基于聚合型涡旋电磁波束的三维SAR成像

国少卿; 何姿; 陈如山

doi:10.12265/j.cjors.2021070

基于聚合型涡旋电磁波束的三维SAR成像

doi: 10.12265/j.cjors.2021070

南京理工大学电子工程与光电技术学院，南京 210094

基金项目: 国家自然科学基金（61731001，61871443，61771246）

详细信息

作者简介:
国少卿：（1990—），男，南京理工大学博士研究生，主要研究方向为计算电磁学、雷达成像

何姿：（1988—），女，南京理工大学副教授，博士，主要研究方向为计算电磁学及工程应用

陈如山：（1965—），男，南京理工大学教授，博士研究生导师，主要研究方向为计算电磁学、天线设计与优化、微波成像等

通讯作者:
何姿 E-mail：zihe@njust.edu.cn

中图分类号: TN959.1
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- 被引次数: 0
出版历程
- 收稿日期: 2021-03-23
- 网络出版日期: 2021-07-19

Three dimensional SAR imaging based on the focused electromagnetic vortex beam

School of Electronic and Optical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China

摘要

摘要: 合成孔径雷达(synthetic aperture radar, SAR)能够突破天线孔径对分辨率的限制，因而得到了广泛应用. 本文提出了一种基于聚合型涡旋电磁波束的三维SAR成像方法，通过设计合适的成像几何构型，利用涡旋电磁波的相位特性实现对高度维的分辨，并推导得到高度维分辨率与模式数及雷达参数之间的关系. 考虑到回波信号中引入的涡旋相位项，对后向投影算法进行改进，实现对观测区域的三维成像，并引入稀疏重构算法减少对模式数的需求. 仿真结果表明，利用多模式聚合型涡旋电磁波束能够对分布在不同高度的目标进行准确重构，利用稀疏重构算法能够用少数模式实现高分辨三维成像. 本文提出的方法为新体制雷达成像研究提供了一定的参考.
- 合成孔径雷达（SAR） /
- 涡旋电磁波 /
- 三维成像 /
- 后向投影 /
- 稀疏重构
Abstract: Synthetic aperture radar(SAR) is widely applied since it can break through the limitation of resolution by antenna aperture. In this paper, the focused electromagnetic(EM) vortex beam is applied to synthetic aperture radar to realize 3D imaging. By appropriately designing the imaging geometry, height resolution can be achieved with the use of the phase characteristics of EM vortex wave, and the relationship between height resolution and the number of orbital angular momentum(OAM) mode and radar parameters is derived. Considering the vortex phase term introduced in the echo signal, the improved back projection algorithm is applied to realize 3D imaging, and then sparse recovery algorithm is introduced to reduce the demand of the number of OAM mode. Simulation results indicate that the targets distributed at different heights can be accurately reconstructed, and high resolution is realized by sparse recovery method with few OAM modes. The method in this paper provides a certain reference for the research of new radar imaging system.
- synthetic aperture radar (SAR) /
- electromagnetic vortex beam /
- 3D imaging /
- back projection /
- sparse recovery

HTML全文

图 1 平面涡旋电磁波^[22]

Fig. 1 Plane spiral OAM wave^[22]

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图 2 不同模式组合后幅度、相位随方位角的变化

Fig. 2 Amplitude and phase distribution for different OAM mode group

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图 3 不同模式数量对波束宽度的影响

Fig. 3 Focused beam width for different number of OAM mode

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图 4 模式间隔对聚合后主瓣个数的影响

Fig. 4 Different number of main lobes for different mode interval

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图 5 三维SAR成像模型

Fig. 5 Diagram of 3D SAR imaging

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图 6 高度向分辨率分析

Fig. 6 Resolution of the height direction

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图 7 成像区域三维网格划分

Fig. 7 Three dimensional mesh grid

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图 8 单个点目标成像结果

Fig. 8 Imaging results of single point

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图 9 两个点目标成像结果

Fig. 9 Imaging result of two points

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图 10 稀疏重构算法得到的两个点目标成像结果

Fig. 10 Imaging result of two point by sparse recovery method

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图 11 稀疏重构算法得到的12个点目标成像结果

Fig. 11 Imaging result of 12 points by sparse recovery method

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表 1 仿真参数

Tab. 1 Simulation parameters

参数	取值
载体平台高度H	1 000 m
速度v	150 m/s
中心频率f_c	5 GHz
带宽B	50 MHz
脉冲宽度T	2.5 μs
调频率K_r	20×10¹² Hz/s
天线半径r	1 m
入射角β	45°

下载: 导出CSV

表 2 12个点目标位置

Tab. 2 locations of the 12 points

点目标	位置/m	点目标	位置/m
P₁	(1 020,−10,0)	P₇	(1 020,10,50)
P₂	(1 040,−10,0)	P₈	(1 040,10,50)
P₃	(1 020,10,0)	P₉	(1 020,−10,100)
P₄	(1 040,10,0)	P₁₀	(1 040,−10,100)
P₅	(1 020,−10,50)	P₁₁	(1 020,10,100)
P₆	(1 040,−10,50)	P₁₂	(1 040,10,100)

下载: 导出CSV

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