Fingerprint Localization Method for Leader-follower Satellite Cluster based on Dynamic Radio Map

Satellite location in a leader-follower satellite cluster is very important to control the satellite cluster topology. Fingerprint localization is a promising method because its simple and low cost requirement for the satellite hardware. However, the received signal strength is always changing in a complex way due to the relative movements of the satellites, which will make the radio map dynamic. Therefore, in this paper we propose to calculate the dynamic radio map based on the satellite cluster ephemeris. In detail, we propose a coarse-fine localization method for localizing the leader-follower satellite cluster. In the offline phase, we calculate the sparse radio map in several moment of the ephemeris so as to achieve coarse localization and small size of the dynamic radio map. Dense radio map is calculated in the satellite online for the fine localization. We finally use the fine localization for trajectory tracking to further improve the localization accuracy. The numerical results demonstrate that the proposed method not only yields a high localization accuracy, but also significantly reduces the space and time complexity.