Objectives Differential code bias (DCB) is one of the important factors affecting the accuracy of ionospheric monitoring and high-precision positioning. The establishment of DCB correction model is of great significance for high-precision positioning.
Methods Aiming at the problem that the BDS-3 satellite clock time references of broadcast ephemeris and precise ephemeris are not uniform, firstly, we introduce the DCB estimation methods of Chinese Academy of Sciences (CAS) and German Aerospace Center(DLR), and give the accuracy evaluation and analysis results of some DCB products. Secondly, the DCB correction models of BDS-3 single-frequency and dual-frequency standard point positioning (SPP), dual-frequency precise point positioning (PPP) are proposed. Finally, both SPP and PPP experiments are carried out with different schemes by using five-day measured data of the multi-GNSS experiments (MGEX) stations.
Results The results show that the MGEX DCB products have high stability. And the accuracies of single-frequency and dual-frequency SPP are increased by 48%—85% and 71%—91% after using DCB correction, respectively. The convergence time of dual-frequency static PPP is reduced by 56%—83% after using DCB correction.
Conclusions It can be concluded that the satellite DCB correction can improve the SPP positioning accuracy and reduce the PPP convergence time.
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