Enhancing the performance of real-time precise point positioning (RT-PPP) holds significant application value, with pseudorange accuracy being one of the key factors constraining its performance. To address this, this paper proposes a novel algorithm called B2b+ID-PPP, which integrates the PPP-B2b service with integrated Doppler observations. Experimental results demonstrate that the satellite-to-ground distance root mean square error (RMSE) characterized by integrated Doppler reaches the subcentimeter level (0.55 cm), enabling high-precision approximation of distance variations. The residual of the pseudorange positioning equation incorporating this observation significantly decreases, with the pseudorange residual RMSE improving from 76.1 to 6.53 cm—an accuracy enhancement of 91.4%. In the single BDS-3 system, B2b+ID-PPP achieves average positioning accuracies of 14.3, 8.7, and 21.4 cm in the east (E), north (N), and up (U) directions, respectively, representing improvements of 5.3%, 16.4%, and 4.5% over B2b-PPP. The convergence time for seven consecutive days of solutions was consistently under 15 min, and the average was 9.2 min. Moreover, given mild ionospheric scintillation conditions, the proposed method further accelerated the convergence speed. Additionally, in simulated severe multipath environments, B2b+ID-PPP effectively enhanced the up-direction accuracy from meter- to decimeter-level. These results confirm that this method effectively enhances pseudorange accuracy through subcentimeter-level integrated Doppler observations, thereby significantly improving the overall performance of PPP-B2b-based RT-PPP in China and its surrounding regions.
Guan et al. (Fri,) studied this question.