|
|
|
|
About the ILRS
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)
The ILRS accomplishes its mission through the following components:
Responsible Government Official:
NASA's
|
|