2003-10-15

The International GPS Service (IGS) - 1995 to 1999

IGS Central Bureau
Jet Propulsion Laboratory
4800 Oak Grove DrivePasadena, 
CA 91109-8099
http://igscb.jpl.nasa.gov

ABSTRACT

The International GPS Service (IGS), formerly the International GPS Service for Geodynamics, is an approved service of the International Association of Geodesy (IAG) since 1994. The primary objective of the IGS is to provide a service to support, through GPS data products, geodetic and geophysical research activities. This report will chronicle the past four years of history of the IGS. (See the IAG Travaux 1996, Tome 30 edited by P. Willis for the report on the formative years of the IGS).

KEY DEVELOPMENTS OF THE IGS 1995-1999

1995 - The ‘Special Topics and New Directions Workshop’ held at GeoForschungsZentrum Potsdam (GFZ), Germany in May initiated the extension of the IGS to various applications, especially exploring atmospheric and climate monitoring. Discussions and decisions at this meeting resulted in shortening IGS Rapid Orbit Production in 1996 and planning for the production of predicted orbits. First meeting between the Permanent Service for Mean Sea Level (PSMSL) and IGS at the GLOSS (Global Ocean Observing System) meeting in Bordeaux, France investigating the use of GPS and the IGS for monitoring sea level. Number of stations in IGS network: 112.

1996 - IGS became a recognized service of the Federation of Astronomical and Geophysical Data Analysis Services (FAGS). A ‘Call for Participation’ was released in January for IGS Regional Network Associate Analysis Centers (RNAAC) for the regional densification of the terrestrial reference frame in support of the ITRF. The IGS Predicted Orbit Combination was made available in early March. The Silver Spring Analysis Center Workshop in March dealt with a variety of issues such as orbit and clock combination processes, phase-centers values and antenna calibration, EOPs, ionospheric and tropospheric applications, etc. A standard format termed ‘Solution INdependent Exchange Format’ (SINEX) was adopted as the exchange format for submission of analysis centers solutions into a global combination enabling the IGS ‘polyhedron’ solution. Rather than simultaneous processing of all stations data in rapidly growing global and regional networks, this approach permits the combination of multi-station solutions produced by different analysis centers (today this is being extended to a multi-technique solutions). During June significant processing changes with IGS orbits occurred when the IGS combinations discontinued polar motion alignment of the different analysis centers (AC) orbit solutions. IGS AC polar motion precision at or below 0.1mas. Number of stations in IGS network: 144 stations.

1997 - The Analysis Center Workshop in March in Pasadena focused on the potential of low Earth orbiter applications within the IGS and interest in GLONASS data handling/analysis within the IGS infrastructure. First joint workshop between the PSMSL and the IGS held in Pasadena, CA. IGS hosted a GLOSS GRE meeting after the joint workshop. The Pilot Project for Precise Time and Time Transfer joint with the Bureau de Poids et Mesures (BIPM) was given conceptual approval at the Governing Board meeting in Rio De Janeiro. The first IGS retreat was held in Napa Valley in December generating many recommendations for continued improvement of the service. IGS analysis focused on length of day/UT and clock correction combinations. In order to facilitate combined prediction products the IGS Rapid orbit delivery was pushed from 24 to 22 hours. Best orbit solutions at or below 5 cm for Final solutions, and 5-10 cm for Rapid solutions. Prediction orbit precision RMS median of ~50cm compared to the Broadcast orbit at ~200cm. Number of stations in IGS network: 167 Stations.

