二维圆周光综合孔径阵的优化排列及其成像特性研究  

Study of Optimization and Imaging Characteristics of Two-Dimensional Circle Array for Optical Synthetic Aperture System

作　　者：陈海亭[1] 江月松[1] 钟宇[1] 

机构地区：[1]北京航空航天大学电子信息工程学院,北京100083

出　　处：《光学学报》2005年第12期1616-1622,共7页Acta Optica Sinica

基　　金：国防预研基金项目(6140434)资助课题

摘　　要：光综合孔径成像的原理是应用干涉原理在空间频率域中进行采样,并通过傅里叶反变换或其他数值变换方法得到空间分辨力远高于单个孔径成像系统的目标图像.由若干个相同的小孔径在二维圆周上优化排列组成的综合孔径成像系统可以在二维空间频率域中实现较为均匀分布的、具有无冗余度的采样点覆盖,为高质量实时成像提供了一个有效的途径.运用模拟退火算法对由7～16个子孔径组成的二维圆周综合孔径阵列进行优化排列.并依据光学衍射成像原理,从空域和频域两个方面详细分析了二维圆周上优化排列与均匀排列光综合孔径阵的成像特性.对7～16个子孔径组成的光综合孔径的仿真结果表明:无论是在空域还是频域上,子孔径直径增大、孔径数目增多以及综合孔径阵的优化排列都是有利于提高成像质量的.但综合后的子孔径的直径的增大,虽然能获得极高的角分辨力,却并不利于成像质量的提高.Optical synthetic aperture imaging system applies the interferometric method to sample object in the spatial frequency domain and retrieve the image whose spatial resolution is much higher than that of monolithic aperture by inverse Fourier or other numerical transformation. An optimized synthetic aperture array which is composed of a number of identical sub-aperture located at a circle can provide a roughly uniform distributed and no- redundant sampling coverage in two-dimensional spatial frequency domain, which can form a high quality and snapshot imaging system. An optimization method called simulated annealing is adopted for the optimization of a two- dimensional circle aperture array composed of 7- 16 sub-apertures. Based on principle of optical diffraction imaging, imaging characteristics of the optimized arrays as well as arrays distributed evenly composed of N sub-apertures at a two-dimensional circle are analyzed in detail by using computer simulation in both spatial domain and frequency domain. The simulated computation results of the arrays composed of 7- 16 sub-apertures show that the optimized array has better quality of image than the arrays of distributed sub-aperture in both point spread function and optical transfer function. Besides, the bigger the size and the more the number of sub-aperture, the better the imaging is. But, on the other hand, although higher resolution can be obtained with bigger size of the circle synthesized by a number of sub-aperture, improved imaging quality is refused.

关 键 词：成像系统 综合孔径 优化阵列 u v平面覆盖 成像特性 

分 类 号：TH742.1[机械工程—光学工程]