schedules for use in data acquisition sessions by IVS Network Stations,

• posting the observing schedule to an IVS Data Center for distribution and to the Coordinating Center for archiving.

IVS Operation Centers follow guidelines from the Coordinating Center for timeliness and schedule

file formats. Operation Centers cooperate with the Coordinating Center in order to define:

• the annual master observing schedule,

• the use of antenna time,

• tape availability and shipping,

• the use of other community resources.

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Terms of Reference

2.3. Correlators

The IVS Correlators process raw VLBI data and station log files following a data acquisition

session. Their other tasks are to:

• provide immediate feedback to the Network Stations about problems that are apparent in

the data,

• jointly maintain the geodetic/astrometric community’s tape pool,

• make processed data available to the Analysis Centers,

• 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 Centers (hereinafter called Analysis Centers),

Associate Analysis Centers, and Combination Centers.

Analysis Centers are committed to produce series of Earth Orientation Parameters (EOP) or

series of individual EOP components, without interruption and at a specified time lag to meet IVS

requirements. In addition, Analysis Centers produce station coordinates and source positions in

regular intervals.

The 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 Analysis Center

makes from IVS recommendations are properly documented. Analysis Centers provide timely

feedback about station performance. In addition to these regular services, 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.

Combination Centers are committed to quality control the submissions of the Analysis Centers

to the IVS Data Centers and to produce combination results from the individual submissions as

official IVS products. The products include, but are not limited to, EOP time series derived from

session-based results for 24-hour network sessions and 1-hour Intensive sessions. The 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.

308 IVS 2010 Annual Report
Terms of Reference

2.5. Data Centers

The IVS Data Centers are repositories for VLBI observing schedules, station log files, and data

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:

• 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,

• 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. They may be engaged in hardware and/or software technology development, or evolve new

approaches that will improve the VLBI technique and enhance compatibility with different data

acquisition terminals. They will:

• design new hardware,

• investigate new equipment,

• develop new software for operations, processing or analysis,

• generate new information systems,

• develop, test, and document prototypes of new equipment or software,

• assist with deployment, installation, and training for any new approved technology.

• After dissemination of the new hardware or software, the centers may continue to provide

maintenance and updating functions.

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 all IVS activities.

The primary functions of the Coordinating Center are to:

• coordinate observing programs approved by the Directing Board,

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Terms of Reference

• maintain the master schedule of observing sessions, coordinating the schedule with astronomical observing programs and with IVS networks,

• foster communications among all components of the IVS,

• define the best use of community resources,

• develop standards for IVS components,

• provide training in VLBI techniques,

• organize workshops and meetings, including an annual IVS technical meeting,

• produce and publish reports of activities of IVS components,

• maintain the IVS information system and archive all documents, standards, specifications,

manuals, reports, and publications,

• provide liaison with the IERS, IAG, IAU, and other organizations,

• provide the Secretariat of the Directing Board.

3. Coordinators

Specific IVS activities for technology, network data quality, and data products 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 Networks 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,

The Network Coordinator works closely with the geodetic and astronomical communities who

are using the same network stations for observations. The Coordinator takes a leading role in

ensuring the visibility and representation of the Networks.

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:

310 IVS 2010 Annual Report
Terms of Reference

• fosters comparisons of results from different VLBI analysis software packages and different

analysis strategies,

• encourages analysis and combination software documentation,

• 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 analysis and combination products from all Analysis Centers are archived and

available for the scientific community, and

• forms the official products of IVS, as decided by the IVS Directing Board, using a suitable

combination of the analysis results submitted by the Analysis Centers.

• supervises the formation of the official IVS products, as decided by the IVS Directing Board,

produced by the Combination Centers.

The Analysis Coordinator works closely with the geodetic and astronomical communities who

are using some of the same analysis methods and software. The Analysis Coordinator plays a

leadership role in the development of methods for distribution of VLBI products so that the

products reach the widest possible base of users in a timely manner. The coordinator promotes the

use of VLBI products to the broader scientific community and interacts with the IVS Coordinating

Center and with the IERS.

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 is

responsible for coordinating the new technology activities of IVS and for stimulating advancement

of the VLBI technique. The Technology Coordinator performs the following functions:

• maintains cognizance of all current VLBI technologies and ongoing development

• coordinates development of new technology among various IVS components

• helps promulgate new technologies to the geodetic/astrometric community

• strives to ensure the highest degree of global compatibility of VLBI data acquisition systems

The Technology Coordinator works closely with the astronomical community because of the

many parallels between the technology development required for both groups.

4. Directing Board

4.1. Roles and Responsibilities

The Directing Board determines policies, adopts standards, and approves 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.

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Terms of Reference

A specific function of the Board is to set scientific goals for the IVS observing program. The

Board will establish procedures for external research programs and will review any proposals thus

received.

The Board may determine appropriate actions to ensure the quality of the IVS products and

that the IVS components maintain the adopted standards.

4.2. Membership

The Directing Board consists of appointed members who serve ex officio, members elected by

the Directing Board, and members elected by the IVS components. The members are:

Appointed members ex officio:

• IAG representative

• IAU representative

• IERS representative

• Coordinating Center Director

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.

Selected by Directing Board upon review of proposals from IVS Member Organizations:

• Technology, Network, and Analysis Coordinators (3 total)

Elected by Directing Board upon recommendation from the Coordinating Center (see below):

• Members at large (3)

Elected by IVS Components (see below):

• Correlators and Operation Centers representative (1)

• Analysis and Data Centers representative (1)

• Networks representatives (2)

• Technology Development Centers representative (1)

Total number: 15

The four appointed members are considered ex officio and are not subject to institutional

restrictions.

The five members of the Directing Board who are elected by IVS Permanent Components must

each be a member of a different IVS Member Organization. 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 2-year terms once renewable.

A 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.

312 IVS 2010 Annual Report
Terms of Reference

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 two consecutive full terms,

the 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 three months notice before resigning.

4.3. Elections

Election of Board members by 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 Board are made by consensus or by simple majority vote of the members

present. In case of a tie, the chair shall vote but otherwise does not vote. 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 change any of the members

elected by the Directing Board before the normal term expires.

4.6. Meetings

The 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. The reviews should be done every four

years.

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.

IVS 2010 Annual Report 313
Terms of Reference

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 Correspondents.

