不同GNSS星载原子钟周期特性分析

高精度的卫星时钟修正是全球卫星导航系统实时精密单点定位和授时服务的重要基础。为了提高GNSS钟差预报精度，需要对GNSS星载原子钟的周期特性进行分析。基于2016年全年的GNSS精密卫星钟差数据，利用中位数方法进行了数据预处理，使用多项式拟合模型分析了卫星钟的拟合残差，利用频谱分析法分析了BDS、GPS卫星钟差的周期特性，全面分析了BDS、GPS星载原子钟的周期特性。分析结果表明：除Cs钟外，其他卫星钟差都表现出较好的周期特性，BDS、GPS的主周期项基本在12h、24h、6h附近；同时不同的轨道、原子钟，其钟差周期项不同，而相同的轨道类型，其钟差周期项也存在一定差异；卫星的钟差主周期分别近似为其卫星轨道周期的1/2倍、1倍、2倍。

Periodicity Analysis of Different GNSS On-board Atomic Clocks

High-precision satellite clock corrections are important basis of the real-time precision single-point positioning and timing services of GNSS. In order to improve the precision of clock error prediction of GNSS system, it is necessary to analyze the periodicity of GNSS satellite-borne atomic clock. Based on the data of GNSS precision satellite clocks in 2016, the median method is used to preprocess the data, and the polynomial fitting model is used to analyze the clocks fitting residual, and BDS and GPS satellite periodicity of the atomic clock is analyzed with spectrum analysis. Based on the above methods and experiments, the BDS and GPS satellite-borne atomic clock periodicity is analyzed comprehensively. The results show that all the satellite clocks except Cs have the obvious periodicity. The main periodic items of BDS and GPS are basically 12h, 24h or 6h.While the periodic items of atomic clocks are affected by the types of orbit and atomic clocks. The main clock periods of satellites are approximated a half time, once or twice the length of their satellite orbital periods, respectively.