星地星间联合时间比对与卫星钟预报

Time Synchronization and Satellite Clock Prediction Based on Combined Satellite-ground and Inter-satellite Observation

星间时间同步观测实现了移动卫星的连续观测，对提升移动卫星钟预报精度具有重要的意义。本文推导了星地、星间时间同步比对模型，给出了星间钟差到星地钟差的一致性归算方法。理论上，加入星间时间比对结果后。移动卫星钟差预报精度能大大提升，但异质观测设备导致钟差观测序列不连续。为此，本文首先研究了小幅钟差跳变的探测与补偿技术；然后，提出了基于传统粗差探测与相邻历元组差相结合的钟差跳变探测方法，有效消除异质观测设备带来的钟差不一致性，提升了卫星钟预报精度；最后，利用实测与仿真数据验证了所提出的理论与方法的正确性和有效性。

Time synchronization with inter-satellite observation can realize continous observation of mobile satellite, which has important significance to the improvement of mobile satellite clock prediction accuracy. Comparison model for satellite-ground and inter-satellite time synchronization is derived, and the consistence reduction method to transform satellite-ground clock error to inter-satellite clock error is put forward in this paper. In theory, the accuracy of mobile satellite clock prediction can be greatly improved after the inter-satellite time comparison result is added. However, the clock error sequence is incontinuous because of the heterogeneity of observation devices. Therefore, a detection and compensation technology for slight jump clock error is studied in this paper. A clock bias jump detection method combining traditional gross error detection with subtraction adjacent epochs is proposed, which can eliminate the inconsistency of clock errors caused by heterogeneous observation equipment and improve the satellite clock prediction accuracy. Finally, experiment with real and simulation data is conducted to verify the validity and effec- tiveness of the proposed theories and methods.