为了实现卫星大侧摆成像时交错拼接时间延迟积分（TDI）CCD准确的重叠度配准和大幅宽无缝影像拼接，提出一种利用错位搭接像元像移速度矢量之间的夹角计算最小搭接像元数目的方法。分析了卫星侧摆成像时像面像移速度矢量的变化，根据侧摆角度计算对应地物点的经纬度和合速度矢量；利用光线追迹和矢量映射等方法将合速度矢量通过成像的物像关系和地球曲率参数等投影至像面坐标系，计算出搭接像元像移速度矢量之间的角度；结合TDI CCD位置矢量关系确立相邻两片TDI CCD的最少搭接像元数目。该算法成功应用到快舟一号卫星工程中，实验和理论对比分析发现，片间搭接像元的实际值和理论值有一个像元的偏差，在图像配准精度范围内。说明该方法能够有效消除卫星大侧摆成像对错位搭接像元拼接精度的影响。

In order to realize the accurate superposition and seamless image assembly of interleaving assembly time delay integration (TDI) CCD imaging under the condition of large lateral swing space in spaceflight camera, it is mentioned in this paper that the number of the minimum overlap pixels can be calculated with the angle of image motion velocity vector among the dislocation lap joint pixels. First, velocity vector of ground object target in the coordinates of surface feature during satellite lateral swing imaging is analyzed. The velocity vector, latitude and longitude of harmony feature point are calculated using lateral swing angle. Then, the relationship of imaging and physical parameters have been projected to the image plane coordinates using the method of ray tracing and vector mapping. And then the angle between imaging velocity of overlap pixel has been calculated. Finally the least lap number pixel of two adjacent pieces TDI CCD is established by TDI CCD relationship. The algorithm is applied to the Fast Boat One satellite. By comparing the experimental and theoretical results, a deviation of pixels exists between actual and theoretical values in the image registration accuracy range. This method can effectively eliminate the large side swing imaging dislocation lap on pixel precision of stitching.