OCS Study

MMS 2002-028

Observation of the Atmospheric

Boundary Layer in the Western and

Central Gulf of Mexico

Final Performance Report

U.S. Department of the Interior

Minerals Management Service

Gulf of Mexico OCS Region
U.S. Department of the Interior

Minerals Management Service

Gulf of Mexico OCS Region

OCS Study

MMS 2002-028

Observation of the Atmospheric

Boundary Layer in the Western and

Central Gulf of Mexico

Final Performance Report

Preparers

Vaisala Meteorological Systems, Inc.

and

Sonoma Technology, Inc.

Prepared under MMS Contract

1435-01-97-CT-30854

by

Vaisala Meteorological Systems Inc.

5600 Airport Boulevard

Boulder, Colorado 80301

and

Sonoma Technology, Inc.

1360 Redwood Way, Suite C

Petaluma, California 94954

Published by

New Orleans

August 2002
iii

DISCLAIMER

This report was prepared under contract between the Minerals Management Service (MMS) and

Vaisala Meteorological Systems Inc. This report has been technically reviewed by the MMS,

and it has been approved for publication. Approval does not signify that the contents necessarily

reflect the views and policies of the MMS, nor does mention of trade names or commercial

products constitute endorsement or recommendation for use. It is, however, exempt from review

and compliance with the MMS editorial standards.

REPORT AVAILABILITY

Extra copies of this report may be obtained from the Public Information Office (Mail Stop 5034)

at the following address:

U.S. Department of the Interior

Minerals Management Service

Gulf of Mexico OCS Region

Public Information Office (MS 5034)

1201 Elmwood Park Boulevard

New Orleans, LA 70123-2394

Telephone: 504-736-2519 or 1-800-200-GULF

CITATION

Vaisala Meteorological Systems Inc. and Sonoma Technology, Inc. 2002. Observation of the

Atmospheric Boundary Layer in the Western and Central Gulf of Mexico. U.S. Dept. of

the Interior, Minerals Management Service, Gulf of Mexico OCS Region, New Orleans,

LA. OCS Study MMS 2002-028. 122 pp.

ACKNOWLEDGMENT

This study was funded by the Minerals Management Services, U.S. Department of the Interior,

Washington, D.C., under Contract Number 1435-01-97-CT-30854.
iv

TABLE OF CONTENTS

LIST OF FIGURES .........................................................x

LIST OF TABLES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xii

ACRONYMS AND ABBREVIATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv

1.0 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

2.0 METHODOLOGY AND IMPLEMENTATION . . . . . . . . . . . . . . . . . . . . . . . 2-1

2.1 Goals and Objectives Specified by MMS at Project Start . . . . . . . . . . . . . . . . . . 2-1

2.1.1 Goals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

2.1.2 Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

2.2 Project Planning and Organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

2.3 Schedule . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4

2.4 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4

2.4.1 Meteorological Measurements Specifications . . . . . . . . . . . . . . . . . . . . . 2-4

2.4.2 Site Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5

2.4.3 Logistics Responsibilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5

2.5 Selection of Sites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

2.6 Site Equipment and Communications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8

2.6.1 Radar Wind Profiler (RWP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8

2.6.2 Surface Meteorolgical Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11

2.6.3 Site Communications and Data Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12

2.6.3.1 Site Communications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12

2.6.3.2 Data Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13

2.7 Site Obstacles and Hazards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14

2.8 Equipment and Site Operating Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-16

2.8.1 Equipment Preparation Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-16

2.8.2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-16
v

2.8.3 Operations and Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17

2.8.3.1 Site Audits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17

2.8.3.2 Scheduled Site Visits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17

2.8.3.3 Remote Problem Resolution and Emergency Site Visits . . . . . 2-18

2.8.4 QA/QC Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-18

2.8.4.1 Instrument Calibrations and Checks . . . . . . . . . . . . . . . . . . . . 2-18

2.8.4.2 Review of Calibrations and Checks . . . . . . . . . . . . . . . . . . . . . 2-19

2.8.4.3 Reasonableness Checks of the Data . . . . . . . . . . . . . . . . . . . . . 2-19

2.8.4.4 Data Validation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-19

2.9 Data Storage and Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-21

2.9.1 On-Site Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-21

2.9.1.1 Moments Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-21

2.9.1.2 Consensus Data Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-21

2.9.1.3 Surface Meteorological Data Files . . . . . . . . . . . . . . . . . . . . . 2-22

2.9.2 Remote Collection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-22

2.9.2.1 GOES Satellite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-22

2.9.2.2 Modem Transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-24

2.9.2.3 Field Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-24

2.9.3 Archives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-24

2.9.4 Use in Reports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-25

3.0 DATA COLLECTION OPERATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

3.1 Project Year One Activities (09/22/97 - 09/30/98) . . . . . . . . . . . . . . . . . . . . . . . . 3-1

3.1.1 Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4

3.1.1.1 Personnel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4

3.1.1.2 Communications and Coordination . . . . . . . . . . . . . . . . . . . . . . 3-4

3.1.1.3 Record Keeping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5
vi

3.1.2 Site and Equipment Preparation Logistics . . . . . . . . . . . . . . . . . . . . . . . . 3-6

3.1.2.1 Site Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6

3.1.2.2 RF Licenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7

3.1.2.3 Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7

3.1.2.4 Data Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9

3.1.2.5 Installation Activities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9

3.1.3 Site Operations and Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10

3.1.4 Data Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11

3.1.4.1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11

3.1.4.2 Data Capture Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12

3.1.4.3 Data Recovery Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-13

3.1.4.4 Examples of Wind and Temperature Profiles . . . . . . . . . . . . . 3-17

3.1.5 Problems Encountered and Corrective Action Taken . . . . . . . . . . . . . . . 3-18

3.1.6 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-21

3.2 Project Year Two Activities (10/01/98 - 09/30/99) . . . . . . . . . . . . . . . . . . . . . . 3-22

3.2.1 Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-22

3.2.1.1 Personnel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-22

3.2.1.2 Communications and Coordination . . . . . . . . . . . . . . . . . . . . . 3-22

3.2.1.3 Record Keeping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-23

3.2.2 Site and Equipment Preparation Logistics . . . . . . . . . . . . . . . . . . . . . . . 3-23

3.2.2.1 Site Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-23

3.2.2.2 RF Licenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-24

3.2.2.3 Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-24

3.2.2.4 Data Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-24

3.2.3 Site Operations and Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-24
vii

3.2.4 Data Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-26

3.2.4.1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-26

3.2.4.2 Data Capture Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-26

3.2.4.3 Data Recovery Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-28

3.2.4.3.1 Radar Profiler High-Mode Wind Data . . . . . . . . . . 3-29

3.2.4.3.2 Radar Profiler Low-Mode Wind Data . . . . . . . . . . 3-30

3.2.4.3.3 RASS Temperature Data . . . . . . . . . . . . . . . . . . . . 3-31

3.2.5 Problems Encountered and Corrective Action Taken . . . . . . . . . . . . . 3-32

3.2.6 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-34

3.3 Project Year Three Activities (10/01/99 - 09/30/00) . . . . . . . . . . . . . . . . . . . . . 3-34

3.3.1 Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-34

3.3.1.1 Personnel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-34

3.3.1.2 Communications and Coordination . . . . . . . . . . . . . . . . . . . . . 3-35

3.3.1.3 Record Keeping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-35

3.3.2 Site and Equipment Preparation Logistics . . . . . . . . . . . . . . . . . . . . . . . 3-36

3.3.2.1 Site Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-36

3.3.2.2 RF Licenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-36

3.3.2.3 Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-37

3.3.2.4 Data Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-37

3.3.3 Site Operations and Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-37

3.3.4 Data Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-38

3.3.4.1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-38

3.3.4.2 Data Capture Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-39

3.3.4.3 Data Recovery Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-40

3.3.4.3.1 Radar Profiler High-Mode Wind Data . . . . . . . . . . 3-41

3.3.4.3.2 Radar Profiler Low-Mode Wind Data . . . . . . . . . . 3-42

3.3.4.3.3 RASS Temperature Data . . . . . . . . . . . . . . . . . . . . 3-43

3.3.5 Problems Encountered and Corrective Action Taken . . . . . . . . . . . . . . . 3-44

3.3.6 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-45
viii

3.4 Project Year Four Activities (10/01/00 - 01/31/02) . . . . . . . . . . . . . . . . . . . . . . 3-46

3.4.1 Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-46

3.4.1.1 Personnel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-46

3.4.1.2 Communications and Coordination . . . . . . . . . . . . . . . . . . . . . 3-46

3.4.1.3 Record Keeping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-47

3.4.2 Site and Equipment Preparation Logistics . . . . . . . . . . . . . . . . . . . . . . . 3-47

3.4.2.1 Site Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-47

3.4.2.2 RF Licenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-48

3.4.2.3 Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-48

3.4.2.4 Data Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-48

3.4.3 Site Operations and Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-48

3.4.4 Data Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-50

3.4.4.1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-50

3.4.4.2 Data Capture Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-50

3.4.4.3 Data Recovery Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-52

3.4.4.3.1 Radar Profiler High-Mode Wind Data . . . . . . . . . . 3-53

3.4.4.3.2 Radar Profiler Low-Mode Wind Data . . . . . . . . . . 3-54

3.4.4.3.3 RASS Temperature Data . . . . . . . . . . . . . . . . . . . . 3-55

3.4.5 Problems Encountered and Corrective Action Taken . . . . . . . . . . . . . . . 3-56

3.4.6 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-58

4.0 DATA COLLECTION RESULTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

4.1 Site Equipment Maintenance and Audit Performance . . . . . . . . . . . . . . . . . . . . . 4-1

4.1.1 Data Collection Remote Maintenance Results . . . . . . . . . . . . . . . . . . . . . 4-1

4.1.2 Data Collection On-Site Maintenance Results . . . . . . . . . . . . . . . . . . . . . 4-2

4.1.3 Data Collection Equipment Audit Results . . . . . . . . . . . . . . . . . . . . . . . . 4-4

4.2 Data Capture Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5

4.3 Data Recovery Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14
ix

5.0 EQUIPMENT PERFORMANCE AND DISPOSITION . . . . . . . . . . . . . . . . . . . . . . . . 5-1

5.1 Equipment Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

5.1.1 Upper Air Meteorological Measurement Equipment . . . . . . . . . . . . . . . . 5-1

5.1.2 Surface Meteorological Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2

5.1.3 Supporting Communications and Other Equipment . . . . . . . . . . . . . . . . . 5-3

5.2 Equipment Disposition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4

6.0 SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1

7.0 REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1
x

LIST OF FIGURES

Figure 2-1. Project Organization Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

Figure 2-2. Locations of Chosen Offshore Meteorological Measurements Sites . . . . . . . . . 2-6

Figure 2-3. Site Equipment Subsystems and Interconnectivity . . . . . . . . . . . . . . . . . . . . . . 2-8

Figure 2-4. RWP Subsystem Interconnectivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8

Figure 2-5. RWP Computers Interconnectivity and Data Storage . . . . . . . . . . . . . . . . . . . 2-10

Figure 2-6. Surface Meteorological Sensors Interconnectivity . . . . . . . . . . . . . . . . . . . . . 2-11

Figure 2-7. Site Communications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12

Figure 2-8. Data Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13

Figure 2-9. Outline of Monthly Project Data Report to MMS . . . . . . . . . . . . . . . . . . . . . . 2-25

Figure 3-1. Location of Selected Monitoring Sites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3

Figure 3-2. Principal Activities of MMS Boundary Layer Study 

September 1997 to September 1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3

Figure 3-3. Data Recovery Rates for Radar Profiler High-Mode Winds, 

June-August 1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-14

Figure 3-4. Data Recovery Rates for Radar Profiler Low-Mode Winds, 

June-August 1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-15

Figure 3-5. Data Recovery Rates for Radar Profiler RASS Mode, June-August 1998 . . . 3-16

Figure 3-6. High-Wind Mode Profiles for SMI160A on August 28, 1998 . . . . . . . . . . . . 3-17

Figure 3-7. Virtual Temperature Profiles for VRM22D on August 28, 1998 . . . . . . . . . . 3-18

Figure 3-8. Data Recovery Rates for Radar Profiler High-Mode Winds, 

September 1998 - August 1999 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-29

Figure 3-9. Data Recovery Rates for Radar Profiler Low-Mode Winds, 

September 1998 - August 1999 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-30

Figure 3-10. Data Recovery Rates for Radar Profiler RASS Mode, 

September 1998 - August 1999 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-31

Figure 3-11. Data Recovery Rates for Radar Profiler High-Mode Winds, 

September 1999 - August 2000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-41

Figure 3-12. Data Recovery Rates for Radar Profiler Low-Mode Winds, 

September 1999 - August 2000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-42
xi

Figure 3-13. Data Recovery Rates for Radar Profiler RASS Mode, 

September 1999 - August 2000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-43

Figure 3-14. Data Recovery Rates for Radar Profiler High-Mode Winds, 

September 2000 - October 2, 2001 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-53

Figure 3-15. Data Recovery Rates for Radar Profiler Low-Mode Winds, 

September 2000 - October 2, 2001 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-54

Figure 3-16. Data Recovery Rates for Radar Profiler RASS Mode, 

September 2000 - October 2, 2001 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-55

Figure 4-1. Data Recovery Rates for Radar Profiler High-Mode Winds, 

June 3, 1998 - October 2, 2001 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-15

Figure 4-2. Data Recovery Rates for Radar Profiler Low-Mode Winds, 

June 3, 1998 - October 2, 2001 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-16

Figure 4-3. Data Recovery Rates for Radar Profiler RASS Mode, 

June 3, 1998 - October 2, 2001 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-17
xii

LIST OF TABLES

Table 2-1 Project Task Goals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

Table 2-2 Project Schedule . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4

Table 2-3 Meteorological Measurements at Each Site . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5

Table 2-4 Sampling Configurations for RWP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9

Table 2-5 Surface Meteorological Sensor Model Numbers . . . . . . . . . . . . . . . . . . . . . . . 2-11

Table 2-6 Obstacles and Hazards with Safeguards Employed . . . . . . . . . . . . . . . . . . . . . 2-14

Table 2-7 Quality Control (QC) Codes for Surface and Upper-Air Data . . . . . . . . . . . . 2-20

Table 2-8 Radar Profiler and Surface Meteorological Data Sent via GOES . . . . . . . . . . 2-23

Table 3-1 Project Year One Key Personnel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5

Table 3-2 Meteorological Equipment Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8

Table 3-3 Project Year One Site Visits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11

Table 3-4 Data Capture Rates for VRM22D Site, June-August 1998 . . . . . . . . . . . . . . . 3-13

Table 3-5 Data Capture Rates for SMI160A Site, June-August 1998 . . . . . . . . . . . . . . . 3-13

Table 3-6 Project Year One Equipment Problems and Corrective Actions . . . . . . . . . . . 3-19

Table 3-7 Project Year Two Key Personnel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-22

Table 3-8 Project Year Two Site Visits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-25

Table 3-9 Data Capture Rates for VRM22D Site, September 1998-August 1999 . . . . . 3-27

Table 3-10 Data Capture Rates for SMI160A Site, September 1998-August 1999 . . . . . 3-27

Table 3-11 Project Year Two Equipment Problems and Corrective Actions . . . . . . . . . . 3-32

Table 3-12 Project Year Three Key Personnel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-35

Table 3-13 Project Year Three Site Visits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-38

Table 3-14 Data Capture Rates for VRM22D Site, September 1999-August 2000 . . . . . 3-39

Table 3-15 Data Capture Rates for SMI160A Site, September 1999-August 2000 . . . . . 3-40

Table 3-16 Project Year Three Equipment Problems and Corrective Actions . . . . . . . . . 3-44

Table 3-17 Project Year Four Key Personnel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-46

Table 3-18 Project Year Four Site Visits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-49

Table 3-19 Data Capture Rates for VRM22D Site, September 2000-October 2, 2001 . . . 3-51
xiv

Table 3-20 Data Capture Rates for SMI160A Site, September 2000-October 2, 2001 . . . 3-51

Table 3-21 Project Year Four Equipment Problems and Corrective Actions . . . . . . . . . . 3-56

Table 4-1 Site Corrective Maintenance Visits, June 3, 1998-October 2, 2001 . . . . . . . . . 4-3

Table 4-2 Site Equipment Audit Visits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5

Table 4-3 VRM22D Monthly Data Capture Rates, June 3, 1998-October 2, 2001 . . . . . . 4-6

Table 4-4 SMI160A Monthly Data Capture Rates, June 3, 1998-October 2, 2001 . . . . . . 4-8

Table 4-5 Combined VRM22D & SMI160A Monthly Data Capture Rates, 

June 3, 1998-October 2, 2001 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-11

Table 4-6 Poor Data Capture Rate Months and Cause Factors . . . . . . . . . . . . . . . . . . . . 4-13

Table 5-1 Equipment Refurbishment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5
xv

ACRONYMS AND ABBREVIATIONS

AGL Above Ground Level

°C Degrees Celsius

CD Compact Disk

CDT Central Daylight Time

CO Contracting Officer

COTR Contracting Officer's Technical Representative

CST Central Standard Time

DCP Data Collection Platform

ERL Environmental Research Laboratory

GC Gateway Computer

GFE Government Furnished Equipment

GOES Geostationary Operational Environmental Satellite

GPS Global Positioning System

KHz Kilohertz

km kilometer

Max Maximum

mb millibar

Met Meteorological

MHz Megahertz

Min Minimum

MMS Minerals Management Service 

m/s meters per second

N North

NA Not Applicable

nsec Nanoseconds

NCDC National Climatic Data Center

NESDIS National Environmental Satellite, Data, and Information Service

NOAA National Oceanic and Atmospheric Administration

NTIA National Telecommunications and Information Administration

NWS National Weather Service

O&M Operations and Maintenance

QA Quality Assurance

QC Quality Control

RASS Radio Acoustic Sounding System

RC Radar Computer

RF Radio Frequency

RH Relative Humidity

RWP Radar Wind Profiler

sec second

SMI South Marsh Island 160A platform designator

STI Sonoma Technology, Inc.

Tv Virtual Temperature

VRM Vermillion 22D platform designator

W West
1-1

1.0 INTRODUCTION

This is the final contractor performance report on the data collection portion of

the Boundary Layer Study in the Western and Central Gulf of Mexico, initiated by the Minerals

Management Service (MMS), U.S. Department of the Interior. 

Surface and upper-air meteorological data were collected at two off-shore

platform sites for a continuous 40-month period from June 3, 1998 through October 2, 2001. 

Surface meteorological data measurements were made using identical suites of commercial

in-situ sensors at each of the two platform sites. The surface data collected were wind speed,

wind direction, air temperature, relative humidity, pressure, and sea surface temperature. 

Upper-air meteorological data measurements were made using an identical commercial

remote-sensing boundary layer radar profiler at each of the two platform sites. The upper-air

data collected were vertical profiles of wind direction, wind speed, and virtual temperature. Data

measurements from each platform site were retrieved hourly throughout the 40-month data

collection period via GOES satellite communications relay. All retrieved data were then quality

controlled and reported monthly to MMS. At the end of the project, an electronic, assimilated

data base of all surface and upper-air meteorological measurements recorded at both sites during

the project was also prepared and delivered to MMS.

The prime contractor for this data collection project was the meteorological

systems group that was under Radian International LLC as of the beginning of this MMS project

and that subsequently became part of Vaisala Inc. during the project. This change resulted in no

discontinuity in the contractor team performing the MMS project, other than the change of the

name of the prime contractor. On September 22, 1997, MMS awarded the original contract for

this project to Radian International LLC (an element of URS Corporation), and, effective

October 29, 2001, MMS novated that contract to Vaisala Meteorological Systems Inc. (an

element of Vaisala Inc.). For simplicity throughout this final performance report, prime

contractor references are to "Vaisala" rather than spelling out in each reference that the prime

contractor was originally "Radian" and changed to "Vaisala."

This report is organized to summarize project activities and results in essentially

chronological order. In the order presented, the report documents the project methodology and

its implementation, the site operations and data collection activities accomplished during each

year of the project, the data measurement results achieved for the entire 40-month data collection

period, and the end-of-project disposition status of the meteorological measurement equipment

used. As reflected in the report, the project spanned a period of more than four years. This

included approximately eight months of preparatory work to obtain and configure the measuring

equipment and sites and to obtain necessary operating licenses, the 40-month data collection

period itself, and finally a wrap-up period of several months to decommission sites, refurbish

equipment, and compile the final data base and other project documentation. 
2-1

2.0 METHODOLOGY AND IMPLEMENTATION

2.1 Goals and Objectives Specified by MMS at Project Start

2.1.1 Goals

For the Gulf of Mexico, present data sets poorly represent how temperature,

winds, and mixing height vary vertically over the atmospheric boundary layer and free

troposphere. Estimates come from two sources: 1) automated weather stations measuring

meteorological variables in the surface layer; and 2) observational satellites sampling the

boundary layer and free troposphere at a few select altitudes. Because these techniques generally

do not accurately or precisely measure for a range of altitudes, empirical constants and

relationships are used to approximate vertical variations in temperature, winds, and other

boundary layer properties. However, direct observations more accurately describe vertical

variations because the cited estimates contain many assumptions and simplifications.

Applications using these estimated winds, temperature, and mixing heights exist,

but they contain uncertainties from above simplifications. For instance, the Minerals

Management Service (MMS) applies such estimates in several ways when assessing changes in

air quality from oil and gas production. The MMS requires meteorological inputs and

computational routines in dispersion modeling. The MMS assessments use conceptual models of

pollutant transport through the marine boundary layer and theoretical analysis on the marine

boundary layer. The MMS then has an interest in collecting field observations of the vertical

structure of the marine boundary layer because such observations would reduce uncertainties in

environmental assessments.

Under this project, the MMS shall obtain field observations describing the

vertical structure of the marine boundary layer over the Western and Central Gulf of Mexico for

ongoing and future applications. The agency will accomplish this goal by establishing two (2)

boundary layer profiler systems on offshore platforms for approximately three (3) years of data

collection. The MMS requires acquisition, installation, and maintenance of equipment, data

collection, data management, and routine reporting over the life of this project. The MMS will

retain ownership during and after the time period.

Each system is to use existing, well-established technologies and procedures. 

Each system needs to make minimal demands on platform resources and produce no hazards to

platform personnel or offshore radio transmissions.

This project will provide a valuable source of information to the National

Weather Service (NWS) operations as the boundary layer observations are collected in real time

and distributed. An arrangement will be set up to permit NWS direct access to the observations. 

The NWS will also supplement quality control and archive the observations at the National

Climatic Data Center (NCDC).
2-2

2.1.2 Objectives

Accurately collect, record, and report meteorological observations for three years

(later amended by MMS to 40 months) in the Western and Central Gulf of Mexico. These

observations shall include temperature, atmospheric refractivity, and winds from the surface

layer into the free troposphere. Surface data collected shall measure air and sea surface

temperatures, pressure, winds, and humidity. Project task goals are as listed in Table 2-1.

Table 2-1. Project Task Goals

Task Goal

1. Equipment All equipment types listed in the contract are to be provided with careful

consideration of cost-benefit trade-offs.

2. Field Plan The most workable sites are to be identified and obtained. A

comprehensive field plan is to be prepared and endorsed by MMS.

3. Deployment and Operations Two sites are to be operated and maintained, in an accident-free manner,

providing all required data types at 90% or greater capture level with

diligent QA/QC and on-time reporting.

4. Discontinuation of Monitoring Equipment is to be fully checked, appropriately refurbished, and

relocated as directed by MMS in a timely manner after the data

collection period.

5. All The project is to be completed within the estimated costing and on a

time schedule approved by MMS.

2.2 Project Planning and Organization

In coordination with MMS, the contractor developed and implemented two master

planning documents that governed the management and operational detail of how the project was

executed. These were the "Project Management Plan" and the "Field Plan" for Profilers and

Data Collection for the MMS Boundary Layer Study in the Western and Central Gulf of Mexico. 

