Quick Links

The International Laser Ranging Service (ILRS) provides global satellite and lunar laser ranging data and their related products to support geodetic and geophysical research activities as well as IERS products important to the maintenance of an accurate International Terrestrial Reference Frame (ITRF). The service develops the necessary global standards/specifications and encourages international adherence to its conventions. The ILRS is one of the space geodetic services of the International Association of Geodesy (IAG).
The ILRS collects, merges, archives and distributes Satellite Laser Ranging (SLR) and Lunar Laser Ranging (LLR) observation data sets of sufficient accuracy to satisfy the objectives of a wide range of scientific, engineering, and operational applications and experimentation. These data sets are used by the ILRS to generate a number of scientific and operational data products including:
- Earth orientation parameters (polar motion and length of day)
- Station coordinates and velocities of the ILRS tracking systems
- Time-varying geocenter coordinates
- Static and time-varying coefficients of the Earth's gravity field
- Centimeter accuracy satellite ephemerides
- Fundamental physical constants
- Lunar ephemerides and librations
- Lunar orientation parameters
The accuracy of SLR/LLR data products is sufficient to support a variety of scientific and operational applications including:
- Realization of global accessibility to and the improvement of the International Terrestrial Reference Frame (ITRF)
- Monitoring three dimensional deformations of the solid Earth
- Monitoring Earth rotation and polar motion
- Support the monitoring of variations in the topography and volume of the liquid Earth (ocean circulation, mean sea level, ice sheet thickness, wave heights, etc.)
- Tidally generated variations in atmospheric mass distribution
- Calibration of microwave tracking techniques
- Picosecond global time transfer experiments
- Astrometric observations including determination of the dynamic equinox, obliquity of the ecliptic, and the precession constant
- Gravitational and general relativistic studies including Einstein's Equivalence Principle, the Robertson-Walker b parameter, and time rate of change of the gravitational constant
- Lunar physics including the dissipation of rotational energy, shape of the core-mantle boundary (Love Number k2), and free librations and stimulating mechanisms
- Solar System ties to the International Celestial Reference Frame (ICRF)
Recent News
View program
Read more...
https://www.youtube.com/watch?v=Jwqz097N2IY&list=PLIIfsJS7iAuxXGqq0YLAUO_m_06za9vqr
Read more...
https://itrf.ign.fr/en/solutions/ITRF2020
The new reference frame realization includes the contributions of all the IAG Geodetic Services (IVS, ILRS, IDS, IGS) and their Analysis Centers and Combination Centers. The ILRS contribution was based on a reprocessing of SLR data to the LAGEOS, LAGEOS-2 & the two Etalon satellites from 1993.0 to 2020.0 and to LAGEOS only from 1983.0 to 1993.0.
The ILRS ASC is working on an ILRS extended version, the SLRF2020, which will include the SLR stations that were not part of the ITRF2020 solution and will provide instructions on how to get the highest accuracy results when implementing this extended model in SLR data analysis.
Read more...
We thank our station colleagues Andrea Di Mira, Jens Steinborn for their efforts, and congratulate them on this achievement!
During the current campaign (April 17- 30, 2022) ILRS stations in the Eastern Region of the Indian Ocean (Asia, Australia) will track IRNSS 1C plus IRNSS -1D. ILRS stations in the Western Region of the Indian Ocean (Europe, Africa) will track IRNSS 1C plus IRNSS- 1I. The IRNSS tracking data from the campaigns will be used to assess the performance of these IRNSS satellites, in a similar way to that used to validate the performance of other GNSS constellations such as Galileo.
Read more...
The following definitions have been agreed to:
- A pass is defined as all tracking that lasts less than a full satellite period. For geosynchronous satellites, the duration is capped at 24 hours; this is the standard product.
- A pass-segment is another term for a session (interval of continuous data) which is a reflection of how the data was taken at the station and submitted to the data centers. A single pass-segment/session is counted from one H1 to H8.
A pass includes all data taken on a satellite during one transit over the station. The pass-segment is just a magnification of how the data was taken and submitted.
Key Dates:
- June 20, 2022 (Abstract deadline)
- July 25, 2022 (Early registration deadline)
For more information, check the URL for the meeting: www.refag2022.org