Abstract: [Purposes] The BeiDou-3 Navigation Satellite System (BDS-3)broadcasts PPP-B2b signals via three geostationary earth orbit (GEO)satellites.This effectively overcomes the reliance of conventional precise point positioning (PPP)technology on ground-based data links.This paper aims to systematically evaluate the performance of the PPP-B2b correction signals broadcast by the BDS-3 GEO satellites in precise point positioning and address the real-world issue of clock offset jump in PPP-B2b corrections. [Methods] Observation data from five MGEX stations in and around China during DOY075—080,2024 were selected for analyzing the real-time positioning accuracy of PPP-B2b.An anomaly detection and correction algorithm based on a sliding window was proposed to mitigate the clock offset jumps,and positioning results before and after processing were compared. [Findings] Experiments show that in static mode,the average RMS of PPP-B2b positioning in the N,E,and U directions are 1.0,1.7,and 2.3 cm,respectively.After applying the sliding-window algorithm,the accuracy in the height direction improved by 15%～28% on average.Specifically,the U-direction RMS decreased from 0.023 m to 0.020 m at station URUM and from 0.029 5 m to 0.023 m at station WUH2,effectively suppressing the fluctuations caused by clock offset jumps. [Conclusions] The results demonstrate that PPP-B2b can achieve centimeter-level real-time static positioning,and the proposed algorithm significantly enhances vertical accuracy,providing technical support for its application in fields such as geological hazard monitoring and high-precision surveying and mapping．

Key words: BDS-3, PPP-B2b, real-time precise point positioning, positioning accuracy analysis, sliding window smoothing