航天TDI CCD相机成像拼接快速配准算法设计与分析  

Fast Registration Algorithm Design and Analysis of TDI CCD Camera Assembly Imaging

作　　者：常琳[1,2] 金光[1] 杨秀彬[1] 

机构地区：[1]中国科学院长春光学精密机械与物理研究所小卫星技术国家地方联合工程研究中心,吉林长春130033 [2]中国科学院大学,北京100049

出　　处：《光学学报》2014年第5期48-56,共9页Acta Optica Sinica

基　　金：国家863计划项目(2012AA121502);吉林省青年基金项目(201201010)

摘　　要：为解决卫星灵活机动多模式成像中多片TDI CCD拼接像元失配的问题,提出了一种实现TDI CCD相机成像搭接与错位像元快速拼接配准的匹配算法。通过分析卫星侧摆成像过程焦平面上像移速度矢量变化导致的多片TDI CCD拼接成像像元失配现象,设计了成像速度矢量光线追迹与齐次坐标变换方法,计算了侧摆成像过程中影响图像失配的偏流角、像移速度矢量和两片TDI CCD拼接纵向错位方向和横向搭接方向的像元数目。利用小卫星姿态控制系统半物理仿真平台和TDI CCD原理样机系统对两片TDI CCD拼接像元匹配算法进行实验验证。结果表明:视场角为10°的TDI CCD相机在卫星侧摆30°成像时,经过1个拼接周期后,两片TDI CCD拼接纵向错位和横向搭接像元数目由初始的148.5和50变为137和49,其中横向搭接像元数目与理论计算结果仅有0.1pixel的偏差,纵向错位像元数目与理论计算结果基本一致。经实验和理论对比分析,所设计的纵向错位与横向搭接像元快速拼接配准算法能够解决TDI CCD图像拼接的准确性,确保图像像元匹配进而获得高质量的图片。In order to solve the problem of multi pieces of TDI CCD stitching pixet mismatch in satellite flexible transformation multimodal imaging, a kind of pixel matching algorithm which can realize overlapping and displacement pixel fast assembly and registration of TDI CCD camera is proposed. Through the analysis of multi pieces of TDI CCD assembly imaging pixel mismatch phenomenon caused by the variation of image motion velocity vector in focal plane during the process of satellite side swing imaging, the imaging velocity vector ray tracing and the homogeneous coordinate transformation method is designed. Based on this method, the image motion velocity and drift angle which influence image mismatch during the process of satellite side swing imaging and the number of pixel in direction of longitudinal displacement and transverse overlapping of two pieces of TDI CCD assembly imaging are calculated. Three-axis air flotation turntable attitude simulation system and a TDI CCD camera are used in experiment to verify the pixel matching algorithm of two pieces of TDI CCD assembly imaging. TDI CCD camera of viewing angle of 10°, after an assembly period, the original number of longitudinal displacement and transverse overlapping pixels of two pieces of TDI CCD assembly imaging turns from 148.5 and 50 to 137 and 49, respectively, which is consistent with theoretical result in longitudinal displacement direction and has a deviation of only 0. 1 pixel in transverse overlapping direction. Compared with the theoretical and experimental result, the design of fast registration algorithm of calculation of longitudinal displacement and transverse overlapping pixel can solve the accuracy of TDI CCD assembly imaging, which guarantees image pixel matching and obtain high quality images.

关 键 词：多模式成像 TDI CCD相机 纵向错位 横向搭接 图像配准 

分 类 号：V474.2[航空宇航科学与技术—飞行器设计]