1998 - Two key and successful workshops were held this year, the Analysis Center Workshop in February in Darmstadt and the Network Systems Workshop held in November in Annapolis. A number of recommendations resulted from each workshop and are contained in the respective workshop proceedings (see IGS Publication list below). The list of IGS fiducial sites for reference frame control were expanded from the original 13 to 47 stations. Call for Participation in the International Glonass Experiment (IGEX) joint with CSTG was announced. Reorganization of the Central Bureau (CB) was initiated due to IGS Napa Valley ‘97 retreat recommendations, including establishment of the IGS Network Coordinator within the CB. The IGS Annual Report Series was revised to a two volume document, the summary Annual Report and a detailed companion volume documenting the IGS Technical Reports for each year. At the May meeting of the Governing Board in Boston, a policy was adopted for the establishment of IGS projects and working groups. At the December meeting in San Francisco a number of changes took place: the Terms of Reference revised under the guidance of Prof. Ivan Mueller was adopted; working group chairs and project heads become non-voting members of the Governing Board; and Prof. Christoph Reigber of GeoForschungsZentrum (GFZ) Potsdam, Germany was unanimously elected as Chairman of the IGS Governing Board, succeeding Prof. Gerhard Beutler from the University of Bern, Switzerland. Prof. Beutler served as Chair of the IGS Oversight Committee (1991-1993) and as Chair of the IGS Governing Board for five years (1994-1998). The responsibilities of Analysis Coordinator transferred from Dr. Jan Kouba of Natural Resources of Canada to Dr. Tim Springer of the University of Bern, Switzerland. Jan Kouba was the AC Coordinator since 1993 and is largely credited with fostering the incredible cooperation and friendly competition of the ACs that resulted in the continual improvement of IGS products. IGS orbits in 1998 continue at the ~5cm level, while some of the best analysis centers are approaching the 3cm level of orbit precision. Adoption of the 47 stations for fiducial control earlier in the year resulted in marked improvement in orbits, AC clocks, ERP and coordinate solutions. IGS subnetwork concept was established, and the flow of hourly GPS data files was formalized. Number of stations in IGS network: 200 stations (see Figure 1).

1999 - In March an IGS workshop dedicated to low Earth orbiter (LEO) missions was held at GFZ Potsdam, Germany. This was a pivotal workshop for the IGS raising questions and increasing awareness of the potential role that IGS could play for operational support of LEO satellites with on-board GPS flight receivers for purposes of precise orbit determination, atmospheric occultation, ionospheric tomography and how these observations will be used by the atmospheric and meteorological community. In June the first meeting of the new Governing Board under the leadership of Prof. Reigber was held one day prior to the Analysis Center workshop in San Diego, California. The workshop focused on real-time applications and long term stability and accuracy. The ‘Travaux" in the year 2003 will be able to describe the resulting status of recommendations stemming from the past three IGS workshops. That there have been three IGS workshops in only eight months demonstrates an unusually active period! (starting with the Network Workshop in November of 1998).

Igs governing Board MEMBERS AND INSTITUTIONS 1999TOTAL SERVICE
MEMBERINSTITUTION & COUNTRYFUNCTIONSTERM (current: 4 years)
Christoph ReigberGeoForschungsZentrum Potsdam, GermanyChair, Appointed (IGS)1999-2002
Gerhard BeutlerUniversity of Bern, SwitzerlandAppointed (IAG)

1996-1999
Mike BevisUniversity of Hawaii, USAAppointed (IGS)1998-2001
Geoff BlewittUniversity of Newcastle upon Tyne, UKAnalysis Center Representative1998-2001
Yehuda BockScripps Inst. of Oceanography, USAAnalysis Center Representative1996-1999
Claude BoucherInstitut Geographique National, ITRF, FranceIERS Representative to IGS---
John DowESA/European Space Operations Center, GermanyNetwork Representative1996-1999
Bjorn EngenStatens Kartverk, NorwayNetwork Representative1998-2001
Joachim FeltensESA/European Space Operations Center, GermanyIonosphere Working Group Chair1999-2000
Remi FerlandNatural Resources CanadaIGS Reference Frame Coordinator1999-2000
Gerd GendtGeoForschungsZentrum Potsdam, GermanyTroposphere Working Group Chair1999-2000
Jan KoubaNatural Resources CanadaAnalysis Center Representative1996-1999
John ManningAustralian Survey and Land Information Group Appointed (IGS)1996-1999
Bill MelbourneJet Propulsion Laboratory, USAIGS Representative to IERS---
Ivan MuellerOhio State University, USAIAG Representative1996-1999
Ruth NeilanJet Propulsion Laboratory, USADirector of IGS Central Bureau---
Carey NollGoddard Space Flight Center, USAData Center Representative1998-2001
Jim RayU. S. Naval Observatory, USAPrecise Time Transfer Project, Chair1999-2000
Tim SpringerUniversity of Bern, SwitzerlandAnalysis Center Coordinator1999-2000
Robert SerafinNatl. Center for Atmospheric Research, USAAppointed (IGS)1998-2001
Michael WatkinsJet Propulsion Laboratory, USALow Earth Orbiter Working Group Chair1999-2000
Pascal WillisInstitut Geographique National, FranceInternational GLONASS Experiment CSTG/IGS Chair1999-2000
FORMER Igs governing Board MEMBERS AND INSTITUTIONSTOTAL SERVICE
Martine FeisselInternational Earth Rotation Service, France1994-1995
Teruyuki KatoERI, University of Tokyo, Japan1994-1995
Gerry MaderGeosciences Reasearch and Development Laboratory, National Oceanic and Atmospheric Administration, USA1994-1997
David PughSouthhampton Oceanography Center, UK1996-1998
Bob SchutzCenter for Space Research, University of Texas-Austin, USA1994-1997

