GEO对BDS精密单点定位的影响分析

Impact analysis of GEO satellite on BDS PPP performance

为了满足亚太地区的定位性能,北斗卫星导航系统(BDS)卫星星座中加入了地球静止轨道(GEO)卫星,该文对GEO卫星对BDS精密单点定位(PPP)的影响进行了研究。该文首先实现了利用非差观测模型的BDS精密单点定位算法,然后分别利用全星座卫星和倾斜地球同步轨道+中圆地球轨道(IGSO+MEO)组合进行精密单点定位处理,分析了GEO卫星参与定位时PDOP值和法方程信息的变化,以及对精密单点定位精度和收敛速度的影响。实验结果表明:BDS全星座的静态PPP单天解优于IGSO+MEO组合的定位结果;动态PPP数据处理时,GEO卫星能稳定增加观测卫星数量,改善BDS星座的PDOP值,GEO卫星能够改善几何构型,进而提高动态PPP的收敛速度和收敛效果,在卫星数较少的时候提高效果尤为显著。

In order to meet the positioning performance of Asia-pacific region,geostationary Earth orbit(GEO) satellite is usually needed in satellite constellation of BeiDou navigation satellite system(BDS). This paper studies the contribution of GEO satellite to precise point positioning(PPP) of BDS. In this paper,we first implement the BDS precise point positioning algorithm using the non difference observation model,and then respectively using full satellite constellation and inclined geosynchronous satellite orbit + medium earth orbit(IGSO+MEO) combination process precise point positioning,changes of position dilution of precision(PDOP) value and normal equation information and their effects on precision point positioning accuracy and convergence rate when GEO satellite participates in positioning are analyzed. Experimental results show that:the single day solution of BDS static PPP is superior to IGSO+MEO combination of positioning results;in the process of dynamic PPP data processing,GEO satellites can steadily increase the number of observation satellites,improve the PDOP value of BDS constellation,and GEO satellites can improve the geometric configuration to improve the convergence rate and effect of dynamic PPP,especially when the number of satellites is small.