Relative radiometric calibration method based on linear CCD imaging the same region of non-uniform scene

Abstract

This paper provides a relative radiometric calibration method based on the linear CCD imaging the same region of non-uniform scene, which makes full use of the ability of yaw angle control to ensure all the linear CCD detectors imaging the same scene. Firstly, when it is needed to perform the satellite relative radiometric calibration task, the initial drift angle will be calculated, according to which the yaw angle can be adjusted to ensure on-orbit satellite performing the calibration imaging mode, and in this mode the linear CCD and the satellite motion are in the approximate direction. Secondly, in calibration imaging process the yaw angle will be continuously adjusted to control the push-broom direction, and the linear CCD camera can be sequentially on the same region of non-uniform scene, which can obtain the remote-sensing image observing the same region with all the CCD detectors. Finally, after obtaining the same region image with the linear CCD camera, histogram matching method is used to establish the high-precision nonlinear relative radiometric calibration model, and this method overcomes the nonlinear response problem caused by the camera photon noise, the dark current noise. This method needs neither the on orbit calibration device, nor the ground uniform scaling field, and the general earth observation scene can meet the requirements. This method does not need a lot of on-orbit imaging data for statistical analysis compared with the statistical method, and each track is scaled to meet the conditions for calibration imaging, which avoids the unreliable problem of the calibration source itself caused by the unstable differences between the different tracks.