时间差分法削弱PPP定位中卫星钟差插值误差影响  

Effect mitigation of satellite clock bias interpolation error on PPP by using time-differenced positioning technique

作　　者：易重海 YI Zhonghai(Hunan Vocational College of Engineering,Changsha 410151,China)

机构地区：[1]湖南工程职业技术学院,长沙410151

出　　处：《导航定位学报》2024年第6期47-53,共7页Journal of Navigation and Positioning

基　　金：湖南工程职业技术学院校级课题(GC22YB02)。

摘　　要：针对在精密单点定位(PPP)中,当全球卫星导航系统(GNSS)接收机采样间隔比卫星钟差产品采样间隔小时,须进行卫星钟差插值计算,从而产生卫星钟差插值误差,该误差会导致PPP定位精度下降的问题,提出一种利用时间差分定位技术削弱卫星钟差插值误差影响的方法:分析目前已有的卫星钟差插值误差处理方法中常规方法、高采样率卫星钟差法、降采样定位法及随机模型法存在的不足;以卫星钟差采样间隔进行PPP定位(不受卫星钟差插值误差的影响),获得与卫星钟差采样率一致的PPP定位结果;然后采用时间差分定位获得高采样率历元间坐标差值;最后将卫星钟差采样间隔PPP定位结果与高采样率历元间坐标差值进行综合处理,获得削弱了卫星钟差插值误差影响的GNSS定位结果。实验结果表明,当卫星钟差采样间隔为30 s(300 s)时,随机模型法相对于常规方法可以提高定位精度约0.2%(14.1%),而时间差分法较之常规方法可以提高定位精度约7.7%(19.1%);与其他方法相比,提出的方法算法简单,易于使用,可有效削弱卫星钟差插值误差对PPP定位的影响,提高动态PPP定位的精度。Aiming at the problem that satellite clock bias interpolation has to be conducted in precision point positioning(PPP)when the sampling interval of global navigation satellite system(GNSS)receiver is smaller than that of the satellite clock bias product,resulting in satellite clock bias interpolation(SCBI)error,which causes the deterioration of PPP accuracy,the paper proposed a method to mitigate SCBI error’s effect on PPP accuracy by using time-differenced positioning(TDP)technique:the shortcomings of existing methods to deal with SCBI error,including the conventional method,the high sampling rate satellite clock bias difference method,the downsampling positioning method and the stochastic modeling method,were analyzed;and the PPP was conducted with satellite clock bias interval(not affected by the SCBI error)to obtain the PPP positioning results consistent with the satellite clock bias sampling rate;then,the TDP was used to obtain high sampling rate coordinate difference between epochs;finally,the PPP positioning results with the satellite clock bias interval were combined with the high sampling rate coordinate differences between epochs to obtain the GNSS positioning results in which the SCBI error was reduced.Experimental results showed that when the satellite clock bias interval is 30 s(300 s),the stochastic modeling method would improve the positioning accuracy by about 0.2%(14.1%)compared with the conventional method,while the TDP method would improve the positioning accuracy by about 7.7%(19.1%)compared with the conventional method;in general,the proposed method could be simple and easy to use for effectively mitigating SCBI error’s effect on PPP accuracy and improve positioning accuracy for kinematic PPP.

关 键 词：全球卫星导航系统(GNSS) 精密单点定位(PPP) 卫星钟差插值误差 时间差分定位 

分 类 号：P228[天文地球—大地测量学与测量工程]