GNSS广播星历精度评估与分析

Evaluation and analysis of GNSS broadcast ephemeris positioning performance

为了进一步探讨全球定位系统(GPS)、北斗卫星导航系统(BDS)、伽利略卫星导航系统(Galileo)、格洛纳斯全球卫星导航系统(GLONASS)的广播星历特性,并分析其精度和定位性能,对2023年3月的数据进行处理。结果表明:除GLONASS系统外,其他全球卫星导航系统(GNSS)广播星历卫星轨道精度在3个方向均优于1 m,GPS和Galileo系统广播星历卫星钟差精度均优于1 ns;当广播星历参数采用相同的更新间隔时,BDS系统对应的轨道精度较高,四大系统按轨道精度从高到低排序依次为BDS、GPS、Galileo、GLONASS;当广播星历采用10 min更新间隔时,不同于卫星轨道,BDS相应卫星钟差精度较低,这可能与BDS广播星历采用的时间同步技术有关;单点定位结果表明,BDS、GPS、Galileo系统对应的广播星历定位平面精度均优于1.3 m。

In order to further explore the broadcast ephemeris characteristics of global positioning system(GPS),BeiDou navigation satellite system(BDS),Galileo navigation satellite system(Galileo)and GLONASS,and analyze their accuracy and positioning performance,the paper processed the data of March 2023.Results showed that except for the GLONASS system,other global navigation satellite systems(GNSS)would have satellite orbital accuracy of broadcast ephemeris better than 1 m in all three directions,and GPS and Galileo systems would have satellite clock error accuracy of broadcast ephemeris better than 1 ns;moreover,when the broadcast ephemeris parameters are updated at the same interval,the corresponding orbital accuracy of the BDS system would be higher,while the four major systems could be BDS,GPS,Galileo and GLONASS in order of orbital accuracy from high to low;furthermore,when the 10 min update interval is used for broadcast ephemeris,the accuracy of BDS corresponding satellite clock error would be lower than that of satellite orbit,which may be related to the time synchronization technology adopted by BDS broadcast ephemeris;in addition,the results of single point positioning indicated that the positioning plane accuracy of the broadcast ephemeris corresponding to BDS,GPS,and Galileo systems would be better than 1.3 m.