Abstract: In order to meet the high-precision orbit calculation requirements of China’s new-generation geostationary orbit satellite, FY-4, the ground tracking system has been designed with a multi-station dual-frequency two-way ranging mode. The ionospheric and tropospheric processing methods in signal propagation medium correction are presented in detail, and the dynamic orbit determination strategy of the FY-4 satellite is given. During the normal period without orbital maneuver, the dynamic orbit determination method is adopted. The RMS of the measurement noise is better than 0.5 m. Through the analysis of track overlap, the accuracy of the normal period is better than 20 m. During the unloading period of the momentum wheel, the method of estimating the empirical force is adopted, and its orbit determination residual is better than 1 m. The multi-arc data processing shows that the proposed method satisfies the high-precision orbit tracking in the two-way ranging mode of geosynchronous satellites.

Key words: FY-4, Orbit determination, Orbit maneuver