GPS卫星钟差高精度模型化及在精密单点定位中的应用

采用多项式和结合周期项的混合函数模型进行GPS卫星钟差高精度模型化与精度分析。结果表明，周期项对于卫星钟差模型化精度的提高具有重要作用。对于Rb 钟卫星，Block ⅡF卫星钟差模型化精度0.03 m（约0.1 ns）左右，Block ⅡR和Block ⅡR-M卫星钟差模型化精度0.05 m（约0.2 ns）左右，而Cs钟卫星钟差模型化精度则低一个数量级。采用精密单点定位进行模型化结果分析得到，混合模型化钟差参与解算的定位结果精度可达cm级，收敛时间约为4 h。以上表明，简单的模型化参数可在一定程度上代替繁琐的序列钟差，实现简化GPS卫星钟差服务模式。

Modeling of GPS Satellite Clock Error and Its Application in Precise Point Positioning

The modeling of the GPS satellite clock is studied to improve and simplify the service mode of GPS satellite clock error, reduce the communication burden, and save storage space. This paper proposes to model and analyze satellite clock error by polynomial model and mixed function model with periodic part. The result shows the periodic part plays an important role in improving the accuracy of modeled satellite clock error: for rubidium clock, the clock error of Block ⅡF can reach an accuracy of 0.03 m (about 0.1 ns), and the clock error of Block ⅡR and ⅡR-M can reach an accuracy of 0.05 m (about 0.2 ns); However, the accuracy of cesium clock is lower by an order of magnitude. Analyzed by precise point positioning, the result shows the accuracy of the positioning results of the mixed function modeled clock error can reach the centimeter level with a 4 h convergence time. The above results show that, within certain areas of application, simple modeling parameters can take the place of the complicated clock error sequence, simplifying the service mode of GPS satellite clock error.