Real-time multipath mitigation based on spatiotemporal correlations in BDS precise point positioning

The BeiDou Navigation Satellite System (BDS) features a heterogeneous constellation, which poses challenges in accurately characterizing the spatiotemporal correlations of multipath effects and effectively mitigating these effects using a single model. The widely used sidereal filtering (SF) and multipath hemispherical map (MHM) models cannot simultaneously reveal the spatiotemporal correlations of multipath. Therefore, we propose a satellite-dependent multipath model based on spatiotemporal correlations to mitigate multipath effects in BDS precise point positioning (PPP). Compared with the high-reliability MHM model with quality control and high-precision SF model with denoising, the static PPP positioning accuracy in the three-dimensional direction using the proposed model can be improved by up to 17.5 and 7.2%, respectively, and 9.3 and 3.5% improvements can be obtained in the kinematic PPP, respectively. For the convergence time of MHM and SF models, up to 0.5 and 49.2 min can be shortened in the static PPP using the proposed model. The proposed model not only exhibits superior accuracy in comparison to the high-reliability MHM and high-precision SF models but also has a relatively short convergence time.