Accuracy evaluation of BeiDou-3 PPP-B2b signal

The BeiDou-3 Navigation Satellite System (BDS-3) B2b signal is a signal broadcast by three geosynchronous orbit satellites of BDS-3, which can provide users with open and free high-precision services, and is of great significance on high-precision applications in several fields such as land surveying, marine surveying and health monitoring of bridges and buildings. The accuracy evaluation of precision single point positioning (PPP)-B2b signals is a key link to realize its high-precision applications. To evaluate the accuracy of PPP-B2b products, by correcting the broadcast ephemeris with PPP-B2b signals using self-compiled program, the precise orbit and clock products corrected by the PPP-B2b products were obtained. Taking the after-event precision products (WUM) provided by the IGS Data Center of Wuhan University as a reference, the precision of the precision products corrected by PPP-B2b is evaluated. The results show that the root-mean-square (RMS) value of the radial direction (R), tangential direction (A) and normal direction (C) of the BeiDou satellite orbit after correction is 6.26 cm, 24.21 cm, and 21.79 cm respectively, and the average value of the standard deviation (STD) of the clock difference is 0.33 ns. Finally, the results of the PPP using the corrected precise orbit and clock products show that the accuracy of PPP positioning in the east (E), north (N) and zenith (U) directions is 0.07 m, 0.07 m and 0.15 m respectively. The precise orbit and clock error products of broadcast ephemeris corrected by BDS-3 B2b are as accurate as IGS post-event precision products, which can meet the application requirements of single-station real-time high-precision positioning and navigation.