The project organization established in these planning documents, and as maintained throughout

the project, is shown in Figure 2-1. The prime contractor, initially Radian International LLC and

subsequently Vaisala Meteorological Systems Inc. , performed all functions shown within the

CONTRACTOR organization, except the Principal Investigator and Data Processing and

Reporting Team functions, which were performed by Sonoma Technology, Inc. (STI) under

subcontract to the prime contractor.
2-3

Figure 2-1. Project Organization Chart
2-4

2.3 Schedule

The project schedule, as originally planned and actually executed, is shown in

Table 2-2.

Table 2-2. Project Schedule

Milestone Originally Planned Actually Executed1

Contract issued and work started to acquire and

prepare sites and equipment (includes start of monthly

management reports to MMS)

22 September 1997 22 September 1997

Start installation of equipment at sites. February 1998 February 1998

Complete installation of equipment at sites. February 1998 February 1998

Complete testing of equipment at sites (ready for start

of data collection period).

March 1998 March 1998

GOES and RF frequency licenses received. February 1998 May 1998

Start data collection period. 1 April 1998 3 June 1998

First monthly data report to MMS (monthly thereafter) May 1998 July 1998

First draft annual report to MMS (annually thereafter) 30 September 1998 30 September 1998

Complete data collection period. 28 February 2001 2 October 2001

Removal of equipment from sites. March 2001 November 2001

Final performance report, assimilated data set, and

draft technical summary to MMS.

July 2001 February 2002

Note 1: Actually executed dates varied from originally planned dates because of an initial delay in receiving 

necessary site licenses and because MMS later extended the data collection period from 36 to 40 months.

2.4 Specifications

2.4.1 Meteorological Measurements Specifications

Table 2-3 lists project requirements established and implemented by

meteorological data types, applicable measurement instruments used, measurement frequency,

and measurement accuracy. 
2-5

Table 2-3. Meteorological Measurements at Each Site

Measured

Parameter

Sensor

Manufacturer

Sensor 

Model Range Accuracy

Upper Air Measurements

Wind Speed Vaisala LAP®-3000 RWP1 0 to 24 m/s (per

beam)

±1.0 m/s

Wind Direction Vaisala LAP®-3000 RWP1 0 to 360 deg. ±10 deg.

Virtual Temperature Vaisala LAP®-3000 RASS2 5 to 40° C ±1.0° C

Surface Meteorological Measurements

Wind Speed RM Young RMY 05305-5 0 to 40 m/s ±0.2 m/s

Wind Direction RM Young RMY 05305-5 0 to 360 deg. ±3.0 deg.

Air Temperature Campbell Scientific, Inc. HMP35C -35 to 

+50.0° C 

±0.5° C

Sea Surface

Temperature

Everest Interscience, Inc. 4000.4GL -40 to 

+100.0° C 

±0.5° C

Relative Humidity Campbell Scientific, Inc. HMP35C 0 to 90% RH ±2% RH

90 to 100% RH ±3% RH

Pressure Vaisala PTA-427 600 to 1060 mb ±0.6 mb 1 Radar Wind Profiler(RWP)

2 Radio Acoustic Sounding System (RASS)

2.4.2 Site Specifications

Each of two offshore oil platform sites in the Louisiana Gulf Coast was

configured to fulfill the specifications in Table 2-3. The preferred locations of the respective

two sites were established by MMS as approximately 10 km within the shoreline and

approximately 50-80 km within the shoreline.

2.4.3 Logistics Responsibilities

The Program Manager was designated responsibility for monitoring all equipment

and data handling logistics and for coordinating as appropriate with the MMS COTR.

The Principal Engineer was designated responsibility for all equipment logistics,

including procurement, pre-deployment testing, shipping, installation, preventive and

emergency maintenance, audits and calibrations, removal, refurbishment, and shipment to MMS

storage.

The Principal Investigator was designated responsibility for all data handling

logistics, including sensor operating parameters, data retrieval, data reasonableness checks,

audit and calibration report reviews, data validation, reporting, and archiving. He performed

these functions through the facilities and personnel of STI's dedicated Weather Operations

Center in Petaluma, California and worked closely with the project QA/QC Manager.
2-6

Figure 2-2. Locations of Chosen Offshore 

Meteorological Measurements Sites

The QA/QC Manager monitored data and report quality and kept the Program

Manager appraised of status, including any problems and recommended corrective action.

2.5 Selection of Sites

The site selection process was completed as the first step in field project

preparation. A location in shallow water was needed to measure how the marine boundary layer

is affected by the land/sea breeze mechanism. Such a location was estimated to be within 10 km

from the shoreline. A location in deep water was needed to measure how the marine boundary

layer is affected by interaction between advecting air masses and colder waters in the Gulf of

Mexico. Such a location was believed to be near the 200 m isobath and approximately 75 km

from the shoreline. Locations of the chosen sites are depicted in Figure 2-2.
2-7

In addition to preferred geographical location, oil platform site selection criteria

included:

• Manned platforms are far preferable to unmanned.

• Adequate open-deck space (10 m x 10 m) is required for the radar

antenna, located within 150 ft. of a shelter.

• The shelter must have reliable mains power and environmental control

for electronics.

• The platform should have a microwave telephone communications link.

• There should be no obstructions or towers above 5 deg. from the surface

of the wind profiler.

The Principal Engineer performed two site surveys, via helicopter, of the

platforms in lease blocks recommended by the MMS COTR. The first survey, on 9/30/97,

evaluated nine platforms in the southern part of the South Marsh Island (SMI) block and four

platforms in the Ship Shoal block. From these, SMI160A was selected as the optimal deepwater site and the platform owner, Chevron, subsequently provided approval for MMS use of

this manned platform. Later in the project, Chevron sold the SMI160A platform to Newfield

Exploration, who also allowed the MMS equipment to remain on the platform and continue

operations.

Eleven unmanned platforms were evaluated in the shallow-water East and West

Cameron lease blocks. After review with the MMS COTR, a second survey was conducted on

10/22/97, during which an additional seven shallow-water platforms in the Vermillion lease

block and six shallow-water platforms in the northern part of the South Marsh Island lease

block were evaluated. In coordination with the MMS COTR, it was decided that the preferred

shallow-water platform site was Vermillion 22D because it meets the siting criteria from an

equipment perspective and it is best located to capture sea breeze information. Approval from

the platform owner, ERT, was subsequently obtained for use of this manned platform.
2-8

Figure 2-3. Site Equipment 

Subsystems and 

Interconnectivity

Figure 2-4. RWP Subsystem 

Interconnectivity

2.6 Site Equipment and 

Communications

Figure 2-3 illustrates the site equipment

subsystems that were installed on each platform site, and

the interconnectivity of these subsystems. The

subsystems are:

• RWP (LAP®-3000 and RASS);

• Surface meteorological sensors;

• Computers; and

• Communications Interfaces.

2.6.1 Radar Wind Profiler (RWP)

Figure 2-4 illustrates the interconnectivity view of the RWP (LAP®-3000/RASS). 

The LAP®-3000 RWP is a remote sensing Doppler radar that produces a profile of the vertical

and horizontal winds in clear air up to

approximately three kilometers above

ground level (atmospheric dependent). The

profile includes wind speed and direction. 

The LAP®-3000's Radio Acoustic Sounding

System (RASS) provides a profile of virtual

temperature up to approximately 1.2

kilometers above ground level (atmospheric

dependent). The radar profiler produces

wind and reflectivity data by transmitting

signal pulses in the vertical and up to four

pointing directions that are each tilted in

elevation about 15 degrees off vertical and

are each separated by 90 degrees in

azimuth. The operating frequency is 915

MHZ (32.8 cm wavelength). After

transmitting a pulse signal, the profiler

receives the return signals that are reflected

by the turbulence in the atmosphere. From

these returns, the radar profiler computes

the wind speed and direction for a selected

number of heights above the ground.
2-9

The radar profiler produces virtual temperature data by automatically halting

wind finding for a preprogrammed period of RASS operation. During RASS operation, the four

acoustic sources are activated and the vertical beam of the radar is used to track the RASS

acoustic transmission in order to measure the speed of sound for a selected number of heights

above the ground. Speed of sound data are then automatically converted to virtual temperature

data by the LAP®-3000. Table 2-4 shows the initial sampling configurations for the radar wind

profilers and RASS for this project. These configurations were adjusted throughout the project

to optimize performance based upon atmospheric and environmental conditions at each profiler

site.

Table 2-4. Sampling Configurations for RWP

Specification Winds Tv Surface Met

Averaging period (min) 55 5 60

Reporting interval (min) 60 60 60

Time standard CST CST CST

Time convention Begin Begin Begin

Vertical resolution (m) ~100 (low mode)

~200 (high mode)

60 -

Minimum altitude (m agl) VRM1 131 120 -

Maximum altitude (m agl) VRM1 4934 1260 -

Minimum altitude (m agl) SMI1 131 135 -

Maximum altitude (m agl) SMI1 4920 1275 -

 1Altitude referenced as “agl” (above ground level) means above platform level.

The LAP®-3000 provides continuous real-time atmospheric wind and virtual

temperature data. The LAP®-3000 operates unattended. For more on the general theory and

physics of how this type of instrument measures virtual temperature and resolves winds, see

Ecklund et al., 1990. 

The LAP®-3000 is a system of interrelated components. The RF antenna

(including final amplifier unit) and RASS antennas are positioned outside an environmentally

controlled shelter area and all other components are positioned inside the environmentally

controlled shelter. The system is configured with an Uninterruptible Power Supply to help

protect the profiler from changes in AC power supply voltage, including AC power loss of up to

20 minutes duration.
2-10

Figure 2-5. RWP Computers Interconnectivity and Data Storage 

The LAP®-3000 operates using two computers, a Radar Computer and a Gateway

Computer, both positioned within the environmentally-controlled shelter. The Radar Computer

controls overall radar operation and data analysis, and transfers measured vertical profiles of

wind and virtual temperature data to the Gateway Computer. The Gateway Computer is

connected to a Global Positioning System (GPS) device that provides accurate time updates,

which the Gateway Computer also relays to the Radar Computer. The Gateway Computer also

receives surface meteorological data measurements from the data logger, which is connected to

the surface meteorological sensors. The Gateway Computer provides external communication

through a modem and a GOES interface. Figure 2-5 shows the interconnectivity and data

storage access of the Radar Computer and Gateway Computer. Profiler supervision and control

by remote connection through the telephone modem is accomplished using remote access

software ProComm.
2-11

Figure 2-6. Surface Meteorological Sensors Interconnectivity

2.6.2 Surface Meteorological Sensors

The surface meteorological measurements at the two platform sites included:

wind speed and direction; air and sea-surface temperature; relative humidity; and pressure.

Figure 2-6 illustrates the interconnectivity of the surface meteorological sensors

installed at each site. 

The specific surface meteorological equipment to be installed on each platform site is listed in

Table 2-5.

Table 2-5. Surface Meteorological Sensor Model Numbers

Item Description Model

Wind Direction/Speed RMY 05305-5

Air Temperature/R.H. CSI HMP35C

Sea Surface Temperature 4000 4GL

Pressure PTA 427

Data Logger CR10

Calibration A.I.R. Barometer

Calibration Rotronic T/RH Probe
2-12

Figure 2-7. Site Communications

2.6.3 Site Communications and Data Flow

2.6.3.1 Site Communications 

Site communications as shown in Figure 2-7 included:

• A data uplink to Geostationary Orbiting Environmental Satellite (GOES)

that served as the primary link for transferring hourly data.

• A telephone/modem served as a secondary data link and for diagnostics

and system configuration. 
2-13

Figure 2-8. Data Flow

2.6.3.2 Data Flow

At each platform measurement site, the profiler and surface meteorological data

were collected every hour on the Gateway Computer. Then, selected data were compressed into

a data packet and were sent by the site's GOES Data Collection Platform (DCP) over the

assigned GOES transmission channel to the NESDIS site at Wallops Island, Virginia. The

assigned GOES transmission channel, authorized by NESDIS for this MMS project, permitted

transmission of up to two minutes duration from each site at specified times after each hour. A

copy of the transmitted data was stored on the NESDIS file server in Virginia for FTP Internet

download or dial-in modem access for at least 72 hours. The project’s data processing and

reporting team at STI automatically downloaded the data as soon as it became available and

performed reasonableness checks to identify problems. The GOES data were also retransmitted

via domestic satellite (DOMSAT) to a downlink at the NOAA laboratories in Boulder, Colorado. 

Data flow detail is illustrated in Figure 2-8.
2-14

2.7 Site Obstacles and Hazards

The establishment of meteorological equipment and radar profilers on platforms

in the Gulf of Mexico created some unique obstacles and hazards that needed special safeguards

as summarized in Table 2-6 below. 

Table 2-6. Obstacles and Hazards with Safeguards Employed

Obstacle or Hazard Safeguards

Down time due to platform environmental problems such as

air conditioner failure or inadvertent disruption by platform

personnel.

Use of manned platforms and fostering of good relationships

with platform workers. Use of standard computers that

incorporate a lockable front panel behind which are the

power switches, floppy drives, and a keyboard lock.

Restrictions on data retrieval/QA due to loss of long-line

communications.

Redundant communications and enhanced on-site data

storage capacity.

Severe weather (lightning, heavy rains, and high speed

winds) and marine environment effects on exposed

equipment.

Humidity protection for electronics (in environmentally

controlled shelter/office); enhanced anchoring (welding and

strong guy wiring); lightning spikes or rods; electricity surge

protection; and in-line surge protection for all lines leading

from the shelter to the antenna. For the surface met.

equipment, an opto-isolating interface in the shelter to

provide isolation for the computer.

RASS noise is potential concern. RASS audio is only a hazard inside the RASS antenna

enclosures. Warning signs are posted. Fiberglass

enclosures make the RASS sources inaccessible to personnel. 

RF radiation potential concern. Within ANSI standards even immediately above the antenna. 

Clutter fences and warning signs provide additional safety. 

Fiberglass enclosures make the antenna inaccessible to

personnel. Under the antenna assembly, a metal cover seals

off this vulnerable side of the antenna from both the weather

and people. The July 1982 RF exposure limits set by the

American National Standards Institute (ANSI) in ANSI

C95.1-1982 are a maximum safe exposure level, at 915

MHZ, of 3 mW/cm2. The LAP-3000 antenna system has a

signal strength of 2 mW/cm2 directly over the antenna array,

a location that is inaccessible to personnel because of the

clutter screen assembly. The exposure level is further

reduced by the vertical pointing of the antenna and the

clutter screen assembly, which attenuate the signal strength

an additional 30 to 50 dB (max 2 mW/cm2). 
2-15

Table 2-6. Obstacles and Hazards with Safeguards Employed (Cont'd)

Obstacle or Hazard Safeguards

Interference with platform operations/personnel. The LAP®-3000 and RASS do not interfere with platform

activities, including cellular phone communications or

aircraft navigation. All support desired from platform-owner

companies and their personnel will be coordinated and

approved in advance. This will include: some

transportation support (on company-scheduled boat or

helicopter); some on-platform support (overnight

accommodations, crane support and welding support during

installation and removal); occasional trouble-shooting calls

to platform personnel to perform simple system checks; etc.

Personnel tripping on cables. Cables across walkways minimized and a conduit or cover

used to protect the cables. High visibility tape or paint to

warn workers of cables’ presence. Power supplies in the

system drop to 0 VDC if the cables are shorted or damaged,

preventing any threat to personnel. 

Walking into or tripping over guy wiring. Guy wires marked with high visibility spiral wrap.

Deteriorating environmental protection steps. Periodic maintenance visits by project team technicians and

cooperation of platform workers to call the project team if an

obvious deterioration is noted (e.g., a loose or broken guy

wire, A/C failure, etc.).

Loss of data due to system failures. Use of radar UPS, auto-restart, remote control operation,

electric power surge protection, battery backup for data

logger, and selected sparing of equipment and parts. The

radar electronics plug into a Toshiba UPS which tolerates a

wide AC input range (+10%,-30%). This unit also supplies a

fully rectified output with line filtering which gives 100%

isolation from AC line noise and surges. The UPS will

provide 20 minutes of backup in the event of a total loss of

power. When the battery capability is exceeded, the system

will shut down without damage to electronics. When power

is restored, the system will boot normally and resume

sampling without operator input. Emergency maintenance

visits will be performed as needed to restore operations and

routine maintenance visits will be performed on a scheduled

basis to help prevent possible failures.

Corrosion and part failure due to corrosion from moisture

and salt spray.

Whenever possible, parts have been upgraded to marine

grade stainless steel to resist corrosion. Additionally, bottom

covers are installed on the antenna unit to minimize the

penetration of corrosive sprays to the antenna feed system

and components. The marine version of the surface ind

sensor has been installed to provide be available performance for this sensor given the harsh environment. Biannual inspections include assessment of the hardware so

that small problem due to corrosion can be corrected in the

early stages.

Note: Although not an “obstacle or hazard” another limiting factor in operating a radar profiler on an 

offshore platform is that seawave motion (which produces a Doppler shift) can interfere with 

wind profile neasurements in the lower altitudes above the profiler’s antenna. This occurs when 

radar sidelobe energy is reflected vack to the profiler’s antenna from the moving seawaves, 
2-16

producing return signals that are much stronger than those produced by the winds. The degree 

and persistence of sea clutter (interference) varies with seawave height and directional 

orientation. It also depends on whether the platform structure extends avove the height of the 

radar antenna, causing radar energy to be reflected off the structure to the seawaves.

2.8 Equipment and Site Operating Procedures

2.8.1 Equipment Preparation Testing

Testing of the equipment was done by the Principal Engineer in two stages: 1)

pre-deployment mockup systems testing at the factory prior to shipment and 2) on each platform

following installation. The installation technician followed prescribed steps to ensure the

systems were running properly. This process included inspection of the signal outputs,

calibrating the meteorological sensors, and a brief data audit. A degree of testing was done

through remote communications whereby the data management team conducted data

reasonableness checks daily. Data reasonableness checks were performed through remote

communications with the sites while the installation team was still on each platform, and over an

approximate one-week period after installation. The Principal Investigator confirmed the

successful completion of this data review testing prior to the official start of the three-year data

collection period.

2.8.2 Installation

The Principal Engineer led the team that installed the equipment at both platform

sites. Installation of each LAP®-3000 required one day for the major assembly and a second day

to complete final details. The installation process included the following actions: 

• Equipment was sent via commercial van lines to nearest on-shore holding facility.

• In preparation of a boat trip, arrangements were made for platform personnel

availability to haul the equipment from the boat to the platform’s deck, for a

welder to be present, and a technician to be at the platform to receive the

equipment. Use of the platform crane and a certified operator were required to lift

the crates from boat to deck.

• The project installation team installed the profiler antennas, RASS assemblies,

and met sensors on each platform at predesignated and agreed to locations. 

• The electronics were housed inside a prior agreed-to office or other air

conditioned enclosure with proper electric power access.

• Once the installation was complete, guy anchors were welded to the platform

deck. Platform personnel were needed to assist for the short time it took to attach

the guy plates. Cables from the profiler antennas, RASS, and meteorological

equipment support posts were routed to the office where the electronics were

housed using appropriate anchoring and protective coverings for personnel safety.
2-17

2.8.3 Operations and Maintenance

The Operations and Maintenance (O&M) program, managed by the Principal

Engineer included :

• A shakedown operations test prior to formal data collection period;

• Scheduled site equipment checks;

• Unscheduled (emergency) site equipment repairs; and

• End-of-program equipment checks.

2.8.3.1 Site Audits

During all scheduled or emergency platform site visits after installation, site

audits were conducted using a Platform Site Audit Checklist, which included: 

• Overall evaluation of the condition of the station; 

• Operating condition of each sensor;

• Placement and/or alignment of each sensor;

• Reasonableness of sensor outputs with atmospheric conditions; 

• Data collection, processing, and archiving functionality; and

• Data acquisition system clocks are compared against a standard.

2.8.3.2 Scheduled Site Visits

Scheduled site visit equipment checks were performed at approximately sixmonth intervals at both platforms. The visiting O&M team member used the Platform Site Audit

Checklist for scheduled visits and the LAP®-3000 O&M Manual to guide the maintenance tasks.

The visiting Equipment and O&M team member took required test equipment and

spare parts on each platform visit. Problems found were corrected during the visit if possible, or

were corrected as soon as possible during a follow-up emergency site visit if they could not be

corrected during the scheduled site visit.

Copies of the completed checklist for each visit were distributed to the QA/QC

Manager for review and were placed in project files immediately after the visit.
2-18

2.8.3.3 Remote Problem Resolution and Emergency Site Visits

The Data Processing and Reporting team attempted to resolve any problem(s)

detected by performing remote system resets or, as appropriate, by obtaining telephone

assistance from on-site platform personnel. If remote problem solving did not work, the Data

Processing Reporting Team passed the problem resolution task to the Principal Engineer for

resolution.

The Principal Engineer then attempted to resolve the problem remotely. As

required, the Principal Engineer then arranged for an Equipment O&M team member to perform

an emergency site visit by helicopter.

All problems noted and their resolution were documented for review by the

QA/QC Manager and in the project file. The Platform Site Audit Checklist for emergency visits

was completed and distributed immediately after the visit. For problems resolved remotely, Data

Processing and Reporting Team personnel or the Principal Engineer, as appropriate, prepared

and distributed a problem resolution report.

If an emergency site visit was performed within about 30 days prior to a

scheduled site visit, it fulfilled the requirement of the next scheduled site visit if the Equipment

O&M team member performing the emergency visit was able to also complete a scheduled visit

Platform Site Audit Checklist, if all problems were resolved during the emergency visit, and if

no new problems were noted. 

2.8.4 QA/QC Program

The QA/QC program implemented for this MMS project included the equipment

and data checks summarized below.

2.8.4.1 Instrument Calibrations and Checks 

 

During scheduled site visits calibrations and checks of the surface meteorological,

LAP®-3000, and RASS upper-air equipment were performed and documented to ensure that the

instruments were operating according to manufacturer’s guidelines. A formal calibration

involved measuring the “conformance to or discrepancy from a specification ... for an instrument

... and an adjustment of the instrument ... to conform to the specification” (U.S. EPA, 1989). A

calibration of the surface meteorological equipment was straightforward and followed U.S. EPA

guidelines. A calibration of the radar profiler and surface meteorological equipment was more

complex since it is difficult to directly compare winds to a known standard. Instead, a series of

diagnostic checks were performed to verify that the electronics and individual components of a

system are working properly. This approach conforms to the EPA’s guidelines for the quality

assurance and management of PAMS upper-air meteorological data (Lindsey et al., 1995).
2-19

2.8.4.2 Review of Calibrations and Checks

Once the on-site calibrations and checks were completed, results of these checks

were sent to the QA/QC Manager for review. For example, if the calibration showed that the

surface wind direction sensor was mis-aligned by 10°, all wind direction data were adjusted by

10°. All calibrations were applied to the data before they were officially released.

2.8.4.3 Reasonableness Checks of the Data 

Daily throughout the study, data reasonableness checks were made to ensure the

measurements produced make sense. This was performed using nearby meteorological

information from surface towers or other upper-air sensors, as available. A project team

meteorologist at STI was responsible for reviewing these upper-air data and comparing them to

nearby measurements. 

This check was not meant to evaluate whether or not the data meet the

manufacturer's data specifications, but rather as a “reasonableness check” to identify problems

such as:

• Component failures;

• Incorrect operating/sampling parameters;

• Instrument failures;

• Antenna azimuth angles mis-measured.

