BDS-3 satellite orbit and clock determination with one-way inter-satellite pseudorange and monitoring station data

In this paper,BDS-3 satellite orbits and clock offsets are determined by using the original one-way inter-satellite-link (ISL) pseudorange data together with the carrier phase and pseudorange data of ground monitoring stations. The satellite clock offsets are expressed by piecewise polynomial with appropriate piecewise intervals (e.g. 1 min), thus the non-simultaneously observed one-way ISL pseudorange data can be processed directly. Experiments of orbit determination and clock estimation for BDS-3 satellites with observation data from 6 iGMAS stations in China and ISL pseudorange data are carried out. The results show that the RMS of the overlapping orbit differences in R, T and N directions are 0.078, 0.321 and 0.375 m, respectively. The RMS and STD of the overlapping clock differences of satellite are 0.589 and 0.519 ns, respectively. Compared with the results obtained with only data from monitoring stations, the improvements of orbit and clock exceed 80% and 60% respectively. The average RMS of one-way ISL pseudo-range residuals is 0.083 m, and the stability of estimated hardware delay bias for transmitting and receiving ISL equipment is 0.53 and 0.72 ns on average, respectively