Objectives Observation quality is one of the key issues to assess the performances of satellite navigation system. As the main error of positioning and navigation, the multipath delay mitigation has become the focus of the research in global navigation satellite system. Because the traditional multipath modelling strategy cannot obtain the global optimal solutions, this paper proposes a real-time multipath correction model for BeiDou navigation satellite system (BDS) observation with information constraints.
Methods Firstly, the regularization algorithm combined with total variation term is used to denoise and solve the multipath delay series based on the estimated BDS multipath delays. Secondly, the trend and random parts of multipath delays are separately processed and together modelled, in which the strategy of least square plus autoregression is used to estimate model coefficients of multipath delay model by one-step solution. Finally, the multipath mitigation model is further optimized by introducing the estimated model coefficients as the prior information constraints in the BDS real-time applications.
Results The results of real-time experiments of BDS precise point positioning show that, compared with the traditional strategy, the position accuracy of BDS-2 PPP in east (E), north (N) and up (U) directions can be improved with 10.6%-64.9%, 0.0%-59.1% and 12.6%-67.2% (B1I+B3I), respectively. Moreover, the position accuracy of BDS-3 PPP can be optimized with at least 13.9%, 60.0%, 45.9% (B1I+B3I) and 19.1%, 46.5%, 23.9% (B1C+B2a) in E, N and U directions, respectively.
Conclusions Therefore, the proposed mitigation multipath delays method can significantly improve the BDS observation quality in the BDS real-time positioning services.
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