Table 1. The IGS Governing Board Members and Former Members, terms as noted. Terms begin on January 1 of the stated year and conclude on December 31 of the stated year. Terms of office are generally 4 years for the elected members, and two years for working group or project chairs.

ORGANIZATION OF THE IGS

The history and development of the IGS demonstrate the unique capability of international groups and agencies to work successfully together for a common goal. In the organization of the IGS, each component has specific responsibilities, and each is dependent on the others to meet performance standards in order for the whole system to operate smoothly and effectively.

The organization of the IGS is depicted in Figure 2. The satellites of the NAVSTAR Global Positioning System are shown in the upper left corner of the figure. The GPS stations shown below the satellites are permanently installed and operate continuously receiving and recording the L-band, dual-frequency signals transmitted by the 24 NAVSTAR GPS satellites. The station data is accessed by Operational Data Centers (see Table 2) through various communication schemes, and the Operational Centers monitor and validate the data, format it according to standards and forward the data sets to the Regional or Global Data Centers. The Regional Data Centers collect all data of interest to people in a particular region, while the IGS Global Data Centers provide primary access and archiving for IGS data and products. The Analysis Centers (Table 3) retrieve the data sets from the Global Data Centers and each produce GPS ephemerides, station coordinates, and earth rotation parameters. These products are then sent to the Analysis Center Coordinator who uses an orbit combination technique to produce the official IGS orbits. The products are sent to the Global Data Centers and the Central Bureau for archival and access by users. IGS Associate Analysis Centers are groups producing special products such as station positions and velocities, ionospheric maps, etc. (Table 4 lists the GNAACs and RNAACs). Working groups and projects (Table 5) are groups with initiative to build on the structure of the IGS for further scientific applications. The Central Bureau acts as the executive arm of the Governing Board and is responsible for the overall coordination and management of the service; the International Governing Board is the oversight body that actively makes decisions determining the activities and direction of the IGS. IGS Associate Members (Table 6) are those people who spend a significant part of the work supporting IGS processes, they are also responsible for electing specific representatives to the Governing Board.

IGS NETWORK STATIONS

The IGS network consists of GPS stations that observe the GPS satellites on a continuous, 24-hour basis. These globally distributed stations are funded, implemented and operated by one of the IGS participating agencies shown in Table 7. At the end of 1998, 167 stations were listed as part of the IGS network. These stations have precision geodetic quality dual-frequency GPS receivers and ancillary equipment that enable transmission of the data set within a one hour to a few hours. Currently, the classic data files span a 24-hour period with 30 second data samples. A subset of the IGS network is generating hourly data files at the 30-second sample rate, and a similar subset is operating at 1-second samples in support of high-rate applications such as the LEO missions.

Figure 2. Schematic diagram of the organization of the IGS depicts addition of Associate Analysis Centers, Working Groups, Pilot Projects and the new Network Coordinator role within the Central Bureau. 

