BeiDou Navigation Satellite System(BDS)-3 has officially provided positioning,navigation and timing services to global users on July 31,2020.Due to the differences in signal modulation modes and characteristics between BDS-2 and BDS-3,there will be inter-system bias(ISB)when the receiver receives and processes BDS-2 and BDS-3 signals.This paper adopts four random models:ig-noring ISB(ISBNO),ISB estimation as constant(ISBCT),ISB estimation as random walk(ISBRW)and ISB estimation as white noise(ISBWN).GBM,WUM and CLK93 real-time precision products are used respectively.Based on the observation data of BRUX,CEDU,CUT0,HOB2,HARB and PTBB,the performance of mimic real-time and post precise point positioning(PPP)and time-frequency transfer of BDS-2/BDS-3 combination was evaluated.The results show that the average PPP positioning accuracy and convergence time of GBM and WUM products are both 1.7 cm and 23.3 min.The positioning and time-frequency transfer performance of the ISB estimation strategy is slightly better than that of the ignoring ISB strategy,and the data processing strategy of ISBCT is the best.The 3D positioning accu-racy of mimic real-time PPP of CLK93 product is better than 4.0 cm,the positioning accuracy of ISB estimation is equivalent to that of ignoring ISB,the convergence time is shortened,and the stability of time-frequency transfer is improved.The average frequency stability of ISBCT,ISBRW and ISBWN is 8.03％,25.32％and 24.21％higher than that of ISBNO solution strategy in 60 000 s,respectively.By comprehensive comparison,ISBCT and ISBRW strategies with BDS-2/BDS-3 combined PPP have better positioning and time-frequency transfer performance than ISBNO and ISBWN strategies.
关键词
北斗卫星导航系统(BDS)/系统间偏差(ISB)/精密单点定位(PPP)/定位/时频传递
Key words
BeiDou Navigation Satellite System(BDS)/inter-system bias(ISB)/precise point positio-ning(PPP)/positioning/time-frequency transfer
维普
万方数据