2.8.4.4 Data Validation

 Data validation is the process of determining the quality of the data and

identifying observations with errors, biases, or physically unrealistic values (Lindsey et al.,

1995). Without data validation, questionable or erroneous data might be used for modeling or

analysis purposes and in decision making. A meteorologist or another trained person who has a

basic understanding of the meteorological phenomena and the operating principles of the

instrument performed data validation weekly. The data validation process involved identifying

physically, spatially, or temporally inconsistent observations (“outliers”) and assigning QC

codes to each data point to indicate its validity. There are several stages or “levels” in the data

validation process:

Level 0 data validation consisted of raw data obtained directly from the data instruments in

the field. Level 0 data are unedited and unreviewed. These data have not received any

adjustments for known biases or problems that may have been identified during preventive

maintenance checks or audits. These data were used to monitor the instrument operations

on a daily basis.

Level 0.5 data validation consisted of using software to perform quantitative screening of

the data. For the radar profiler and RASS data, quantitative checks were performed by the

software-screening program developed by Wuertz and Weber (1989) that examines the 
2-20

temporal and vertical continuity of the data to identify possible outliers. For the surface

meteorological data, STI's SurfDat software was used to automatically screen the surface

data using quantitative criteria developed by the EPA (U.S. EPA 1989).

Level 1 data validation took place after the data had been collected and passed the Level

0.5 data validation. During this validation step, the data received qualitative reviews for

accuracy, completeness, and internal consistency. Qualitative checks were performed by

meteorologists and trained personnel who manually reviewed the data for outliers and

problems. Quality control flags, consisting of numbers or letters, were assigned to each

datum to indicate its quality. A list of QC codes is given in Table 2-7. The surface and

upper-air data were only considered at Level 1 after calibration reports had been reviewed

and any adjustments, changes, or modifications to the data had been made.

Table 2-7. Quality Control (QC) Codes for Surface and Upper-Air Data

QC Code

QC Code Name Definition

0 Valid Observations that were judged accurate within the performance

limits of the instrument.

1 Estimated Observations that required additional processing because the

original values were suspect, invalid, or missing. Estimated

data may be computed from patterns or trends in the data (e.g.,

via interpolation).

2 Calibration applied Observations that were corrected using a known, measured

quantity (e.g., instrument offsets measured during audits).

3 Unassigned Reserved for future use.

4 Unassigned Reserved for future use.

5 Unassigned Reserved for future use.

6 Failed automatic QC check Observations that were flagged with this QC code did not pass

screening criteria set in automatic QC software.

7 Suspect Observations that, in the judgment of the reviewer, were in

error because their values violated reasonable physical criteria

or did not exhibit reasonable consistency, but a specific cause

of the problem was not identified (e.g., excessive wind shear in

an adiabatic boundary layer).

8 Invalid Observations that were judged inaccurate or in error, and the

cause of the inaccuracy or error was known (e.g., winds

contaminated by ground clutter or a temperature lapse rate that

exceeded the autoconvective lapse rate). Besides the QC flag

signifying invalid data, the data values themselves should be

assigned invalid indicators.

9 Missing Observations that were not collected.
2-21

2.9 Data Storage and Handling

2.9.1 On-Site Data

The instrument systems on each platform created and stored three types of data

files: moments data, consensus data, and surface meteorological data. This section describes the

contents of these data files.

2.9.1.1 Moments Files

 The moments data files contain individual 20-30 second wind profiles with

information about the Doppler shift, the spectral width, the noise power, and the signal-to-noise

ratio measurements. These data may be needed in the future to diagnose the instrument

performance, re-compute winds with a shorter averaging period (e.g., 15 minutes), and to

compute the refractive index structure function (Cn

2

). The moments data consist of two types of

files: header and data. The header files contain project and site-specific information and the

data files contain the actual data. These data files are in a binary format and are produced by the

radar software. The combined size of the header and data moments files are approximately 1000

to 1500 KB per day. These data are stored on the Radar Computer in the “C:\RADAR\DATA”

directory with a “.MOM” file extension. The moments file naming convention is:

DYYJJJA.MOM (moments data)

HYYJJJA.MOM (moments header)

Where: YY =Year

JJJ = Julian day

A = File sequencer in 1 MB steps

For example, D98011A.MOM is a moments data file for January 11, 1998.

2.9.1.2 Consensus Data Files

There are two types of consensus files: wind and virtual temperature. The radar

software produces both types of consensus files every hour by processing and averaging the 20-

30 second moments data. The LAP®-3000 uses a technique referred to as “consensus averaging”

to compute hourly wind profiles (Fischler and Bolles, 1981). Using this technique, a radial

velocity is determined for each beam direction and each measurement height every 20-30

seconds, and the software selects the largest subset of the radial velocities measured during the

hour that fall within a user-selectable velocity window (typically 2 m/s). The hourly horizontal

wind direction and speed is then computed for each measurement height using the chosen subset

of radial velocities. If at least 60 percent of the radial velocities do not fall within 2 m/s of each

other, no winds would be reported at that altitude for that hour.

The consensus data are in an ASCII text format and contain hourly averaged wind

and virtual temperature profiles. The size of each type of consensus data file is approximately 
2-22

100 to 200 KB per day. The consensus data files are stored on the gateway computer in the

“C:\GATEWAY\DATA” directory with a “.CNS” file extension. The consensus data file

naming conventions are:

WYYJJJ.CNS (wind data)

TYYJJJ.CNS (virtual temperature data)

Where: YY = Year

JJJ = Julian day

For example, W99308.CNS is a wind file for November 4, 1999.

2.9.1.3 Surface Meteorological Data Files

The surface meteorological data include wind speed and direction, air

temperature, sea-surface temperature, relative humidity, and pressure. These surface data are

stored in the Campbell Scientific Inc. (CSI) surface meteorological data logger. Software

located on the gateway computer communicates with the CSI data logger and retrieves the latest

surface meteorological data every hour. The raw surface meteorological data are stored in an

ASCII text file in a comma separated variable (CSV) format. This file is located on the gateway

computer in the “C:\CSI” directory with a “.DAT” extension. The surface meteorological data

file naming convention is:

SIDH.DAT 

Where: SID = Three letter site identification code

H = Hourly averaged data

2.9.2 Remote Collection

Three pathways were used to receive data remotely. The primary data pathway

was through the GOES satellite transmission, the secondary link was via modem, and the third

method of data collection was via the routine maintenance trips.

2.9.2.1 GOES Satellite 

As noted in Section 2.6.3.2, data were automatically transmitted every hour

through a GOES satellite link. Within the constraints of the GOES time allotments, the data sent

via GOES consisted of the parameters listed in Table 2-8. 
2-23

Table 2-8. Radar Profiler and Surface Meteorological Data Sent via GOES

Parameter Units Reporting Convention

Site Information

Site ID

Date and begin time of consensus period

N/A

yy mm dd hh mm ss (in CST)

AAA

xx xx xx xx xx xx

Surface Meteorological Data

Averaging Interval

Software Version

Year

Julian Day (day of year)

Hour

Wind Speed

Wind Direction

Resultant Wind Speed

Resultant Wind Direction

Std. of Wind Direction

Ambient Temperature

Sea Surface Temperature

Relative Humidity

Atmospheric Pressure

60 minutes

N/A

N/A

N/A

CST

Meters per second (m/s)

Degrees true

Meters per second (m/s)

Degrees true

Degrees 

Degrees Celsius (°C)

Degrees Celsius (°C)

Percent

millibars (mb)

xx

x.xx

xxxx

xxx

xxxx

xx.x

xxx.x

xx.x

xxx.x

xxx.x

xx.x

xx.x

xxx.x

xxxx.x

Upper-Air Winds (Mode 1)

Pulse width

Number of Range Gates

Gate Spacing

Height

Wind Speed

Wind Direction

Vertical Velocity

Signal-to-Noise Ratio (vertical beam)

100 meters

25

100 meters 

Meters (m)

Meters per second (m/s)

Degrees from true north

Meters per second (m/s)

Decibels (dB)

xxxx

xx

xxxx

xxxx

xx.x

xxx.x

xx.x

xxx

Upper-Air Winds (Mode 2)

Pulse width

Number of Range Gates

Gate Spacing

Height

Wind Speed

Wind Direction

Vertical Velocity

Signal -to-Noise Ratio (Vertical Beam)

400 meters

25

200 meters

Meters (m)

Meters per second (m/s)

Degrees true

Meters per second (m/s)

Decibels (dB)

xxxx

xx

xxxx

xxxx

xx.x

xxx.x

xx.x

xxx
2-24

Table 2-8. Radar Profiler and Surface Meteorological Data

 Sent via GOES (Cont'd)

Parameter Units Reporting Convention

Upper-Air Virtual Temperature

Pulse Width

Number of Range gates

Gate Spacing

Height

Virtual Temperature

Virtual Temperature (Corrected)

Vertical Velocity

60 meters

20

60 meters

Meters (m)

Degrees Celsius (°C)

Degrees Celsius (°C)

Meters per second (m/s)

xxxx

xx

xxxx

xxxx

xx.x

xx.x

xx.x

Note: x=numbers, and A=characters.

2.9.2.2 Modem Transmission

The dial-up modem pathway served as a redundant backup to access and

download data in the event that the primary GOES transmission was unsuccessful. Another

important aspect of the modem connection was to remotely control the instruments to

troubleshoot, configure, maintain, and conduct diagnostics.

2.9.2.3 Field Data

A project O&M team member collected the field data from each site during the

scheduled site maintenance visits. The field data consisted of ZIP disks with the moments,

consensus, and surface meteorological data. This was mailed to STI, where its receipt was

recorded and the data and information were archived.

2.9.3 Archives

Archiving of the surface and upper-air data was critically important to ensure that

the data were not lost, destroyed, or corrupted. A reliable archive was updated frequently and

included redundant backups. Two copies of all data for the project was maintained at all times

and data were archived at the earliest possible opportunity. The two major data sets that were

archived included the hourly GOES data and the field data received from the scheduled regular

maintenance visits. 

As the hourly GOES data were received at STI, they were logged and stored in an

MS ACCESS database. This database resided on STI’s HUB computer. It was automatically

backed-up each night across a local area network (LAN) onto a separate hard drive. The

database was archived to a compact disk (CD) and a ZIP disk every month. The CD remained at

STI and the ZIP disk will be sent to Vaisala to provide a redundant offsite backup of the data on

different media. 
2-25

1. INTRODUCTION

Table 1. Site locations and information

2. SUMMARY OF OPERATIONS

2.1 Sampling Configurations.

Table 2. Sampling configurations of sensors used.

Table 3. Specifications of sensors used.

2.2 Data Completeness

Table 4. Data Capture Rates for Both Sites During the Reporting Period

Table 5. Data Recovery for Valid Level 1.0 RASS Data at VRM

Table 6. Data Recovery for Valid Level 1.0 Low-Mode Wind Data at VRM

Table 7. Data Recovery for Valid Level 1.0 High-Mode Wind Data at VRM

Table 8. Data Recovery for Valid Level 1.0 RASS Data at SMI

Table 9. Data Recovery for Valid Level 1.0 Low-Mode Wind Data at SMI

Table 10. Data Recover for Valid Level 1.0 High-Mode Wind Data at SMI

Table 11. Events at Affected the Data Recovery and/or the Data Quality

2.3 Data Adjustments

Table 12. Data adjustments

3. DATA FORMATS

Table 13. Description of the data fields in the "WINDdata" table

Table 14. Description of the data fields in the "RASSdata" table

Table 15. Description of the data fields in the "SURFdata" table

Attachment: CD containing the month's observations.

Figure 2-9. Outline of Monthly Project Data Report to MMS

When the project O&M team member sent the field data to STI after a scheduled

site visit, approximately every six months, the data from the ZIP disks were logged and backedup onto a computer hard-drive and to a CD. The CD remained at STI as part of the archive, and

the ZIP disks were sent to Vaisala to provide offsite storage of the data on different media.

2.9.4 Use in Reports

The project team used the GOES data and other log/status data to compile a

monthly project data report that was sent to MMS. Each monthly report included a summary of

operations, an explanation of the data formats, and the data. Figure 2-9 shows the contents

outline of the monthly data report.
3-1

3.0 DATA COLLECTION OPERATIONS

Project team activities spanned the timeframe from September 1997 through

February 2002 and included the three project phases of preparing for data collection operations,

conducting data collection operations, and performing follow-up tasks after the completion of

data collection operations. As originally specified by MMS, the planned data collection period

was to be 36 months. As implemented, the data collection period began on June 3, 1998, and

was therefore scheduled for completion on June 2, 2001. However, prior to that scheduled

completion date, MMS elected to change the data collection period to 40 months in order to

expand the data base to fully encompass the time period of the complementary Breton

Aerometric Monitoring Program (BAMP) data collection project. The BAMP project was

sponsored by the Off-Shore Operator's Committee. It included six data measurement sites, five

of which were also on off-shore platforms in the Gulf of Mexico near Breton Island. The BAMP

data collection period was from September 2000 through September 2001. As a result of the

extension of the data collection period from 36 to 40 months, MMS data collection operations

that began on June 3, 1998 were completed on October 2, 2001.

Data collection operations conducted are summarized in Sections 3.1 through 3.4

below in approximately annual increments. Section 3.1 covers the period leading up to the June

3, 1998 start of the 40-month data collection period and it also includes the first four months of

actual data collection operations. Sections 3.2 and 3.3 document the second and third full years

of the project, all of which were part of the 40-month data collection period. Finally, Section 3.4

covers the final year of the data collection period, and also includes the approximately 4-month

follow-up period during which the sites were de-commissioned, equipment was refurbished, the

full project data base was compiled, and project reports were prepared.

3.1 Project Year One Activities (09/22/97 - 9/30/98)

Work accomplished and results achieved during the first year of the project, 

September 22, 1997 through September 30, 1998, are detailed below.

Meteorological monitoring systems were installed on two platforms in the

northern Gulf of Mexico as illustrated in Figure 3-1. SMI160A was owned by Chevron at the

beginning of this MMS project, but was sold to Newfield Exploration during the project. The

sensors on each platform included a 915 MHZ boundary layer profiler to measure vertical

profiles of wind speed and direction, a 2 KHz RASS unit to measure virtual temperature profiles,

and a suite of surface meteorological instruments. A GOES DCP (Data Collection Platform) was

also installed at each site to transmit hourly data via satellite communications to the project data

management facility.
3-2

Activities during the first year included: 

• Preparing and testing the radar profilers;

• Purchasing additional surface meteorological sensors;

• Obtaining GFE sensors and other hardware;

• Integrating the sensor and communications components;

• Developing procedures for data collection, analysis, and reporting;

• Modifying hardware and software to meet special MMS field conditions and

communications requirements; 

• Selecting and preparing oil platform sites;

• Obtaining RF licenses for communications and profiling operations;

• Installing the systems on the oil platforms;

• Operating and maintaining the data collection systems; and

• Submitting monthly status and data reports.

Installation and testing of the meteorological monitoring systems at the two

platform sites was completed during March 1998, but the monitoring systems were shut down

temporarily while awaiting necessary RF licenses. The originally planned three-year data

collection period started on June 3, 1998. An overview of the first year of the project is shown

in Figure 3-2, and a description of the activities of this startup period is provided in the sections

below.
3-3

Figure 3-1. Location of Selected Monitoring Sites

Sep 97 Oct 97 Nov 97 Dec 97 Jan 98 Feb 98 Mar 98 Apr 98 May 98 Jun 98 Jul 98 Aug 98

Contract Award

Site Survey

STI Subcontract Award

Procure and test equipment

Obtain RF Licenses

Installation Site Visits

Shutdown - Await RF Licenses

Receive RF Approvals

Site Reactivation

3-Year Collection Period

System Integration

Sep 98

Site Audit Visits

Figure 3-2. Principal Activities of MMS Boundary Layer Study

September 1997 to September 1998
3-4

3.1.1 Management

MMS and contractor participants implemented a highly effective project team

working relationship, using e-mail and telephone conferences to coordinate implementation

actions and to resolve potential problems as they arose.

3.1.1.1 Personnel

Table 3-1 shows the key personnel participants in the project during the first year. 

As noted in that table, Dr. Alexis Lugo-Fernandez replaced Bill Hutzel as MMS COTR during

the first year of the project. 

3.1.1.2 Communications and Coordination

Authority for all required project team decision actions to ensure timely, efficient,

and competent accomplishment of all work under the contract was vested in the Program

Manager. Authority for day-to-day decision making was delegated to the Principal Engineer for

all equipment-related matters and to the Principal Investigator for all data collection and

processing matters.

The flow of internal team communications and coordination began with the

issuance of written Project Instructions by the Program Manager and a kick-off meeting of all

projects participants hosted by the Program Manager. Project contractual requirements, the

responsibilities of all product team members in fulfilling those requirements, as well as detailed

scheduling and budget planning were discussed in detail. Team meetings were held at the call of

the Program Manager on an as-required basis. The Principal Engineer and Principal Investigator

convened meetings with project personnel supporting their respective functional areas on a

regular basis to ensure the continued flow of effective and timely internal communications

throughout the project.

Meetings of the project key personnel were convened on a scheduled basis at the

end of each month at the call of the Program Manager or as requested by the Principal Engineer

or Principal Investigator. These meetings provided assurances for timely flow of

communications within the leadership of the project team and for the coordination on all matters

requiring decision actions. Regularly scheduled monthly meetings included a review of all

actions completed during the prior month which then served as the basis for monthly status

reports issued by the Program Manager to MMS. Projected activities for the ensuing month

were also reviewed at each monthly meeting.
3-5

Table 3-1. Project Year One Key Personnel

Project Function Person Performing Function Comments

MMS Contracting Officer (CO) Wally Adcox

MMS Contracting Officer's

Technical Representative (COTR)

Alex Lugo-Fernandez Replaced Bill Hutzel, who served

as COTR at the beginning of the

project.

Program Manger Gary Zeigler Radian (later Vaisala)

Principal Investigator Tim Dye STI

Principal Engineer Carlton Schneider Radian (later Vaisala)

 

All formal external communications and coordination by project team members

were directed through the Program Manager. Informal communications and coordinating with

personnel and agencies outside the project team were encouraged by individual team members as

necessary to ensure effective accomplishment of the routine work within the responsibility of the

respective team participant. Issues that arose during such informal external contacts were

immediately reported through the project management chain to the Program Manager for formal

resolution.

3.1.1.3 Record Keeping

The project contract file, including copies of all correspondence with the MMS

Contracting Officer was maintained in the office of the Contract Specialist.

A copy of all documentation related to project accomplishment was maintained in

the office of the Program Manager. These documents included all project directives, reports of

trips and meetings, record copies of all written deliverables submitted to MMS, and copies of all

written correspondence between the Program Manager and the MMS COTR.

Data collection and processing, chain of custody, and other quality assurance

records were maintained by the Principal Investigator. These records served as the basis of

monthly and annual reporting, as well as other formal submissions.

Equipment testing, installation, operation, maintenance, and quality assurance

records were maintained by the Principal Engineer. The Principal Engineer also maintained a

log of all scheduled and unscheduled site visit activities and the results thereof. These records

served as the basis of monthly and annual reporting, as well as other formal submissions, that

were initiated by the Principal Engineer, through the Program Manager, to MMS as contract

deliverables.
3-6

Photographic records of all significant project activities were taken by project

team members, under the direction of project key personnel, as inputs to MMS under the

“Presentation Slide Sets” deliverable requirement of the contract.

3.1.2 Site and Equipment Preparation Logistics

3.1.2.1 Site Selection

On September 22, 1997 the MMS COTR provided the project team a list of

candidate oil platforms to serve as data collection sites for the boundary layer study. He

requested that the shallow water site be selected on a line between Cameron and Sabine Pass,

and that the deep water site be selected on the 150m to 200m isobath between the Ship Shoal and

Garden Banks blocks. Additional criteria included:

• Manned platform, if possible, to help assure continuous operations;

• Adequate space for the radar profiler antenna;

• Minimal obstructions or towers which would cause radar profiler interference

clutter;

• Environmentally controlled shelter space available for electronics; and

• Shelter within 150m of the radar profiler antenna location.

On September 30, 1997 a project team field engineer surveyed the candidate

platforms to assess their suitability as data collection sites. He first flew through the area to

make a quick visual inspection of the platforms, looking for adequate space for the radar profiler

antenna, presence of a shelter for the electronics, and the absence of structures which could

cause radar clutter. He took pictures of the platforms and visited the most promising deep water

platform. A suitable shallow water platform was not located on this visit.

The area was visited again on October 22, 1997 to further attempt to locate a

usable manned platform near the coast. Several workable candidates were identified.

After coordination with the MMS staff and the platform operators, the following

two platforms were selected for the study:

1) South Marsh Island 160A, operated by Chevron, as the deep water site; and

2) Vermillion 22D, operated by ERT, as the shallow water site.
3-7

3.1.2.2 RF Licenses

 RF licenses were required for the GOES satellite data up-link and for the wind

profiler operating frequency.

• The profiler data was transmitted using a two-minute per hour channel of the

NOAA/NESDIS Geostationary Operational Environmental Satellite (GOES)

system. Allocation of the channel from NESDIS and permitting from NTIA to

transmit to the GOES satellite at 402 MHZ were required.

• The wind profiler measurements were based on radar pulses centered at 915

MHZ. Permission from NTIA to operate the two profilers in the Gulf of Mexico

in this band was required.

Contractor project team members coordinated with NOAA ERL staff on

procedures for communicating profiler data via GOES, and also on the steps required to request

GOES allocations. The necessary applications for the GOES channel allocations were

completed and submitted to NESDIS in December 1997. On January 20, 1998 an allocation for

one minute per hour was received. The project team immediately went back to NESDIS and

received the necessary two minute per hour allocation, as originally requested.

The RF license applications for operating at 402 MHZ and 915 MHZ were

completed and submitted through MMS to the Department of the Interior in January 1998. 

In February, the project team arranged to temporarily borrow GOES channels

from the NOAA Aeronomy Laboratory so that system integration and testing could proceed

while waiting for the NTIA approvals. 

In the last week of March 1998, the Department of the Interior submitted the RF

applications to NTIA. Soon thereafter, NOAA withdrew the temporary loan of the GOES

channels because they were required for a NOAA field project.

The RF broadcast approvals were received from NTIA on May 26, 1998, and the

planned three-year data collection period began a few days later, on June 3, 1998.

3.1.2.3 Equipment

The radar wind profilers employed in this MMS project were manufactured at

Radian’s (now Vaisala's) assembly plant in Boulder, CO. Each was integrated with surface

meteorological sensors and data communications components from MMS and from commercial

vendors. Custom modifications to the two systems were made to adapt to the harsh

environmental conditions expected on the platforms and also to support the unique data

communications requirements. The components were also tested at the Boulder facility before
3-8

deployment to ensure the reliability of the fielded systems. Table 3-2 lists the equipment

deployed.

Table 3-2. Meteorological Equipment Specifications

Measured

Parameter

Sensor Manufacturer

Sensor Model Sensor Specifications

Wind Speed RM Young RMY 05305-5 Accuracy: ±0.2 m/s

Range: 0 to 40 m/s

Wind Direction RM Young RMY 05305-5 Accuracy: ±3°

Range: 0 to 360°

Temperature Campbell Scientific, Inc. HMP35C Accuracy: ±0.5°C

Range: -35° to +50.0°C

Relative Humidity Campbell Scientific, Inc. HMP35C Accuracy: ±2% RH

Range: 0-90% RH

Accuracy: ±3% RH

Range: 90 to 100% RH

Pressure Vaisala PTA-427 Accuracy: ±0.6 mb

Range: 600 to 1060 mb

Sea Surface

Temperature

Everest Interscience, Inc. 4000.4GL1 Accuracy: ±0.5°C

Range: -40°C to 100°C

Upper-air Wind

Speed 

Vaisala LAP®-3000 RWP2 Accuracy: ±1.0 m/s

Range: 0 to 24 m/s

(per beam)

Upper-air Wind

Direction

Vaisala LAP®-3000 RWP2 Accuracy: ±10°

Range: 0 to 360°

Upper-air Virtual

Temperature

Vaisala LAP®-3000 RASS3 Accuracy: ±1.0°C

Range: 5°C to 40°C

1 An infrared remote sensor mounted on a platform guardrail and pointed downward at the water surface

2

 Radar Wind Profiler (RWP)

3

 Radio Acoustic Sounding System (RASS)

The key steps in assembling and integrating the equipment suites for the two

platforms were:

• Prepare and test the two 915-MHZ wind profilers;

• Add custom modifications to the profilers for platform operation;

• Adapt Gateway software to support surface met sensors and GOES data transfer;

• Purchase Radian-procured portion of surface met equipment;

• Receive and integrate MMS-provided surface met components;

 • Procure GOES Data Collection Platforms;

• Write custom software modules to compress data for GOES data links; and

• Integrate and test complete systems at the contractor’s Boulder facility.
3-9

3.1.2.4 Data Processing 

The data processing and communications tasks planned for the project included

preparing the data at the sites, transmitting the data back through GOES, receiving the data at

the STI Weather Operations Center, analyzing and storing the data, and submitting data reports. 