5.3. Associate Members

Individuals associated with organizations that support an IVS component may become IVS

Associate Members. Associate Members are generally invited to attend non-executive sessions of

the Directing Board meetings with voice but without vote. Associate Members take part in the

election of the incoming members of the Directing Board representing the IVS components.

5.4. Corresponding Members

IVS Corresponding Members are individuals on a mailing list maintained by the Coordinating

Center. They do not actively participate in IVS but 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 General Secretary

• President of IAG Commission 1 – Reference Frames

• President of IAG Commission 3 Geodynamics and Earth Rotation

• 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 J – Radio Astronomy

Individuals are accepted as IVS Corresponding Members upon request to the Coordinating Center.

Last modified: 12 February, 2010

314 IVS 2010 Annual Report
Members

IVS Member Organizations

(alphabetized by country)

Organization Country

Commonwealth Scientific and Industrial Research Organisation Australia

Geoscience Australia Australia

University of Tasmania Australia

Vienna University of Technology Austria

Centro de R ́adio Astronomia e Aplica ̧c ̃oes Espaciais Brazil

Geodetic Survey Division, Natural Resources Canada Canada

Dominion Radio Astrophysical Observatory Canada

Universidad de Concepci ́on Chile

Instituto Geogr ́afico Militar Chile

Chinese Academy of Sciences China

Observatoire de Paris France

Observatoire de Bordeaux France

Deutsches Geod ̈atisches Forschungsinstitut Germany

Bundesamt f ̈ur Kartographie und Geod ̈asie 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

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 Defence Research Establishment Norway

Norwegian Mapping Authority Norway

Astronomical Institute of St.-Petersburg University Russia

Central (Pulkovo) Astronomical Observatory Russia

Institute of Applied Astronomy Russia

Sternberg State Astronomical Institute, Lomonosov Moscow State University Russia

Hartebeesthoek Radio Astronomy Observatory South Africa

Korea Astronomy and Space Science Institute South Korea

Instituto Geogr ́afico Nacional Spain

Chalmers University of Technology Sweden

Karadeniz Technical University Turkey

Main Astronomical Observatory, National Academy of Sciences, Kiev Ukraine

IVS 2010 Annual Report 315
Members

Organization Country

Laboratory of Radioastronomy of Crimean Astrophysical Observatory Ukraine

NASA Goddard Space Flight Center USA

U. S. Naval Observatory USA

Jet Propulsion Laboratory USA

316 IVS 2010 Annual Report
Affiliates

IVS Affiliated Organizations

Organization Country

Australian National University Australia

University of New Brunswick Canada

Satellite Geodetic Observatory Hungary

Joint Institute for VLBI in Europe (JIVE) Netherlands

Westerbork Observatory Netherlands

National Radio Astronomy Observatory USA

IVS 2010 Annual Report 317
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@urania.rtf32s.nw.ru

Artz, Thomas Institut f ̈ur Geod ̈asie und

Geoinformation der Universit ̈at

Bonn

Germany thomas.artz@uni-bonn.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./GSFC USA karen.d.baver@nasa.gov

Behrend, Dirk NVI, Inc./GSFC 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

Bergman, Per Onsala Space Observatory Sweden bergman@oso.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 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 Institute of Geodesy and

Geophysics

Austria johannes.boehm@tuwien.ac.at

B ̈ohm, Sigrid Institute of Geodesy and

Geophysics

Austria sigrid.boehm@tuwien.ac.at

Boer, Armin BKG/Project TIGO Chile armin.boer@bkg.bund.de

Bolotin, Sergei NVI, Inc./GSFC USA sergei.bolotin@nasa.gov

318 IVS 2010 Annual Report
Associate Members

Name Institution Country E-mail

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 bcarlson@drao.nrc.ca

Carter, Merri

Sue

U. S. Naval Observatory,

Flagstaff Station

USA msc@maia.usno.navy.mil

Charlot, Patrick Laboratoire d’Astrophysique de

Bordeaux

France charlot@obs.u-bordeaux1.fr

Cho, Jungho Korea Astronomy & Space

Science Institute

Korea jojh@kasi.re.kr

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@telespazio.com

Combrinck,

Ludwig

Hartebeesthoek Radio

Astronomy Observatory

South

Africa

ludwig@bootes.hartrao.ac.za

Conway, John Onsala Space Observatory Sweden jconway@chalmers.se

Corey, Brian MIT Haystack Observatory USA bcorey@haystack.mit.edu

Curtis, Ronald ITT USA ronald.curtis@itt.com

Dassing, Reiner Bundesamt f ̈ur Kartographie

und Geod ̈asie

Germany reiner.dassing@bkg.bund.de

Del Rosso,

Domenico

Telespazio SpA Italy domenico delrosso@telespazio.it

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

Diegel, Irv Honeywell TSI USA irv.diegel@honeywell-tsi.com

Doi, Koichiro National Institute of Polar

Research

Japan doi@nipr.ac.jp

Dong, Yousuo Urumqi Astronomical

Observatory

China dongys@ms.xjb.ac.cn

Drewes,

Hermann

Deutsches Geod ̈atisches

Forschungsinstitut

Germany drewes@dgfi.badw.de

Dube, Maurice SSAI/GSFC USA maurice.p.dube@nasa.gov

Elgered, Gunnar Onsala Space Observatory Sweden kge@chalmers.se

IVS 2010 Annual Report 319
Associate Members

Name Institution Country E-mail

Engelhardt,

Gerald

Bundesamt f ̈ur Kartographie

und Geod ̈asie

Germany gerald.engelhardt@bkg.bund.de

Engen, Bjorn Norwegian Mapping Authority Norway bjorn.engen@statkart.no

Evangelista,

Mark

Honeywell TSI USA mark.evangelista@honeywelltsi.com

Fan, Qingyuan Shanghai Astronomical

Observatory

China qyfan@center.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

Finkelstein,

Andrey

Institute of Applied Astronomy Russia amf@quasar.ipa.nw.ru

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

Gipson, John NVI, Inc./GSFC USA john.m.gipson@nasa.gov

Gomez, Frank Raytheon/GSFC USA frank.g.gomez@nasa.gov

G ́omezGonz ́alez,

Jes ́us

Instituto Geogr ́afico Nacional Spain gomez@oan.es

Gordon, David NVI, Inc./GSFC USA david.gordon-1@nasa.gov

Govind, Ramesh Geoscience Australia Australia ramesh.govind@ga.gov.au

Gubanov,

Vadim

Institute of Applied Astronomy Russia gubanov@quasar.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

