刘喆,,
武俊杰
电子科技大学信息与通信工程学院 成都 611731
基金项目:国家自然科学基金(61922023, 61771113)
详细信息
作者简介:廖杏杏(1996–)，女，电子科技大学信息与通信工程学院硕士研究生，主要研究方向为SAR成像及信号处理研究
刘喆：刘 喆(1978–)，女，博士，电子科技大学信息与通信工程学院副教授，主要研究方向为SAR成像及信号处理研究
武俊杰(1982–)，男，博士，电子科技大学信息与通信工程学院教授，主要研究方向为双多基地合成孔径雷达、认知成像雷达、微波光子成像雷达等新体制雷达成像技术
通讯作者:刘喆 liuzhe@uestc.edu.cn
责任主编：张冰尘 Corresponding Editor: ZHANG Bingchen中图分类号:TN958
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被引次数:0
出版历程
收稿日期:2021-07-22
修回日期:2021-09-27
网络出版日期:2021-10-01
刊出日期:2021-12-28
Azimuth Unambiguity Suppression for Low-oversampled Staggered SAR Images
LIAO Xingxing,LIU Zhe,,
WU Junjie
School of Information and Communication Engineering, University of Electronic Science and Technology of China, Chengdu 611731, China
Funds:The National Natural Science Foundation of China (61922023, 61771113)
More Information
Corresponding author:LIU Zhe, liuzhe@uestc.edu.cn
摘要
摘要:低过采样Staggered SAR利用变脉冲重复间隔技术有效分散盲区，可实现连续观测的高分宽幅成像，同时采用低过采样率可降低系统对数据存储的要求，因此具有重要的研究价值。然而，低过采样Staggered SAR存在的非均匀采样、回波丢失和非理想方位天线方向图(AAP)问题会导致成像结果中出现严重的方位模糊。该文提出了一种基于压缩感知的成像方法，可解决已有方法模糊抑制性能差和效率低的问题。首先，建立了准确描述低过采样Staggered SAR非均匀采样、回波丢失和距离徙动的创新性频域模型(IFDM)，利用二维快速迭代收缩阈值算法对基于该IFDM构造的优化问题进行迭代求解可抑制非均匀采样和回波丢失造成的方位模糊；然后，利用选择滤波方法处理迭代结果可抑制非理想AAP造成的方位模糊。实验结果表明该文方法在成像性能和效率上均优于已有方法。
关键词:合成孔径雷达/
变脉冲重复间隔/
低过采样/
高分宽幅
Abstract:Low-oversampled staggered synthetic aperture radar can achieve continuously observed high-resolution and wide-swath imaging by utilizing the variable pulse repetition interval to distribute blind ranges. Moreover, adopting a low oversampling ratio can reduce the data storage requirements, contributing to its research significance. However, non-uniform sampling, echo data loss, and non-ideal Azimuth Antenna Pattern (AAP) cause severe azimuth ambiguities in a directly focused image. This study proposes a compressive sensing-based method with better ambiguity removal performance and higher efficiency compared to existing methods. First, an Innovative Frequency-Domain Model (IFDM) is constructed, which accurately describes the non-uniform sampling, echo data loss, and coupled range cell migration. Based on the IFDM, an optimization problem is constructed and solved by the two-dimensional fast iterative shrinkage thresholding algorithm to remove the ambiguity caused by non-uniform sampling and echo data loss. Subsequently, selective filtering is used to suppress the ambiguity caused by the AAP. The experiments demonstrate that the proposed method can more effectively and efficiently suppress the azimuth ambiguities compared to existing methods.
Key words:Synthetic Aperture Radar (SAR)/
Variable pulse repetition interval/
Low oversampling/
High Resolution and Wide Swath (HRWS)
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