北斗三号全球卫星导航系统空间信号精度评估

针对北斗三号 (BDS-3)正式开通后的空间信号精度情况，选取2020-08-01—2021-07-31共 1 a的混合广播星历数据，以德国波茨坦地学研究中心(GFZ)和武汉大学国际GNSS服务(IGS)数据中心(WHU)提供的精密星历为参考分别从轨道精度、钟差精度和空间信号测距误差(SISRE)来进行BDS-3的空间信号精度评估. 结果表明:BDS-3的轨道精度在径向(R)、切向(A)、法向(C)三个方向上分别优于0.100 m、0.405 m、0.547 m，钟差精度优于1.926 ns，仅受轨道影响的SISRE (orb)为0.134 m，SISRE为0.612 m. 地球静止轨道(GEO)卫星的SISRE为1.137 m，倾斜地球同步轨道(IGSO)卫星和中圆地球轨道(MEO)卫星的SISRE相比GEO卫星分别减少36.3%、51.3%. 

Accuracy assessment of BDS-3 satellite signal-in-space

Aiming at the accuracy of the signal-in-space after BeiDou-3 (BDS-3) is officially opened, The paper selected one-year Global Navigation Satellite System (GNSS) mixed broadcast ephemeris data (from August 1st, 2020 to July 31st, 2021) and used the precision orbit and clock offset provided by the German Potsdam Geoscience Research Center (GFZ) and International Global Navigation Satellite System Service (IGS) data center of Wuhan as reference to evaluate the accuracy of the BDS-3 signal-in-space. The research showed the orbit accuracy of the BDS-3 is better than 0.100 m, 0.405 m, and 0.547 m in the radial, along-track, and cross-track respectively, and the clock error accuracy is better than 1.926 ns, and SISRE statistical accuracy only affected by the orbit error is 0.134 m, and signal-in-space range error (SISRE) statistical accuracy is 0.612 m. SISRE of the geostationary orbit (GEO) satellites is 1.137 m. Compared with the GEO satellites, and SISRE of the inclined geosynchronous orbit (IGSO) satellites and the medium earth orbit (MEO) satellites are reduced by 36.3% and 51.3% respectively.