Abstract:In order to meet the requirements of wide-width imaging, the coastal zone imager (CZI) onboard HY-1C satellite adopts the combination of two cameras for imaging and splices two 4-color charge-coupled devices (CCD) between single phase. Based on the rigorous geometric imaging model, this paper analyzes the systematic errors existing in the imaging process of the camera, adopts a geometric calibration model based on the directional angle of probe, and designs a geometric calibration scheme for the CZI camera based on the design of camera characteristics and geometric characteristics. CZI reference band images and high-precision reference images are used to carry out absolute calibration, and the internal and external calibration parameters of reference band images are calculated by step iterative method. According to the bands’ constraint relation, the calibration results of non-reference band images are obtained by relative calibration between bands. The experimental results show that, the positioning accuracy of plane-free control points is better than 5 pixels after on-orbit geometric calibration, and the geometric quality of the images is obviously improved, which indicates that the calibration model and scheme adopted in this paper are reasonable and effective.