北斗卫星广播星历精度评估与单点定位优化模型

Beidou Satellite Broadcast Ephemeris Accuracy Evaluation and SPP Optimization Model

利用精密星历产品对BDS-2和BDS-3广播星历的精度进行系统评估,进一步比较分析不同BDS-2和BDS-3卫星星座组合对单点定位的影响,提出一种基于SISRE(signal in space range error)的单点定位加权优化模型。实验结果表明,BDS-2星座中MEO、IGSO和GEO卫星广播星历轨道误差的RMS分别为2.404 m、3.030 m、12.574 m;BDS-3星座中MEO、IGSO卫星广播星历轨道误差的RMS约为0.5 m和0.8 m;对于SISRE,BDS-2平均优于2 m,BDS-3平均优于1 m;BDS-3配备H钟和Rb钟的卫星钟差及稳定性基本相同。同时单点定位结果表明,BDS-2/BDS-3 IGSO/MEO星座组合定位精度最高。利用提出的SISRE加权模型进行单点定位解算,定位精度在N、E、U方向的平均优化率分别为9.61%、18.55%、11.19%,平均总体优化率达到12.26%,证明了模型的有效性。

We evaluate the precision of broadcast ephemeris of BDS-2 and BDS-3 using precise ephemeris products.We further compare and analyze the influence of different BDS-2 and BDS-3 constellation combinations on single point positioning(SPP).We propose a SPP weighted optimization model based on SISRE(signal in space range error).The experimental results show that the broadcast ephemeris orbit errors of MEO,IGSO and GEO satellites in BDS-2 constellation are 2.404 m,3.030 m and 12.574 m respectively.The broadcast ephemeris orbit errors of MEO and IGSO satellites in BDS-3 are about 0.5 m and 0.8 m respectively.For SISRE,BDS-2 is on average better than 2 m and BDS-3 is on average better than 1 m.BDS-3 satellite clock error and stability with H clock and Rb clock are basically the same.At the same time,SPP results show that BDS-2/BDS-3 IGSO/MEO constellation combination has the highest positioning accuracy.The SISRE weighted model is used to solve the SPP,and the optimized positioning accuracy is 9.61%,18.55%,and 11.19%respectively in the N,E,U directions,proving the effectiveness of the model.