Repeatability Investigation of BeiDou Receiver Differential Code Bias

Currently, the Chinese BeiDou satellite system is extensively used in ionosphere modeling and space weather applications. For precise ionosphere modeling, however, the differential code bias (DCB) for both the satellite and receiver must be accounted for. The objective of this paper is to investigate the repeatability of the BeiDou receiver DCB. GPS/BeiDou observations from a number of globally distributed stations over a period of 7 days are used. The stations are selected from different latitudes in order to reflect different ionospheric characteristics. The observations are processed in the zero-differenced mode. The single-station bi-linear expansion is used in order to model the vertical total electron content (VTEC), the satellite and the receiver differential code biases. The findings indicate that the BeiDou receiver DCB has repeatability with level less than 0.8 ns. Then, the estimated DCB values are compared with the international GNSS service multi-GNSS experiment (IGS-MGEX) counterpart. The results show that the BeiDou receiver DCB has good agreement with the IGS-MGEX counterpart with mean difference and standard deviation (STD) values less than 0.7 ns.