BDS spaceborne cesium clock on orbit performance evaluation method and application

Beidou satellite navigation system equipped with a high precision atomic clock provides high accuracy, high stability and low drift rate. A cesium atomic clock is equipped on a satellite , turning as a thermal backup, providing backup of the reference frequency is equipped with a well-equipped work clock to a hydrogen atomic clock. Through the statistics, processing and analysis of the phase difference per second between main clock (H clock) and Cs clock from 6/12/2019 to 17/5/2020, then this paper evaluates the on-orbit performance of the space-borne Cs clock, the analysis of this satellite is completed. Evaluation shows that space-borne Cs clock’s frequency characteristic is basically consistent as on-ground testing result, including frequency accuracy, stability above 10 seconds and frequency drift per day. The analytical method of phase difference between on-orbit main clock and Cs clock is feasible, and it has a high degree of credibility. The high-precision cesium atomic clock developed in China has reached the level of serving the satellite.