Hammargren,

Roger

Onsala Space Observatory Sweden rogham@chalmers.se

Hanssen, Rune Norwegian Mapping Authority Norway rune.hanssen@statkart.no

Harms, Matt Honeywell TSI USA kokee@pele.kpgo.hawaii.edu

Hase, Hayo BKG/Project TIGO Chile hayo.hase@bkg.bund.de

Heinkelmann,

Robert

Deutsches Geod ̈atisches

Forschungsinstitut

Germany heinkelmann@dgfi.badw.de

Helldner, Leif Onsala Space Observatory Sweden helldner@chalmers.se

Herrera,

Cristian

TIGO/Universidad de

Concepci ́on

Chile cristian.herrera@tigo.cl

Himwich, Ed NVI, Inc./GSFC USA Ed.Himwich@nasa.gov

Hirabaru,

Masaki

National Institute of Information

and Communications Technology

Japan masaki@nict.go.jp

Hobiger,

Thomas

National Institute of Information

and Communications Technology

Japan hobiger@nict.go.jp

320 IVS 2010 Annual Report
Associate Members

Name Institution Country E-mail

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

Ihde, Johannes Bundesamt f ̈ur Kartographie

und Geod ̈asie

Germany johannes.ihde@bkg.bund.de

Ilijin, Gennadiy Institute of Applied Astronomy Russia

Ipatov,

Alexander

Institute of Applied Astronomy Russia ipatov@ipa.rssi.ru

Ipatova, Irina Institute of Applied Astronomy Russia ipatova@isida.ipa.rssi.ru

Ishihara, Misao Geospatial Information

Authority of Japan

Japan vlbi@gsi.go.jp

Ishii, Atsutoshi National Institute of Information

and Communications Technology

Japan ishii@nict.go.jp

Ivanov, D.V. Institute of Applied Astronomy Russia

Jacobs, Chris Jet Propulsion Laboratory USA chris.jacobs@jpl.nasa.gov

Jara, Cristobal TIGO/Universidad de

Concepci ́on

Chile cristobal.jara@tigo.cl

Jike, Takaaki National Astronomical

Observatory of Japan

Japan jike@miz.nao.ac.jp

Johansson, Jan Onsala Space Observatory Sweden jmj@chalmers.se

Johansson,

Karl- ̊Ake

Onsala Space Observatory Sweden karlake@chalmers.se

Johnson, Heidi MIT Haystack Observatory USA hjohnson@haystack.mit.edu

Johnston,

Kenneth

U. S. Naval Observatory USA kjj@astro.usno.navy.mil

Karasawa,

Masao

Geospatial Information

Authority of Japan

Japan vlbi@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 vlbi@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@isida.ipa.rssi.ru

IVS 2010 Annual Report 321
Associate Members

Name Institution Country E-mail

Kharinov,

Mikhail

Institute of Applied Astronomy Russia kharinov@ipa.rssi.ru

Kimura,

Moritaka

National Institute of Information

and Communications Technology

Japan mkimura@nict.go.jp

Kingham, Kerry U. S. Naval Observatory USA kak@usno.navy.mil

Kobayashi,

Hideyuki

National Astronomical

Observatory of Japan

Japan hideyuki.kobayashi@nao.ac.jp

Kokado,

Kensuke

Geospatial Information

Authority of Japan

Japan vlbi@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

Kronschnabl,

Gerhard

Bundesamt f ̈ur Kartographie

und Geod ̈asie

Germany gerhard.kronschnabl@bkg.bund.de

Kuboki,

Hiromitsu

National Institute of Information

and Communications Technology

Japan kuboki@nict.go.jp

Kudryashova,

Maria

Astronomical Institute of

St.-Petersburg

Russia kudryashova@mercury.astro.spbu.ru

Kurdubov,

Sergey

Institute of Applied Astronomy Russia ksl@quasar.ipa.nw.ru

Kurihara,

Shinobu

Geospatial Information

Authority of Japan

Japan skuri@gsi.go.jp

Kuroda, Jiro Geospatial Information

Authority of Japan

Japan vlbi@gsi.go.jp

Labelle, Ruth SSAI/GSFC USA ruth.e.labelle@nasa.gov

Lambert,

S ́ebastien

Observatoire de Paris France sebastien.lambert@obspm.fr

Langkaas, Line Norwegian Mapping Authority Norway Line.Langkaas@statkart.no

Lanotte,

Roberto

Telespazio SpA Italy lanotte@asi.it

Lauber, Pierre Fundamentalstation Wettzell Germany lauber@fs.wettzell.de

Lavrov, Alexey Institute of Applied Astronomy Russia

Le Bail, Karine NVI, Inc./GSFC USA karine.lebail@nasa.gov

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

322 IVS 2010 Annual Report
Associate Members

Name Institution Country E-mail

Liu, Xiang Urumqi Astronomical

Observatory

China liux@ms.xjb.ac.cn

Long, Jim NASA Goddard Space Flight

Center

USA jim.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 bjl@maia.usno.navy.mil

Ma, Chopo NASA Goddard Space Flight

Center

USA chopo.ma-1@nasa.gov

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./GSFC USA daniel.s.macmillan@nasa.gov

Malkin, Zinovy Pulkovo Observatory Russia malkin@gao.spb.ru

Manabe, Seiji National Astronomical

Observatory of Japan

Japan manabe@miz.nao.ac.jp

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

Mathiassen,

Geir

Norwegian Mapping Authority Norway matgei@statkart.no

Matsuzaka,

Shigeru

Geospatial Information

Authority of Japan

Japan shigeru@gsi.go.jp

McCarthy,

Dennis

U. S. Naval Observatory USA dmc@maia.usno.navy.mil

Melnikov,

Alexey

Institute of Applied Astronomy Russia melnikov@quasar.ipa.nw.ru

Michailov,

Andrey

Institute of Applied Astronomy Russia agm@isida.ipa.rssi.ru

Miller, Natalia Pulkovo Observatory Russia natmiller@list.ru

Mitchell,

Donald

Honeywell TSI USA kokee@pele.kpgo.hawaii.edu

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

IVS 2010 Annual Report 323
Associate Members

Name Institution Country E-mail

Nakajima,

Junichi

National Institute of Information

and Communications Technology

Japan nakaji@nict.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@bootes.hartrao.ac.za

