相位平移误差与子孔径自身像差对稀疏光学合成孔径系统成像质量的综合影响分析

摘要

稀疏光学合成孔径系统成像质量的提高需要综合考虑子孔径间相位平移误差和子孔径自身像差的影响.本文基于稀疏光学合成孔径系统的光瞳结构,利用傅里叶光学基本原理对系统的斯特列尔比（Strehl Ratio,SR）进行了理论推导,得到了包含相位平移误差和子孔径自身像差分离形式的该类系统的SR指标的理论公式.以两子孔径系统为例,计算并分析了在相位平移误差校正后和未校正时,系统SR指标在不同子孔径像差下的变化规律,研究了相位平移误差与子孔径像差对系统SR指标的综合影响.结果阐明了该类系统的成像质量受相位平移误差和子孔径自身像差双重制约的物理机理,且表明只有将子孔径自身像差校正至某限度内时,相位平移误差的校正才对系统SR指标的提高有明显意义.%To improve the image quality of sparse-optical-synthetic-aperture system,the effects of sub-aperture self aberrations and piston errors among different sub-apertures should be considered comprehensively.Based on the pupil of sparse-optical-synthetic-aperture system,the system Strehl Ratio（SR） is deduced using the principle of Fourier optics,which leads to the theoretical result of the systems SR metric with the form of separated sub-aperture aberration and piston error.As for the bi-aperture system,the variances of the system SR metric are calculated and analyzed with different sub-apertures＇ aberrations for conditions of corrected piston error and un-corrected piston error.Therefore,the comprehensive effects of sub-aperture aberrations and the piston errors among different sub-apertures on the system image quality are analyzed theoretically.From these analyses,the physical mechanism for the comprehensive effect of sub-aperture aberration and the piston error on the sparse-optical-synthetic-aperture system image quality is revealed,and it could be seen that the compensation of piston error is meaningful only if the sub-aperture self aberration is corrected to be in a certain limit.