Abstract:In this paper, we discuss the effects on the accuracy of solutions of GPS/BDS long baseline, on the commonly used equalization model, the height angle model, and the Helmert posterior variance estimation model. We use data of the ZHJJ and QLA measuring stations (Sichuan CORS network). The results show that: (1) a BDS/GPS combination system can achieve long baseline high-precision solutions; (2) the solution accuracy of the Helmert posterior variance estimation random model is highest, and can achieve horizontal and vertical accuracy of 140 km long baseline solution in BDS/GPS combination system better than 8 mm and 10 mm respectively; (3) the performance of the equivalent entitlement model and the height angle random model is equivalent in solving BDS/GPS long baseline single epoch.