Motion of the image presented to an electro-optical imaging system blurs the incoming energy and degrades the system's ability to detect or recognize distant targets. The motion that occurs during a sensor integration period or frame generally produces the most significant effect, although, frame-to-frame motion can also be important depending on the application and the image processing involved. Thus, line-of-sight stabilization specifications that limit only the amplitude of image motion without regard for frequency may be conservative and over- constrain the design in some cases. This paper addresses the effects of image motion on the performance of electro-optical imaging systems and investigates alternate methods of specifying the allowable image motion for the stabilization system. Specifically, the effects of both the spatial and temporal frequency content of the motion spectrum on the system MTF (modulation transfer function) and on the system's ability to recognize and detect distant targets are discussed. Types of image stabilization specifications considered include RMS jitter amplitude, maximum allowable motion amplitude during an integration interval, allowable MTF degradation and allowable motion versus temporal frequency. These are then compared according to whether or not they can be readily measured, whether they can be easily understood and converted to meaningful design parameters, and whether they inadvertently over-constrain or under-constrain the design.
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