轨道末期星载相机侧摆成像匹配分析与实验

通过分析卫星轨道末期星载TDI CCD相机成像面临的数据读出频率过大、像移失配严重等瓶颈问题, 提出了轨道末期卫星侧摆成像匹配方案. 依据轨道衰减高度, 设计侧摆成像匹配模型, 计算出轨道高度与匹配成像侧摆角度之间的变化关系, 对侧摆成像时的像移速度矢量、偏流角度、成像畸变等进行了定量的可行性分析, 并利用蒙特卡洛方法分析了满足侧摆成像的卫星姿态指向精度和稳定度. 利用基于小型三轴气浮台的小卫星姿态控制系统和TDI CCD相机成像系统进行仿真试验, 结果表明, 仿真图像的MTF函数和互相关相似性测度均在0.85以上, 侧摆成像匹配方案能较好地满足轨道末期成像需求. 

Image Matching Analysis and Experiment of Spaceborne Camera Swayed in the End of Orbit Life

Satellite sways matching image is established by analyzing the bottlenecks problem of that the data read-out frequency is too large, and the serious mismatch shift which spaceborne TDI CCD camera might face in the end of orbit life. Based on orbital decay height, the model of swaying match image is designed, the relation between orbit height and angle of the matching image is calculated, quantitative analysis on the feasibility of image motion vector, deviant angle, image distortion are carried out, and then satellite attitude pointing accuracy and stability which meet the requirement of imaging are analyzed through Monte Carlo methods. Finally, physical simulation of TDI CCD camera swaying-imaging is conducted on the mini-type three-axis air bearing table constructed for attitude control simulation of small satellite. Simulation results suggest that the MTF simulation and cross-correlation function of the similarity measurement are both more than 0.85, and satellite swaying to match image can meet the imaging requirement well in the end of the orbit life.