关键词: 新一代导航卫星, 钟差预报, 星载原子钟, 性能评估

Abstract: The atomic clock is the core equipment of navigation satellite, and its performance and prediction accuracy directly determine the PNT accuracy. The authors evaluated the in-orbit performance and prediction accuracy on atomic clock of new generation navigation satellite using bi-directional time synchronization data. Firstly, the performance evaluation method of satellite clock is studied. The clock error data are preprocessed by the combined MAD gross error detection method. The frequency accuracy and frequency drift rate are evaluated by the least square method and polynomial function method. The frequency stability of the satellite clock is calculated and discussed by the overlapping Hadamard variance. Secondly, the weighted combined clock error prediction model is established, which synthesize the polynomial model and the gray model by the classical weighted method. Finally, the performance and prediction accuracy of the atomic clock is evaluated by using the measured data of the new generation satellites and the regional satellites. The results illustrate that the frequency accuracy, stability and prediction accuracy of the new generation satellites are improved. Moreover, the inter-satellite link increases greatly the measure arc of MEO satellite, and simultaneously improves the prediction accuracy of re-entry.

Key words: new generation satellites, clock error prediction, atomic clock, performance evaluation