Effects of satellite platform’s vibrations on the image quality of a remote sensing payload: system level design and challenges

Abstract

Image motion due to satellite platform vibrations often limits the resolution and performance of remote sensing payloads, especially for the missions with high resolution objectives. Vibration blurs the incoming energy and degrades the overall payload’s ability to detect the target with proper quality. Effects of Linear and high frequency vibrations on the overall MTF are known exactly in closed-form but the low frequency vibration effect is a random process and must be considered statistically. It should be considered in system level payload design to know whether or not the overall MTF is limited by the vibration blur radius. The maximum resolvable spatial frequency of the camera may be limited by this vibration effects. Here we fully analyzed different vibration effects on the image quality and have specified the allowable image motion. Image motion velocity due to the Earth rotation around its axis and the satellite motion in its orbit considered separately. Degradation in the modulation transfer function due to this kind of movement is calculated to define the required pointing stability of the satellite. In this paper we have considered the effects of a single and double harmonics low frequency vibration on the Modulation Transfer Function (MTF). Because of its random effects, the majority of this paper deals with the statistical analysis of its blur radius and its consequent MTF budget.