Operational Data Centers
ASIItalian Space Agency
AUSLIGAustralian Surveying and Land Information Group
AWIAlfred Wegener Institute for Polar and Marine Research, Germany
CNESCentre National d'Etudes Spatiales, France
DUTDelft University of Technology, The Netherlands
ESOCEuropean Space Agency (ESA) Space Operations Center, Germany
GFZGeoForschungsZentrum, Germany
GSIGeographical Survey Institute, Japan
ISRInstitute for Space Research, Austria
JPLJet Propulsion Laboratory, USA
KAOKorean Astronomical Observatory
NGINational Geography Institute, Korea
NIMANational image and Mapping Agency, USA
NMANorwegian Mapping Authority
NOAANational Oceanic and Atmospheric Administration, USA
NRCanNatural Resources of Canada
RDAACRussian Data Analysis and Archive Center
SIOScripps Institution of Oceanography, USA
UNAVCOUniversity NAVSTAR Consortium
USGSUnited States Geological Survey
Regional Data Centers
AUSLIGAustralian Surveying and Land Information Group
BKGBundesamt fuer Kartographie und Geodasie, Germany
JPLJet Propulsion Laboratory, USA
NOAANational Oceanic and Atmospheric Administration, USA
NRCanNatural Resources of Canada
Global Data Centers
CDDISCrustal Dynamics Data Information System, NASA GSFC, USA
IGNInstitut Geographique National, France
SIOScripps Institution of Oceanography, USA

Table 2. Data Centers Supporting the IGS in 1999.

IGS Analysis Centers
CODE Astronomical Institute-University of BernSwitzerland
European Space Operations Center / European Space AgencyGermany
FLINN Analysis Center, Jet Propulsion Laboratory/Caltech,NASAUSA
GeoForschungsZentrum PotsdamGermany
National Geodetic Survey, Geosciences Research Lab, NOAAUSA
Natural Resources CanadaCanada
Scripps Institution of OceanographyUSA

 Table 3. The Seven IGS Analysis Centers. 

 


GLOBAL NETWORK (GNAAC)
Jet Propulsion LaboratoryUSA
Massachusetts Institute of TechnologyUSA
University of NewcastleUK
REGIONAL NETWORK CENTERS FOR THE DENSIFICATION OF THE TERRESTRIAL REFERENCE FRAME (RNAACS)
Australian Survey & Land Information Group (AUSLIG)Australia
EUREF-IAG Commission X - Global and Regional Geodetic Networks, Subcommission for Europe (European Coordinating RNAAC):
Centers within EUREF:
Bundesamt fur Landestopographie (L+T)Switzerland
Center for Orbit Determination in EuropeSwitzerland
Geodetic Observatory Pecny (GOP)Czech Republic
Bundesampt für Kartographie und Geodæsie (BKG) Germany
International Commission for Global Geodesy of the Bavarian Academy of Sciences Germany
Nordic Geodetic Commision Scandinavia
Nuova Telespazio S.p.A., Space Geodesy CenterItaly
Observatory Lustbuehel Graz Austria
Royal Observatory of Belgium Belgium
Warsaw University of Technology Poland
Geographical Survey Institute of Japan Japan
Geophysical Institute of the University of Alaska USA
Onsala Space Observatory Sweden
Pacific Geosciences Center Canada
SIRGAS, Deutsches Geodatishes Forschungsinstitut Germany

Table 4. IGS Associate Analysis Centers for Reference Frame Densification.


 scsac

IGS Working Groups and Pilot Projects
ChairAgency & Country
IGS Reference Frame Coordinator Remi Ferland NRCan, Canada
IGS/BIPM Time Transfer Project Jim Ray, Co-Chair, IGS, US Naval Observatory, USA
Gerard Petit, Co-Chair BIPM, France
Working Group on IGS Ionosphere Products Joachim FeltensEuropean Space Operations Center, Germany
IGS Combination of Tropospheric Estimates Gerd Gendt GeoForschungsZentrum Potsdam(GFZ)
Working Group on Low-Earth Orbiters Michael Watkins Jet Propulsion Laboratory (JPL)
International GLONASS Experiment (IGEX) Joint with CSTG Pascal Willis Institut Geographique National ENSG/LAREG
Tide Gauges, CGPS, and the IGS (Seed Activity) Mike BevisUniversity of Hawaii
Phil Woodworth Permanent Service for Mean Sea Level, UK

