Closed-Loop Control of Earth Observation Satellites

Low-altitude satellite orbits, while enabling high-resolution imagery of the Earth surface, have limited coverage properties. This disadvantage of the remote sensing satellites can be offset by the low-thrust electric propulsion capability, which permits to combine high-resolution with short revisit times. The purpose of this work is to present a simple closed-loop control function that allows the direct control of the orbit, making the spacecraft to pass over prescribed sites on the terrestrial surface without the need of precomputed reference trajectories. The simplicity of application contributes to the autonomy of the remote sensing satellites. The performance of the new control algorithm is illustrated by representative numerical simulation results.