To prepare for these tasks, the following steps were accomplished between the start of the

project and March 1998:

• Adapt Gateway computer to ingest surface meteorological data;

• Write Gateway module to generate compressed data packets for GOES

transmission;

• Configure Gateway to send hourly data packets to NESDIS via the GOES 

RF up-link;

• Develop procedures to retrieve data packets from NESDIS computer;

• Develop procedures to decode and analyze the data;

• Specify, in coordination with the MMS COTR, the content and format of monthly

data reports; and

• Develop software and procedures to support data archival and report generation.

3.1.2.5 Installation Activities

As described in Section 3.1.2.1, the two platform sites were selected on the basis

of information gathered during two visits to the Gulf of Mexico area in September and October

of 1997, in coordination with MMS and platform operations staff. 

Special requirements for the two sites were identified. For example, there was

limited space in the air conditioned shelter at SMI160A for the Radar and Gateway Computers.

Also shared telephone connections to the computers at each site were arranged. The positioning

of electronic and antenna components and the resulting cabling requirements were determined

for each site.

The equipment was shipped to the Louisiana coast in early February 1998. The

monitoring equipment was installed at the SMI160A site on February 16-19, and at VRM 22D

on February 20-22. The spares were positioned in Lafayette, LA on February 23, 1998.
3-10

Project team members made two return visits to the sites on 3-8 March 1998 and

24-26 March. During these visits a number of identified instrumentation issues were addressed

and resolved. Although all equipment installation had been completed, the two sites had to be 

placed in a temporary shutdown mode on March 25, 1998 when NOAA had to withdraw their

GOES channel loan (as noted in Section 3.1.2.2 of this report).

The RF broadcast licenses requested from NTIA by the Department of the Interior

for this MMS project were received on May 26, 1998. Site reactivation was started on May 27

and the sites were visited on June 1-3. Equipment readiness checks were completed and both

sites were operational as of the afternoon of June 2 and the data collection period began on June

3, 1998.

3.1.3 Site Operations and Maintenance

The planned three-year data collection period began on June 3, 1998. Regularly

scheduled site visits were planned at six-month intervals, with the first such visit scheduled in

September 1998.

No unscheduled site visits were required between June and September, 1998. 

Data collection continued without interruption for all sensors on both platforms during this

period, except for a period of about four days in late September due to Hurricane Georges (as

described below). 

Tropical storm Earl passed through the Gulf of Mexico in early September. Both

platforms were evacuated for several days. Before departure, the VRM22D platform’s power

was shut off causing 38 hours of radar data loss spanning 1-2 September. The surface

meteorological data at VRM22D was, however, successfully captured as its battery powered

backup was sufficient to last through the passage. No data were lost at the SMI160A platform as

power there was not shut down upon evacuation.

As shown in Table 3-3, the first scheduled visit to the sites following the start of

the data collection period was performed 14-17 September 1998. This visit included equipment

audits and several corrective maintenance actions.

Hurricane George passed through the area in late September. Both sites were

evacuated and the power was turned off at both sites. Power outages caused loss of 98 hours of

radar data at VRM22D spanning 26-30 September and 94 hours of radar data at SMI160A

spanning 25-29 September. The surface data collection continued uninterrupted because the

battery-backup was able to keep this portion of the system working during the four-day

evacuation period at each platform. 

At SMI160A, GOES transmission of the data did not resume when the platform

operators returned to the platform and restored power to the system on September 29. One of the

operators accidentally broke the power switch on the GOES Data Collection Platform unit while

restoring power. It was confirmed that the profiler was collecting data. An unscheduled
3-11

maintenance visit was planned for October 9, 1998 to install the spare GOES unit on the

SMI160A platform so that the failed unit’s power switch can be repaired. As documented in

section 3.2.3 of this report, that visit was successfully completed.

Table 3-3 lists all site visits performed during the first year of the project, both

before and after the June 3, 1998 start of the data collection period.

Table 3-3. Project Year One Site Visits

Visit Date Site(s)

Visited

Visit Type Visit Tasks Completed

9/30/97 Multiple Scheduled Surveyed candidate sites

10/22/97 Multiple Scheduled Surveyed candidate sites

2/16/98 –

2/19/98

SMI160A Scheduled Installed equipment

2/20/98 –

2/22/98

VRM22D Scheduled Installed equipment

3/03/98 –

3/08/98

VRM22D &

SMI160A

Scheduled Tested/audited equipment and communications

3/24/98 –

3/26/98

VRM22D &

SMI160A

Scheduled Tested /audited equipment and communications

Note: After completion of all equipment installation and

testing, as listed above, both sites were ready for

operation, but the start of the data collection period was

then delayed until 6/3/98 pending receipt of necessary site

RF operating licenses (permitting radar profiler and GOES

up-link RF transmissions). 

9/14/98 –

9/17/98

VRM22D &

SMI160A

Scheduled Performed periodic equipment audits

At VRM22D, restored GOES transmissions by clearing a

Gateway Computer interrupt

At both VRM22D and SMI1601, adjusted the RASS

configuration setting to increase the expected range of

upper air temperatures to be potentially measured.

3.1.4 Data Measurements

3.1.4.1 Description

The radar profiler was pre-programmed to take measurements continuously, and

to alternate between recording vertical profiles of wind and recording vertical profiles of virtual

temperature. During periods in which it is recording wind measurements, it was also pre-
3-12

programmed to do so using alternating short (700 nsec) and long (2800 nsec) transmission

pulses. The resultant "dual-mode winds" produced included "low-mode winds" and "high-mode

winds." Low-mode winds are the wind measurements made using the short transmission pulse. 

Advantages of low-mode winds are that they start at the lowest possible altitude above the radar

profiler and that they have the best possible vertical resolution. High-mode winds are the wind

measurements made using the long transmission pulse. The advantage of the high-mode winds

is that they extend to the highest possible altitude above the radar profiler.

The Gateway computer on each platform collected data from the radar profiler,

the surface meteorological instrument datalogger, and the GPS receiver. Once each hour, the

latest data are packed into a compressed format and transmitted through the GOES satellite link

to a database on the NOAA/NESDIS system in Wallops Island, VA. 

Automated procedures in the STI weather operations facility were used to retrieve

and unpack the data files. The STI staff reviewed the data daily to ensure that all of the

collection systems were operating correctly. At the end of each month, the prior month’s data

were processed to quality-stamp any suspect and invalid measurements. A monthly data report

was then generated. The validated monthly data were also loaded into a database archive.

3.1.4.2 Data Capture Rate

The data capture rate measures the up-time of the integrated data collection and

communications systems at each site. It is defined using:

Data Capture Rate = ( NumRec/NumPos)*100

where:

NumRec = number of hours of data received at STI during the reporting period

NumPos = number of hours of data possible during the reporting period 

(for example, 30 x 24 = 720 in a 30 day reporting period)

As of the September 30, 1998 end of the first year of the project, data rates for

June, July and August 1998 were available (and data for September 1998 were being processed).

The data capture rates for June-August 1998 for the VRM22D site are shown in

Table 3-4. The data capture rates for the same period for the SMI160A site are shown in Table

3-5. The goal of the MMS program was to achieve a capture rate of 90% or higher. The actual

average capture rate for all sensors for the initial three-month collection period was 97.5%. 
3-13

Table 3-4. Data Capture Rates for VRM22D Site, June-August 1998

Month Upper Air Winds Upper Air Tv Surface Met

June 1998 99.3% 99.3% 99.3%

July 1998 93.8% 93.8% 93.8%

August 1998 97.0% 97.0% 97.0%

Table 3-5. Data Capture Rates for SMI160A Site, June-August 1998

Month Upper Air Winds Upper Air Tv Surface Met

June 1998 98.2% 98.2% 98.2%

July 1998 97.4% 96.2% 97.5%

August 1998 99.7% 99.7% 99.6%

3.1.4.3 Data Recovery Rate

The data recovery rate is defined as the percentage of valid data captured by each

instrument while the integrated system is operational. It is calculated using:

Data Recovery Rate = (NumVal/NumRec)*100

where:

NumVal = Number of valid hours of data received during the reporting period

NumRec = Number of hours of data received at STI during the reporting period.

The data recovery rate provides a method to evaluate the performance of the

instruments.

As of the September 30, 1998 end of the first year of the project, data rates for

June, July and August 1998 were available (and data for September 1998 were being processed).
3-14

20 30 40 50 60 70 80 90 100

Meters AGL

Percent Data Recovery

4934

4742

4549

4357

4164

3972

3779

3587

3394

3202

3010

2817

2625

2432

2240

2047

1855

1663

1470

1278

1085

893

700

508

316

Max %

Average

Min %

VRM-22D Site, High-Mode Winds

30 40 50 60 70 80 90 100

Meters AGL

Percent Data Recovery

4920

4728

4535

4343

4150

3958

3765

3573

3380

3188

2996

2803

2611

2418

2226

2033

1841

1649

1456

1264

1071

879

686

494

302

Max %

Average

Min %

SMI-160A Site, High-Mode Winds

The data recovery rates for the two sites for the high- mode winds are shown in

Figure 3-3. The relatively low data recovery rates at low altitudes at the SMI site were attributed

to interference from sea clutter. The VRM22D profiler installation was less sensitive to sea

clutter and did not experience similar data losses.

Figure 3-3. Data Recovery Rates for Radar Profiler High-Mode Winds, 

June-August 1998
3-15

0 10 20 30 40 50 60 70 80 90 100

Meters AGL

Percent Data Recovery

2440

2344

2247

2151

2055

1959

1862

1766

1670

1574

1478

1381

1285

1189

1093

996

900

804

708

612

515

419

323

227

131

Max %

Average

Min %

VRM-22D Site, Low-Mode Winds

0 10 20 30 40 50 60 70 80 90 100

Meters AGL

Percent Data Recovery

2440

2344

2247

2151

2055

1959

1862

1766

1670

1574

1478

1381

1285

1189

1093

996

900

804

708

612

515

419

323

227

131

Max %

Average

Min %

SMI-160A Site, Low-Mode Winds

The data recovery rates for the two sites for the low-mode winds are shown in

Figure 3-4. Both sites experienced data recovery losses at the lowest altitudes due primarily to

sea clutter interference.

Figure 3-4. Data Recovery Rates for Radar Profiler Low-Mode Winds,

June-August 1998
3-16

0 10 20 30 40 50 60 70 80 90 100

Meters AGL

Percent Data Recovery

1260

1200

1140

1080

1020

960

900

840

780

720

660

600

540

480

420

360

300

240

180

120

Max %

Average

Min %

VRM-22D Site, RASS Mode

0 10 20 30 40 50 60 70 80 90 100

Meters AGL

Percent Data Recovery

1275

1215

1155

1095

1035

975

915

855

795

735

675

615

555

495

435

375

315

255

195

135

Max %

Average

Min %

SMI-160A Site, RASS Mode

In the RASS mode, virtual temperature profiles are measured by using the

scattering of radar pulses from acoustic waves. The data recovery rates for the radar profiler

RASS mode are shown in Figure 3-5. 

Figure 3-5. Data Recovery Rates for Radar Profiler RASS Mode, 

June-August 1998
3-17

Figure 3-6. High-Mode Wind Profiles for SMI160A on August 28, 1998

RASS data losses at the lower altitudes during July and August were due to a

configuration problem, and not due to clutter interference as in the wind modes. In the RASS

mode, the acoustic source is programmed to sweep across a frequency band that corresponds to

the range of expected atmospheric virtual temperatures. For the initial part of the collection

period, the maximum temperature was set too low, resulting in lost data at low altitudes on hot

days. During a site visit in September 1998, the parameter set was adjusted to cover a higher

temperature range so that the lower altitude data would not be lost.

3.1.4.4 Examples of Wind and Temperature Profiles

Wind profiles for the high-mode winds at the South Marsh Island deep water site

for August 28 are shown in Figure 3-6. 
3-18

Figure 3-7. Virtual Temperature Profiles for VRM22D on 

August 28, 1998

Advancing time runs along the horizontal scale (x-axis from right to left). In this

example, measured winds above approximately 2000 m were consistently from the east, whereas

winds below that altitude show changing boundary layer conditions in detail.

Sample virtual temperature profiles measured by the radar profiler in the RASS

mode at the Vermillion site on August 28 are shown in Figure 3-7. 

The left-most temperature profile is at 10:00 am with right-most at 3:00 pm

(15:00). This showed typical expected warming of the lower atmosphere into the day’s heating

cycle.

3.1.5 Problems Encountered and Corrective Action Taken

No problems involving the management of the project were experienced during

the first year of the project.
3-19

Table 3-6 lists the equipment problems encountered, and the corrective action

implemented, during the first year of the project.

Table 3-6. Project Year One Equipment Problems and Corrective 

Actions

Ref No. Problem Project Team Corrective Action

1-1 Long lead time for initial receipt of

GOES DCP equipment and channel

allocations. 

Borrowed a GOES DCP and channel allocation from

NOAA’s Aeronomy Laboratory for use during the software

development, testing, and integration prior to the start of the

data collection period. 

1-2 Delay in receiving RF broadcast

licenses for the measurement sites. 

Government licenses were required for

both sites to permit radar profiler

operations (transmission of RF

signals) and to permit RF

communications up-link of the data

from the sites to the GOES satellite.

Worked closely with all Government agencies involved to

help move the process forward as quickly as possible. In

spite of these efforts, the start of the data collection period

was delayed from late March 1998 (at which time both sites

had been installed and fully tested) until early June 1998 (at

which time the RF licenses had been received and necessary

site retesting to confirm operational readiness had been

completed). 

1-3 Failures of MMS-furnished

temperature/RH sensors during initial

systems integration and testing prior to

site deployments.

MMS purchased two new sensors and provided them to the

prime contractor as additional Government Furnished

Equipment (GFE) in June 1998. 

1-4 Poor telephone line quality to the

selected platform sites. The digital

links to the Gateway Computer at each

site initially had high failure rate

because of noise on the telephone

lines. 

Changed the communications software in use to connect to

the Gateway Computer at each site from PC Anywhere to

ProComm. It was determined that ProComm operated much

more reliably in high noise conditions.

1-5 The circuit breakers controlling the

platform-provided power to the radar

profiler at VRM22D initially failed

often because of high sensitivity to the

“noisy” power on the platforms.

Replaced the circuit breakers with a more robust commercial

model.

1-6 At VRM22D the RASS antennas had

to be installed near the crew quarters. 

Noise generated by the antennas

potentially interfered with crew sleep. 

Reduced the audio amplifier transmit level to reduce the

noise output of the antennas and the associated annoyance

potential. Note: This necessarily also reduced RASS virtual

temperature sensing height somewhat. 

1-7 The GOES Data Collection Platform

(DCP) failed at SMI160A during

installation. 

Replaced the failed GOES DCP unit with the project’s spare,

and returned the failed unit to Synergetics for repair.
3-20

Table 3-6. Project Year One Equipment Problems and Corrective 

Actions (Cont’d)

Ref No. Problem Project Team Corrective Action

1-8 Sale of SMI160A by Chevron to

Newfield Exploration in July 1998,

one month after the start of the data

collection period.

Obtained approval from the new owner to continue to use the

platform as one of the two measurement sites for this MMS

project. Also, after a prolonged negotiation period, secured

Newfield agreement to waive their standard liability policy

regarding platform access by project personnel to perform

site equipment checks. As written, that policy was

unacceptable to the prime contract for this MMS project

because it would hold Newfield harmless for any injury to

project personnel even if it were determined that negligence

by Newfield had caused the injury. 

1-9 RASS data recovery rates

unexpectedly dropped during July and

August 1998 and it was determined

that the configuration settings in the

radar profiler software needed to be

further optimized for summer

conditions in the Gulf ( to increase the

range of upper air temperatures that

the RASS was set to measure). 

Adjusted the configuration settings to implement the needed

RASS temperature range increase. This was accomplished at

both sites during the scheduled visits performed 9/14/98 –

9/17/98.

1-10 VRM22D and SMI160A were

evacuated and the power was shut

down at VRM22D for a 2 day period

in early September 1998 due to

Tropical Storm Earl. No upper air

data were collected at VRM22D

during this period, but surface met

data at VRM22D continued to be

collected since that portion of the

equipment was able to continue to

operate on battery power.

Worked with platform personnel to help assure the radar

profiler was restored to operation at VRM22D as soon as

possible after the tropical storm threat passed and power was

restored at VRM22D. No tropical storm damage to project

equipment was sustained at either site.

1-11 VRM22D and SMI160A were

evacuated and the power was shut

down on both platforms for a 4 day

period in late September 1998 due to

Hurricane Georges. No upper air data

were collected during this period, but

surface met data continued to be

collected since that portion of the

equipment was able to continue to

operate on battery power. 

Worked with platform personnel to help assure the radar

profiler was restored to operation at each site as soon as

possible after the hurricane passed and power was restored to

the sites. No hurricane damage to project equipment at either

site was sustained.
3-21

Table 3-6. Project Year One Equipment Problems and Corrective 

Actions (Cont’d)

Ref No. Problem Project Team Corrective Action

1-12 An SMI160A platform worker

accidently broke the power switch on

the GOES DCP while attempting to

restore site operations on 9/29/98 after

a 4-day platform power shutdown

caused by Hurricane George. 

Replaced the GOES DCP with the spare unit during an

unscheduled visit to SMI160A on 10/10/98. Subsequently

sent the failed unit to Synergetics for repair of the broken

power switch. 

3.1.6 Summary

Tasks completed during the first year of work on this project successfully

supported project objectives. Site and equipment preparation were completed as planned, except

that RF license applications took longer to process through the Department of Interior

(requesting agency) and the NTIA (approving agency) than anticipated. Following receipt of the

necessary RF licenses in late May 1998, the three year data collection period was initiated as of

June 3, 1998. All data measurements collected were quality checked on a daily basis and were

processed and documented by formal reporting on a monthly basis. 

The project's data capture rate goal of 90% or greater was achieved during each of

the first three data months.
3-22

3.2 Project Year Two Activities (10/01/98 - 09/30/99)

Work accomplished and results achieved during the second year of the project, 

October 1, 1998 through September 30, 1999, are detailed below.

3.2.1 Management

MMS and contractor participants continued to maintain a highly effective project

team working relationship, using e-mail and telephone conferences to coordinate implementation

actions and to resolve potential problems as they arose.

3.2.1.1 Personnel

Table 3-7 shows the key personnel participants in the project during the second

year. Richard West replaced Carlton Schneider as the Prinicipal Engineer during the second

year of the project.

Table 3-7. Project Year Two Key Personnel

Project Function Person Performing Function Comments

MMS Contracting Officer (CO) Wally Adcox

MMS Contracting Officer's

Technical Representative (COTR)

Alex Lugo-Fernandez

Program Manger Gary Zeigler Radian (later Vaisala)

Principal Investigator Tim Dye STI

Principal Engineer Richard West Radian (later Vaisala). Replaced

Carlton Schneider

 

3.2.1.2 Communications and Coordination

Authority for all required project team decision actions to ensure timely, efficient,

and competent accomplishment of all work under the contract continued to be vested in the

Program Manager. Authority for day-to-day decision making continued to be delegated to the

Principal Engineer for all equipment-related matters and to the Principal Investigator for all data

collection and processing matters.

Routine meetings necessary for smooth implementations of the measurement sites

were replaced with as-needed teleconferences.

 

 All formal external communications and coordination by project team members

continued to be directed through the Program Manager. Informal communications and
3-23

coordinating with personnel and agencies outside the project team were encouraged by

individual team members as necessary to ensure effective accomplishment of the routine work

within the responsibility of the respective team participant. Issues that arose during such

informal external contacts were immediately reported through the project management chain to

the Program Manager for formal resolution.

3.2.1.3 Record Keeping

The project contract file, including copies of all correspondence with the MMS

Contracting Officer, continued to be maintained in the office of the Contract Specialist.

A copy of all documentation related to project accomplishment continued to be

maintained in the office of the Program Manager. These documents include all project

directives, reports of trips and meetings, record copies of all written deliverables submitted to

MMS, and copies of all written correspondence between the Program Manager and the MMS

COTR.

Data collection and processing, chain of custody, and other quality assurance

records continued to be maintained by the Principal Investigator. These records serve as the

basis of monthly and annual reporting, as well as other formal submissions.

Equipment testing, installation, operation, maintenance, and quality assurance

records continued to be maintained by the Principal Engineer. The Principal Engineer also

continued to maintain a log of all scheduled and unscheduled site visit activities and the results

thereof. These records serve as the basis of monthly and annual reporting, as well as other

formal submissions, that were initiated by the Principal Engineer, through the Program Manager,

to MMS as contract deliverables.

Photographic records of all significant project activities continued to be taken by

project team members, under the direction of project key personnel, as inputs to MMS under the

“Presentation Slide Sets” deliverable requirement of the contract.

3.2.2 Site and Equipment Preparation Logistics

3.2.2.1 Site Selection

Details on the original site-finding efforts and results are described in Section

3.1.2.1 of this report. To recap, the following two platforms were selected for the study:

 1) Vermillion 22D, operated by ERT, as the shallow water site; and

 2) South Marsh Island 160A, originally operated by Chevron, and subsequently by

Newfield Exploration, as the deep water site.
3-24

3.2.2.2 RF Licenses

As described in Section 3.1.2.2 of this report, RF licenses were required (and

obtained) for the GOES satellite data up-link and for the wind profiler operating frequency.

• The profiler data were transmitted using a two-minute per hour channel of the

NOAA/NESDIS Geostationary Operational Environmental Satellite (GOES)

system. Allocation of the channel from NESDIS and permitting from NTIA to

transmit to the GOES satellite at 402 MHz were required and received.

• The wind profiler measurements were based on radar pulses centered at 915 MHz. 

Permission from NTIA to operate the two profilers in the Gulf of Mexico in this

band was required and received.

There were no problems with our licenses during the second year of the project. 

3.2.2.3 Equipment

During the second year of the project, there were no changes to the measurement

equipment used at the two sites, as previously listed in Table 3-2, except that lens-protecting

tubes were added to the sea surface temperature sensors as described in Table 3-11, reference

number 2-3.

3.2.2.4 Data Processing

The data processing and communications tasks continued to include include

preparing the data at the sites, transmitting the data back through GOES, receiving the data at

the STI Weather Operations Center, analyzing and storing the data, and submitting data reports. 

During the second year of the project, no procedure or data flow changes were

needed or made. There were some problems with real-time data collection due to GOES DCP

and platform power disruptions, but all were addressed in timely fashion to keep capture rates

high.

3.2.3 Site Operations and Maintenance

During the second year of the project, two scheduled site visits and three

unscheduled visits were performed, as listed in Table 3-8.
3-25

Table 3-8. Project Year Two Site Visits

Visit

Date

Site(s)

Visited

Visit Type Visit Tasks Completed

10/9/98 –

10/10/98

VRM22D &

SMI160A

Unscheduled At VRM22D, replaced SST sensor that failed 10/1/98. 

