摘要
稀疏孔径系统作为高分辨率成像解决方案,其成像性能却受子孔径之间活塞误差和各独立子孔径波前残差强烈影响。以均匀环五孔构型为研究对象,通过对点扩散函数和调制传递函数的表征,数值模拟得到了该构型的成像相关误差指标。从频域覆盖无截断的角度分析了环五孔构型的填充因子,选择范围为27.8%至68.5%。以斯特列尔比(大于0.80)为评价准则,填充因子为43.2%时的子孔径之间的活塞误差最大容忍度约为λ/6,含有独立自适应光学系统的各子孔径的波前残差均方根最大容忍度约为λ/14。填充因子的选择范围从根本上受到子孔径波前残差的限制,而子孔径之间的共相则需以一定的自适应光学校正水平为前提。
High-resolution imaging plays a crucial role in various fields such as astronomical observations,earth sciences,and national defense.Traditionally,the main approach to improve angular resolution is via increasing the aperture of optical system.However,manufacturing and maintaining large aperture telescopes often come with high costs,and space-based optical systems are particularly constrained by payload limitations.Sparse aperture systems have emerged as a solution that can simultaneously reduce cost budgets and process requirements,garnering widespread attention since their inception.The high-resolution imaging capability of sparse aperture systems is essentially achieved through the interference between sub-apertures,resulting in a reduction of the half-width of the sub-aperture′s Airy disk.To achieve effective interference between subapertures,the control of optical path difference,or the co-phasing of sub-apertures is of great importance and therefore can largely determine the imaging performance of the sparse aperture system.Although adaptive optics systems can provide a relatively flat wavefront,the correction process is performed independently for each subaperture,and the relative optical path of the sub-paths used for coherent interference can not be simultaneously controlled.In this study,a annular-5 configuration is firstly discussed based on the constraints imposed by the frequency domain.The annular-5 configuration exhibits a five-fold symmetry,with non-redundant baseline directions between sub-apertures.The resulting modulation transfer function possesses a ten-fold symmetry,providing certain advantages on an equivalent single-aperture telescope.The analytical expression for the point spread function of the annular-5 configuration has been derived based on the theory of Fourier optics.Theoretically,the peak of the point spread function for the annular-5 configuration is 25 times larger than the peak of the point spread function for an individual sub-aperture.This is because the annular-5 configurat
作者
朱剑凯
梁永辉
刘冀林
霍卓玺
杨慧哲
ZHU Jiankai;LIANG Yonghui;LIU Jilin;HUO Zhuoxi;YANG Huizhe(College of Advanced Interdisciplinary Studies,National University of Defense Technology,Changsha 410073,China;Nanhu Laser Laboratory,National University of Defense Technology,Changsha 410073,China;China Academy of Aerospace Science and Innovation,Beijing 100176,China;Qian Xuesen Laboratory of Space Technology,China Academy of Space Technology,Beijing 100081,China)
出处
《光子学报》
EI
CAS
CSCD
北大核心
2024年第7期135-144,共10页
Acta Photonica Sinica
基金
国家自然科学基金(Nos.62005314,U23B6002)
科工局十四五民用航天预先研究项目(Nos.D010104,D010301)。
关键词
稀疏孔径系统
环五孔构型
干涉成像
波前残差
填充因子
Sparse aperture system
Annular-5 configuration
Interference imaging
Wavefront residual
Fill factor
