GEO卫星条件下的辅助式定位算法性能分析

在卫星导航定位过程中，当辅助式定位算法在信号质量不佳时，利用更多的观测卫星数据进行冗余计算，能够补齐缺失的信号时间并得到定位结果. 由我国自行研制的北斗卫星导航系统(BDS)采用了混合卫星星座，有一类地球同步轨道(GEO)卫星，具有24 h可见、轨道高覆盖面大、信号功率强等优势. 论文分析了在特殊情况下，只能接收到GEO卫星时的辅助式定位算法以及算法的性能差异. 结果表明:在没有高程等先验信息辅助的情况下，直接使用5颗GEO卫星也能获得一定的定位精度保障. 

Performance analysis of auxiliary positioning algorithm under the condition of GEO Satellite

In the process of satellite navigation and positioning, when the signal quality is poor, the auxiliary positioning algorithm can use more observed satellite data for redundant calculation, supplement the missing signal time and obtain the positioning results. The Beidou Satellite Navigation System (BDS) independently developed by China adopts a hybrid satellite constellation, including a class of Geostationary Earth Orbit (GEO) satellites, which has the advantages of 24 h visibility, high orbit, large coverage and strong signal power. This paper analyzes the auxiliary positioning algorithm and the performance difference of the algorithm when only GEO satellites can be received in special cases. The conclusion shows that without the assistance of prior information such as elevation, the direct use of five GEO satellites can also obtain a certain positioning accuracy guarantee.