北斗三号全球系统空间信号精度评估分析

Accuracy Assessment of Signal in Space of BDS-3 Global System

以精密星历和钟差为基准,对BDS-3广播星历的轨道精度、钟差精度和3类空间信号测距误差(signal-in-space range error,SISRE)精度进行评估。结果表明,BDS-3广播星历的轨道精度明显优于BDS-2同类卫星,其轨道径向RMS精度优于0.18 m,切向和法向RMS精度优于0.6 m;BDS-3广播星历钟差的误差基本小于5 ns,且较BDS-2卫星变化更为平稳,其平均RMS统计精度为1.86 ns,平均95%统计精度为3.23 ns,均优于BDS-2卫星;BDS-3卫星仅受轨道影响的SISRE、全球平均SISRE和最差SISRE的RMS统计精度分别为0.12 m、0.58 m和0.60 m,相应95%统计精度分别为0.22 m、0.99 m和1.02 m,较BDS-2均有明显提升。

Based on the precise ephemeris and clock product,we evaluate the orbit accuracy,clock accuracy and 3 kinds of signals in space ranging error(SISRE)of BDS-3 broadcast ephemeris.The results show that the broadcast orbit accuracy of BDS-3 satellites is obviously better than that of BDS-2 satellites.Radial RMS accuracy of BDS-3 satellites is better than 0.18 m,along-track and cross-track RMS accuracy is better than 0.6 m.The broadcast clock errors of BDS-3 satellites are maintained within 5 ns and are more stable than those of BDS-2.The RMS and 95%statistical accuracy of BDS-3 broadcast clock errors are 1.86 ns and 3.23 ns respectively,which are better than that of BDS-2 satellites.The RMS statistical accuracy of orbit-only SISRE,global-average SISRE and worst SISRE of BDS-3 satellites are 0.12 m,0.58 m and 0.60 m respectively and the corresponding 95%statistical accuracy are 0.22 m,0.99 m and 1.02 m,and both of them are significantly better than BDS-2.