Abstract：The positioning accuracy of medium-long baseline RTK has not been determined in the newly added B1C and B2a signals of BDS-3 MEO satellite and IGSO satellite, so to resolve this problem we analyze the data quality of new signals of BDS-3, B1I and B3I signals of BDS-3 and L1 and L2 signals of GPS. We further study the positioning of dual-frequency RTK using four groups of measured data of medium-long baseline. The results show that, in terms of data quality, the number of visible satellites and PDOP of BDS-3 are better than GPS, and the SNR ratio and multipath error of new signals of BDS-3 are equivalent to B11 and B3I signals of BDS-3 and L1 and L2 signals of GPS. In RTK positioning of medium-long baseline, the ambiguity of the new signal B1C+B2a combination of BDS-3 is better than B1I+B3I combination of BDS-3 for the first time, and the positioning accuracy of new signal combination is slightly better than B1I+B3I combination of BDS-3 and L1+L2 combination of GPS. This can provide users with centimeter-level positioning accuracy.
