Abstract:In order to support the first Mars exploration mission of China, State Key Laboratory of Astronautic Dynamics independently develops a precise orbit determination (POD) system and tries to use it in this mission. To meet the requirements of multi-object, multi-arc and multiple centre bodies, the system designed 4 basic structures including: satellite structure, station structure, observation structure and celestial body structure. Above the 4 basic structures, a flexible arc structure and solver structure is designed. To test the POD capacity of orbit around mars, 2020 tracking data of MEX (Mars Express) is used to verify the measurement model. The difference between calculated ranging and observation changes from 11m to 21m. Then 2009 ranging rate data of MEX is used to test POD. The position difference with ESA is not larger than 100m and RMS of observation is 0.0137 cm/s using a two-way ranging rate. The position difference with ESA is not larger than 250m and RMS of observation is 0.0137 cm/s using a three-way ranging rate. In the end, the orbit and RMS converged back to the value of simulation using 3-days 2-stations ranging simulation. The results show that Precise Orbit Determination System of State Key Laboratory of Astronautic Dynamics meets the fundamental needs of mars exploration.