Analysis of the Mid-long Term Characterization for BDS On-orbit Satellite Clocks

Rb clock products of BDS on-orbit satellites in 2013 are used to analyze the satellite clock qualities such as frequency stabilities and clock noise level. Quadratic polynomial model is used to fit BDS satellite clock offsets. The short-term frequency stabilities are achieved using Hadamard total variance method. Based on above indexes, BDS satellite clock characteristics which include phase, frequency, frequency shift and residual indexes have been analyzed. It can be concluded by the actual numerical examples that, the frequency stabilities of BDS satellite clocks in ten-thousand seconds is about 10^-13. The stabilities of GEO satellite clocks are worse than that of the other satellite clocks. The satellite clocks of PRN04 and PRN08 have phase jumps during running time, and the stabilities of these satellite clocks have been enhanced after jump times. The stabilities of other satellite clocks are relatively steady. In general, the qualities of MEO satellite clocks are better than that of GEO and IGSO satellite clocks.