北斗精密定轨及广播星历轨道精度评估

Precise orbit determination and broadcast ephemeris accuracy assessment and analysis for BDS

目前各类用户对基于北斗卫星导航定位服务需求在不断扩大,由于广播星历实时、易获取,北斗广播星历精度是实时导航定位用户关心的问题,也是检验系统是否达成设计指标的关键因素。文中基于国家基准站和MGEX站计算北斗精密轨道,重复弧段精度优于利用国际站计算结果。将计算的北斗精密轨道作为参考,更加准确地评估分析北斗广播星历轨道误差的精度。分析结果显示,北斗广播星历轨道径向精度优于法向和切向精度,且法向误差具有较为明显的周期性。各类卫星中,GEO卫星精度稍差,而IGSO和MEO卫星与GPS在同一量级。随着北斗卫星系统逐步组网完善,地面监测站分布趋于合理,北斗系统整体性能将会不断提高。

Currently the demand for all types of users based on BDS navigation and positioning services continues to expand.With the real-time and accessible features,BDS broadcast ephemeris accuracy is the issue of interest for users in real-time navigation and positioning,and a key factor whether the design specifications of the inspection system is achieved.In this paper,the BDS precise orbit is calculated based on the national reference stations and MGEX stations,of which the overlap accuracy is better than that only using international stations.Taking the precise orbit as reference,the broadcast ephemeris orbit accuracy is analyzed.The result indicates that the precision of radical direction is excel in tangential and normal direction,and the normal error has obvious periodicity.BDS IGSO and MEO satellites have comparable precision with GPS,while GEO satellites remain a little worse.As BDS network gradually improves,and the distribution of ground stations becomes uniform,the overall performance of BDS will continue to be improved.