Table 5. Working Groups and Pilot Projects established by the IGS

ASSOCIATE MEMBERS OF THE IGS, JUNE 1999
FirstLast Name Institution
ZuheirAltamimiInstitut Geographique National, Paris, France
Boudewijn AmbrosiusDelft University of Technology, Netherlands
YoazBar-SeverJet Propulsion Laboratory, Caltech, Pasadena, CA, USA
JohnBeavanInstitute of Geological and Nuclear Sciences, New Zealand
Gerhard Beutler Astronomical Institute, University of Bern, Switzerland
MikeBevisUniversity of Hawaii
GeoffBlewittUniversity of Newcastle upon Tyne, UK
Graeme BlickLand Information New Zealand
YehudaBockScripps Institution of Oceanography, San Diego, CA, USA
ClaudeBoucherInstitut Geographique National, Paris, France
CarineBruyninxRoyal Observatory of Belgium
AlessandroCaporali University of Padova, Italy
MirandaChin Geosciences Research and Development Lab, National Geodetic Survey, USA
LoicDanielInstitut Geographique National, Paris, France
JeffDeanScripps Institution of Oceanography, San Diego, CA, USA
JohnDowEuropean Space Operations Center, Germany
HerbDragertPacific Geoscience Center, Geological Survey of Canada, NRCan, Canada
HermanDrewesDeutsches Geodäetisches Forschungsinstitut, Munich, Germany
MauriceDubeGoddard Space Flight Center, USA
RobertDuvalNatural Resources of Canada, Ottawa, Canada
BjornEngenStatens Kartverk, Norwegian Mapping Authority, Honefoss, Norway
PengFangScripps Institution of Oceanography, San Diego, CA, USA
Martine FeisselParis Observatory, International Earth Rotation Service, Paris, France
JoachimFeltensEuropean Space Operations Center, Germany
Meng-hua FengNational Bureau of Surveying and Mapping, Beijing, China
RemiFerlandNatural Resources of Canada, Ottawa, Canada
Luis Paulo FortesInstituto Brasileiro de Geografia de Estatistica, Brazil
RomanGalasGeoforschungsZentrum, Potsdam, Germany
DanielGambisParis Observatory, International Earth Rotation Service, Paris, France
CarlosGarcia-MartinezEuropean Space Operations Center, Germany
Gerd GendtGeoforschungsZentrum, Potsdam, Germany
RameshGovindAustralian Survey and Land Information Group, Canberra, Australia
WernerGurtnerAstronomical Institute, University of Bern, Switzerland
HeinzHabrichBundesamt fuer Kartographie und Geodaesie, Germany
RuneHanssenStatens Kartverk, Norwegian Mapping Authority, Honefoss, Norway
YukiHatanaka Geographical Survey Institute, Tsukuba, Japan
MichaelHeflinJet Propulsion Laboratory, Caltech, Pasadena, CA, USA
MartinHendyAustralian Survey and Land Information Group, Canberra, Australia
PierreHerouxNatural Resources of Canada, Ottawa, Canada
ThomasHerringMassachusetts Institute of Technology, Boston, MA, USA
DavidJeffersonJet Propulsion Laboratory, Caltech, Pasadena, CA, USA
JanJohanssonOnsala Space Observatory, Sweden
TeruyukiKatoEarthquake Research Institute, University of Tokyo, Japan
MarkKaufmanInstitute for Metrology of Time and Space, Mendeleevo, Russia