At SMI160A, installed spare GOES DCP (replacing unit with

power switch that was accidently broken by platform personnel

during their platform power shutdown for Hurricane Georges). 

12/17/98 VRM22D Unscheduled Replaced SST sensor that failed 11/2/98

As precaution, also replaced RH sensor because data starting to

become suspect 

4/20/99 VRM22D &

SMI160A

Scheduled Performed periodic equipment audits

At SMI160A, replaced corroded SST sensor.

8/6/99 –

8/7/99

VRM22D Unscheduled Repaired radar profiler and restored GOES transmission of

upper air data following a lightning strike on 8/3/99. Attempted

unsuccessfully to restore GOES transmission of surface met

data. Confirmed surface met data being recorded at the site,

however, so planned further repair to restore GOES surface met

data transmission during next scheduled site visit.

9/29/99 –

9/30/99

VRM22D &

SMI160A

Scheduled Performed periodic equipment audits

At VRM22D, repaired connection between the data logger and

Gateway computer (damaged by 8/3/99 lightning strike) and

restored GOES surface met data transmission. As precautions,

also added surge protectors on the serial line between the data

logger and Gateway Computer, and replaced the short-haul

modem with direct RS-232 connection to improve met data

transfer. Replaced the temp/RH and SST sensors (due to audit

results).

At SMI160A, added precautionary surge protectors on the serial

line between the data logger and Gateway computer. Restored

GOES transmissions by clearing a Gateway Computer interrupt. 

Also removed a failed UPS unit and made arrangements to have

platform personnel ship it to Vaisala for repair. 
3-26

3.2.4 Data Measurements

3.2.4.1 Description

The Gateway computer on each platform continued to collect data from the radar

profiler, the surface meteorological instrument datalogger, and the GPS receiver. Once each

hour, the latest data continued to be packed into a compressed format and transmitted through

the GOES satellite link to a database on the NOAA/NESDIS system in Wallops Island, VA. 

Automated procedures in the STI weather operations facility continued to be used

to retrieve and unpack the data files. The STI staff continued to review the data daily to ensure

that all of the collection systems were operating correctly. At the end of each month, the prior

month’s data continued to be processed to quality-stamp any suspect and invalid measurements.

A monthly data report is then generated. The validated monthly data also continued to be loaded

into a database archive.

3.2.4.2 Data Capture Rate

The data capture rate measures the up-time of the integrated data collection and

communications systems at each site. It is defined using:

Data Capture Rate = ( NumRec/NumPos)*100

where:

NumRec = number of hours of data received at STI during the reporting period

NumPos = number of hours of data possible during the reporting period

(for example, 30 x 24 = 720 in a 30 day reporting period) 

As of the September 30, 1999 end of the second year of the project, data rates for

September 1998 through August 1999 were available (and data for September 1999 were being

processed). The data capture rates for September 1998 through August 1999 from the VRM22D

site are shown in Table 3-9, and from the SMI160A site in Table 3-10. The goal of the MMS

program was to achieve a capture rate of 90% or higher. The actual average data capture rate for

all sensors for the September 1998-August 1999 collection period was 92.4%. The capture rate

for the total program through August 1999 was 93.4%.
3-27

Table 3-9. Data Capture Rates for VRM22D Site, 

September 1998-August 1999

Date Upper Air Winds Upper Air Tv Surface Met

Sep-98 80.7% 81.0% 100%

Oct-98 95.2% 95.3% 95.3%

Nov-98 96.8% 96.7% 96.9%

Dec-98 97.3% 97.3% 97.3%

Jan-99 94.2% 94.2% 94.2%

Feb-99 97.6% 97.6% 97.6%

Mar-99 95.4% 95.4% 95.8%

Apr-99 74.4% 74.4% 71.9%

May-99 97.9% 97.9% 98.7%

Jun-99 72.8% 72.6% 72.4%

Jul-99 98.8% 91.8% 98.8%

Aug-99 87.0% 78.4% 8.7%

Annual Average 90.7% 89.4% 85.6%

Table 3-10. Data Capture Rates for SMI160A Site, 

September 1998-August 1999

Date Upper Air Winds Upper Air Tv Surface Met

Sep-98 85.3% 85.5% 100%

Oct-98 90.7% 91.0% 87.6%

Nov-98 98.9% 98.8% 99.0%

Dec-98 87.5% 87.4% 94.8%

Jan-99 99.5% 99.5% 99.5%

Feb-99 96.1% 96.1% 96.1%

Mar-99 97.7% 97.7% 98.1%

Apr-99 98.9% 99.0% 99.3%

May-99 98.5% 98.5% 99.3%

Jun-99 98.1% 98.1% 98.1%

Jul-99 97.9% 97.9% 97.9%

Aug-99 99.3% 99.5% 99.5%

Annual Average 95.7% 95.8% 97.4%
3-28

3.2.4.3 Data Recovery Rate

The data recovery rate is defined as the percentage of valid data captured by each

instrument while the integrated system is operational. It is calculated using:

Data Recovery Rate = (NumVal/NumRec)*100

where:

NumVal = Number of valid hours of data received during the reporting period

NumRec = Number of hours of data received at STI during the reporting period.

The data recovery rate provides a method to evaluate the performance of the

instruments.

As of the September 30, 1999 end date of the second year of the project, data

rates for September 1998 through August 1999 were available (and data for September 1999

were being processed). These figures illustrate data capture rate for each site in a series of

graphs that are labeled “Max %”, “Average”, and “Min %”. The graphs are, respectively:

 The maximum monthly capture rate over the twelve months in the sample;

 The average monthly capture rate over the twelve months in the sample;

 The minimum monthly capture rate over the twelve months in the sample.

The horizontal (or x) scale is the percent of data capture and the vertical (or y)

scale is the measurement altitude in meters AGL.
3-29

0 10 20 30 40 50 60 70 80 90 100

Meters AGL

Percent Data Recovery

4934

4742

4549

4357

4164

3972

3779

3587

3394

3202

3010

2817

2625

2432

2240

2047

1855

1663

1470

1278

1085

893

700

508

316

Max %

Average

Min %

VRM-22D Site, High-Mode Winds

0 10 20 30 40 50 60 70 80 90 100

Meters AGL

Percent Data Recovery

4920

4728

4535

4343

4150

3958

3765

3573

3380

3188

2996

2803

2611

2418

2226

2033

1841

1649

1456

1264

1071

879

686

494

302

Max %

Average

Min %

SMI-160A Site, High-Mode Winds

3.2.4.3.1 Radar Profiler High-Mode Wind Data

The data recovery rates for the two sites for the high-mode winds are shown in

Figure 3-8. The relatively low data recovery rates at low altitudes at the SMI site were attributed

to interference from sea clutter. The VRM profiler installation is less sensitive to sea clutter and

did not experience similar data losses.

Figure 3-8. Data Recovery Rates for Radar Profiler High-Mode Winds, 

 September 1998 - August 1999
3-30

0 10 20 30 40 50 60 70 80 90 100

Meters AGL

Percent Data Recovery

2440

2344

2247

2151

2055

1959

1862

1766

1670

1574

1478

1381

1285

1189

1093

996

900

804

708

612

515

419

323

227

131

Max %

Average

Min %

VRM-22D Site, Low-Mode Winds

0 10 20 30 40 50 60 70 80 90 100

Meters AGL

Percent Data Recovery

2440

2344

2247

2151

2055

1959

1862

1766

1670

1574

1478

1381

1285

1189

1093

996

900

804

708

612

515

419

323

227

131

Max %

Average

Min %

SMI-160A Site, Low-Mode Winds

3.2.4.3.2 Radar Profiler Low-Mode Wind Data

The data recovery rates for the two sites for low-mode winds are shown in Figure 3-9. 

Both sites experienced data recovery losses at the lowest altitudes due primarily to sea clutter

interference.

Figure 3-9. Data Recovery Rates for Radar Profiler Low-Mode Winds,

September 1998 - August 1999
3-31

0 10 20 30 40 50 60 70 80 90 100

Meters AGL

Percent Data Recovery

1260

1200

1140

1080

1020

960

900

840

780

720

660

600

540

480

420

360

300

240

180

120

Max %

Average

Min %

VRM-22D Site, RASS Mode

0 10 20 30 40 50 60 70 80 90 100

Meters AGL

Percent Data Recovery

1275

1215

1155

1095

1035

975

915

855

795

735

675

615

555

495

435

375

315

255

195

135

Max %

Average

Min %

SMI-160A Site, RASS Mode

3.2.4.3.3 RASS Temperature Data

In the RASS mode, virtual temperature profiles are measured by using the scattering

of radar pulses from acoustic waves. The data recovery rates for the radar profiler RASS mode are

shown in Figure 3-10. 

Figure 3-10. Data Recovery Rates for Radar Profiler RASS Mode,

September 1998 - August 1999
3-32

3.2.5 Problems Encountered and Corrective Action Taken

No problems involving the management of the project were experienced during the

second year of the project.

Table 3-11 lists the equipment problems encountered, and the corrective action

implemented during the second year of the project.

Table 3-11. Project Year Two Equipment Problems and 

 Corrective Actions

 Ref No. Problem Project Team Corrective Action

2-1 At VRM22D the SST sensor failed on

10/1/98.

Replaced with spare during unscheduled visit to

VRM22D on 10/10/98.

2-2 The GOES transmission system was

inoperative for 18 hours on 10/27/98.

The GOES systems was restored by NESDIS. 

The project team retrieved the collected data

during this period from the computers at the

sites during the unscheduled site visits

performed on 12/17/98.

 2-3 At VRM22D the SST sensor again

failed on 11/2/98. 

Replaced with spare during unscheduled visit to

VRM22D on 12/17/98. Also worked with the

SST manufacturer to attempt to identify failure

cause and resolution. The manufacturer

subsequently advised that the only likely

problem is that the lens was being contaminated

with sea spray and then giving unrepresentative

readings. In an attempt to reduce sea spray

contamination, a lens-protecting tube was

fabricated and installed on the VRM22D SST

sensor during our 12/17/98. An identical tube

was sent to the SMI160A platform and was

installed by platform personnel.

2-4 At VRM22D the RH sensor began

providing periodically unstable

readings in October and November

1998. 

Replaced with spare during unscheduled visit to

VRM22D on 12/17/98.

2-5 Discovered in December 1998 that the

computer time stamps at both sites had

changed to CDT. They have been

configured to remain on CST.

Adjusted data taken since the start of CDT back

to CST and sent replacement (corrected) data to

MMS in January 1999. Began investigating

cause of the problem, but no immediate

conclusions were reached.
3-33

Table 3-11. Project Year Two Equipment Problems and 

Corrective Actions(Cont’d)

Ref No. Problem Project Team Corrective Action

 2-6 At VRM22D the computers started

having problems keeping track of

time as of 4/10/99.

Resolved by remote connection to the VRM22D

computer and with the help of platform personnel. 

Cause appeared to be platform power instability,

which apparently caused the problem when power was

lost during a GPS clock update to the computer. Took

five days to resolve because of the complexity of the

problem and time lost awaiting platform power and

personnel availability.

 2-7 At VRM22D the GOES transmitter

was found to be unreliable (and

was considered failed) during the

scheduled 4/20/99 visit to that site. 

At SMI160A the SST sensor was

found to be highly corroded during

the scheduled 4/20/99 visit to that

site. 

Replaced the GOES transmitter with spare during the

4/20/99 site visit. 

Replaced the SST sensor with spare during the 4/20/99

site visit.

 2-8 At VRM22D the GOES

transmissions began having

software interrupt problems on

6/15/99.

Resolved on 6/23/99 by remote connection to the

VRM22D computer and with the help of platform

personnel. This fix was delayed by a platform

telephone outage and awaiting availability of platform

personnel to assist.

 2-9 The VRM22D platform sustained a

direct lightning strike on 8/3/99,

stopping all project met equipment

operation. 

Repaired the radar profiler and restored GOES

transmission of upper air data from VRM22D during

an unscheduled visit to the platform on 8/6/99 and

8/7/99. Attempted unsuccessfully to restore GOES

transmission of surface met data during this visit, but

did confirm the data were being collected and

therefore deferred further action until the next

scheduled platform visit in September 1999.

On 9/29/99 repaired the connection between the data

logger and Gateway Computer at VRM22D, restoring

GOES transmission of surface met data. Also installed

additional surge protection at both VRM22D and

SMI160A during this visit to attempt to prevent

recurrence due to future lightning strikes.

 2-10 At VRM22D the temperature/RH

sensor and the SST sensors failed

audit criteria during the 9/29/99

site visit. 

Replaced both sensors during the visit.
3-34

Table 3-11. Project Year Two Equipment Problems and 

Corrective Actions(Cont’d)

Ref No. Problem Project Team Corrective Action

2-11 At SMI160A the UPS unit was

found to have an internal battery

problem during the 9/30/99 site

visit.

Removed the UPS unit and shipped it for repair.

This UPS unit was subsequently repaired and was

reinstalled at SMI160A during a scheduled site visit in

June 2000.

3.2.6 Summary

Tasks completed during the second year of work on this project successfully

supported the objective. Sites and equipment were rigorously monitored, problems quickly

addressed, and reports submitted on time. All data measurements collected were quality

checked on a daily basis and were processed and documented by formal reporting on a monthly

basis.

During the second year of the project, the average data capture rate was 92.4%,

which met the project’s 90% or higher goal. As of the end of the second year of the project, the

cumulative data capture rate for the project was 93.4%, which also met the project’s 90% or

higher goal.

3.3 Project Year Three Activities (10/01/99 - 09/30/00)

Work accomplished and results achieved during the third year of the project, 

October 1, 1999 through September 30, 2000, are detailed below.

3.3.1 Management

MMS and contractor participants continued to maintain a highly effective project

team working relationship, using e-mail and telephone conferences to coordinate and to resolve

potential problems as they arose.

3.3.1.1 Personnel

Table 3-12 shows the key personnel participants in the project during the third

year. Dr. Chester Huang replaced Dr. Alex Lugo-Fernandez as COTR and Bill Burton replaced

Richard West as Principal Engineer.
3-35

Table 3-12. Project Year Three Key Personnel

Project Function Person Performing Function Comments

MMS Contracting Officer (CO) Wally Adcox

MMS Contracting Officer's

Technical Representative (COTR)

Chester Huang Replaced Alex Lugo-Fernandez

Program Manger Gary Zeigler Radian (later Vaisala)

Principal Investigator Tim Dye STI

Principal Engineer Bill Burton Radian (later Vaisala). Replaced

Richard West

3.3.1.2 Communications and Coordination

Authority for all required project team decision actions to ensure timely,

efficient, and competent accomplishment of all work under the contract continued to be vested

in the Program Manager. Authority for day-to-day decision making continued to be delegated

to the Principal Engineer for all equipment-related matters and to the Principal Investigator for

all data collection and processing matters.

Routine meetings were conducted by as-needed teleconferences.

All formal external communications and coordination by project team members

continued to be directed through the Program Manager. Informal communications and

coordinating with personnel and agencies outside the project team were encouraged by

individual team members as necessary to ensure effective accomplishment of the routine work

within the responsibility of the respective team participant. Issues that arose during such

informal external contacts were immediately reported through the project management chain to

the Program Manager for formal resolution.

3.3.1.3 Record Keeping

The project contract file, including copies of all correspondence with the MMS

Contracting Officer, continued to be maintained in the office of the Contract Specialist.

A copy of all documentation related to project accomplishment continued to be

maintained in the office of the Program Manager. These documents include all project

directives, reports of trips and meetings, record copies of all written deliverables submitted to

MMS, and copies of all written correspondence between the Program Manager and the MMS

COTR.

Data collection and processing, chain of custody, and other quality assurance

records continued to be maintained by the Principal Investigator. These records serve as the

basis of monthly and annual reporting, as well as other formal submissions.
3-36

Equipment testing, installation, operation, maintenance, and quality assurance

records continued to be maintained by the Principal Engineer. The Principal Engineer also

continued to maintain a log of all scheduled and unscheduled site visit activities and the results

thereof. These records serve as the basis of monthly and annual reporting, as well as other

formal submissions, that were initiated by the Principal Engineer, through the Program

Manager, to MMS as contract deliverables.

Photographic records of all significant project activities continued to be taken by

project team members, under the direction of project key personnel, as inputs to MMS under the

“Presentation Slide Sets” deliverable requirement of the contract.

3.3.2 Site and Equipment Preparation Logistics

3.3.2.1 Site Selection

Details on the original site-finding efforts and results are described in Section

3.1.2.1 of this report. To recap, the following two platforms were selected for the study:

1) Vermillion 22D, operated by ERT, as the shallow water site; and

2) South Marsh Island 160A, originally operated by Chevron, and subsequently by

Newfield Exploration, as the deep water site.

3.3.2.2 RF Licenses

 

As described in Section 3.1.2.2 of this report, RF licenses were required (and

obtained) for the GOES satellite data up-link and for the wind profiler operating frequency.

• The profiler data were transmitted using a two-minute per hour channel of the

NOAA/NESDIS Geostationary Operational Environmental Satellite (GOES)

system. Allocation of the channel from NESDIS and permitting from NTIA to

transmit to the GOES satellite at 402 MHz were required and received.

• The wind profiler measurements were based on radar pulses centered at 915

MHz. Permission from NTIA to operate the two profilers in the Gulf of Mexico

in this band was required and received.

There were no problems with our licenses during the third year of the project. 

3.3.2.3 Equipment

During the third year of the project, there were no changes to the measurement

equipment used at the two sites, as previously listed in Table 3-2.
3-37

3.3.2.4 Data Processing 

The data processing and communications tasks continued to include preparing

the data at the sites, transmitting the data back through GOES, receiving the data at the STI

Weather Operations Center, analyzing and storing the data, and submitting data reports. 

During the third year of the project, no procedure or data flow changes were

needed or made.

3.3.3 Site Operations and Maintenance

During the third year of the project, one scheduled site visit and two unscheduled

visits were performed, as listed in Table 3-13.
3-38

Table 3-13. Project Year Three Site Visits

Visit

Date

Site(s)

Visited

Visit Type Visit Tasks Completed

1/14/00 –

1/16/00

VRM22D &

SMI160A

Unscheduled At both sites, corrected a GPS problem that had caused

the radar profilers to cease operations on 1/1/00

because the computers were being told the year was

1900 rather than 2000.

Performed periodic equipment audits

3/24/00 –

3/26/00

VRM22D &

SMI160A

Unscheduled At VRM22D, replaced a failed power supply in the

charger for the data logger and restored GOES

transmissions of surface met data that had ceased on

2/26/00. Also at VRM22D, as a precaution (because

of possible performance degradation), replaced the

radar profiler’s final amplifier 

At both sites, installed a software patch to help prevent

potential future leap year problems.

6/14/00 –

6/16/00

VMR22D &

SMI160A

Scheduled Performed periodic equipment audits

At both sites, also installed a Windows 95 patch to

keep time stamps at CST all year

At VRM22D, replaced the temp/RH sensor (due to

audit results). Also restored GOES transmissions by

clearing a Gateway Computer interrupt.. 

At SMI160A, replaced temp/RH and SST sensors (due

to audit results). Also installed repaired UPS unit. 

3.3.4 Data Measurements

3.3.4.1 Description

The Gateway computer on each platform continued to collect data from the radar

profiler, the surface meteorological instrument datalogger, and the GPS receiver. Once each

hour, the latest data continued to be packed into a compressed format and transmitted through

the GOES satellite link to a database on the NOAA/NESDIS system in Wallops Island, VA. 

Automated procedures in the STI weather operations facility continued to be

used to retrieve and unpack the data files. The STI staff continued to review the data daily to

ensure that all of the collection systems were operating correctly. At the end of each month, the 
3-39

prior month’s data continued to be processed to quality-stamp any suspect and invalid

measurements. A monthly data report was then generated. The validated monthly data also

continued to be loaded into a database archive.

3.3.4.2 Data Capture Rate

The data capture rate measures the up-time of the integrated data collection and

communications systems at each site. It is defined using:

Data Capture Rate = ( NumRec/NumPos)*100

where:

NumRec = number of hours of data received at STI during the reporting period

NumPos = number of hours of data possible during the reporting period 

As of the September 30, 2000 end of the third year of the project, data rates for

September 1999 through August 2000 were available (and data for September 2000 were being

processed). The data capture rates for September 1999 through August 2000 from the

VRM22D site are shown in Table 3-14, and from the SMI160A site in Table 3-15. The goal of

the MMS program was to achieve a capture rate of 90% or higher. The actual average capture

rate for all sensors for the September 1999-August 2000 collection period was 86.9%. The

capture rate for the total program through August 2000 was 90.5%. 

Table 3-14. Data Capture Rates for VRM22D Site, 

September 1999-August 2000

Date Upper Air Winds Upper Air Tv Surface Met

Sep-99 96.7% 96.7% 1.4%

Oct-99 95.8% 95.7% 96.8%

Nov-99 96.5% 96.5% 96.4%

Dec-99 90.5% 90.3% 90.6%

Jan-00 49.9% 49.7% 94.5%

Feb-00 93.7% 93.7% 84.2%

Mar-00 60.2% 60.1% 23.7%

Apr-00 99.9% 99.9% 99.9%

May-00 98.9% 98.5% 100%

Jun-00 76.1% 59.0% 96.4%

Jul-00 98.0% 98.0% 98.0%

Aug-00 99.9% 99.9% 99.9%

Annual Average 88.0% 86.5% 85.2%
3-40

Table 3-15. Data Capture Rates for SMI160A Site, 

September 1999-August 2000

Date Upper Air Winds Upper Air Tv Surface Met

Sep-99 79.4% 79.4% 76.0%

Oct-99 69.5% 69.4% 83.7%

Nov-99 99.2% 99.2% 99.2%

Dec-99 94.2% 94.1% 97.7%

Jan-00 38.2% 40.5% 62.9%

Feb-00 96.8% 96.8% 97.0%

Mar-00 98.5% 98.5% 98.5%

Apr-00 95.0% 94.9% 95.0%

May-00 96.1% 96.2% 97.3%

Jun-00 97.1% 96.8% 96.4%

Jul-00 92.7% 92.6% 92.7%

Aug-00 90.5% 90.5% 90.5%

Annual Average 87.3% 87.1% 90.6%

3.3.4.3 Data Recovery

The data recovery rate is defined as the percentage of valid data captured by each

instrument while the integrated system is operational. It is calculated using:

Data Recovery Rate = (NumVal/NumRec)*100

where:

NumVal = Number of valid hours of data received during the reporting period

NumRec = Number of hours of data received at STI during the reporting period.

The data recovery rate provides a method to evaluate the performance of the

instruments.

As of the September 30, 2000 end of the third year of the project, data rates for

September 1999 through August 2000 were available (and data for September 2000 were being

processed). These figures illustrate data capture rate for each site in a series of graphs that are

labeled “Max %”, “Average”, and “Min %”. The graphs are, respectively:

 The maximum monthly capture rate over the twelve months in the sample;

 The average monthly capture rate over the twelve months in the sample;

 The minimum monthly capture rate over the twelve months in the sample.

The horizontal (or x) scale is the percent of data capture and the vertical (or y) scale

is the measurement altitude in meters AGL.
3-41

0 10 20 30 40 50 60 70 80 90 100

Meters AGL

Percent Data Recovery

4934

4742

4549

4357

4164

3972

3779

3587

3394

3202

3010

2817

2625

2432

2240

2047

1855

1663

1470

1278

1085

893

700

508

316

Max %

Average

Min %

VRM-22D Site, High-Mode Winds

0 10 20 30 40 50 60 70 80 90 100

Meters AGL

Percent Data Recovery

4920

4728

4535

4343

4150

3958

3765

3573

3380

3188

2996

2803

2611

2418

2226

2033

1841

1649

1456

1264

1071

879

686

494

302

Max %

Average

Min %

SMI-160A Site, High-Mode Winds

3.3.4.3.1 Radar Profiler High-Mode Wind Data

The data recovery rates for the two sites for the high-mode winds are shown in

Figure 3-11. The relatively low data recovery rates at low altitudes at the SMI site were

attributed to interference from sea clutter. The VRM profiler installation is less sensitive to sea

clutter and did not experience similar data losses.

