A Novel Differential Doppler Measurement-Aided Autonomous Celestial Navigation Method for Spacecraft during Approach Phase

The combination of celestial measurement and ground Doppler measurement has been successfully used for orbit determination in many deep-space exploration missions. However, one of the inherent drawbacks of ground tracking is the long communication delay. Using the Doppler measurement from the sun instead of the ground station is a feasible strategy for real-time navigation, but the accuracy of this Doppler measurement is affected by the frequency fluctuation of the solar spectrum. To solve this problem, a differential Doppler measurement-aided celestial navigation method is proposed in this paper, which uses the differential Doppler measurement to reduce the influence caused by instability of the solar spectrum frequency and improve the navigation accuracy. Simulations demonstrate the feasibility and effectiveness of this method.