北斗卫星导航系统空间信号用户测距误差计算方法研究

Research on calculation method of signal in space user range error for BeiDou Navigation Satellite System

按照空间信号用户测距误差(User Range Error,URE)定义,参考GPS标准定位服务性能规范中URE的计算方法,结合北斗卫星导航系统(BDS)多星混合星座类型,在考虑仰角限制情况下,详细推导了适用于BDS的瞬时URE和均方根URE计算公式。利用广播星历和精密星历计算的卫星轨道误差和卫星钟钟差,带入所推导的公式,对BDS URE进行分析评估;并使用GNSS接收机原始观测量和伪距观测方程计算BDS URE,最后将两种计算结果进行对比分析。研究结果表明,两种方法 BDS URE的计算结果基本一致,在95%置信度情况下均小于2.5m,满足北斗公开服务性能规范中对空间信号URE的基本要求。

According to the definition of signal in space user range error（URE）and the root mean square URE（rmsURE） calculation method given in the Global Positioning System Standard Positioning Service Performance Standard（GPS-SPS-PS）,the BeiDou Navigation Satellite System（BDS）instantaneous URE（IURE）and rmsURE formulas were deduced considering the elevation constrains.In addition,BDS URE was calculated by the ephemeris data,and the BDS receiver raw observations.The results show that the two methods match well,and both are less than 2.5 meters in the case of 95% confidence which meets the basic requirements of the signal in space URE given in the BDS open service performance standard（BDS-OS-PS）.