ILRS Study Group on Datum Sites

Name:
ILRS Study Group on Datum Sites
Established:
by the ILRS Analysis Coordinators within the ILRS ASC
Goals:
The main objectives of this study group are to review and improve the ILRS datum site list (former: ILRS core station list), formulate clear inclusion criteria, and develop strategies for its ongoing maintenance and updating. The ILRS datum site list contains a set of SLR stations used to realize the datum by aligning the SLR network with a reference frame through the estimation of Helmert transformation parameters. Reliable and accurate determination of this transformation requires stations with stable coordinates, sufficiently long observation histories and high-quality range measurements. However, the sparse and uneven global distribution of SLR stations may necessitate the inclusion of stations with lower temporal stability to achieve a more homogeneous geographical distribution of ILRS datum sites.

To distinguish these stations from the GGOS core stations (see https://geodesy.science/ggos/obs/ggos-core-sites/), we agreed to refer to the stations as “ILRS Datum Sites” and the list as the “ILRS Datum Site List”.

The current members of the group are:

  • Linda Geisser (AIUB, Switzerland) - Chair
  • Antonio Basoni (ASI/e-GEOS, Italy)
  • Mathis Bloßfeld (DGFI-TUM, Germany)
  • Claudia Carabajal (ILRS CB Secretary, SSAI @NASA/GSFC, USA)
  • Michael Croteau (ILRS CB Director, NASA/GSFC, USA)
  • Johann Eckl (BKG, Germany)
  • Van Husson (Peraton @ NASA/GSFC, USA)
  • Magda Kuzmicz-Cieslak (UMBC/JCET, USA)
  • Frank G. Lemoine (NASA/GSFC, USA)
  • José Carlos Rodríguez Pérez (IGN, Spain)
  • David Sarrocco (ASI/e-GEOS, Italy)
  • Andreja Susnik (NERC, UK)
  • Matthew Wilkinson (NERC, UK)

An ILRS mailing list (ilrs-datumsites@lists.nasa.gov) consisting of the emails for the membership listed above has been established at NASA GSFC and will be used for communication within the group.

The chair (currently: Linda Geisser, AIUB (Astronomical Institute of the University of Bern; linda.geisser@unibe.ch) coordinates work within study group, organizes meetings, when necessary, provides progress reports at ILRS ASC meetings.


Related Information:


Activities and Meetings

2026

Perspective of SLR Datum Sites

Additional Materials