Figure 3-11. Data Recovery Rates for Radar Profiler High-Mode 

 Winds, September 1999 - August 2000
3-42

0 10 20 30 40 50 60 70 80 90 100

Meters AGL

Percent Data Recovery

2440

2344

2247

2151

2055

1959

1862

1766

1670

1574

1478

1381

1285

1189

1093

996

900

804

708

612

515

419

323

227

131

Max %

Average

Min %

VRM-22D Site, Low-Mode Winds

0 10 20 30 40 50 60 70 80 90 100

Meters AGL

Percent Data Recovery

2440

2344

2247

2151

2055

1959

1862

1766

1670

1574

1478

1381

1285

1189

1093

996

900

804

708

612

515

419

323

227

131

Max %

Average

Min %

SMI-160A Site, Low-Mode Winds

3.3.4.3.2 Radar Profiler Low-Mode Wind Data

The data recovery rates for the two sites for low-mode winds are shown in

Figure 3-12. Both sites experienced data recovery losses at the lowest altitudes due primarily to

sea clutter interference.

Figure 3-12. Data Recovery Rates for Radar Profiler Low-Mode 

 Winds, September 1999 - August 2000
3-43

0 10 20 30 40 50 60 70 80 90 100

Meters AGL

Percent Data Recovery

1260

1200

1140

1080

1020

960

900

840

780

720

660

600

540

480

420

360

300

240

180

120

Max %

Average

Min %

VRM-22D Site, RASS Mode

0 10 20 30 40 50 60 70 80 90 100

Meters AGL

Percent Data Recovery

1275

1215

1155

1095

1035

975

915

855

795

735

675

615

555

495

435

375

315

255

195

135

Max %

Average

Min %

SMI-160A Site, RASS Mode

3.3.4.3.3 RASS Temperature Data

In the RASS mode, virtual temperature profiles are measured by using the

scattering of radar pulses from acoustic waves. The data recovery rates for the radar profiler

RASS mode are shown in Figure 3-13. 

Figure 3-13. Data Recovery Rates for Radar Profiler RASS Mode,

 September 1999 - August 2000
3-44

3.3.5 Problems Encountered and Corrective Action Taken

Table 3-16 lists the problems encountered, and the corrective actions

implemented, during the third year of the project.

Table 3-16. Project Year Three Equipment Problems and 

Corrective Actions

Ref No. Problem Project Team Corrective Action

3-1 The radar profilers ceased operation

at both sites on 1/1/00.

Remote troubleshooting efforts failed to diagnose

the problem. However, it was determined that

other (non-MMS) radar profilers using a GPS clock

connection to update time stamps on the radar

profiler computers were suffering the same

problem. It was then determined that the problem

was a Y2K problem in the GPS system that caused

the computers to stop because they were being told

it was the year 1900 rather than 2000. An

unscheduled visit to both sites was then performed

during the period 1/14/00 to 1/16/00. System

configuration changes were implemented that

resolved the “wrong year” problem and restored

the profilers and GOES data flow to normal

operations.

 3-2 At VRM22D the surface met data

collection ceased on 2/26/00. 

Remote troubleshooting efforts failed to diagnose

the problem. An unscheduled site visit to

VRM22D was performed on 3/24/00, during which

a failed power supply in the charger for the data

logger was identified and replaced and GOES

transmission of surface met data from VRM22D

were restored.

 3-3 On 2/29/00 a leap year date problem

was noted transmitted met data from

both sites. 

Diagnosed the problem as caused by a fault in the

GOES software. Installed a software patch at both

sites, correcting the leap year problem, during

unscheduled platform visits during the period

3/24/00-3/26/00.

 3-4 On 4/2/00 the GOES transmissions

from VRM22D ceased.

Remote troubleshooting efforts failed to diagnose

the problem. Since it was confirmed that the met

data were all being collected (just not transmitted),

further corrective action was deferred until the next

scheduled site visit on 6/14/00. On that date, the

problem was found to be due to an interrupt in the

Gateway Computer, which was cleared during the

visit and GOES transmissions were restored.
3-45

Table 3-16. Project Year Three Equipment Problems and 

 Corrective Actions (Cont’d)

Ref No. Problem Project Team Corrective Action

3-5 The GOES transmission system was

inoperative from 3/30/00 until

4/10/00.

The GOES systems was restored by NESDIS. The

project team retrieved the collected data during this

period from the computers at the sites during the

scheduled visits performed during the period

6/14/00-6/16/00.

3-6 In early April 2000, it was discovered

that the data time stamps had again

changed to DST even though the

configurations were set for them to

remain on CST.

Note: This is a repeat of the daylight

savings time problem that occurred in

the late 1999 (see ref item 2-5 in

Table 3-12 of this report).

Researched the Microsoft web site and found

technical reference information acknowledging this

problem and providing a software patch fix.

Installed the patch on the computers at both sites

during the scheduled site visits performed during

the period 6/14/00-6/16/00.

3-7 At VRM22D the temperature/RH

sensor failed audit criteria during the

6/14/00 site visit. 

Replaced the sensor during the visit.

3-8 At SMI160A the temperature/RH

sensor and the SST sensor failed

audit criteria during the 6/16/00 site

visit.

Replaced both sensors during the visit.

3-9 On 9/8/00 the GOES transmissions

from SMI160A ceased. 

Remote troubleshooting isolated the problem to a

failed GOES DCP. The spare unit was shipped to

the platform and installed by platform personnel on

9/27/00, restoring GOES transmissions from

SMI160A.

3.3.6 Summary

Tasks completed during the third year of work on this project

successfully supported the objective. Sites and equipment were rigorously monitored,

problems quickly addressed, and reports submitted on time. All data measurements

collected were quality checked on a daily basis and were processed and documented by

formal reporting on a monthly basis. 

During the third year of the project, the average data capture rate was

86.9%, which did not quite meet the project’s 90% or higher goal. As of the end of the

third year of the project, the cumulative data capture rate for the project was 90.5%,

which met the project’s 90% or higher goal.
3-46

3.4 Project Year Four Activities (10/01/00 - 01/31/02)

Work accomplished and results achieved during the fourth year of the project,

October 1, 2000 through January 31, 2002, are detailed below. During the fourth year of the

project the contract was amended by MMS to extend the data collection period from 36 to 40

months.

3.4.1 Management

MMS and contractor participants continued to maintain a highly effective project

team working relationship, using e-mail and telephone conferences to coordinate and to resolve

potential problems as they arose.

3.4.1.1 Personnel

Table 3-17 shows the key personnel participants in the project during the fourth

year. There were no changes of the key personnel participants in the project during the fourth

year.

Table 3-17. Project Year Four Key Personnel

Project Function Person Performing Function Comments

MMS Contracting Officer (CO) Wally Adcox

MMS Contracting Officer's

Technical Representative (COTR)

Chester Huang

Program Manger Gary Zeigler Radian (later Vaisala)

Principal Investigator Tim Dye STI

Principal Engineer Bill Burton Radian (later Vaisala). 

3.4.1.2 Communications and Coordination

Authority for all required project team decision actions to ensure timely, efficient,

and competent accomplishment of all work under the contract continued to be vested in the

Program Manager. Authority for day-to-day decision making continued to be delegated to the

Principal Engineer for all equipment-related matters and to the Principal Investigator for all data

collection and processing matters.

Routine meetings were conducted by teleconferences as needed.
3-47

All formal external communications and coordination by project team members

continued to be directed through the Program Manager. Informal communications and

coordinating with personnel and agencies outside the project team were encouraged by

individual team members as necessary to ensure effective accomplishment of the routine work

within the responsibility of the respective team participant. Issues that arose during such

informal external contacts were immediately reported through the project management chain to

the Program Manager for formal resolution.

3.4.1.3 Record Keeping

The project contract file, including copies of all correspondence with the MMS

Contracting Officer, continued to be maintained in the office of the Contract Specialist.

A copy of all documentation related to project accomplishment continued to be

maintained in the office of the Program Manager. These documents include all project

directives, reports of trips and meetings, record copies of all written deliverables submitted to

MMS, and copies of all written correspondence between the Program Manager and the MMS

COTR.

Data collection and processing, chain of custody, and other quality assurance records

continued to be maintained by the Principal Investigator. These records serve as the basis of

monthly and annual reporting, as well as other formal submissions.

Equipment testing, installation, operation, maintenance, and quality assurance

records are maintained by the Principal Engineer. The Principal Engineer also continued to

maintain a log of all scheduled and unscheduled site visit activities and the results thereof. 

These records serve as the basis of monthly and annual reporting, as well as other formal

submissions, that were initiated by the Principal Engineer, through the Program Manager, to

MMS as contract deliverables.

3.4.2 Site and Equipment Preparation Logistics

3.4.2.1 Site Selection

Details on the original site-finding efforts and results are described in Section 3.1.2.1

of this report. To recap, the following two platforms were selected for the study:

1) Vermillion 22D, operated by ERT, as the shallow water site; and

2) South Marsh Island 160A, originally operated by Chevron, and subsequently by

Newfield Exploration, as the deep water site.
3-48

3.4.2.2 RF Licenses

 

As described in Section 3.1.2.2 of this report, RF licenses were required (and

obtained) for the GOES satellite data up-link and for the wind profiler operating frequency.

• The profiler data were transmitted using a two-minute per hour channel of the

NOAA/NESDIS Geostationary Operational Environmental Satellite (GOES)

system. Allocation of the channel from NESDIS and permitting from NTIA to

transmit to the GOES satellite at 402 MHz were required and received.

• The wind profiler measurements were based on radar pulses centered at 915

MHz. Permission from NTIA to operate the two profilers in the Gulf of Mexico

in this band was required and received.

There were no problems with our licenses during the fourth year of the project. 

3.4.2.3 Equipment

During the fourth year of the project, there were no changes to the measurement

equipment used at the two sites, as previously listed in Table 3-2.

3.4.2.4 Data Processing 

The data processing and communications tasks continued to include preparing

the data at the sites, transmitting the data back through GOES, receiving the data at the STI

Weather Operations Center, analyzing and storing the data, and submitting data reports. 

During the fourth year of the project, no procedure or data flow changes were

needed or made.

3.4.3 Site Operations and Maintenance

During the fourth year of the project, three scheduled visits and four unscheduled

visits were performed, as listed in Table 3-18.
3-49

Table 3-18. Project Year Four Site Visits

Visit Date Site(s)

Visited

Visit Type Visit Tasks Performed

10/23/00 –

10/30/00

VRM22D

&

SMI160A

Scheduled Performed periodic equipment audits

At VRM22D, replaced the surface wind and temp/RH sensors

(due to audit results)

1/9/01 SMI160A Unscheduled Replaced failed power supply in the Radar Computer (which

had also caused the Gateway Computer to interrupt and not

send GOES transmissions) and restored system to full

operation

1/31/01 VRM22D Unscheduled Replaced failed RH sensor, and replaced the SST sensor

because calibration was expiring.

3/7/01 –

3/8/01

VRM22D

&

SMI160A

Unscheduled At VRM22D, replaced the failed phase shifter in the radar

profiler.

At SMI160A, replaced the suspect RH sensor.

4/25/01 –

4/27/01

SMI160A Unscheduled Moved the radar profiler antenna about 30 feet on the

SMI160A platform deck to allow room for a drilling rig being

installed by the platform owner.

6/4/01 –

6/9/01

VRM22D

&

SMI160A

Scheduled Performed periodic equipment audits

At VRM22D, replaced the temp/RH sensor (due to audit

results)

At SMI160A, replaced the failed phase shifter in the radar

profiler. Also replaced the failed UPS unit and the failed

GOES DCP.

Note: The 40-month data collection period was completed as

of 10/2/01. Coordination with the platform owners confirmed

agreement that an equipment de-installation visit to each

platform should be planned for mid November 2001, to allow

necessary intervening time for equipment crates to be moved to

the platforms. 

11/15/01 –

11/15/01 

VRM22D

&

SMI160A

Scheduled Performed end-of-project equipment audits 

De-installed equipment
3-50

3.4.4 Data Measurements

3.4.4.1 Description

The Gateway computer on each platform continued to collect data from the radar

profiler, the surface meteorological instrument datalogger, and the GPS receiver. Once each

hour, the latest data continued to be packed into a compressed format and transmitted through

the GOES satellite link to a database on the NOAA/NESDIS system in Wallops Island, VA. 

Automated procedures in the STI weather operations facility continued to be

used to retrieve and unpack the data files. The STI staff continued to review the data daily to

ensure that all of the collection systems were operating correctly. At the end of each month, the

prior month’s data continued to be processed to quality-stamp any suspect and invalid

measurements. A monthly data report was then generated. The validated monthly data also

continued to be loaded into a database archive.

3.4.4.2 Data Capture Rate

The data capture rate measures the up-time of the integrated data collection and

communications systems at each site. It is defined using:

Data Capture Rate = ( NumRec/NumPos)*100

where:

NumRec = number of hours of data received at STI during the reporting period

NumPos = number of hours of data possible during the reporting period 

The data capture rates for September 2000 through October 2, 2001 from the

VRM22D site are shown in Table 3-19, and from the SMI160A site in Table 3-20. The goal of

the MMS program is to achieve a capture rate of 90% or higher. The average capture rate for

all sensors for the September 2000- October 2001 collection period was 86%. The capture rate

for the total program through October 2, 2001 was 89.3%. 
3-51

Table 3-19. Data Capture Rates for VRM22D Site, 

September 2000-October 2, 2001

Date Upper Air Winds Upper Air Tv Surface Met

Sep-00 97.9% 97.9% 97.9%

Oct-00 98.3% 98.3% 90.7%

Nov-00 94.0% 93.9% 86.1%

Dec-00 99.0% 99.0% 99.0%

Jan-01 98.9% 98.9% 98.7%

Feb-01 99.0% 98.8% 99.9%

Mar-01 48.5% 48.3% 95.3%

Apr-01 85.4% 85.0% 86.7%

May-01 81.3% 80.9% 99.6%

Jun-01 93.8% 93.8% 98.6%

Jul-01 99.1% 98.9% 99.1%

Aug-01 92.9% 92.7% 92.9%

Sep 011 97.0% 97.0% 97.0%

Annual Average 91.2% 91.0% 97.0%

1

Note 1: Through October 2, 2001.

Table 3-20. Data Capture Rates for SMI160A Site, 

2000-October 2, 2001

Date Upper Air Winds Upper Air Tv Surface Met

Sep-00 37.2% 37.2% 37.2%

Oct-00 87.4% 87.4% 96.8%

Nov-00 97.2% 97.1% 78.5%

Dec-00 87.5% 87.4% 97.0%

Jan-01 60.3% 60.2% 60.6%

Feb-01 97.2% 97.0% 97.2%

Mar-01 96.9% 96.9% 96.9%

Apr-01 89.9% 90.1% 91.5%

May-01 76.9% 76.5% 76.9%

Jun-01 67.9% 67.6% 68.3%

Jul-01 72.6% 72.2% 72.6%

Aug-01 91.8% 91.7% 93.0%

Sep 011 88.2% 75.9% 88.2%

Annual Average 80.8% 79.8% 81.1%

1

Note 1: Through October 2, 2001
3-52

3.4.4.3 Data Recovery Rate

The data recovery rate is defined as the percentage of valid data captured by each

instrument while the integrated system is operational. It is calculated using:

Data Recovery Rate = (NumVal/NumRec)*100

where:

NumVal = Number of valid hours of data received during the reporting period

NumRec = Number of hours of data received at STI during the reporting period.

The data recovery rate provides a method to evaluate the performance of the

instruments.

As of the September 30, 2000 end date of the fourth year of the project, data

rates for September 1999 through August 2000 were available (and data for September 2000

were being processed). These figures illustrate data capture rate for each site in a series of

graphs that are labeled “Max %”, “Average”, and “Min %”. The graphs are, respectively:

 The maximum monthly capture rate over the twelve months in the sample;

 The average monthly capture rate over the twelve months in the sample;

 The minimum monthly capture rate over the twelve months in the sample.

The horizontal (or x) scale is the percent of data capture and the vertical (or y)

scale is the measurement altitude in meters AGL.
3-53

0 10 20 30 40 50 60 70 80 90 100

Meters AGL

Percent Data Recovery

4934

4742

4549

4357

4164

3972

3779

3587

3394

3202

3010

2817

2625

2432

2240

2047

1855

1663

1470

1278

1085

893

700

508

316

Max %

Average

Min %

VRM-22D Site, High-Mode Winds

0 10 20 30 40 50 60 70 80 90 100

Meters AGL

Percent Data Recovery

4920

4728

4535

4343

4150

3958

3765

3573

3380

3188

2996

2803

2611

2418

2226

2033

1841

1649

1456

1264

1071

879

686

494

302

Max %

Average

Min %

SMI-160A Site, High-Mode Winds

3.4.4.3.1 Radar Profiler High-Mode Wind Data

The data recovery rates for the two sites for the high-mode winds are shown in

Figure 3-14. The relatively low data recovery rates at low altitudes at the SMI site were

attributed to interference from sea clutter. The VRM profiler installation is less sensitive to sea

clutter and did not experience similar data losses.

Figure 3-14. Data Recovery Rates for Radar Profiler High-Mode 

 Winds, September 2000 - October 2, 2001
3-54

0 10 20 30 40 50 60 70 80 90 100

Meters AGL

Percent Data Recovery

2440

2344

2247

2151

2055

1959

1862

1766

1670

1574

1478

1381

1285

1189

1093

996

900

804

708

612

515

419

323

227

131

Max %

Average

Min %

VRM-22D Site, Low-Mode Winds

0 10 20 30 40 50 60 70 80 90 100

Meters AGL

Percent Data Recovery

2440

2344

2247

2151

2055

1959

1862

1766

1670

1574

1478

1381

1285

1189

1093

996

900

804

708

612

515

419

323

227

131

Max %

Average

Min %

SMI-160A Site, Low-Mode Winds

3.4.4.3.2 Radar Profiler Low-Mode Wind Data

The data recovery rates for the two sites for the low-mode winds are shown in

Figure 3-15. Both sites experienced data recovery losses at the lowest altitudes due primarily to

sea clutter interference.

Figure 3-15. Data Recovery Rates for Radar Profiler Low-Mode Winds,

September 2000 - October 2, 2001
3-55

0 10 20 30 40 50 60 70 80 90 100

Meters AGL

Percent Data Recovery

1260

1200

1140

1080

1020

960

900

840

780

720

660

600

540

480

420

360

300

240

180

120

Max %

Average

Min %

VRM-22D Site, RASS Mode

0 10 20 30 40 50 60 70 80 90 100

Meters AGL

Percent Data Recovery

1275

1215

1155

1095

1035

975

915

855

795

735

675

615

555

495

435

375

315

255

195

135

Max %

Average

Min %

SMI-160A Site, RASS Mode

3.4.4.3.3 RASS Temperature Data

In the RASS mode, virtual temperature profiles are measured by using the

scattering of radar pulses from acoustic waves. The data recovery rates for the radar profiler

RASS mode are shown in Figure 3-16. 

Figure 3-16. Data Recovery Rates for Radar Profiler RASS Mode,

September 2000 - October 2, 2001
3-56

3.4.5 Problems Encountered and Corrective Action Taken

No problems involving the management of the project were experienced during

the fourth year of the project.

Table 3-21 lists the equipment problems encountered, and corrective action

implemented, during the fourth year of the project.

Table 3-21. Project Year Four Equipment Problems and Corrective 

 Actions

Ref No. Problem Project Team Corrective Action

4-1 At VRM22D the surface wind

sensor and temperature/RH sensor

failed audit criteria during the

10/23/00 site visit.

Replaced both sensors during the visit.

4-2 At VRM22D surface met data

collection ceased on 11/5/00.

Remote troubleshooting isolated the problem to failures

of the data logger’s 18VAC power supply, 12V battery,

and battery charger. A lightning strike was strongly

suspected. Replacement parts were shipped to the

platform and were installed by VRM22D personnel,

restoring surface met data collection on 11/12/00.

4-3 At VRM22D SST sensor data

were invalid beginning on 11/8/00. 

Remote troubleshooting isolated the suspected cause to a

storm having caused water ingestion into the SST sensor. 

A replacement SST sensor was shipped to the platform

and was installed by VRM22D personnel, restoring valid

SST data collection.

4-4 At SMI160A upper air data

collection ceased on 12/7/00. 

Remote troubleshooting isolated the suspected cause to a

power interrupt in the Radar Computer. Normal

operations were successfully resumed by performing

remote power cycling.

4-5 At SMI160A upper air data

collection ceased on 1/2/01. 

Remote troubleshooting isolated the suspected cause to a

failed power supply in the Radar Computer. An

unscheduled visit to SMI160A was performed on 1/9/01,

during which the power supply in the Radar Computer

was replaced, restoring normal operations. 

4-6 At VRM22D the RH sensor began

providing periodically unstable

readings in December 2000 and

January 2001.

Replaced with spare during unscheduled visit to

VRM22D on 1/25/01. As a target of opportunity, the

SST sensor at VRM22D was also replaced (with a freshly

calibrated SST sensor) during this visit. 
3-57

Table 3-21. Project Year Four Equipment Problems and Corrective 

 Actions(Cont’d)

Ref No. Problem Project Team Corrective Action

4-7 On 2/28/01, after closely

monitoring for some time the

VRM22D upper air wind directions

being reported by the radar profiler

at that site, the STI data processing

center alerted project field team

participants of a possible problem

with that radar profiler.

Data symptoms provided by STI and remote

troubleshooting of the site’s computer data system

suggested a diagnosis of a failed phase shifter in the radar

profiler. An unscheduled visit to VRM22D was

performed on 3/7/01, during which the failed phase

shifter was replaced. STI subsequently reported that this

action corrected the wind data quality problem previously

observed.

4-8 At SMI160A the RH sensor began

providing periodically unstable

readings in February 2001.

Replaced with spare during unscheduled visit to

SMI160A on 3/8/01.

4-9 In early April 2001, Newfield

Exploration notified the project

team that the radar profiler antenna

on their SMI160A platform would

need to be moved about 30 feet

before the end April 2001. 

Performed an unscheduled visit to SMI160A during the

period 4/25/01 – 4/27/01 and moved the radar profiler

antenna as required by Newfield.

Note: This action complied with the Newfield

requirement. However, the team could do nothing to

mitigate the data quality impact that the addition of the

drilling rig to the SMI160A platform had on the MMS

project. Since the MMS data collection period was

nearing completion, it was not economical to relocate the

equipment to another platform at that point in the project

and it was left in place at SMI160A to gather whatever

useful data was possible during the Newfield drilling

operations. Primary impacts were that the RASS had to

be shut off to preclude bothering the drilling workers on

the platform around the clock, and the upper air winds

and surface met data both experienced reduced quality

due to the physical obstruction posed by the presence of

the drilling rig in close proximity to the meteorological

measurement equipment. 

4-10 In May 2001 the STI data

processing center alerted project

field team participants of a possible

problem with the SMI160A wind

direction measurements.

Data symptoms provided by STI and remote

troubleshooting of the site’s computer data system

suggested the diagnosis of a failed phase shifter in the

site’s radar profiler. That phase shifter was replaced

during the scheduled site visit to SMI160A on 6/9/01. 

This action restored the radar profiler to normal

operation, although interference from the drilling rig

continued to cause SMI160A upper air data to be of little

value. 

