Large aperture high accuracy satellite laser tracking

A satellite laser ranging station has been established in order to range both low and high earth-orbiting satellites with a few-mm accuracy; this entails precision pointing of a 15-ton, azimuth-elevation-mounted coude telescope. Because tracking is performed under open loop computer control with no feedback from laser returns, the initial acquisition data and the algorithms for orbit computation must be accurate enough to maintain the satellite within the narrow laser beam width. The system is currently being used to track the LAGEOS and STARLETTE satellites.