Niell, Arthur MIT Haystack Observatory USA aniell@haystack.mit.edu

Nielsen,

Carl-Petter

Norwegian Mapping Authority Norway carl-petter.nielsen@statkart.no

Nikitin, Pavel Crimean Astrophysical

Observatory

Ukraine nikitin@crao.crimea.ua

Nilsson, Tobias Institute of Geodesy and

Geophysics

Austria tnilsson@tuwien.ac.at

Noll, Carey NASA Goddard Space Flight

Center

USA Carey.Noll@nasa.gov

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

Olofsson, Hans Onsala Space Observatory Sweden hans.olofsson@chalmers.se

O ̃nate, Eric TIGO Chile eric.onate@tigo.cl

Orfei, Sandro Istituto di Radioastronomia

INAF

Italy a.orfei@ira.inaf.it

Pany, Andrea Institute of Geodesy and

Geophysics

Austria apany@mars.hg.tuwien.ac.at

Petrachenko,

William

Natural Resources Canada Canada Bill.Petrachenko@nrc-cnrc.gc.ca

Pettersson, Lars Onsala Space Observatory Sweden d8lars@chalmers.se

Plank, Lucia Institute of Geodesy and

Geophysics

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

Qian, Zhihan Shanghai Astronomical

Observatory

China qzh@center.shao.ac.cn

Quick, Jonathan Hartebeesthoek Radio

Astronomy Observatory

South

Africa

jon@bootes.hartrao.ac.za

324 IVS 2010 Annual Report
Associate Members

Name Institution Country E-mail

Rahimov, Ismail Institute of Applied Astronomy Russia rahimov@urania.rtf32s.nw.ru

Redmond, Jay Honeywell TSI USA jay.redmond@honeywell-tsi.com

Reid, Brett University of Tasmania Australia brett.reid@utas.edu.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

Ruszczyk,

Chester

MIT Haystack Observatory USA chester@haystack.mit.edu

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 hgs@chalmers.se

Schuh, Harald Institute of Geodesy and

Geophysics

Austria harald.schuh@tuwien.ac.at

Schwarz, Walter Bundesamt f ̈ur Kartographie

und Geod ̈asie

Germany walter.schwarz@bkg.bund.de

Sciarretta,

Cecilia

Telespazio SpA Italy cecilia@asi.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 nanshan@ms.xjb.ac.cn

Shibuya, Kazuo National Institute of Polar

Research

Japan shibuya@nipr.ac.jp

Shishikin,

Alexandr

Institute of Applied Astronomy Russia

Shu, Fengchun Shanghai Astronomical

Observatory

China sfc@center.shao.ac.cn

Skurikhina,

Elena

Institute of Applied Astronomy Russia sea@quasar.ipa.nw.ru

Smolentsev,

Sergey

Institute of Applied Astronomy Russia smolen@isida.ipa.rssi.ru

Smythe, Dan MIT Haystack Observatory USA dsmythe@haystack.mit.edu

Sobarzo, Sergio TIGO/Universidad de

Concepci ́on

Chile sergio.sobarzo@tigo.cl

Sousa, Don MIT Haystack Observatory USA dsousa@haystack.mit.edu

Sovers, Ojars Remote Sensing Analysis Inc. USA ojars@rsasys.com

IVS 2010 Annual Report 325
Associate Members

Name Institution Country E-mail

Spicakova, Hana Institute of Geodesy and

Geophysics

Austria hana@mars.hg.tuwien.ac.at

Stanghellini,

Carlo

Istituto di Radioastronomia

INAF

Italy c.stanghellini@ira.inaf.it

Steppe, Alan Jet Propulsion Laboratory USA as@logos.jpl.nasa.gov

Surkis, Igor Institute of Applied Astronomy Russia surkis@isida.ipa.rssi.ru

Takashima,

Kazuhiro

Geospatial Information

Authority of Japan

Japan takasima@gsi.go.jp

Takiguchi,

Hiroshi

National Institute of Information

and Communications Technology

Japan htaki@nict.go.jp

Tamura,

Yoshiaki

National Astronomical

Observatory of Japan

Japan tamura@miz.nao.ac.jp

Tanır, Emine Karadenic Technical University Turkey etanir@ktu.edu.tr

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,

Department of Geodesy and

Photogrammetry Engineering

Turkey kteke@hacettepe.edu.tr

Tesmer n ́ee

B ̈ockmann,

Sarah

Institut f ̈ur Geod ̈asie und

Geoinformation der Universit ̈at

Bonn

Germany boeckmann@uni-bonn.de

Thomas,

Cynthia

NVI, Inc./GSFC 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@casa.usno.navy.mil

Titov, Oleg Geoscience Australia Australia Oleg.Titov@ga.gov.au

Titus, Mike MIT Haystack Observatory USA mtitus@haystack.mit.edu

Todorova, Sonja Institute of Geodesy and

Geophysics

Austria stodo@mars.hg.tuwien.ac.at

Tornatore,

Vincenza

Politecnico di Milano Italy vincenza.tornatore@polimi.it

Trigilio,

Corrado

Istituto di Radioastronomia

INAF

Italy ctrigilio@oact.inaf.it

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

Ullrich, Dieter Bundesamt f ̈ur Kartographie

und Geod ̈asie

Germany dieter.ullrich@bkg.bund.de

Venturi, Tiziana Istituto di Radioastronomia

INAF

Italy t.venturi@ira.inaf.it

326 IVS 2010 Annual Report
Associate Members

Name Institution Country E-mail

Verdugo, Carlos TIGO/Universidad de

Concepci ́on

Chile carlos.verdugo@tigo.cl

Vespe,

Francesco

Agenzia Spaziale Italiana Italy 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@ms.xjb.ac.cn

