联合变换相关器像移测量试验系统设计

Design of test system for image motion measurement based on joint transform correlator

为了测量由于卫星姿态不稳定或振动等原因引起的空间相机亚像元像移,设计了基于联合变换相关器的像移测量试验系统,提出了像移测量方法。阐述了该测量方法的数学原理,给出了面阵CCD的安装位置以及输入图像序列的获取方法。根据相关参数确定了试验系统的傅里叶透镜结构和参数,最终设计了试验系统。应用线性插值和像元合并方法获得具有亚像元像移的输入图像。试验结果表明,像移测量的精度不随景物的内容而变化,测量得到的像移误差均方根值<0.2pixel。

To measure the sub-pixel image motion of a space camera caused by the satellite attitude instability or vibration, a test system for image motion measurements based on a joint transform correlator was designed,and the image motion measurement method was presented. After deducing the mathematics principles of the measuring method, the position of a matrix CCD on the focal plane and the method of getting input images were presented. The Fourier lens structure and parameters in the test system were determined by related parameters, then a test system was designed. Finally, an input image with sub-pixel image motion was obtained by a linear interpolation and pixel combination method. The results show that the error does not change with different scenes of input images, and the error RMS of image motion is less than O. 2 pixe｜.