Experimental evaluation of tilted secondary mirror-based forward motion compensation in high-resolution earth observation systems

This study comprehensively investigates the utilization of the opto-mechanical Tilted Secondary Mirror Method for Forward Motion Compensation (TSM-FMC) in satellite cameras. Unlike the approaches existing in the literature, the forward motion caused by the orbital movement of the satellite has been compensated by intentionally misaligning the secondary mirror of the Ritchey-Chretien (RC) Cassegrain telescope by applying tilt movement to generate image flow in reverse direction. The primary objective is to offer a cost-effective and mechanically simpler alternative to Time Delay Integration (TDI) sensors and scanning mirrors, which are widely used in high-resolution Earth Observation Satellite (EOS) cameras. In order to simulate the effects of satellite orbital motion a laboratory-based imaging simulator has been used. The experimental studies have demonstrated that satellite camera exposure time can be increased by 52 times and that focal plane image shifts due to satellite orbital motion can be compensated with a residual pixel shift of 0.62.