Abstract:We analyze the error characteristics of GPS and BDS-3 satellite broadcast ephemeris, study the compensation strategy of the inaccuracy of broadcast ephemeris, and propose a SISRE compensated undifferenced uncombined positioning model. The experiment adopts the observation data of 15 MGEX stations in 2022 for one week. The results show that when a SISRE compensated undifferenced and uncombined model is adopted, the RMS of GPS and BDS-3 static three-dimensional positioning errors are about 24 cm and 23 cm, respectively. The GPS/BDS-3 dual system combination can further improve the accuracy to about 18 cm. The RMS of GPS and BDS-3 imitation dynamic 3D positioning errors are about 73 cm and 74 cm, respectively. The GPS/BDS-3 dual system combination can further improve the accuracy to about 45 cm. The positioning accuracy of SISRE compensated undifferenced and uncombined model is equivalent to that of SISRE compensated ionosphere-free combination model.