Centralized Autonomous Orbit Determination of Beidou Satellites Under the Constraint of Anchor Station

Abstract

Autonomous Navigation Based on Inter-Satellite Link (ISL) is a hot spot in the future development of satellite navigation system. The new generation Beidou navigation satellites are equipped with Ka-band ISL test verification platform. The processing flow of ISL observation data and the algorithm of centralized orbit determination are derived. Analysis of centralized orbit determination for 3 day arcs is carried out with measured data of five new generation BD satellites and an anchor station. Some 4 experiments were carried out on the effect of anchor station. Meanwhile, some 2 experiments were carried out on the effect of observation frequency. The result shows that: (a) The working time length of anchor station has little influence on the accuracy of orbit determination; (b) When the intersatellite observation is healthy, the anchor station and single satellite chain can maintain the orbit determination accuracy of 1 m, otherwise the improvement of anchor station’s observation quantity will not improve its constraint function. (c) When the anchor station is well linked to all the satellites, the centralized algorithm can survive a lower number of observations, which means the orbit determination accuracy can remain being better than 1 m even though all links’ observational frequencies dropped to 240 min.