Research on Autonomous Detection and Recovery Technology of Satellite Clock Anomaly During the Autonomous Navigation of BDS-3 Constellation

During BDS-3’s autonomous navigation period, the on-board atomic clocks may experience frequency-hopping and phase-hopping anomalies, which cause the abnormal clock deviating from the constellation’s unified time. This paper propose an on-board clock anomaly detection and recovery algorithm for the BDS-3 constellation. The anomaly detector is implemented with an O-C value (also known as innovation) detector in Kalman filtering. The recovery algorithm reconstructs the filter starting parameters of the abnormal clock and reconnect the clock to the constellation’s autonomous time synchronization algorithm. The simulation results based on the in-orbit data of BD-3 show that the algorithm provided in this paper can achieve the phase jump anomaly detection accuracy of 3ns and frequency jump anomaly detection accuracy of 2E-11 under the condition that the false alarm probability is less than 1E-6.