Wang, Weixia Urumqi Astronomical

Observatory

China wangwx@ms.xjb.ac.cn

Wei, Wenren Shanghai Astronomical

Observatory

China wwr@center.shao.ac.cn

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

Ye, Shuhua Shanghai Astronomical

Observatory

China ysh@center.shao.ac.cn

Yusup, Aili Urumqi Astronomical

Observatory

China aliyu@ms.xjb.ac.cn

Zeitlh ̈ofler,

Reinhard

Fundamentalstation Wettzell Germany zeitlhoefler@fs.wettzell.de

Zhang, Ali Urumqi Astronomical

Observatory

China zhangal@uao.ac.cn

Zhang, Jin Urumqi Astronomical

Observatory

China zhangj@ms.xjb.ac.cn

Zhang,

Xiuzhong

Shanghai Astronomical

Observatory

China xzhang@shao.ac.cn

Zhao, Rongbing Shanghai Astronomical

Observatory

China zhaorb@center.shao.ac.cn

Zheng, Weimin Shanghai Astronomical

Observatory

China zhwm@shao.ac.cn

Zhou, Ruixian Shanghai Astronomical

Observatory

China zrx@center.shao.ac.cn

IVS 2010 Annual Report 327
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, Mt. Pleasant Radio Observatory University of Tasmania Australia

Kashima 34m National Institute of Information and

Communications Technology (NICT)

Japan

Key Stone Project Kashima 11m 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

Mizusawa 10m 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

Seshan Joint Laboratory for Radio Astronomy

(JLRA), CAS and Shanghai Observatory,

CAS

China

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

328 IVS 2010 Annual Report
IVS Permanent Components

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

Fundamentalstation 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

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

Tsukuba VLBI Center Geospatial Information Authority of Japan

(GSI)

Japan

Washington Correlator National Earth Orientation Service

(NEOS)

USA

IVS 2010 Annual Report 329
IVS Permanent Components

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

Observatoire de Bordeaux Observatoire de Bordeaux France

Centro di Geodesia Spaziale (CGS) Agenzia Spaziale Italiana Italy

DGFI Deutsches Geod ̈atisches Forschungsinstitut Germany

Forsvarets forskningsinstitutt (FFI) Norwegian Defence Research

Establishment

Norway

IGGB-BKG Analysis Center Institut f ̈ur Geod ̈asie und Geoinformation

der Universit ̈at Bonn and Bundesamt f ̈ur

Kartographie und Geod ̈asie

Germany

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

Institute of Geodesy and Geophysics

(IGG)

Institute of Geodesy and Geophysics

(IGG) of Vienna University of Technology

Austria

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

330 IVS 2010 Annual Report
IVS Permanent Components

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

Technology Development Centers

Component Name Sponsoring Organization Country

Canadian VLBI Technology Development

Center

NRCan, DRAO Canada

Forsvarets forskningsinstitutt (FFI) Norwegian Defence Research

Establishment

Norway

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

IVS 2010 Annual Report 331
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://www.phys.utas.edu.au

Institute of Geodesy and Geophysics/Vienna University of Technology

Gusshausstrasse 27-29

1040 Vienna

Austria

http://www.hg.tuwien.ac.at

CRAAM, Universidade Presbiteriana Mackenzie, S ̃ao Paulo

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

61760-000 Eus ́ebio

CE

Brazil

http://www.roen.inpe.br

332 IVS 2010 Annual Report
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/eng/

Urumqi Observatory, NAO–CAS

40-5 South Beijing Road

Urumqi

Xinjiang Uygur Autonomous Region

830011

China

http://www.uao.ac.cn

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

Bundesamt f ̈ur Kartographie und Geod ̈asie (BKG)

Richard-Strauss-Allee 11

60598 Frankfurt am Main

Germany

http://www.bkg.bund.de

IVS 2010 Annual Report 333
Contributing Institutions

Deutsches Geod ̈atisches Forschungsinstitut, DGFI

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 K ̈otzting

Germany

http://www.fs.wettzell.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-Institute for Radioastronomy

Auf dem H ̈ugel 69

53121 Bonn

Germany

http://www.mpifr-bonn.mpg.de

Agenzia Spaziale Italiana

Centro di Geodesia Spaziale (CGS)

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

Istituto di Radioastronomia, Medicina

C.P. 14

40060 Villafontana

Bologna

Italy

http://www.med.ira.inaf.it

334 IVS 2010 Annual Report
Contributing Institutions

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://vldb.gsi.go.jp/sokuchi/vlbi/ja/

Mizusawa VLBI Observatory, National Astronomical Observatory of Japan

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 314-08501

Japan

http://www2.nict.go.jp/w/w114/stsi/index e.html

National Institute of Polar Research

10-3

Midori-cho

Tachikawa-shi

Tokyo 190-8518

Japan

http://www.nipr.ac.jp/welcome.html

IVS 2010 Annual Report 335
Contributing Institutions

Institute for Radio Astronomy and Space Research, Auckland University of Technology

Private Bag 92006

Auckland 1142

New Zealand

http://www.irasr.ac.nz

GNS Science

PO Box 30368

Lower Hutt 5040

New Zealand

http://www.gns.cri.nz

Land Information New Zealand

160 Lambton Quay

PO Box 5501

Wellington 6145

New Zealand

http://www.linz.govt.nz

Forsvarets forskningsinstitutt (FFI) (Norwegian Defence Research Establishment)

FFI/E

Box 25

2007 Kjeller

Norway

http://www.ffi.no/

Geodetic Institute, Norwegian Mapping Cadastre Authority

Kartverksveien

Hønefoss

Norway

http://www.statkart.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

336 IVS 2010 Annual Report
Contributing Institutions

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 Moscow State University

Universitetskij prospekt 13

Moscow

119991

Russia

http://www.sai.msu.ru

HartRAO, NRF

PO Box 443

Krugersdorp

1740

South Africa

http://www.hartrao.ac.za

Ajou University

442-743

South Korea

http://www.ajou.ac.kr/english

Korea Astronomy and Space Science Institute

305-348

South Korea

http://www.kasi.re.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

IVS 2010 Annual Report 337
Contributing Institutions

Hacettepe University, Department of Geomatics Engineering

Beytepe

06800

Ankara

Turkey

http://geomatik.hacettepe.edu.tr

Karadeniz Technical University, Department of Geomatics Engineering

Trabzon

61080

Turkey

http://www.harita.ktu.edu.tr

Main Astronomical Observatory, National Academy of Sciences of Ukraine

Main Astronomical Observatory

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 238-600

4800 Oak Grove Dr.

Pasadena, CA 91109

USA

http://www.jpl.nasa.gov

Kokee Park Geophysical Observatory

Kokee State Park

P.O. Box 538

Waimea, Hawaii 96796

USA

MIT Haystack Observatory

Off Route 40

Westford, MA 01886

USA

http://www.haystack.mit.edu/

338 IVS 2010 Annual Report
Contributing Institutions

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/

U.S. Naval Observatory, Flagstaff Station

10391 West Naval Observatory Rd.

Flagstaff, AZ 86001

USA

http://www.nofs.navy.mil

IVS 2010 Annual Report 339
List of Acronyms

List of Acronyms

AAS American Astronomical Society

AC (IVS) Analysis Center

ACU Antenna Control Unit

ADB Analog to Digital Board

ADC Analog to Digital Converter

AEB Agˆencia Espacial Brasileira (Brazilian Space Agency)

