基于PPP-B2b改正产品的北斗实时精密星历精度分析

Assessment of BDS real-time precise ephemeris based on PPP-B2b correction products

实时改正产品对于北斗实时精密定位和定时至关重要,北斗三号通过PPP-B2b信号播发实时轨道和钟差改正产品。为了验证PPP-B2b改正产品恢复的实时精密轨道和钟差的精度,利用接收机获取的PPP-B2b实时轨道和钟差改正产品对广播星历和广播钟差进行改正,然后以GFZ最终产品作为参考,分析评估了北斗三号MEO(medium Earth orbit)卫星和IGSO(inclined geosynchronous orbit)卫星实时精密产品的精度。试验结果表明:BDS-3卫星R方向实时轨道误差RMS值优于0.1215 m,T方向误差RMS值优于0.2922 m,N方向误差RMS值优于0.3605 m,三维RMS值优于0.6402 m;BDS-3卫星实时钟差误差RMS值优于1.6192 ns,STD值优于0.0920 ns。结果表明:PPP-B2b实时改正产品基本可满足BDS-3实时高精度定位和定时的需求。

Real-time correction products are very important for Beidou real-time precise positioning and timing.Beidou-3 broadcasts real-time orbit and clock correction products through PPP-B2b signals.In order to verify the accuracy of the real-time precise orbit and clock error recovered by the PPP-B2b correction product,the broadcast ephemeris and broadcast clock error were corrected using the PPP-B2b real-time orbit and clock error correction product obtained by the receiver.The final GFZ product was then used as the reference.The analysis evaluates the accuracy of the real-time precision products of the Beidou-3 MEO and IGSO satellites.The test results showed that the RMS value of the real-time orbital error in the radial direction of the BDS-3satellite is better than 0.1215 m,the RMS value of the along-track direction error is better than 0.2922 m,the RMS value of the cross-track direction error is better than 0.3605 m,and the three-dimensional RMS value is better than 0.6402 m.The RMS value of Beidou-3 satellite real-time clock error is better than 1.6192 ns.The results verified that the PPP-B2b real-time correction product can basically meet the needs of the BDS-3 realtime high-precision positioning and timing.