摘要
基于超表面的关联成像系统解决了关联成像系统探测效率低的问题,但其探测模式数量不足导致了其有效成像点数受限。针对这个问题,该文以参考辐射场空间分布1阶统计特征为基础,建立了基于随机调制超表面的关联成像信号模型,分析了成像误差,并与差分关联成像(DCI)方法相结合,给出了具有鲁棒性的基于超表面的关联成像方法,该方法利用不同模式的差分形成了新的探测模式,降低了相关函数的副瓣干扰,从而提升了成像质量。同时,对一种特殊的差分关联成像方法—梯度关联成像(GCI)方法的成像分辨率进行了分析,该方法通过对超表面单元的特殊设计,可以在不获取图像的情况下,直接在成像过程中提取出目标方位向的边缘信息,可以有效提升关联成像系统对目标边缘的提取能力。最后,通过仿真实验验证了该文理论分析的正确性。
The coincidence imaging system based on a metamaterial surface solves the problem of low detection efficiency.Nevertheless,the number of effective imaging points is limited owing to the lack of the detection mode.To solve this problem,based on the first-order statistical characteristics of a reference-radiation field,a correlation-imaging signal model based on a randomly-modulated metamaterial surface is established,and the imaging error is analyzed.This study presents a robust coincidence imaging called Differential Coincidence Imaging(DCI),which uses the differential of different modes to form a new detection mode.The DCI analysis proves that it can improve the imaging quality.At the same time,the resolution of a special DCI method called the Gradient Coincidence Imaging(GCI)method is analyzed,which effectively improves the ability of extracting a target edge.With the special design of a metasurface unit,the edge information of a target can be extracted directly in the imaging process without obtaining an image.Finally,the proposed methods are validated through simulation experiments.
作者
年毅恒
周宁宁
朱士涛
张安学
NIAN Yiheng;ZHOU Ningning;ZHU Shitao;ZHANG Anxue(School of Information and Communication Engineering,Xi’an Jiaotong University,Key Laboratory of Multifunctional Materials and Structures,Ministry of Education,Xi’an 710049,China)
出处
《雷达学报(中英文)》
CSCD
北大核心
2021年第2期296-303,共8页
Journal of Radars
基金
国家自然科学基金(62071371)
超高速电路设计与电磁兼容教育部重点实验室资助(LHJJ/2020-04)
雷达信号处理国防科技重点实验室资助。
关键词
一阶关联
随机调制超表面
差分关联成像
梯度关联成像
边缘信息
成像分辨率
First-order correlation
Randomly modulated metamaterial surface
Differential Coincidence Imaging(DCI)
Gradient Coincidence Imaging(GCI)
Edge information
Imaging resolution