JanKoubaNatural Resources of Canada, Ottawa, Canada
UlfLindqwisterJet Propulsion Laboratory, Caltech, Pasadena, CA, USA
JingnanLiu Wuhan Technical University, China
RobLiu Raytheon STX, Pasadena, CA, USA
Chi-cheng Liu Institute of Earth Science, Academy of Science, Taiwan
GerryMaderGeosciences Research and Development Lab, National Geodetic Survey, USA
BoMadsenNationalSurvey and Cadastre, Copenhagen, Sweden
JohnManningAustralian Survey and Land Information Group, Canberra, Australia
TomasMartin-MurEuropean Space Operations Center, Germany
DennisMcCarthy U.S. Naval Observatory, Washington, D.C., USA
ChuckMeertensUniversity NAVSTAR Consortium, Boulder, CO, USA
BillMelbourneJet Propulsion Laboratory, Caltech, Pasadena, CA, USA
YvesMireaultNatural Resources of Canada, Ottawa, Canada
IvanMuellerOhio State University, Columbus, Ohio USA
AngelynMooreJet Propulsion Laboratory, Caltech, Pasadena, CA, USA
RuthNeilanJet Propulsion Laboratory, Caltech, Pasadena, CA, USA
CareyNoll Goddard Space Flight Center, USA
Pil-ho ParkKorean Astronomy Observatory, Taejon, Korea
MattiPaunonenFinnish Geodetic Institute,Helsinki, Finland
PeterPesecInsitute for Space Research, Austrian Academy of Sciences, Graz, Austria
Hans-Peter Plag Statens Kartverk, Norwegian Mapping Authority, Honefoss, Norway
JimRayUS Naval Observatory, Washington, D.C., USA
Svein RekkedalStatens Kartverk, Norwegian Mapping Authority, Honefoss, Norway
ChristophReigberGeoforschungsZentrum, Potsdam, Germany
ChrisRockenUniversity NAVSTAR Consortium, Boulder, CO, USA
MarkusRothacherAstronomical Institute, University of Bern, Switzerland
MarkSchenewerkGeosciences Research and Development Lab, National Geodetic Survey, USA
WolfgangSchlueter Bundesamt fuer Kartographie und Geodaesie, Germany
MikeSchmidtPacific Geoscience Center, Geological Survey of Canada, NRCan, Canada
BobSchutzCenter for Space Reserach, Univ. of Texas-Austin, USA
BobSerafinNational Center for Atmospheric Research
AndrewSinclairRoyal Greenwich Observtory, UK
JimSlaterNational imagery and Mapping Agency, Washington, D.C., USA
JanuszSledzinskiWarsaw University of Technology, Poland
TimSpringerAstronomical Institute, University of Bern, Switzerland
David StowersJet Propulsion Laboratory, Caltech, Pasadena, CA, USA
SuryiaTatevianAstronomical Institute, Russian Academy of Sciences
PierreTetreaultNatural Resources of Canada, Ottawa, Canada
FrancescoVespe Italian Space Agency, Matera, Italy
MikeWatkinsJet Propulsion Laboratory, Caltech, Pasadena, CA, USA
UrsWildBundesamt für Landestopographie (Federal Topography), Switzerland
PascalWillisInstitut Geographique National, Paris, France
ShuhuaYeChinese Academy of Sciences, China
VjacheslavZalutskyEast-Siberian Research Institute for Physico- and Radiotechnical Measurements, Irkutsk, Russia
Wen-yao Zhu Shanghai Astronomical Observatory, China
JamesZumbergeJet Propulsion Laboratory, Caltech, Pasadena, CA, USA