AES Advanced Engineering Services Co., Ltd (Japan)

AGU American Geophysical Union

AIPS Astronomical Image Processing System

ALMA Atacama Large Millimeter Array

AMRFP Access to Major Research Facilities Program

APEX Atacama Pathfinder EXperiment (Chile)

API Application Programming Interface

APSG Asia-Pacific Space Geodynamics program

APTF Asian Pacific Time and Frequency

ARC Astrometric Radiointerferometric Correlator

ASI Agenzia Spaziale Italiana (Italy)

ASKAP Australian Square Kilometre Array Pathfinder (Australia)

ATA Advanced Technology Attachment

ATM Asynchronous Transfer Mode

ATNF Australia Telescope National Facility (Australia)

AUT Auckland University of Technology (New Zealand)

BADW Bavarian Academy of Sciences (Germany)

BBC Base Band Converter

BIPM Bureau Internacional de Poids et Mesures (France)

BKG Bundesamt f ̈ur Kartographie und Geod ̈asie (Germany)

BPE Bernese Processing Engine

BPF Band Pass Filter

BVID Bordeaux VLBI Image Database

BW Band Width

BWG Beam WaveGuide

CARAVAN Compact Antenna of Radio Astronomy for VLBI Adapted Network (Japan)

CAS Chinese Academy of Sciences (China)

CAY Centro Astron ́omico de Yebes (Spain)

CC (IVS) Combination Center

CC (IVS) Coordination Center

CDDIS Crustal Dynamics Data Information System (USA)

CDP Crustal Dynamics Project

CGE Centrum f ̈ur Geod ̈atische Erdsystemforschung (Germany)

CGS Centro di Geodesia Spaziale (Italy)

CHAMP Challenging Mini-Satellite Payload

CIB Correlator Interface Board

340 IVS 2010 Annual Report
List of Acronyms

CNES Centre National d’Etudes Spatiales (France)

CNRS Centre National de la Recherche Scientifique (France)

CNS Communication, Navigation and Surveillance systems, Inc. (USA)

COL Combination at the Observation Level

CONGO COoperative Network for GIOVE Observation

CORE Continuous Observations of the Rotation of the Earth

CP Circularly Polarized

CPO Celestial Pole Offset

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

CRF Celestial Reference Frame

CRL Communications Research Laboratory (now NICT) (Japan)

CSIR Council for Scientific and Industrial Research (South Africa)

CSIRO Commonwealth Scientific and Industrial Research Organisation (Australia)

CVN Chinese VLBI Network

CW Continuous Wave

DAR Data Acquisition Rack

DAS Data Acquisition System

DB database

DBBC Digital Base Band Converter

DBE Digital BackEnd

DDC Digital DownConverter

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)

DLR Deutsches Zentrum f ̈ur Luft- und Raumfahrt (German Aerospace Center)

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

DRAO Dominion Radio Astrophysical Observatory (Canada)

DSN Deep Space Network

DSS Deep Space Station

D-VLBI Differential VLBI

ECMWF European Centre for Medium-Range Weather Forecasts

IVS 2010 Annual Report 341
List of Acronyms

EDM Electronic Distance Measurement

EIA Environmental Impact Assessment

ENVISAT ENVIronmental SATellite

EOP Earth Orientation Parameter

ERP Earth Rotation Parameter

ERS European Remote Sensing Satellites

ESA European Space Agency

ESO European Southern Observatory

ETS-8 Engineering Test Satellite 8

ETS-VIII Engineering Test Satellite 8

EUREF EUropean REFerence Frame

EVGA European VLBI for Geodesy and Astrometry

EVLA Expanded Very Large Array

e-VLBI Electronic VLBI

EVN European VLBI Network

FACH Fuerza A ́erea de Chile (Air Force of Chile) (Chile)

FCN Free Core Nutation

FES Finite Element Solution

FESG Forschungseinrichtung Satellitengeod ̈asie/Technical University of Munich (Germany)

FFI Forsvarets ForskningsInstitutt (Norwegian Defence Research Establishment) (Norway)

FFTS Fast Fourier Transform Spectrometer

FINEP Financiadora de Estudos e Projetos (Brazilian Innovation Agency)

FPGA Field-programmable Gate Array

FS Field System

FTP File Transfer Protocol

FWF Fonds zur F ̈orderung der wissenschaftlichen Forschung (Austrian Science Fund)

GA Geoscience Australia (Australia)

GAPE Great Alaska and Pacific Experiment

GARR Gruppo per l’Armonizzazione delle Reti della Ricerca

(Italian Academic and Research Network) (Italy)

GARS German Antarctic Receiving Station (Germany)

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)

GGN Global GPS Network

GGOS Global Geodetic Observing System

GGP Global Geodynamics Project

GICO GIga-bit COrrelator

GINS G ́eod ́esie par Int ́egrations Num ́eriques Simultan ́ees

GIOVE Galileo In-Orbit Validation Element

GISTM GPS Ionospheric Scintillation and TEC Monitor

342 IVS 2010 Annual Report
List of Acronyms

GLONASS GLObal NAvigation Satellite System (Russia)

GLORIA GLObal Radio Interferometry Analysis

GNS Science Geological and Nuclear Sciences Research Institute (New Zealand)

GNSS Global Navigation Satellite Systems

GOCE Gravity field and steady-state Ocean Circulation Explorer

GOW Geodetic Observatory Wettzell

GPS Global Positioning System

GR General Relativity

GRACE Gravity Recovery and Climate Experiment (USA)