4-11 At the end of May 2001 the GOES

transmissions from SMI160A

ceased.

Replaced the failed GOES DCP unit at SMI160A during

a scheduled visit to the site on 6/9/01.
3-58

Table 3-21. Project Year Four Site/Equipment Problems and Corrective 

 Actions(Cont’d)

Ref No. Problem Project Team Corrective Action

4-12 At VRM22D the temperature/RH

sensor failed audit criteria during

the 6/4/01site visit. 

Replaced the sensor during the visit.

4-13 At VRM22D the RH sensor began

providing periodically unstable

readings in July 2001. 

Replacement was scheduled for the opportune site visit,

but no further site visits occurred prior to the end of the

data collection period.

3.4.6 Summary

Tasks completed during the fourth year of work on this project successfully

supported the objective. Sites and equipment were rigorously monitored, problems quickly

addressed, and reports submitted on time. All data measurements collected were quality

checked on a daily basis and were processed and documented by formal reporting on a monthly

basis.

During the fourth year of the project, the average daily capture rate was 86.0%,

which did not quite meet the project’s 90% or higher goal. As of the end of the fourth year of

the project, the cumulative data capture rate for the project was 89.3% which was slightly below

the project’s 90% or greater goal.
4-1

4.0 DATA COLLECTION RESULTS

As planned, data were collected for a continuous 40-month period at two Gulf of

Mexico platform sites, VRM22D and SMI160A, beginning on June 3, 1998 and concluding on

October 2, 2001. Upper air data were collected using a 915 MHz pulsed-Doppler radar profiler,

with RASS, installed at each site, and included wind direction, wind speed, and virtual

temperature. Surface (platform level) data were collected using a suite of standard in-situ

meteorological sensors installed at each site, and included wind direction, wind speed,

temperature, relative humidity, and pressure. Sea surface temperature data were also collected

using a remote-sensing infrared sensor that was installed at platform level at each site and

pointed downward to make measurements of water surface temperature. All measurement

equipment used was owned by MMS, was installed by project team personnel prior to the data

collection period, and was removed by project team personnel following the data collection

period.

All data measurements were made and transmitted from each site each hour

throughout the data collection period. Site GPS equipment kept data time stamps synchronized

and current. Site communications equipment was pre-programmed to transmit collected hourly

data from each site, at assigned channel times, via the GOES satellite communications link. All

successfully-transmitted data were received and immediately quality checked at the project

teams’s data center at Sonoma Technology, Inc. in Petaluma, California. Data were also made

available in real time to NOAA’s Forecast Systems Laboratory in Boulder, Colorado. 

4.1 Site Equipment Maintenance and Audit Performance

Project field team personnel diagnosed and corrected equipment problems 

remotely when possible, and by performing unscheduled site visits as necessary. Visits to both

sites were also performed on a scheduled basis to perform equipment preventive maintenance

and periodic audits. 

4.1.1 Data Collection Remote Maintenance Results

Project data center personnel alerted project field site operations and

maintenance personnel when data non-receipt or data quality deficiencies made site equipment

checks necessary. These checks were first attempted by remote telephone connection to the

site’s Gateway Computer, with corrective action also implemented remotely if possible either

by remote adjustments to the computer or by getting help from platform personnel to perform

simple equipment checks or adjustments.

Attempts to diagnose and correct site data measurement and communications

equipment problems remotely were necessary and were performed during almost every month

of the data collection period. In the great majority of cases, the remote maintenance attempt

was in response to the project data center reporting either no GOES data files being received or

GOES data files being received empty of data. These frequent interrupts in data flow that
4-2

occurred throughout the project were normally due to an interrupt occurring in the controlling

GOES, GPS, Radar Computer, or Gateway Computer hardware or software at the impacted site. 

Remote troubleshooting was normally possible very quickly by dial-in telephone modem

connection to the Gateway Computer. Where diagnosis or resets could not be accomplished

remotely, attempts were then made to contact platform personnel by telephone and solicit there

help in performing needed checks and resets.

Data collection results were benefited by the quick-response remote maintenance

actions implemented throughout the project. However, in spite of these efforts, data recovery

rates were often negatively impacted by two factors. First, significant delays in connecting to

site modems were regularly experienced due to poor quality telephone lines servicing the

platforms. Second, significant delays in obtaining platform personnel assistance to perform

even very simple and quick diagnostic and corrective actions were increasingly experienced

throughout the project. This was always, and understandably, because platform personnel had

to complete their primary duties before they could provide the project team the requested

assistance. During the early stages of the project, however, the delay (and associated data loss

time period) was normally only a few hours, whereas during the latter stages of the project, it

was frequently several days. At SMI160A, in particular, it was evident that platform personnel

were fully occupied with active drilling operations during the latter stage of the data collection

period. 

 

4.1.2 Data Collection On-Site Maintenance Results

When corrective maintenance could not be performed remotely, an unscheduled

site visit was planned and performed as quickly as possible. Time delays in performing

unscheduled site visits, and therefore data loss impacts, were most frequently dictated by the

availability of helicopter transportation to the platforms. Commercial helicopter charter was

normally readily available (except during storm evacuations), but was only used in the most

urgent situations because of the high cost. Platform-owner provided helicopter transportation

was used for most visits. This required project team members to travel on a space-available

basis, and resultant delays in reaching platform sites to complete repairs and restore data

collection operations were experienced.

Site corrective maintenance visits were performed as listed in Table 4-1.
4-3

Table 4-1. Site Corrective Maintenance Visits,

June 3, 1998- October 2, 2001

Site Visit

Date

Site

Visited

Corrective Maintenance Tasks Performed

9/14/98 VRM22D Restored GOES transmissions by clearing a Gateway Computer interrupt.

10/9/98 VRM22D Replaced failed SST sensor.

10/10/98 SMI160A Replaced GOES DCP unit (because platform had broken the power switch on the

original DCP when they attempted to power site equipment back up after

Hurricane Georges evacuation).

12/17/98 VRM22D Replaced failed SST sensor. Also replaced RH sensor as precaution because it

appeared to be becoming unstable.

8/6/99 VRM22D Repaired radar profiler components damaged by lightning strike. Restored GOES

transmission of upper air data. Could not make lightning damage repairs needed

to restore GOES transmission of surface met data, but confirmed surface data

being collected.

9/29/99 VRM22D Made remaining lightning strike damage repairs and restored GOES transmission

of surface met data. Also added surge protection to help better protect equipment

against future lightning strikes. Also replace short-haul modem with direct RS232 connection to improve met data transfer.

9/30/99 SMI160A Restored GOES transmissions by clearing a Gateway Computer interrupt. 

Removed a failed UPS and made arrangements for platform personnel to ship it to

Vaisala for repair. Also added surge protection to help better protect equipment

against future lightning strikes.

1/14/00 VRM22D Corrected a GPS Y2K problem that had caused the radar profiler to cease

operations on 1/1/00 because it was being told the year was 1900.

1/16/00 SMI160A Corrected a GPS Y2K problem that had caused the radar profiler to cease

operations on 1/1/00 because it was being told the year was 1900.

3/24/00 VRM22D Replaced failed power supply in the charger for the data logger and restored

GOES transmissions of surface met data. Replaced the radar profiler=s final

amplifier unit as a precaution because of potential performance degradation. 

Installed a software patch to help prevent future leap year problems.

3/26/00 SMI160A Installed a software patch to help prevent future leap year problems.

6/14/00 VRM22D Restored GOES transmissions by clearing a Gateway Computer interrupt. 

Installed a Windows 95 patch to help keep time stamps at CST all year.

6/16/00 SMI160A Installed repaired UPS unit (previously removed during 9/30/99 visit. Installed a

Windows 95 patch to help keep time stamps at CST all year.
4-4

Table 4-1. Site Corrective Maintenance Visits,

June 3, 1998- October 2, 2001 (Cont’d)

Site Visit

Date

Site

Visited

Corrective Maintenance Tasks Performed

1/9/01 SMI160A Replaced failed power supply in the Radar Computer and restored equipment

operation and GOES data transmissions.

1/31/01 VRM22D Replaced failed RH sensor. Replaced the SST sensor because its calibration was

expiring.

3/7/01 VRM22D Replaced failed radar profiler phase shifter RF relays.

3/8/01 SMI160A Replaced the RH sensor because its data were becoming unstable.

4/27/01 SMI160A Moved the radar profiler antenna about 30 feet on the platform deck to make

room for a drilling rig being installed by the platform owner.

6/9/01 SMI160A Replaced failed radar profiler phase shifter RF relays. Also replaced failed UPS

and GOES DCP units

.

4.1.3 Data Collection Equipment Audit Results 

Audits of site equipment significantly enhanced data collection results by

detecting and correcting equipment problems in a timely manner. Audits were planned on

approximately a six month basis. Actual audit frequency was adjusted to merge audits with

unscheduled corrective maintenance visits where reasonable and most cost effective. A total

of nine audits were performed during the 40-month data collection period, including the

readiness audit prior to the start of data collection and the final audit following the completion

of data collection. All audits included both upper air and surface measurement equipment at

both sites. A list of audits performed and equipment components that failed audit criteria and

were replaced during the audit visit is shown in Table 4-2. The sensors that most frequently

failed audit criteria and that required replacement were the relative humidity and sea surface

temperature sensors.
4-5

Table 4-2. Site Equipment Audit Visits

Month Audit Performed Sites Audited Audit Results

March 1998

(Readiness Audit Before Start of 

 Data Collection Period)

VRM22D All Sensors Passed

 SMI160A All Sensors Passed

September 1998 VRM22D All Sensors Passed

SMI160A All Sensors Passed

April 1999 VRM22D All Sensors Passed

SMI160A Replaced Corroded SST Sensor

September 1999 VRM22D Replaced Temp/RH Sensor

SMI160A All Sensors Passed

January 2000 VRM22D All Sensors Passed

SMI160A All Sensors Passed

June 2000 VRM22DI Replaced Temp/RH Sensor

SMI160A Replaced Temp/RH & SST Sensors

October 2000 VRM22D Replaced Temp/RH & Wind Sensors

SMI160A All Sensors Passed

June 2001 VRM22D Replaced Temp/RH Sensor

SMI160A Replaced Radar Profiler Phase Shifter RF 

 Relays

 November 2001

 (Final Audit After End of

 Data Collection Period)

VRM22D Temp/RH Sensor Failed Audit

SMI160A All Sensors Passed

4.2 Data Capture Results 

One of the goals of the project was to achieve an overall data capture rate of 90%

or higher. The actual data capture rate achieved during the 40-month data collection period was

89.3%, slightly below the goal. Except for factors beyond the project team’s control that

impacted data collection results, the data capture rate achieved during the 40-month data

collection period would have been well above the 90% goal. Example impacts on data rates

that could not be controlled included equipment power shutdowns for tropical storm and
4-6

hurricane evacutions, equipment damage due to lightning strikes, and equipment operating

restrictions caused by the addition of a drilling rig to one of the platform sites.

Average data capture rate results for the 40-month data collection period

 are listed by data types, sites, and data months in Table 4-3, Table 4-4, and Table 4-5.

 Months with poorest average data capture rates and cause factors are listed in Table 4-6. 

Table 4-3. VRM22D Monthly Data Capture Rates,

 June 3, 1998 - October 2, 2001

Month

/Year

Upper Air

Wind

Average Data

Capture Rate

for the Month

Upper Air

Temperature

Average Data

Capture Rate

for the Month 

Surface Met

Data 

Average Data

Capture Rate

for the Month

All Data Types

Average Data

Capture Rate

for the Month 

All Data Types

Running Average

Data Capture

Rate for all

Months to Date

in Project

06/98 99.3% 99.3% 99.3% 99.3% 99.3%

07/98 93.8% 93.8% 93.8% 93.8% 96.6%

08/98 97.0% 97.0% 97.0% 97.0% 96.7%

09/98 80.7% 81.0% 100.0% 87.2% 94.3%

10/98 95.2% 95.3% 95.3% 95.3% 94.5%

11/98 96.8% 96.7% 96.9% 96.8% 94.9%

12/98. 97.3% 97.3% 97.3% 97.3% 95.2%

01/99 94.2% 94.2% 94.2% 94.2% 95.1%

02/99 97.6% 97.6% 97.6% 97.6% 95.4%

03/99 95.4% 95.4% 95.8% 95.5% 95.4%

04/99 74.4% 74.4% 71.9% 73.6% 93.4%

05/99 97.9% 97.9% 98.7% 98.2% 93.8%

06/99 72.8% 72.6% 72.4% 72.6% 92.2%

07/99 98.8% 91.8% 98.8% 96.5% 92.5%

08/99 87.0% 78.4% 8.7% 58.0% 90.2%
4-7

Table 4-3. VRM22D Monthly Data Capture Rates,

 June 3, 1998 - October 2, 2001 (Cont’d)

Month

/Year

Upper Air

Wind

Average Data

Capture Rate

for the Month

Upper Air

Temperature

 Average Data

Capture Rate for

the Month

Surface Met

Data 

Average Data

Capture Rate

for the Month

All Data Types

Average Data

Capture Rate

for the Month 

All Data Types

 Running

Average Data

Capture Rate for

all Months to

Date in Project

09/99 96.7% 96.7% 1.4% 64.9% 88.6%

10/99 95.8% 95.7% 96.8% 96.1% 89.1%

11/99 96.5% 96.5% 96.4% 96.5% 89.5%

12/99 90.5% 90.3% 90.6% 90.5% 89.5%

01/00 49.9% 49.7% 94.5% 64.7% 88.3%

02/00 93.7% 93.7% 84.2% 90.5% 88.4%

03/00 60.2% 60.1% 23.7% 48.0% 86.6%

04/00 99.9% 99.9% 99.9% 99.9% 87.1%

05/00 98.7% 98.5% 100.0% 99.1% 87.7%

06/00 76.1% 59.0% 96.4% 77.2% 87.2%

07/00 98.0% 98.0% 98.0% 98.0% 87.7%

08/00 99.9% 99.9% 99.9% 99.9% 88.1%

09/00 97.9% 97.9% 97.9% 97.9% 88.5%

10/00 98.3% 98.3% 90.7% 95.8% 88.7%

11/00 94.0% 93.9% 86.1% 91.3% 88.8%

12/00 99.0% 99.0% 99.0% 99.0% 89.1%

01/01 98.9% 98.9% 98.7% 98.8% 89.4%

02/01 99.0% 98.8% 99.9% 99.2% 89.7%

03/01 48.5% 48.3% 95.3% 64.0% 89.0%

04/01 85.4% 85.0% 86.7% 85.7% 88.9%

05/01 81.3% 80.9% 99.6% 87.3% 88.8%
4-8

Table 4-3. VRM22D Monthly Data Capture Rates,

 June 3, 1998 - October 2, 2001 (Cont’d)

Month/

Year

Upper Air

Wind

Average Data

Capture Rate

for the Month

Upper Air

Temperature

Average Data

Capture Rate

for the Month 

Surface Met

Data 

Average Data

Capture Rate

for the Month

All Data Types

Average Data

Capture Rate

for the Month 

All Data Types

Running Average

Data Capture

Rate for all

Months to Date

in Project

06/01 93.8% 93.8% 98.6% 95.4% 89.0%

07/01 99.1% 98.9% 99.1% 99.0% 89.3%

08/01 92.9% 92.7% 92.9% 92.8% 89.4%

09/01 97.0% 97.0% 97.0% 97.0% 89.6%

All 40

Months

90.5% 89.6% 88.5% 89.6% 89.6%

Table 4-4. SMI160A Monthly Data Capture Rates,

 June 3, 1998 - October 2, 2001

Month

/Year

Upper Air

Wind

Average Data

Capture Rate

for the Month

Upper Air

Temperature 

Average Data

Capture Rate

for the Month 

Surface Met

Data 

Average Data

Capture Rate

for the Month

All Data Types

Average Data

Capture Rate

for the Month 

All Data Types

Running Average

Data Capture

Rate for all

Months to Date

in Project

06/98 98.2% 98.2% 98.2% 98.2% 98.2%

07/98 97.4% 96.2% 97.5% 97.0% 97.6%

08/98 99.7% 99.7% 99.6% 99.7% 98.3%

09/98 85.3% 85.5% 100.0% 90.3% 96.3%

10/98 90.7% 91.0% 87.6% 89.8% 95.0%

11/98 98.9% 98.8% 99.0% 98.9% 95.6%
4-9

Table 4-4. SMI160A Monthly Data Capture Rates,

 June 3, 1998 - October 2, 2001 (Cont’d)

Month

/Year

Upper Air

Wind

Average Data

Capture Rate

for the Month

Upper Air

Temperature 

Average Data

Capture Rate for

the Month 

Surface Met

Data 

Average Data

Capture Rate

for the Month

All Data Types

Average Data

Capture Rate

for the Month

All Data Types

Running Average

Data Capture

Rate for all

Months to Date

in Project

12/98 87.5% 87.4% 94.8% 89.9% 94.8%

01/99 99.5% 99.5% 99.5% 99.5% 95.4%

02/99 96.1% 96.1% 96.1% 96.1% 95.5%

03/99 97.7% 97.7% 98.1% 97.8% 95.7%

04/99 98.9% 99.0% 99.3% 99.1% 96.0%

05/99 98.5% 98.5% 99.3% 98.8% 96.3%

06/99 98.1% 98.1% 98.1% 98.1% 96.4%

07/99 97.9% 97.9% 97.9% 97.9% 96.5%

08/99 99.3% 99.5% 99.5% 99.4% 96.7%

09/99 79.4% 79.4% 76.0% 78.3% 95.6%

10/99 69.5% 69.4% 83.7% 74.2% 94.3%

11/99 99.2% 99.2% 99.2% 99.2% 94.6%

12/99 94.2% 94.1% 97.7% 95.3% 94.6%

01/00 38.2% 40.5% 62.9% 47.2% 92.2%

02/00 96.8% 96.8% 97.0% 96.9% 92.5%

03/00 98.5% 98.5% 98.5% 98.5% 92.7%

04/00 95.0% 94.9% 95.0% 95.0% 92.8%

05/00 96.1% 96.2% 97.3% 96.5% 93.0%

06/00 97.1% 96.8% 96.4% 96.8% 93.1%

07/00 92.7% 92.6% 92.7% 92.7% 93.1%
4-10

Table 4-4. SMI160A Monthly Data Capture Rates,

 June 3, 1998 - October 2, 2001 (Cont’d)

Month/

Year

Upper Air

Wind

Average Data

Capture Rate

for the Month

Upper Air

Temperature 

Average Data

Capture Rate for

the Month 

Surface Met

Data 

Average Data

Capture Rate

for the Month

All Data Types

Average Data

Capture Rate

for the Month

All Data Types

Running Average

Data Capture

Rate for all

Months to Date

in Project

08/00 90.5% 90.5% 90.5% 90.5% 93.0%

09/00 37.2% 37.2% 37.2% 37.2% 91.0%

10/00 87.4% 87.4% 96.8% 90.5% 91.0%

11/00 97.2% 97.1% 78.5% 90.9% 91.0%

12/00 87.5% 87.4% 97.0% 90.6% 91.0%

01/01 60.3% 60.2% 60.6% 60.4% 90.0%

02/01 97.2% 97.0% 97.2% 97.1% 90.3%

03/01 96.9% 96.9% 96.9% 96.9% 90.4%

04/01 89.9% 90.1% 91.5% 90.5% 90.4%

05/01 76.9% 76.5% 76.9% 76.8% 90.1%

06/01 67.9% 67.6% 68.3% 67.9% 89.5%

07/01 72.6% 72.2% 72.6% 72.5% 89.0%

08/01 91.8% 91.7% 93.0% 92.2% 89.1%

09/01 88.2% 75.9% 88.2% 84.1% 89.0%

All 40

Months

88.5% 88.2% 90.2% 89.0% 89.0%
4-11

Table 4-5. Combined VRM22D & SMI160A Monthly Data 

 Capture Rates, June 3, 1998 - October 2, 2001

Month

/Year

Upper Air

Wind

Average Data

Capture Rate

for the Month

Upper Air

Temperature 

Average Data

Capture Rate for

the Month 

Surface Met

Data 

Average Data

Capture Rate

for the Month

All Data Types

Average Data

Capture Rate

for the Month 

All Data Types

Running Average

Data Capture

Rate for all

Months to Date

in Project

06/98 98.8% 98.8% 98.8 98.8% 98.8%

07/98 95.6% 95.0% 95.7 95.4% 97.1%

08/98 98.4% 98.4% 98.3 98.4% 97.5%

09/98 83.0% 83.3% 100.0 88.8% 95.4%

10/98 93.0% 93.2% 91.5 92.6% 94.8%

11/98 97.8% 97.8% 98.0 97.9% 95.3%

12/98. 92.4% 92.4% 96.1 93.6% 95.1%

01/99 94.9% 96.9% 96.9% 96.2% 95.2%

02/99 96.8% 96.9% 96.9% 96.9% 95.4%

03/99 96.6% 96.6% 95.5% 96.2% 95.5%

04/99 86.7% 86.7% 85.6% 86.3% 94.6%

05/99 98.2% 98.2% 99.0% 98.5% 95.0%

06/99 85.5% 85.4% 85.3% 85.4% 94.2%

07/99 98.4% 94.9% 98.4% 97.2% 94.4%

08/99 93.2% 89.0% 54.1% 78.8% 93.4%

09/99 88.1% 88.1% 38.7% 71.6% 92.0%

10/99 82.7% 82.6% 90.3% 85.2% 91.6%

11/99 97.9% 97.9% 97.8% 97.9% 92.0%

12/99 92.4% 92.2% 94.2% 92.3% 92.0%

01/00 44.1% 45.1% 78.7% 56.0% 90.2%
4-12

Table 4-5. Combined VRM22D & SMI160A Monthly Data Capture

 Rates, June 3, 1998 - October 2, 2001 (Cont’d)

Month/

Year

Upper Air

Wind

Average Data

Capture Rate

for the Month

Upper Air

Temperature 

Average Data

Capture Rate for

the Month 

Surface Met

Data 

Average Data

Capture Rate

for the Month

All Data Types

Average Data

Capture Rate

for the Month

All Data Types

Running Average

Data Capture

Rate for all

Months to Date

in Project

02/00 95.3% 95.3% 90.6% 93.7% 90.4%

03/00 79.4% 79.3% 61.1% 73.3% 89.6%

04/00 97.5% 97.4% 97.5% 97.5% 89.9%

05/00 97.4% 97.4% 98.7% 97.8% 90.3%

06/00 86.6% 77.9% 96.4% 87.0% 90.1%

07/00 95.4% 95.3% 95.4% 95.4% 90.3%

08/00 95.2% 95.2% 95.2% 95.2% 90.5%

09/00 67.6% 67.6% 67.6% 67.6% 89.7%

10/00 92.9% 92.9% 93.8% 93.2% 89.8%

11/00 95.6% 95.5% 82.3% 91.1% 89.9%

12/00 93.3% 93.2% 98.0% 94.8% 90.0%

01/01 79.6% 79.6% 80.2% 79.8% 89.7%

02/01 98.1% 97.9% 98.6% 98.2% 90.0%

03/01 72.7% 72.6% 96.1% 80.5% 89.7%

04/01 87.7% 87.5% 89.1% 88.1% 89.6%

05/01 79.1% 78.7% 88.3% 82.0% 89.4%

06/01 80.9% 80.7% 83.5% 81.7% 89.2%

07/01 85.9% 85.6% 85.9% 85.8% 89.1%

08/01 92.4% 92.2% 93.0% 92.5% 89.2%

09/01 92.6% 86.5% 92.6% 90.6% 89.3%

All 40

Months

89.5% 88.9% 89.4% 89.3% 89.3%
4-13

Table 4-6. Poor Data Capture Rate Months and Cause Factors

Month/Year Poor Data Capture Rate Cause Factors

04/99 VRM22D 

All data 72-74% 

GOES transmitter failure and computer timekeeping failure (due to platform power instability).