Table 6. Associate Members of the IGS dated June 1999. 

  CONTRIBUTING AGENCIES OF THE IGS 1999
AIUB Astronomical Institute, University of Bern, Switzerland
ALO Astronomical Latitude Observatory, Poland
AWI Alfred Wegener Institute, Germany
AUSLIG Australian Survey and Land Information Group, Australia
BKG Bundesamt fuer Kartographie und Geodaesie, Germany
BfL Bundesamt für Landestopographie (Federal Topography), Switzerland
CSR Center for Space Research, University of Texas at Austin, USA
CNES Centre National de Etudes, Toulouse, France
CEE Centro de Estudios Espaciales, Chile
CICESE Centro de Investigación Científica y de Educación Superior de Ensenada, Mexico
CAS Chinese Academy of Sciences, China
CDDIS Crustal Dynamics Data Information System, GSFC/NASA, USA
CMMACS CSIR Centre for Mathematical Modeling and Computer Simulation, Bangalore, India
DUT Delft University of Technology, Netherlands
DLR/DFD Deutsche Forschungsanstalt für Luft-und Raumfahrt e.V., Neustrelitz, Germany
ERI Earthquake Research Institute, University of Tokyo, Japan
VS NIIFTRI East-Siberian Research Institute for Physicotechnical and Radiotechnical Measurements, Irkutsk, Russia 
ESA European Space Agency, Germany
ESOC European Space Operations Center, Germany
FGI Finnish Geodetic Institute, Finland
FOMI FOMI Satellite Geodetic Observatory, Budapest, Hungary
GOPE Geodetic Observatory Pecny, Ondrejov, Czech Republic
GSD Geodetic Survey Division, NRCan, Canada
GFZ GeoForschungsZentrum, Potsdam, Germany
GSI Geographical Survey Institute, Tsukuba, Japan
GIUA Geophysical Institute, University of Alaska, Fairbanks, AK, USA
GRDL Geosciences Research and Development Laboratory, NOAA, Silver Spring, MD, USA
GSFC Goddard Space Flight Center / NASA, USA
HRAO Hartebeesthoek Radio Astronomy Observatory, South Africa
IRIS Incorporated Research Institutions for Seismology, USA
ICC Institut Cartografic de Catalunya, Barcelona, Spain
IGN Institut Geographique National, Paris, France
IMVP Institute for Metrology of Time and Space, GP VNIIFTRI, Mendeleevo, Russia
ISAS Institute for Space and Astronautic Science, Sagamihara, Japan
ISRO Institute for Space Research Observatory, Graz, Austria
IAA Institute of Applied Astronomy, St. Petersburg , Russia
INASAN Institute of Astronomy, Russian Academy of Sciences, Moscow, Russia
IESAS Institute of Earth Sciences, Academia Sinica, Taiwan
IGNS Institute of Geological and Nuclear Sciences, New Zealand
IBGE Instituto Brasileiro de Geografia de Estatistica, Brazil
INPE Instituto Nacional de Pesquisas Espaciais, Brazil
IDA International Deployment of Accelerometers / IRIS, Scripps Institution of Oceanography, USA
ASI Italian Space Agency, Matera, Italy
JPL Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
KAO Korean Astronomy Observatory, Taejon, Korea
KMS Kort & Matrikelstyrelsen, National Survey and Cadastre, Denmark
LINZ Land Information New Zealand, Wellington
MIT Massachusetts Institute of Technology, USA
NASA National Aeronautics and Space Administration, USA
NCAR National Center for Atmospheric Research
NBSM National Bureau of Surveying and Mapping, China
NGRI National Geophysical Research Institute, Hyderabad, India
NIMA National imagery and Mapping Agency, USA
INGM National Institute in Geosciences, Mining and Chemistry (INGEOMINAS), Colombia
NOAA National Oceanic and Atmospheric Administration, USA
NRCan Natural Resources of Canada, Ottawa, Canada
ROB Observatoire Royal de Belgium, Brussels, Belgium
OUAT Olsztyn University of Agriculture and Technology, Poland
OSO Onsala Space Observatory, Sweden
GSC Pacific Geoscience Center, Geological Survey of Canada, NRCan, Canada
IERS Paris Observatory, International Earth Rotation Service, Paris, France
POL Proudman Oceanographic Laboratory, UK
ROA Real Instituto y Observatorio de la Armada, Spain
RGO Royal Greenwich Observatory, UK
SIO Scripps Institution of Oceanography, San Diego, CA, USA
SAO Shanghai Astronomical Observatory, China
SCIGN Southern California Integrated GPS Network, USA
SK Statens Kartverk, Norwegian Mapping Authority, Norway
SOEST School of Ocean and Earth Science and Technology, University of Hawaii,USA 
UCAR University Consortium for Atmospheric Research
USNO U.S. Naval Observatory, USA
UFPR University Federal de Parana, Brazil
UNAVCO University Navstar Consortium, Boulder, CO, USA
UB University of Bonn, Germany
CU University of Colorado at Boulder, Boulder, CO, USA
NCL University of Newcastle on Tyne, United Kingdom
UPAD University of Padova, Italy
WUT Warsaw University of Technology, Poland
WING Western Pacific Integrated Network of GPS, Japan
WTU Wuhan Technical University, China

Table 7. Contributing Agencies of the International GPS Service 1999

IGS Publications

Available through the Central Bureau (address below).

The publications listed above along with brochures, resource information package, and the IGS Directory (printed annually), are available upon request. Send your request and mailing address to:

These documents are also available at the IGS website (http://igscb.jpl.nasa.gov/overview/pubs.html)

ACKNOWLEDGMENTS

The Central Bureau would like to thank G. Beutler and J. Kouba for their significant contribution to the IGS and their leadership in the past five years. Their influence will continue to be felt. We also acknowledge the contributions of the participating agencies worldwide which have made the IGS such a successful organization. Part of the work described in this report was carried out at the Jet Propulsion Laboratory, California Institute of Technology and sponsored by the National Aeronautics and Space Administration.

IAG Events