Pre-launch geometric calibration methodology of a high-resolution push-broom payload

Abstract

Linear array imaging systems are widely used in remote sensing satellites. The data of these sensors can only be used when they are geometrically, radiometrically, and spectrally calibrated. Therefore, calibration procedures before and after launch must be carefully planned, at the first stages of sensor design, in such a way that the measured payloads data during the satellite lifetime is still validated. As for the push-broom imaging, each line of data has its own independent geometry, there are many sets of independent data in each images which could be used for accurate geometric calibration. In this paper, focusing on optical distortion, a step-by-step procedure for pre-launch geometric calibration of a high resolution push-broom payload is investigated and the mathematical approaches of the calibration coefficients are presented here. Finally an error-budget analysis is done to investigate the methodology sensitivity. The simulation results show that the nonlinear effects of distortion can be minimized and the accuracy of the geometric position of this method on the image screen can be improved to the order of sub-pixels.