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 (formerly Geographical Survey Institute) (Japan)

GSK Generalized Spectral Kurtosis

GSOS GPS Surface Observing System

HartRAO Hartebeesthoek Radio Astronomy Observatory (South Africa)

HAT-Lab High Advanced Technology-Lab (Italy)

HEMT High Electron Mobility Transistor

HF-EOP High Frequency Earth Orientation Parameters

HIA Herzberg Institute for Astrophysics (Canada)

HIRLAM High Resolution Limited Area Model

Honeywell- Honeywell Technology Solutions Inc. (USA)

TSI

HOPS Haystack Observatory Postprocessing System

HPBW Half Power Beam Width

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 Institute of Astronomical and Physical Geodesy (Germany)

IAU International Astronomical Union

IBGE Instituto Brasileiro de Geografia e Estatistica (Brazil)

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

IDS International DORIS Service

IDV IntraDay Variability

IERS International Earth Rotation and Reference Systems Service

IF Intermediate Frequency

IGFN Italian Space Agency GPS Fiducial Network (Italy)

IGG Institute of Geodesy and Geophysics (Austria)

IGGB Institut f ̈ur Geod ̈asie und Geoinformation der Universit ̈at Bonn (Germany)

IVS 2010 Annual Report 343
List of Acronyms

IGM Instituto Geogr ́afico Militar (Chile)

IGN Institut Geographique National (France)

IGN Instituto Geogr ́afico Nacional (Spain)

IGS International GNSS Service

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

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

IP Internet Protocol

IRA Istituto di RadioAstronomia (Italy)

IRASR Institute for Radio Astronomy and Space Research (New Zealand)

IRIS International Radio Interferometric Surveying

ISACCO Ionospheric Scintillations Arctic Campaign Coordinated Observation

ISBN International Standard Book Number

ITRF International Terrestrial Reference Frame

IUGG International Union of Geodesy and Geophysics

IVS International VLBI Service for Geodesy and Astrometry

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

JIVE Joint Institute for VLBI in Europe

JLRA Joint Laboratory for Radio Astronomy (China)

JPL Jet Propulsion Laboratory (USA)

KARAT KAshima RAy-tracing Tools (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

KPGO Kokee Park Geophysical Observatory (USA)

KSP KeyStone Project (Japan)

KSRC Kashima Space Research Center (Japan)

KTU Karadeniz Technical University (Turkey)

KTU-GEOD Karadeniz Technical University (KTU), Department of Geomatics Engineering

(Turkey)

KVG Korea VLBI system for Geodesy (Korea)

KVN Korean VLBI Network

LAB Laboratoire d’Astrophysique de Bordeaux (France)

LBA Long Baseline Array (Australia)

LCP Left Circular Polarization

344 IVS 2010 Annual Report
List of Acronyms

LEO Low Earth Orbit

LHC Left Hand Circular

LINZ Land Information New Zealand (New Zealand)

LLR Lunar Laser Ranging

LNA Low Noise Amplifier

LO Local Oscillator

LOD Length Of Day

LPF Low Pass Filter

LSM Least Squares Method

MAO Main Astronomical Observatory (Ukraine)

MARBLE Multiple Antenna Radio-interferometry for Baseline Length Evaluation

MCB Monitor and Control Bus

MCI Monitor and Control Infrastructure

MERIT Monitoring of Earth Rotation and Intercomparison of the Techniques of Observation and Analysis

MEX Mars Express

MIT Massachusetts Institute of Technology (USA)

MLRO Matera Laser Ranging Observatory (Italy)

MOBLAS MOBile LASer Ranging System

MODEST MODel and ESTimate

MPI Max-Planck-Institute (Germany)

MPIfR Max-Planck-Institute for Radioastronomy (Germany)

MTLRS Modular Transportable Laser Ranging System

NAO National Astronomical Observatories (China)

NAOJ National Astronomical Observatory of Japan (Japan)

NAR Noise-Adding Radiometer

NASA National Aeronautics and Space Administration (USA)

NASU National Academy of Sciences of Ukraine (Ukraine)

NCAR National Center for Atmospheric Research (USA)

NCEP National Centers for Environmental Prediction (USA)

NCRIS National Collaborative Research Infrastructure Strategy (Australia)

NDRE Norwegian Defence Research Establishment (Norway)

NEOS National Earth Orientation Service (USA)

NEQ Normal Equation System

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

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

IVS 2010 Annual Report 345
List of Acronyms

NNT No-Net-Translation

NOAA National Oceanic and Atmospheric Administration (USA)

NOFS U.S. Naval Observatory, Flagstaff Station (USA)

NRAO National Radio Astronomy Observatory (USA)

NRCan Natural Resources Canada (Canada)

NRF National Research Foundation (South Africa)

NSF National Science Foundation (USA)

NTT New Technology Telescope (Chile)

NVI NVI, Inc. (USA)

Ny-SMAC Ny- ̊Alesund Science Managers Committee

OAN Observatorio Astron ́omico Nacional (Spain)

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

OS Operating System

OSI Operator Software Impact

OSO Onsala Space Observatory (Sweden)

PARNASSUS Processing Application in Reference to NICT’s Advanced Set of Softwares Usable

for Synchronization

PCB Printed Circuit Board

PEACESAT Pan-Pacific Education and Communication Experiments by Satellite

PERSAC Pulkovo EOP and Reference Systems Analysis Center (Russia)

PFB Polyphase Filter Bank

PLO Phase Locked Oscillator

PMD Politecnico di Milano DIIAR (Italy)

POLARIS POLar motion Analysis by Radio Interferometric Surveying

POP Point of Presence

PPP Precise Point Positioning

PRARE Precise RAnge and Range-rate Equipment

PSD Power Spectrum Density

QRFH Quad Ridge Feed Horn

QZSS Quasi Zenith Satellite System (Japan)

RAEGE Red Atl ́antica de Estaciones Geodin ́amicas y Espaciales

RAS Russian Academy of Sciences (Russia)

RCP Right Circular Polarization

RDBE Roach Digital Back End

RDV Research and Development sessions using the VLBA

REFAG Reference Frames for Applications in Geosciences

RF Radio Frequency

RFI Radio Frequency Interference

RHC Right Hand Circular

ROEN R ́adio-Observat ́orio Espacial do Nordeste (Brazil)

