Autonomous Precision Orbit Control Considering Observation Planning: ALOS-2 Flight Results

Earth-observation satellites carrying synthetic aperture radar instruments have stringent requirements on control of Earth-referenced repeat-track orbits. This precision control leads to frequent orbital maneuvers, thus burdening daily ground operations. To achieve high accuracy with minimal ground-based workload, we propose a novel autonomous orbit control method that allows both in-plane and out-of-plane maneuvers to be planned and performed autonomously. Furthermore, a maneuver slot concept is proposed to prevent conflicts with payload data-take opportunities. The proposed method has been implemented on the Advanced Land Observing Satellite-2 and has been in practical use since August 2014. This is the first attempt to apply autonomous precision orbit control within a tube-shaped control window for regular operation of an Earth-observation satellite. Details of the proposed method and Advanced Land Observing Satellite-2 flight results are presented in this paper, and experiences and lessons learned fro...