北斗卫星导航系统空间信号误差统计分析

SIS Error Statistical Analysis of Beidou Satellite Navigation System

针对我国北斗卫星导航系统的在轨卫星,通过一定的事后定轨策略得到精密轨道数据,用以对广播星历空间信号误差进行分析。不仅对用户测距误差进行估计,还进行了相关分析和正态性检验。通过分析2012年10月份的观测数据发现,所有卫星SISURE的平均值为1.45m;其径向-钟差和切向-法向为低度相关,其他分量之间为微相关;在正态性分析中发现,所有的空间信号误差分量都不符合正态分布,且峰度异常值可以检测偏离较大的误差,偏度异常值可以检测系统偏差。

For in-orbit Beidou satellites, we make use of precise orbit for broadcast ephemeris SIS error analysis. We not only estimate SISURE, but also take correlation analysis and normality test. Through observational data of October 2012 we find that the average SISURE is 1.45 m; the R-T and T-N have low correlation, while among the other components are micro-correlation. We also find that nearly all the SIS error components do not fit the normal distribution, and large errors can be detected by kurtosis abnormal values, while systematic bias can be detected by skewness abnormal values.