Estimation of Inter-System Biases between BDS-3/GPS/Galileo and Its Application in RTK Positioning

For the development of a global navigation satellite system (GNSS), third generation BeiDou Navigation Satellite System (BDS-3) achieved full constellation for worldwide service on 23 June 2020. The new signals, B1C and B2a BDS-3, further enhance compatibility interoperability between different GNSSs. In this study, we first assessed quality all signals in BDS-3/GPS/Galileo. Then, to achieve among BDS-3/GPS/Galileo, inter-system bias (ISB), which appears if an difference exists two GNSSs, was estimated at overlapping frequencies. Finally, used ISBs real-time kinematic (RTK) positioning. results show higher frequency B2a/L5/E5a than B1C/L1/E1 terms pseudo range multipath. are stable both short term one day long over year, fit zero-mean normal distribution well when identical type receiver is applied. Thus, it reasonable ignore differences. With ISBs, double-difference RTK can be achieved, called tightly combined model (TCM) RTK. Compared with traditional intra-system RTK, loosely (LCM) TCM success rate (SR) ambiguity resolution positioning accuracy. addition, cutoff elevation angle set, greater promotion obtained SR. Even 50°, SR 80%. important apply observation conditions limited, such as dense jungles or urban canyons.