Analysis and Modeling of the Inter-system Bias Between BDS-2 and BDS-3

摘要

The BDS-3 system has provided positioning navigation and timing (PNT) service since December 2018, while applications show that there is inter-system bias (ISB) between the BDS-2 and BDS-3 systems. Origin of the ISB and its influences on Beidou positioning are analyzed, and then the positioning algorithm including ISB is presented in order to improve Beidou navigation and positioning precision from the perspective of users. Judging by improvement effect on the BDS-2 and BDS-3 joint positioning, three ISB estimation models, such as white noise model, piecewise constant model, and random walk model, are analyzed, using Asia-Pacific observations and precision orbit and clock products of IGS. Results show that ISB estimation methods can effectively improve the precision of BDS-2 and BDS-3 joint standard point positioning (SPP), and the improvement of three methods can reach 22%, 23% and 36% respectively, while for BDS-2 and BDS-3 joint precise point positioning (PPP), the improvement is 17%, 16% and 18% respectively.