直线阵光学综合孔径成像中的子孔径尺寸效应

Size Effects of Sub-Aperture on Imaging of Linear Array of Optical Synthetic Aperture

光学综合孔径阵列中的子孔径的位置和直径的大小对成像质量有着重要的影响。详细分析了几种不同优化排列的光学综合孔径直线阵列的无像差点扩展函数、光学传递函数和衍射成像特性,结果表明,子孔径的位置不同,光学传递函数的空间频率覆盖有很大的差异。增大子孔径的直径可以增大空间频率覆盖程度,但子孔径直径过大时又会产生空间频率冗余度和增加制造成本。直线阵光学综合孔径的衍射成像是多重像,子孔径直径的增大还可以减小重影的程度,提高成像质量。结果说明,在进行光学综合孔径阵列优化排列时必须考虑子孔径的直径大小这个重要的因素。

Positions and diameters of sub-aperture in optical synthetic aperture array are two important factor for imaging. The characteristics of point spread function, optical transfer function and diffraction image of several different optimized linear array configuration of optical aperture synthesis with aberration-free are discussed by using an approach based on ratio of diameter of sub-aperture to length of arrays. The results of simulated computation show that cover of spatial frequencies for optical transfer function are very different for different position of sub-aperture.The bigger the diameter of sub-aperture is, the more complete the spatial frequency covers. But when the ratio exceeds some extent, the spatial frequencies will be redundant and cost of system construction will increase. Besides,increase of sub-aperture can decrease the intensity of the ghost images and intensified the quality of imaging. The results show that the factors of diameter of sub-aperture and total length of arrays must be taken into account in the optimizations.