高分CMOS相机垂轨引导凝视搜索成像设计

Design of Pendulum Staring Search Imaging Along the Track with High Resolution CMOS Camera

为实现高分面阵相机对垂直轨道方向的长条带区域一定重叠率的凝视搜索成像,设计了凝视姿态与地速运动互补偿的垂轨凝视搜索模型。通过划分垂轨长条带区域与构建目标三维运动速度,设计成像实时姿态变化与地球自转互补偿的引导策略,计算垂轨自适应搜索成像参数与实时变化指向姿态,并对卫星姿控精度对成像的影响进行了分析。最后,利用姿控三轴气浮仿真系统与CMOS相机对曲面LED目标模拟系统进行等比缩放物理仿真实验。结果表明:垂轨凝视自适应搜索成像参数为0.95时,可实现垂轨方向边缘帧间重叠率为85%、中心帧间重叠率为100%的渐变垂轨长条带成像区域,比全凝视成像区域扩大近4倍,姿控精度和姿态稳定性优于0.05°与0.003(°)s^(-1)时,像移失配量小于0.9pixel,对应的调制传递函数值为0.1559。

In order to realize the staring search imaging with a certain overlap of long strip area in the vertical direction of high resolution array camera,apendulum staring search imaging model is designed with the staring gesture and earth movement complement.Based on the division of the strip layer by layer and the construction of three-dimentional movement rate,the guiding strategy of real-time posture change and earth rotation compensation is designed.Besides,the pendulum adaptive search imaging parameters and real-time variation point orientation are calculated,and the effect of attitude control precision on imaging is analyzed.Finally,aground scaling simulation experiment is carried out through the CMOS prototype,the attitude control three-axis flotation simulation platform and curved LED target system.The result shows that a gradually variational strip area with the inter frame overlap ratio more than 85%can be obtained using the pendulum staring search imaging when the pendulum staring adaptive search imaging parameter is 0.95,which is enlarged by four times than the staring imaging area.When the attitude control precision is better than 0.05°and attitude stability is better than 0.003（°）s^-1,the image motion mismatching quantity is less than 0.9pixel and the corresponding modulation transfer function can reach up to 0.1559.