北斗三号全球卫星导航系统的广播星历精度评估

为了及时评估北斗三号全球卫星导航系统（BDS-3）广播星历的精度，本文基于2018年3月10—22日和2019年7月2—14日的BDS-2、BDS-3广播星历，以及武汉大学发布的精密星历数据，从北斗卫星的星历误差、轨道误差和空间信号测距精度（SISRE）3个方面进行了全面比较与分析。结果表明：BDS-3的广播星历星历误差的RMSE基本优于1.5 m，BDS-2的GEO、IGSO和MEO卫星的广播卫星星历误差的RMSE分别为3.0、3.0、2.0 m；BDS-3的轨道误差RMSE基本优于1.0 m，其中径向R方向的精度高于切向T和法线N方向，分别为0.1、1.0、0.5 m，BDS-2在R、T、N 3个方向上的精度分别为1、3、3 m；BDS-3广播星历SISRE的RMSE基本优于0.25 m，BDS-2的GEO、IGSO和MEO卫星的SISRE分别优于0.5、2.0、0.5 m。本文的结果整体上反映出BDS-3信号稳定且精度逐渐提升。

Accuracy assessment of BDS-3 broadcast ephemeris

In order to evaluate the accuracy of Bei Dou-3 global navigation satellite system( BDS-3),broadcast ephemeris timely,this paper makes a comprehensive comparison and analysis of ephemeris error,orbital error and SISRE,signal in space range error. The data of broadcast ephemeris and precise ephemeris is released by Wuhan University of BDS-2 and BDS-3 from March 10 to March 22,2018 and July 2 to July 14,2019. The results show that the RMSE of the broadcast ephemeris of BDS-3 are basically better than 1.5 m,and the RMSE of BDS-2 GEO,IGSO and MEO satellites are less than respectively 3. 0,3. 0,2. 0 m. The orbit errors of BDS-3 are basically better than 1.0 m,and the errors in the R direction are superior than the T and N directions,respectively 0.1,1.0,0.5 m.The orbit errors of the BDS-2 in the three directions of the radial R,T and N are 1,3,3 m. The SISRE of BDS-3 are better than 0.25 m,and SISRE of BDS-2 GEO,IGSO and MEO satellites are better than 0.5,2.0,0.5 m respectively. The results of this paper reflect that the BDS-3 signal is stable and its accuracy is improved.