For the  ILRS we routinely analyse satellite laser ranging (SLR) data from geodetic satellites such as LAGEOS-1 und -2 sowie Etalon-1 und -2. We create daily and weekly products that contain loosely tied station coordinates and Earth rotation parameters (ERPs). These are incorporated into the official ILRS products, which are generated by combining the results from all analysis centres.

The daily combination is used primarily to predict Earth orientation parameters (EOPs) from the International Earth Rotation and reference systems Service (IERS). In addition, reprocessing campaigns are carried out at regular intervals in consultation with the IERS and based on uniform processing standards that apply to all analysis centres. These reprocessings contribute to the development of new international coordinate systems such as the ‘International Terrestrial Reference Frame’ (ITRF). Furthermore, innovations and scientific research are being developed as part of the AWG's pilot projects, in which we are actively involved.

The following graph shows an analysis of the daily products of all the ILRS ACs. It illustrates the differences in the coordinates of the contributing solutions with respect to the combined solution. Our solution, labelled 'gfz', is shown in blue and demonstrates the consistently high quality of our solution compared to other ACs over the course of a year.

Project Partners:

• ASI (Agenzia Spaziale Italiana, Rom, Italy)
• BKG (Bundesamt für Kartographie und Geodäsie, Frankfurt, Germany)
• CNES (Centre national d'études spatiales, Toulouse, France)
• DGFI-TUM (Deutsches Geodätisches Forschungsinstitut - Technische Universität München, München, Germany)
• ESA/ESOC (European Space Agency/European Space Operation Center, Darmstadt, Germany)
• JCET/GSFC (Goddard Space Flight Center, Greenbelt, USA)
• NSGF (NERC Space Geodesy Facility, Herstmonceux, England)

Project duration:

• Continuous since 2003

Funding:

• GFZ (As part of the Modular Earth Science Infrastructure (MESI))

Project-related publications:

• Latest ILRS Activity Report: ilrs.gsfc.nasa.gov/docs/2020/ilrsreport_2016.pdf
• König R., et al. (1997): Surface forces parameterization of GFZ-1 orbits and gravity field recovery, https://www.sciencedirect.com/science/article/abs/pii/S0273117797003244?via%3Dihub
• König R., et al (1999): Improvement in global gravity field recovery using GFZ-1 satellite laser tracking data, link.springer.com/article/10.1007/s001900050259