GPS卫星钟差改正数实时预报算法

Real-time Prediction of GPS Satellite Clock Bias Correction

实时卫星钟差（satellite clock bias,SCB）的获取是实时精密单点定位（real-time precise point positioning,RTPPP）需要解决的关键问题。给出了国际GNSS服务（International GNSS Service,IGS）所提供的实时服务（real-time service,RTS）钟差产品的修复方法,分析了IGS02、IGS03实时数据流中GPS卫星钟差改正数的稳定性及其精度。同时,从原理上推导证明了钟差一次差分数据符合一次多项式模型,并结合对GPS卫星钟差改正数的分析提出了一种基于一次差分的钟差改正数预报算法,通过与一次多项式模型、二次多项式模型以及灰色模型的预报精度进行对比试验,结果表明,该钟差改正数预报算法预报精度有明显提高,预报30s的精度达到0.06ns,可满足实时精密单点定位的要求。

Obtaining satellite clock bias（SCB）in real-time is a key problem in real-time precise point positioning（RTPPP）.A repair method specific to SCB correction derived from the International GNSS Service（IGS）real-time service（RTS）is proposed,and the stability and precision of GPS SCB correction in the real-time data stream of IGS02 and IGS03 are analyzed.Based on the characteristics of SCB correction,a new SCB correction prediction algorithm is theoretically derived and established by making a single difference for the provided data.The new prediction algorithm is compared with the linear model,quadratic polynomial model,and grey model in prediction tests.The results show that the prediction accuracy of the new algorithm is the best,with a prediction accuracy of 0.06 ns and prediction length of 30 s,meeting the requirements for RTPPP.