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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

The passing of Professor George Veis - It is with great sadness that we convey the passing of George Veis, scientist, teacher, and a good friend to all of us; truly one of the fathers of Space Geodesy. George continued to be endlessly creative, engaging, seducing, elegant, modern and forever young scientist, who shared his ideas with enthusiasm, and helped everyone with whom he had contact. He was a part of space geodesy from its birth, through its evolution from many meters to mm's, and he continued to think about its future until his death. He had celebrated his 92nd birthday last September 8, 2021.

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The passing of Thomas Clark - Space Geodesy lost a longtime colleague and friend with the passing of Thomas Arvid Clark on September 28, 2021. Tom was a pioneer in Space Geodesy and Very Long Baseline Interferometry (VLBI), and a founding member of the NASA Crustal Dynamics Project.

Tom received his B.S. in Engineering Physics and his Ph.D. in Astro-Geophysics from the University of Colorado in 1961 and 1967 respectively. From 1966 to 1968, he served as Chief of the Astronomy Branch at NASA Marshall Space Flight Center and as Project Scientist on the Spacelab Coronagraph. At GSFC, where he moved in 1968, Tom received numerous NASA awards for his pioneering work on Radio Astronomy Explorer 1 and 2 and several generations of Very Long Baseline Interferometry systems. Tom developed the Totally Accurate Clock (TAC), an inexpensive GPS timing receiver that found widespread use in a number of global networks. Tom was named a Fellow of the American Geophysical Union (AGU) in 1991 and a Fellow of the International Association of Geodesy (IAG) in 1999. Tom was also a pioneer in amateur and digital radio; he designed and flew several low cost satellites for relaying amateur radio messages around the globe and is a past president of AMSAT. He was one of only 50 initial inductees into the CQ Amateur Radio Hall of Fame, a list which included such engineering luminaries and inventors as Guglielmo Marconi (radio), Samuel Morse (telegraph), Nikola Tesla (HF generators and radio), and John Bardeen and William Schockley (transistor). Tom retired from GSFC in 2001 but remained active in Amateur Radio activities.

Those of us who worked with Tom during the Crustal Dynamics period remember him as a brilliant mind, a very interesting and sometimes caustic character, but someone who was kind, supportive, and very helpful to those of us around him. We will miss him.

Meetings

Many meetings have been canceled or postponed due to COVID-19. Please see the Meetings page for futher information.

ION PTTI Meeting, Long Beach, California, USA, January 24- 27, 2022

Tour de l'IGS 3rd Stop: GNSS processing based on IGS products, Virtual, February 17, 2022

Munich Satellite Navigation Summit 2022 - hybrid, Munich, Germany, March 7-9, 2022

Updated list of Conferences and workshops related to earth rotation, reference frames, geophysical fluids, GNSS, SLR, VLBI, DORIS, etc. posted by the IERS

Publications

2016-2019 ILRS Report

Proceedings from the 19th International Workshop on Laser Ranging

International Laser Ranging Service

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