ILRS

The International Laser Ranging Service, or ILRS, is a global cooperative effort that collects and disseminates precise range measurements to satellites and the Moon using laser beams. It is a component of the International Association of Geodesy (IAG) and is managed by the International Laser Ranging Service International Data Center (ILRS IDC). The primary goal of the ILRS is to provide a data infrastructure for a wide range of scientific and geodetic applications.

The service operates a network of ground stations equipped with sophisticated laser ranging systems. These stations emit short laser pulses towards specifically designed targets, called retroreflectors, placed on satellites or the Moon. By measuring the round-trip travel time of these pulses, the exact distance between the station and the target can be determined with millimeter-level accuracy. This data is then processed and archived by the ILRS IDC, making it accessible to scientists worldwide.

The data generated by the ILRS is crucial for numerous applications. It enables precise orbit determination for satellites, which is vital for navigation systems, Earth observation, and space traffic management. Furthermore, ILRS data contributes to fundamental research in geodesy, including the monitoring of Earth's rotation, the determination of global geodetic reference frames, and the study of plate tectonics and sea-level rise. The service also plays a role in tracking near-Earth objects and supporting space missions.