空间相机CCD像面拼接重叠像元数分析与计算

Analysis and Calculation of Overlapping Pixels of Assembly CCD Image Plane in Space Camera

为了避免空间相机在侧摆成像时多片CCD的拼接处出现缝隙,造成部分目标信息缺失且获取的图像无法正常拼接的问题,根据CCD推扫成像的工作原理和像移补偿残差对图像出现缝隙的原理进行分析,通过采用重叠像元的方法克服了图像缝隙的问题;根据实际工程需求对像面重叠像元数进行计算,对重叠像元数提出具体要求;根据实例计算得出,在96级积分级数下允许的偏流角误差不大于12'和偏流机构的偏差为1'的前提下,像面拼接时相邻两片CCD之间的重叠像元数计算值应大于15,考虑误差及安装多重因素增加一定的余量,重叠像元数为40完全满足地面覆盖宽度10km的要求。

In order to avoid multi chip CCD stitching the gap space camera side of the pendulum imaging, resulting in loss of part of the target information and the acquired image can not be normal splicing problems, according to the CCD push-broom imaging principle and image motion compensation residual image the principle of analysis, overlapping like element method to overcome the problem of image gap pixel is calculated according to the actual engineering requirements on the image plane overlap, the specific requirements of overlapping pixel. Instance of the calculated drift angle error is less than the allowed 96 points series 12′and the bias eurrent institutions deviation 1′of a premise, like the surface of splicing overlap between adjacent two CCD pixel calculated value should be greater than 15, consider the error and the installation of multiple factors to increase the margin, overlaps the pixel number 40 to meet the ground to cover the requirements of the width to 10 kin. This article proposed the method is simple and easy to implement, which is suitable for the research of image motion compensation of space camera.