ROM Real Observatorio de Madrid (Spain)

RRFID Radio Reference Frame Image Database

346 IVS 2010 Annual Report
List of Acronyms

RT Radio Telescope

RTK Real-Time Kinematic

RTW Radio Telescope in Wettzell

SAC Satellite Application Centre

SAI Sternberg State Astronomical Institute (Russia)

SATA Serial Advanced Technology Attachment

SBIR Small Business Innovation Research

SCG SuperConducting Gravimeter

SDK Software Development Kit

SEAC Sociedad Espa ̃nola de Aplicaciones Cibern ́eticas (Spain)

SEFD System Equivalent Flux Density

SHAO SHanghai Astronomical Observatory (China)

SI Special Issue

SINEX Solution INdependent EXchange

SK Spectral Kurtosis

SKA Square Kilometre Array

SLR Satellite Laser Ranging

SMHI Swedish Meteorological and Hydrological Institute (Sweden)

SNAP Standard Notation for Astronomical Procedures

SNR Signal to Noise Ratio

SOD Site Occupation Designator

SPb Saint-Petersburg (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)

STEREO Solar TErrestrial RElations Observatory

TAC Totally Accurate Clock

TAI Temps Atomique International (International Atomic Time)

TAL Terrestrial Air Link

TANAMI Tracking Active galactic Nuclei with Australia Milliarcsecond Interferometry (Australia)

TanDEM-X TerraSAR-X add-on for Digital Elevation Measurement (Germany)

TCE Time Comparison Equipment

TDC (IVS) Technology Development Center

TEC Total Electron Content

TEMPO Time and Earth Motion Precision Observations

TerraSAR-X Terra Synthetic Aperture Radars X-band (Germany)

TIGO Transportable Integrated Geodetic Observatory (Germany, Chile)

TLRS Transportable Laser Ranging System

TRF Terrestrial Reference Frame

IVS 2010 Annual Report 347
List of Acronyms

TTW TWIN-Telescope Wettzell (Germany)

TU Technische Universit ̈at

TUM Technical University of Munich (Germany)

TWSTFT Two-Way Satellite Time and Frequency Transfer

UEN Up East North

UMTS Universal Mobile Telecommunications System

UNAVCO University NAVSTAR Consortium

UNICAMP Universidade Estadual de Campinas (Brazil)

UNITEC-1 UNIsec Technological Experiment Carrier-1 (Japan)

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

UT Universal Time

UT1 Universal Time

UTAS University of TASmania (Australia)

UTC Coordinated Universal Time

u-VLBI Ultra High Sensitivity VLBI

V2PEG VLBI2010 Project Executive Group

VC Video Converter

VDIF VLBI Data Interchange Format

VERA VLBI Exploration of Radio Astrometry

VEX VLBI EXchange format

VHDL Very High-level Design Language

VieVS Vienna VLBI Software

VLBA Very Long Baseline Array (USA)

VLBI Very Long Baseline Interferometry

VMF Vienna Mapping Function

VSI VLBI Standard Interface

VSI-C Mets ̈ahovi VSI-H Converter board

VSI-H VLBI Standard Interface Hardware

VSI-S VLBI Standard Interface Software

VSOP VLBI Space Observatory Program

VSR VLBI Science Recorder

VSSP Versatile Scientific Sampling Processor

VTP VLBI Transport Protocol

VTRF VLBI Terrestrial Reference Frame

WACO WAshington COrrelator (USA)

WEGENER Working Group of European Geoscientists for the Establishment of Networks for

Earth-science Research

WG Working Group

WVR Water Vapor Radiometer

WVSR Wideband VLBI Science Recorder

WWW World Wide Web

348 IVS 2010 Annual Report
List of Acronyms

XDM eXperimental Development Model

ZTD Zenith Total Delay

ZWD Zenith Wet Delay

IVS 2010 Annual Report 349


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31-05-2011 Technical Publication

International VLBI Service for Geodesy and Astrometry 2010 Annual Report

Dirk Behrend, Karen D. Baver

Goddard Space Flight Center

Greenbelt, MD 20771

National Aeronautics and Space Administration

Washington, DC 20546-0001

NASA GSFC

NASA/TP-2011-215880

Unclassified-Unlimited, Subject Category: 46

Report available from the NASA Center for Aerospace Information, 7115 Standard Drive, Hanover, MD 21076. (443) 757-5802

Dirk Behrend, NVI, Inc., Greenbelt, MD; Karen Baver, NVI, Inc., Greenbelt, MD

This volume of reports is the 2010 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

components of IVS. The 2010 Annual Report documents the work of these IVS components over the period January 1, 2010

through December 31, 2010. The reports document changes, activities, and progress of the IVS. The entire contents of this Annual

Report also appear on the IVS Web site at http://ivscc.gsfc.nasa.gov/publications/ar2010.

Geodesy, astrometry, VLBI, geophysics, Earth orientation, very long baseline interferometry, interferometry, radio astronomy,

geodynamics, reference frames, terrestrial reference frame, celestial reference frame, length of day, Earth system science, Earth

rotation.

 Unclassified Unclassified Unclassified

Unclassified

349

 Dirk Behrend

(301) 614-5939
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Front cover: The year 2010 marks the beginning of construction of the IVS next generation VLBI network. The network will consist of fast slewing 12-meter 

class antennas with signal electronics that have been completely revised to process four bands each independently settable to any frequency in 

the full 2-14 GHz range. The new broadband system was designed to achieve extremely precise delays at modest SNR and to have the 

frequency flexibility to avoid RFI. The network is expected to grow over the next several years. The use of four frequency bands within the 2-14 

GHz range to determine the phase delay is likely to require correction for the structure of the radio sources as part of the VLBI2010 

observations and data analysis. This volume contains several reports from components that describe advances in VBLI2010 technology 

and network evolution.
International VLBI Service for Geodesy and Astrometry

IVS Coordinating Center

NASA Goddard Space Flight Center

Code 698.2

Greenbelt, MD 20771

http://ivscc.gsfc.nasa.gov

ivscc@ivscc.gsfc.nasa.gov

phone: 301-614-5939

fax: 301-614-6522