Attitude Guidance Effects on Image Quality for Spaceborne Electro-Optic Imagers with TDI

In this paper, we present mathematical derivations and relations of assessing image quality degradation due to attitude guidance and control errors. The method uses satellite attitude, angular rate, on orbit position, velocity, and sensor parameters to evaluate image quality based on Modulation Transfer Function (MTF). The analysis includes typical push- broom Time Delay Integration (TDI) sensors. After the mathematical derivations are presented, we provide a guidance method to correct yaw angle and calculate necessary TDI integration time during the acquisition. Furthermore, we investigate the effect of controlling the satellite attitude on fixed orbit frame and using single integration time for the acquisition of entire latitude range. Simulation results show that using single integration time and constant attitude is acceptable for a Sun-Synchronous orbit. Importance of Attitude Guidance and Control methods for better image quality on spaceborne imaging are emphasized.