Coordination of Space Geodetic Techniques

Chair: Urs Hugentobler (Germany)


Terms of Reference

Space techniques play a fundamental role for the realization and dissemination of highly accurate and long term stable terrestrial and celestial reference frames as well as for accurate monitoring of the Earth orientation parameters linking the two fundamental frames. The current space geodetic techniques contributing to ITRF and ICRF, i.e., Very Long Baseline Interferometry (VLBI), Satellite and Lunar Laser Ranging (SLR/LLR), Global Navigation Satellite Systems (GNSS) and Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS) have particular strengths and technique-specific weaknesses.

Strengths of the techniques are exploited by combining them making use of fundamental sites co-locating more than one technique. Sub-commission 1.1 focusses on the coordination of research related to the geodetic space techniques with emphasis on co-location aspects at fundamental geodetic observatories as well as on co-location targets in space, considering common parameters such as coordinates of stations and satellites, troposphere parameters, and clock parameters.


  • Coordinate research on co-location using common parameters in space;
  • Coordinate research on co-location using common parameters at fundamental geodetic observatories;
  • Explore the use of new techniques and technologies;
  • Interface with IERS WG on Site Survey and Co-location;
  • Interface with the GGOS Committee on Performance Simulations and Architectural Trade-Offs (PLATO);
  • Interface with Joint WG on Tropospheric Ties.