北斗三号卫星伪距测量误差特征分析

随着卫星导航系统广播星历和钟差参数的精度提升，下行导航信号伪距测量误差对于用户定位授时精度的提升益发显著。由于独特的卫星星座和系统体制，北斗二号卫星伪距测量与仰角呈现线性相关的变化特征，且幅度显著于 GPS 卫星，是北斗二号服务性能提升的关键瓶颈。 随着北斗三号系统的建设，空间星座逐步以 MEO 卫星为主。本文利用 iGMAS 公开数据全面评估北斗卫星下行伪距测量的多路径误差特征，结果表明，北斗三号卫星伪距多路径误差随仰角变化的趋势已得到明显改善，峰峰值为±1m，分布较为随机，与 GPS 卫星特征类似。

Analysis of Deviation Characteristics of Pseudo-Range Measurement of Beidou-III Satellites

As the accuracy of the broadcast ephemeris and clock difference parameters of the satellite navigation system increases, the pseudo-range measurement deviation of the downlink navigation signal is significant for the improvement of the user positioning timing accuracy. Due to the unique satellite constellation and system constitution, the Beidou-II satellites pseudo-range measurement exhibits a linear correlation with the elevation angle, and the amplitude is significantly higher than that of the GPS satellites, which is the key bottleneck for the service performance improvement of the Beidou-II. With the construction of the Beidou-III system, the space constellation is gradually dominated by MEO satellites. In this paper, the iGMAS public data is used to comprehensively evaluate the multipath deviation characteristics of the Beidou satellite downlink pseudo-range measurement. The results show that the pseudo-range multipath deviation of the Beidou-III satellites has been significantly improved with the elevation angle, the peak-to-peak value is ±1m, and the distribution is random, similar to GPS satellite features.