Objectives The accuracy of relative track between orbiter and ascender can ensure success and safety during the meeting and docking process of Lunar.
Methods Based on dual-target joint measurement of Chang’E-5, we established the same beam interferomery(SBI) measurement and inter-satellite measurement model, and designed a statistical orbit determination algorithm combined with orbiter and ascender.
Results We used the reference orbit to analyze delay and delay rate of SBI, and the range and range accuracy of microwave radar/laser radar. The accuracy of SBI is equivalent to that of very long baseline interferometry, and the range accuracy of microwave radar/laser radar is at meter level.
Conclusions By establishing the relative motion relationship between the two targets, the relative orbit accuracy can be significantly improved in orbit determination.