光学合成孔径一维旋转阵列多帧成像优化方法

为提高一维合成孔径阵列的成像分辨率,研究 利用旋转基 线的方式实现含相位误差情况下的一维阵列多帧成像与复原。首先比较不同子孔径数及排列 方式的优劣,确定合适的阵列结 构；然后通过旋转基线进行多帧成像,实现频谱在各方向上的覆盖；利用多帧维纳滤波进行 复原,以相关系数为评价准则, 并结合成像性能与效率在3种备选方案中确定理想的旋转方式；最后通过增加旋转次数,实 现频谱的重复覆盖,以消除考虑相 位误差对成像质量的影响。实验表明,以60°旋转5次成像时,一维三孔径阵列的活塞误差 容限为0.07,倾斜误差容限为 40μrad。本文提出的一维旋转阵列多帧成像方法可以在消除一 定相位误差影响的同时实现高清晰复原,具有较强的实用价值。

Multi-frame imaging optimization of optical synthetic aperture 1D rotati on array

D synthetic aperture array has obvious advantages on imaging effic iency while the unequal distribution of its intensity reduces the resolution.Hence this research is focused on the multi-f rame imaging and restoration by rotating the baseline of 1D optical synthetic aperture system with phase errors.Firstly,1D arrays wi th various sub-aperture numbers or arrangements are compared thoroughly and the proper array structure is determined;then multi-f rame images are obtained by rotating the baseline which covers most of the frequency domain,and then multi-frame Wiener filter algorithm is proposed and applied to restore the collected images with various frequency spectrums.Furthermore,the restoration quality is assessed by correlation coefficient. Taking both performance and efficiency into account,the ideal rotation method w as determined among three given candidates.Finally, by increasing the rotation times,the spectrum is covered repeatedly so as to e liminate the influence of phase errors.While imaging by rotating 5times with 60°,the piston and tip/tilt error tolerances of 1D th ree-aperture array are 0.07and 40,separately.The proposed multi-frame imaging method of 1D rotation array can realize the high r esolution restoration as well as eliminating the influence of phase errors.