一种空间推扫型光学成像系统几何映射方法

卫星光学遥感器在轨成像会受到颤振的影响,因此图像品质受姿态稳定度的影响很大,而高分辨率图像受到平台误差的影响更加明显。通过研究空间相机的几何模型,提出了一种从地球坐标系到空间光学遥感器坐标系之间的转换关系;分析了在轨卫星的姿态误差和运动源,并在几何模型中加入了内外方位元素特征;然后进行了空间TDICCD相机的成像仿真实验。为了在像面上模拟颤振,分别进行不同模态的颤振仿真,并且对视线范围内多模态综合作用进行仿真。仿真实验是基于三个轴系方向的,并且计算了TDICCD仿真图像的几何畸变量,模型中几何畸变量的测量尺度达到亚像素级,结果有利于指导卫星平台和遥感器的参数设计。

A Geometrical Mapping Method for Space Push-broom Optical Imaging System

Space imaging system is affected by flutter of satellite platform on orbit. Therefore, image quality is degraded due to variance of attitude angle. High resolution image is liable to be smeared by motion error of satellite. By studying geometry model of space camera, a transformation relationship between earth coordinate system and space remote sensor coordinate system is put forward. Firstly, attitude error and motion source of TDI camera on orbit are analysed. Then, the transformation matrix is analyzed between earth coordinate and image plane coordinate. The in-out orientation elements are involved in the geometry model. Secondly, imaging procedure of TDI space camera is simulated. Different modals of flutter are added to imaging model in order to simulate flutter on the image. Integrated effects of multi-modals flutter are simulated on the line Of sight. The experiment simulation is based on three axis. Finally, the geometry distortion of pixel position is calculated on image plane. The measurement accuracy of geometry distortion is sub-pixel scale. The result is good for analyzing the parameters of satellite platform and guiding the design of remote sensor.