Abstract:We systematically compare the differences between the modeled attitude and nominal attitude derived by the published yaw attitude models for BDS-3 SECM and CAST MEOs during deep eclipse seasons, and evaluate its influence on the calculation of antenna phase wind-up and phase center offsets(PCO) and PPP performance for the first time. The research shows that, for BDS-3 MEOs during maneuvers, adopting nominal attitude will cause the PCO correction errors for CAST and SECM satellites to reach 0.2 m and 0.02 m, respectively, and the wind-up correction errors to reach 0.1-0.2 cycles. Due to the shorter duration of satellite maneuvers and stronger geometric strength, compared with the modeled attitude, the use of the nominal attitude will not cause a significant drop in the PPP results.