基于快速采样的剪切光束成像图像重构算法  

Fast sampling based image reconstruction algorithm for sheared-beam imaging

作　　者：陈明徕 马彩文[1,2,3] 刘辉 罗秀娟[1,2,3] 冯旭斌[1,2] 岳泽霖 赵晶[1,3] Chen Ming-Lai;Ma Cai-Wen;Liu Hui;Luo Xiu-Juan;Feng Xu-Bin;Yue Ze-Lin;Zhao Jing(Xi’an Institute of Optics and Precision Mechanics,Chinese Academy of Sciences,Xi’an 710119,China;Key Laboratory of Space Precision Measurement Technology,Chinese Academy of Sciences,Xi’an 710119,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院西安光学精密机械研究所,西安710119 [2]中国科学院空间精密测量技术重点实验室,西安710119 [3]中国科学院大学,北京100049

出　　处：《物理学报》2024年第2期156-166,共11页Acta Physica Sinica

基　　金：陕西省自然科学基础研究计划(批准号:2020JQ-438)资助的课题。

摘　　要：剪切光束成像是一种非传统地基光学成像技术,在对位姿快速变化的目标成像时,为重构目标高分辨率清晰图像,其成像系统的回波数据采样速率仍不够快.本文提出一种五光束快速采样的图像重构方法,通过改变成像系统编码和解码方法,采用中心对称结构呈“十”字形排布的发射光束阵型,利用所提的快速图像重构算法,单次采样的回波数据所能重构的目标图像从1幅增加到8幅,快速抑制了重构图像的散斑效应.仿真结果表明,与传统三光束图像重构方法相比,获得相同质量图像所需的回波数据采样次数从20次减少至5次,大幅减少了回波数据采样次数,提高了回波数据采样速率.Sheared-beam imaging(SBI)is an unconventional ground-based optical imaging technique.It breaks through the traditional optical imaging concept by using three coherent laser beams,which are laterally displaced at the transmit plane,to illuminate the target,reconstructing the target image from echo signals.However,the echo data sampling of the imaging system is still not fast enough to reconstruct the high resolution and clear image of the target when imaging the target that is at rapidly changing position and attitude.In order to solve this problem,in this work an image reconstruction method is proposed based on fivebeam fast sampling.An emitted beam array arranged in the cross shape with a central symmetrical structure is proposed,and the encoding and decoding method of the imaging system are changed.With a single exposure,the echo signals carry more spectrum information of the target,and the number of reconstructed images can be increased from 1 to 8,which quickly suppresses the speckle effect of the reconstructed image.Firstly,the principle of the imaging technique based on fast sampling is presented.Then,an image reconstruction algorithm based on fast sampling is studied.Eight groups of phase differences and amplitude information of the target can be extracted from echo signals.The wavefront phases are solved by the least-squares method,and wavefront amplitude can be obtained by the algebraic operation of speckle amplitude.The target image is reconstructed by the inverse Fourier transform.The simulation results show that comparing with the traditional three-beam image reconstruction method,the sampling times of echo data needed to obtain the same quality image are reduced from 20 to 5,which greatly reduces the sampling times of echo data and improves the sampling rate of echo data.

关 键 词：剪切光束成像 快速采样 图像重构 采样速率 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术]