ESA GNC Conference Papers Repository

The demand for higher image resolution of Earth Observation and science missions is driving complex designs at payload and platform level, with very accurate sensors and expensive means to compensate on-board disturbances. This is becoming critical for current missions, and will become a show stopper for future very high demanding missions. This work focuses on the design and performance assessment of an image stabilization system for the ESA GEO-High Resolution (GEO-HR) future mission, with its stringent stability and accuracy requirements. The system designed consists in an image processing optical flow based algorithm to estimates the line of sight motion, and a fast steering mirror, controlled in closed loop to stabilize the images. Modern robust control techniques have been used to design the stabilization controller. A high fidelity simulator has been built using Finite Element opto-mechanical model for the platform and the telescope line of sight, and a performance model of the image processing algorithm with extensive simulation campaign using typical scenes. A prototype of the stabilization system has been developed in laboratory, confirming the feasibility of the system and providing insight on the stabilization results. The clear benefit of the image stabilization for long exposure observations is shown, allowing the extension of the GEO-HR mission availability for observation.