Precise Orbit Determination of BeiDou Satellites Using Satellite Laser Ranging

As a highly accurate technique of satellite orbit tracking, a precise determination method of satellite orbit, and an independent way of external validation on the orbits obtained by other satellite precise orbit determination (POD) means, satellite laser ranging (SLR) has been applied in many international and Chinese satellite projects. In China's BeiDou (Compass) Navigation Satellite System, as the cooperative targets of international SLR monitoring, multiple satellites have been equipped with on-board laser retro-reflector array, and highquality observation data have been obtained from around 20 tracking stations distributed all over the world. In this work, we summarized the SLR tracking status on BeiDou satellites and determined the proper SLR dynamic POD strategy. Using SLR tracking data, we determined orbits of four BeiDou satellites, assessed SLR orbits' accuracies by orbit overlap and orbit comparison with precise ephemeris produced from radio navigation bands, and analyzed characters and possible causes of orbit errors. The results demonstrated that SLR-derived orbits on BeiDou satellites are on the level of meter, and the precisions along radial direction can achieved decimeter level. For current BeiDou satellites in different types of orbits, and in the future construction and improvement of BeiDou Navigation Satellite System, SLR has already and will continue to play an important role in the process of POD and orbit validation.