Abstract:Three BD-2 satellites in different orbits are analyzed in this paper. Based on the clock bias of two-way satellite-ground time comparison by wireless radio in some periods, the frequency accuracy, stability and drift of their primary atomic clocks are calculated. The results indicate that their frequency accuracy, stability and drift are respectively better than 1011,1013 and 1014, respectively. In addition, for the GEO-1 satellite, the performance of atomic clock meets the design requirements and is still healthy enough to not influence the service quality of the BD-2, even as it is about to reach its projected lifespan.