06/99 VRM22D 

All data ~72% 

GOES software interrupt, complicated by phone

outage at platform that delayed contact with

platform personnel to correct the GOES problem.

08/99 VRM22D

Surface met data 8.7%

Lightning strike damage.

09/99 VRM22D

Surface met data 1.4%

Lightning strike damage (continuation of outage

that began in early August and was repaired in late

September).

01/00 VRM22D

Upper air data ~50%

Radar Profiler outage due to GPS Y2K problem

(which caused the radar profiler computers to stop

because they were given the year 1900 instead of

2000 by the GPS). Required extensive time to find

and fix the problem).

 03/00 VRM22D

Surface met data ~24%

Power supply failure in the charger for the data

logger.

03/00 VRM22D

Upper air data ~60%

Radar Computer software interrupts.

06/00 VRM22D

Upper air data 59-76%

Gateway Computer software interrupts.

03/01 VRM22D

Upper air data ~48%

Gateway Computer software interrupts

(complicated by delays in platform personnel

availability to help resolve).

 09/00 SMI160A

All data ~79%

Gateway Computer interrupt and failed UPS unit

(due to platform power problems).

10/99 SMI160A

Upper air data ~69% 

Radar Computer and Software Computer software

interrupts.

01/00 SMI160A

Upper air data ~39%

Radar profiler outage due to GPS Y2K problem

(which caused the radar profiler computers to stop

because they were given the year 1900 instead of

2000 by the GPS). Required extensive time to find

and fix the problem.

01/00 SMI160A

Surface met data ~63%

GOES software interrupts.

09/00 SMI160A

All data ~37%

GOES transmitter failure.
4-14

Table 4-6. Poor Data Capture Rate Months and Cause Factors (Cont’d)

Month/Year Poor Data Capture Rate Cause Factors

11/00 SMI160A

Surface met data ~79%

Data logger power supply, battery and charger failure

(suspected lightning strike).

01/01 SMI160A

All data ~60%

Radar Computer power supply failure (which also

caused the Gateway Computer to stop).

05/01 SMI160A

All data ~76%

Platform power fluctuations and shutdowns (due to

drilling operations in progress).

 06/01 SMI160A

All data ~68%

Platform power fluctuations and shutdowns (due to

drilling operations in progress) and GOES transmitter

failure.

07/01 SMI160A

All data ~72% 

Gateway and Radar Computer software interrupts

(complicated by delays in platform personnel availability

to help resolve).

09/01 SMI160A

Upper air temp~76%

Gateway and Radar Computer software interrupts

(complicated by delays in platform personnel availability

to help resolve).

4.3 Data Recovery Results

Data recovery rates achieved for the 40-month data collection period are 

shown in Figure 4-1, Figure 4-2, and Figure 4-3 for upper air data and in Table 4-7 for

the surface meteorological data. These recovery rates are about as expected for similar 

projects using radar profilers and surface sensors of the type employed for this project. 

Recovery rates for radar profilers are heavily dependent upon the height to which upper 

air winds and temperatures can be measured based upon atmospheric conditions. Also, 

as used on platform sites in this project, the lowest heights at which upper air winds and 

temperatures can be measured by a radar profiler is limited by interference from the 

platform structure itself and by interference from the Doppler shift of wave movements in 

the vicinity of the platform site (within the sidelobe viewing distance of the radar). 
4-15

0 10 20 30 40 50 60 70 80 90 100

Meters AGL

Percent Data Recovery

4934

4742

4549

4357

4164

3972

3779

3587

3394

3202

3010

2817

2625

2432

2240

2047

1855

1663

1470

1278

1085

893

700

508

316

Max %

Average

Min %

VRM-22D Site, High-Mode Winds

0 10 20 30 40 50 60 70 80 90 100

Meters AGL

Percent Data Recovery

4920

4728

4535

4343

4150

3958

3765

3573

3380

3188

2996

2803

2611

2418

2226

2033

1841

1649

1456

1264

1071

879

686

494

302

Max %

Average

Min %

SMI-160A Site, High-Mode Winds

Figure 4-1. Data Recovery Rates for Radar Profiler High-Mode Winds, 

June 3, 1998 - October 2, 2001 
4-16

0 10 20 30 40 50 60 70 80 90 100

Meters AGL

Percent Data Recovery

2440

2344

2247

2151

2055

1959

1862

1766

1670

1574

1478

1381

1285

1189

1093

996

900

804

708

612

515

419

323

227

131

Max %

Average

Min %

VRM-22D Site, Low-Mode Winds

0 10 20 30 40 50 60 70 80 90 100

Meters AGL

Percent Data Recovery

2440

2344

2247

2151

2055

1959

1862

1766

1670

1574

1478

1381

1285

1189

1093

996

900

804

708

612

515

419

323

227

131

Max %

Average

Min %

SMI-160A Site, Low-Mode Winds

Figure 4-2. Data Recovery Rates for Radar Profiler Low-Mode Winds, 

June 3, 1998 - October 2, 2001
4-17

0 10 20 30 40 50 60 70 80 90 100

Meters AGL

Percent Data Recovery

1260

1200

1140

1080

1020

960

900

840

780

720

660

600

540

480

420

360

300

240

180

120

Max %

Average

Min %

VRM-22D Site, RASS Mode

0 10 20 30 40 50 60 70 80 90 100

Meters AGL

Percent Data Recovery

1275

1215

1155

1095

1035

975

915

855

795

735

675

615

555

495

435

375

315

255

195

135

Max %

Average

Min %

SMI-160A Site, RASS Mode

Figure 4-3. Data Recovery Rates for Radar Profiler RASS Mode, 

June 3, 1998 - October 2, 2001
5-1

5.0 EQUIPMENT PERFORMANCE AND DISPOSITION

All meteorological and communications equipment used in this data

collection project were owned by MMS. The prime contractor was responsible for custody

of all equipment during the preparation, installation, operation and maintenance, removal,

and refurbishment phases of the project, as well as for return shipping of the equipment to

MMS after the project.

5.1 Equipment Performance 

The performance of all equipment used in the project was satisfactory, although

failure experience varied as summarized below.

5.1.1 Upper Air Meteorological Measurement Equipment 

The Radian (now Vaisala) radar profilers used to measure upper air winds and

temperatures at the two project sites performed reliably throughout the 40-month data collection

period, but experienced some hardware and software problems requiring project team corrective

maintenance. Of note, neither of the two radar profilers were new at the beginning of the

project and the component and configuration failure problems experienced during the project

were within expected levels for equipment of this type, age, and interface with other sensor and

communications devices.

Except for lightning damage repair to the VRM22D profiler in August 1999, the

only hardware repairs required to the radar profilers during the project were the replacement of

a power supply in the Radar Computer at SMI160A in January 2001 and the replacement of RF

relays in the radar profiler’s phase shifter in February 2001 at VRM22D and in May 2001 at

SMI160A. Of note, the RF relays at both sites had more than fulfilled their life expectancy at

the time of their respective failures at the two sites, and their required replacement was normal

maintenance. 

Software problems experienced were of several types and external causes. 

While none of the failures were due to deficiencies in the radar profiler software itself, the

impacts experienced were manifest as radar profiler software interrupts. In one case, the

interrupts were simultaneous at both sites, on 1/1/00 when the Global Positioning System (GPS)

external device began telling the radar software that the year was 1900 rather than 2000 and

both profilers stopped. This problem was difficult and time-consuming to identify, but was

simple to fix and was a one-time problem. Throughout the data collection period, however, the

radar profiler software experienced numerous interrupts caused by either the system’s Radar

Computer or Gateway Computer “hanging” while dealing with internal data transfer of radar

profiler files and surface meteorological data files to the GOES Data Collection Platform

(DCP). In each instance, the interrupts were quickly identified by the project team’s data

processing center and restoral action was initiated by the project team’s field operations and

maintenance personnel. These restorals were sometimes readily accomplished by system resets
5-2

performed by remote dial-in to the computers via telephone modems. However, the required

resets were frequently delayed while making multiple attempts to reach the modems or because

platform personnel assistance was needed to perform the resets. Although platform personnel

were always very cooperative and helpful, they were frequently not near a telephone to be

reached or were reached but couldn’t help until later because of higher priority duties in

progress. As a problem class, the interrupts were largely a function of the then-current

generation of Microsoft systems operating software in use not being capable of handling multitasking well. At the end of the project, the refurbishment of equipment provided for in the

MMS contract included upgrades of the radar profiler software that now operate in a Windows

NT environment, which is much more multi-tasking capable. 

 

5.1.2 Surface Meteorological Equipment

A data logger and suite of wind, temperature, relative humidity (RH), pressure,

and sea surface temperature (SST) sensors was used at each site to record surface

meteorological data measurements throughout the 40-month data collection period. The data

logger was connected to the site’s Gateway Computer, part of the radar profiler equipment, for

transmitting hourly observations into the site’s GOES DCP. 

The data logger at SMI160A operated without failure throughout the project. 

The data logger at VRM22D suffered confirmed lightning strike damage in August 1999 and

suspected lightning strike damage in November 2000. Both instances resulted in outages that

were corrected by replacing the damaged components. The VRM22D data logger also

experienced one outage not related to lightning, which was a failed power supply that was

replaced in March 2000.

The wind sensors initially provided by MMS were not robust enough to maintain

reliable operation in platform site usage, and were replaced by a marine version at the

beginning of the project. The only wind sensor problem experienced during the data collection

period was that the VRM22D wind sensor failed to meet audit criteria in October 2000 and was

replaced at that time.

The temperature/RH sensor at each site had to be replaced multiple times during

the data collection period because of RH sensor data instability and/or failure to meet audit

criteria. The RH sensor was the worst-performing of all sensors during the project. It had to be

replaced six times at VRM22D and twice at SMI160A during project site visits, either because

it had failed prior to the visit or because it failed to meet audit criteria during the visit.

The pressure sensor at each site performed without failure during the data

collection period.

The SST sensor was the second-worst performing sensor during the data

collection period. It had to be replaced three times at VRM22D and twice at SMI160A during

the project during site visits, either because it had failed prior to the visit or because it failed to
5-3

meet audit criteria during the visit. It also had to be replaced at VRM22D during one additional

visit because the installed sensor was soon to need calibration. 

5.1.3 Supporting Communications and Other Equipment 

Communications equipment used at each site included a telephone modem for

as-needed remote connectivity to the Gateway Computer and a GOES Data Collection Platform

(DCP) for hourly transmission of collected upper air and surface meteorological data. 

Supporting equipment used at each site included a GPS antenna/receiver for providing time

stamp updates to the Radar and Gateway Computers and an Uninterruptible Power Supply

(UPS) for providing backup power to the radar profiler to sustain operations during brief power

outages.

The telephone modem at each site operated without failure during the project. 

However, multiple attempts were required to connect remotely to them because of the poor

quality of the platform telephone lines.

Use of the GOES communications system, operated by NOAA’s National

Environmental Satellite Data and Information Services (NESDIS), made possible the near realtime retrieval of hourly measurements recorded at both project platform sites. Although the

GOES communications system operated with a good up-time rate, there were periods during the

40-month data collection period when it was out of operation until restored by NESDIS. This

occurred, for example, from March 30 to April 10, 2000.

A Synergetics GOES DCP unit was used at each site during the project to transmit data,

collected by the Gateway Computer and relayed to the DCP, each hour to the GOES system. 

The DCP at VRM22D operated without failure throughout the project. The DCP at SMI160A,

however, failed during installation and in October 1998, September 2000, and May 2001. In

each case, it was replaced with the project’s spare DCP and the failed unit was repaired and

became the spare.

The GPS antenna/receiver used at each site to provide current time stamps to the

Radar and Gateway Computers operated without hardware failure during the 40-month data

collection period. However, on April 10, 1999 a platform power failure unfortunately occurred

just as a GPS update was being made to the computers and they 

“lost track of time” until the problem could be diagnosed and reset. More seriously, on

January1, 2000 the computers both stopped because the GPS began feeding them the year 1900

as part of time stamp updates. This Y2K problem in the GPS software was difficult to find, and

data were lost from both sites until the cause was identified and a corrective visit to each

platform site could be completed in mid-January 2000.

The UPS unit at each site provided battery-backup power that kept the radar

profiler operating during platform power fluctuations and outages of less than about 20 minutes. 

No records are available to specify the number of such occurrences during which the UPS

prevented downtime that would have otherwise occurred. However, platform power was
5-4

observed to be less stable than typically experienced at similar land-based sites and the UPS

units were therefore estimated to be very valuable to the project. Only one UPS hardware

failure occurred during the project, when the unit at SMI160A experienced an internal battery

malfunction in September 1999. It was removed during a site visit on September 30, 1999 and

was re-installed during a site visit on 16 June 2000. No spare UPS unit was available for the

project and repair time for the failed unit took longer than anticipated. 

5.2 Equipment Disposition 

During the data collection period, equipment refurbishment was performed on a

continuous basis. Preventative maintenance routines were accomplished during every site visit

to help assure optimal equipment performance. This included routine tasks such as checks and

adjustments of outside equipment to maintain the physical alignment, orientation, and secure

attachment of the radar profiler antennas and the surface meteorological sensors. It also

included offload of computer data files to preclude their exceeding capacity limitations, and

download of data from ZIP auxiliary data storage devices to provide backup data records. 

Equipment refurbishment was also conducted on an as-needed basis associated with corrective

maintenance. This included spares replenishment by sending failed components and sensors to

the respective manufacturers for repair in a timely manner after their removal from the platform

sites during corrective maintenance visits. It also included having sensors recalibrated as

needed in advance of calibration expiration dates.

After the completion of the data collection period, all equipment was removed

from the platform sites and was shipped to the prime contractor’s facility in Boulder, Colorado

for inspection and applicable refurbishment prior to reshipment to MMS. Table 5-1 lists all

MMS project equipment and shows refurbishment actions taken. For surface meteorological

equipment, this included having sensors recalibrated as necessary to assure their readiness for

any near term follow-on use by MMS in other field projects. For the radar profilers, this

included selected component replacements and repair, as well as planned upgrade of the Radar

Computers to current-technology LAP®

-XM applications software and Windows NT® operating

system software. 
5-5

Table 5-1. Equipment Refurbishment

Equipment Type Manufacturer/Model Qty Refurbishment Accomplished at

Project Completion

Upper Air Meteorological Measurement Equipment

Radar Profiler with RASS

for upper air wind and

temperature measurements

Vaisala LAP®3000

(including UPS unit and

marine environmental

upgrade) 

2 LAP®-XM Software Upgrade (with

Windows NT), wear and tear repair of

outdoor components, and replacement

of antenna relays and guy wires.

Spare Final Amplifier Vaisala PN600010009 1 None required

Spare RASS Diaphram Electro-Voice PN81157A 5 None required

Spare Fuses Vaisala MDL-3, MDL-6,

MDL-10 

15 None required

Spare Radar Processor Vaisala PN60011007 1 LAP®-XM Software

Spare Gateway Computer Vaisala PN60001033 1 None required

Spare Phase Shifter Vaisala PN40001024 1 None required

Spare Cable Set (excluding

RASS)

Vaisala PN40001012,

40001013, 40004014, and

40004015 

1 None required

Spare RASS Cable Set Vaisala PN40001016 1 None required

Audio Amplifier Peavey CS-800X 1 None required

Surface Meteorological Measurement Equipment

Wind Direction and Speed

Sensor

R.M. Young 05305

(non-marine model)

2 Calibration

Wind Direction and Speed

Sensor

R.M. Young 05106-5

(marine model)

2 Calibration

Temperature/Relative

Humidity Sensor

Campbell Scientific

HMP35C

5 Calibration

Pressure Sensor Vaisala 2 None required

Sea Surface Temperature

(SST) Sensor

Everest Interscience

4000.4GL

4 Repair/Calibration (2)

(The other two have valid calibration

through 2003)

Cable for SST Everest Interscience 3 None required

Serial Interface for SST Vaisala PTA-427 3 None required
5-6

Table 5-1. Equipment Refurbishment (Cont’d)

Equipment Type Manufacturer/Model Qty Refurbishment Accomplished at

Project Completion

Data Logger Campbell Scientific CR10 2 None required

Aspirator Radiation Shield R.M Young 43408-2 2 None required

10-Meter Tower Unknown UT930 2 None required

Mounting Hardware Set Various 3 None required

Meteorological Sensor

Calibration Kit

Unknown (1 barometer, 2

thermometer, 1

hygrometer)

1 Calibration

Communications and Data Storage Equipment

GOES Data Collection

Platform

Synergetics 3421A 3 None required

UDS Cellular Modem Hayes Optima 14400 2 None required

UDS Cellular Modem Accura 14400 1 None required

ZIP Data Storage Device Iomega 2 None required
6-1

6.0 SUMMARY

The objective of this MMS project was to obtain field observations to better

describe the vertical structure of the marine boundary layer over the Western and Central

Gulf of Mexico for ongoing and future dispersion modeling applications. A three-year data

collection period was originally planned, but was subsequently extended to 40 months by

MMS. Data collection included hourly upper air and surface meteorological measurements

recorded at two selected platform sites in the Gulf of Mexico, at respective distances of

approximately 10km and 75km from the Louisiana shoreline. 

A project team of contractor personnel performed all planning, data collection,

and reporting work phases under the technical direction of the designated MMS COTR. A

comprehensive Program Management Plan and a detailed Field Plan were prepared and

approved at the beginning of the work effort and were kept current throughout the project. 

Progress reporting by the project team included monthly management reports throughout the

contract period and monthly data reports throughout the 40-month data collection period.

With the concurrence of the respective platform owners, VRM22D was selected

as the near-shore platform site and SMI160A was selected as the far-shore platform site. 

Support provided by the platform owners throughout the data collection period, at no cost to the

project, included boat and helicopter transportation, space and power for the equipment,

overnight accommodations for visiting project team personnel, and assistance by platform

personnel with equipment installation, de-installation, and maintenance resets on a timeavailable basis.

Equipment used in the project is owned by MMS and included a 915 MHz

pulsed-Doppler radar profiler, with RASS, at each site that provided upper air wind and virtual

temperature measurements, a suite of surface meteorological sensors at each site that provided

wind direction, wind speed, temperature, humidity, pressure, and sea surface temperature

measurements, and a GOES Data Collection Platform at each site that provided the data

transmission capability by which all measurements were retrieved each hour throughout the

data collection period. At the end of the 40-month data collection period, the project team

performed needed component refurbishment and sensor re-calibrations before returning the

equipment to MMS. 

All retrieved data measurements were received and quality controlled at the

contractor’s facility, and were also made available in near real-time to NOAA. As data receipt

or quality problems were detected, project team personnel immediately attempted resolution by

remote telephone modem contact with platform site equipment, and subsequently performed site

corrective maintenance visits as required. In addition to these unscheduled site maintenance

visits, scheduled audit visits to each site were also performed at approximately six month

intervals throughout the 40-month data collection period.
6-2

The planned 40-month period of continuous data measurements was successfully

completed on October 2, 2001. All equipment had been installed and tested by the project team

at both sites by March 1998. However, the start of the data collection period was then delayed

until June 3, 1998 while awaiting needed RF transmission site licenses for operating the radar

profilers and for transmitting the data to the GOES satellite. With the exception of this

unavoidable delay in the start date for the data collection period, all project work tasks were

completed on schedule throughout the period of the contract.

The performance of the MMS-provided measurement equipment throughout the

data collection period was satisfactory, although a number of operating interrupts and

component failures were experienced. In each case these were resolved by project team

personnel using remote telephone connection to the equipment when possible, or by performing

a corrective maintenance site visit when necessary. During the 40-month data collection period,

a total of 18 individual, unscheduled corrective maintenance site visits were required. In

addition, project team personnel performed 14 scheduled audit visits, 7 to each site, during the

40-month period of operations. Equipment audits were also separately performed at each site

following installation and prior to de-installation. Of all equipment used in the project, the

relative humidity sensors and the sea surface temperature sensors were the least reliable. 

Relative humidity sensor replacements were required nine times and sea surface temperature

replacements were required five times during the 40-month data collection period. External

factors that most significantly limited equipment performance and maintenance during the

project included platform power shutdowns for hurricane and tropical storm evacuations,

lightning strikes and power fluctuations, active drilling on SMI160A during the last year of data

collection, and the restricted availability of platform personnel or transportation to help support

timely repairs. 

The overall data capture rate achieved for the 40-month measurement period was

89.3%, which was slightly below the project goal of 90%. Since the 89.3% capture rate

achieved did not vary significantly between upper air and surface meteorological data, or

between sites, the predominant factor that impacted this rate was simply that platform sites were

used, bringing into effect the types of challenges associated with remote site operations. 

Thanks in large measure to the outstanding help provided to the project team by platform

personnel, within the limits permitted by their other duties, these remote site challenges were

dealt with as effectively as possible during the data collection period and the overall data base

assimilation objective of the project was successfully accomplished. Thanks to the efforts of all

participants, the project was completed within budget and with no accidents. 
7-1

7.0 REFERENCES

Ecklund, W.L., D.A. Carter, B.B. Balsley, P.E. Currier, J.L. Green, B.L. Weber, and K.S.Gage. 

1990. Field tests of a lower tropospheric wind profiler. Radio Sci. 25: 899-906.

Fischler, M.A. and R.C. Bolles. 1981. Random sample consensus: A paradigm for model fitting 

with applications to image analysis and automated cartography. CACM 24/6. Pp. 381-

395.

Lindsey, C.G., T.S. Dye, P.T. Roberts, J.A. Anderson, and S.E. Ray. 1995. Meteorological 

aspects of ozone episodes in southeast Texas. Paper No. 95-WP96.02 presented at the 

Air & Waste Management Association 88th Annual Meeting, San Antonio, TX, June 18-

23.

U.S. Environmental Protection Agency. 1989. Quality assurance handbook for air pollution 

measurement systems, Volume IV - Meteorological Measurements. Prepared by Office 

of Research and Development, Atmospheric Research and Exposure Assessment 

Laboratory, Research Triangle Park, NC. EPA/600/4-90-003

Wuertz, D.B. and F.L. Weber. 1989. Editing wind profiler measurements. Prepared by 

NOAA/WPL, Boulder, CO. ERL 438-WPL 92.

 
The Department of the Interior Mission

As the Nation's principal conservation agency, the Department of the Interior has responsibility

for most of our nationally owned public lands and natural resources. This includes fostering

sound use of our land and water resources; protecting our fish, wildlife, and biological diversity;

preserving the environmental and cultural values of our national parks and historical places;

and providing for the enjoyment of life through outdoor recreation. The Department assesses

our energy and mineral resources and works to ensure that their development is in the best

interests of all our people by encouraging stewardship and citizen participation in their care.

The Department also has a major responsibility for American Indian reservation communities

and for people who live in island territories under U.S. administration.

The Minerals Management Service Mission

As a bureau of the Department of the Interior, the Minerals Management Service's (MMS)

primary responsibilities are to manage the mineral resources located on the Nation's Outer

Continental Shelf (OCS), collect revenue from the Federal OCS and onshore Federal and Indian

lands, and distribute those revenues.

Moreover, in working to meet its responsibilities, the Offshore Minerals Management Program

administers the OCS competitive leasing program and oversees the safe and environmentally

sound exploration and production of our Nation's offshore natural gas, oil and other mineral

resources. The MMS Minerals Revenue Management meets its responsibilities by ensuring the

efficient, timely and accurate collection and disbursement of revenue from mineral leasing and

production due to Indian tribes and allottees, States and the U.S. Treasury.

The MMS strives to fulfill its responsibilities through the general guiding principles of: (1) being

responsive to the public's concerns and interests by maintaining a dialogue with all potentially

affected parties and (2) carrying out its programs with an emphasis on working to enhance the

quality of life for all Americans by lending MMS assistance and expertise to economic

development and environmental protection.