THz全尺寸凸体粗糙目标雷达回波散射建模与成像仿真

高敬坤; 邓彬; 秦玉亮; 王宏强; 黎湘

doi:10.12000/JR17086

THz全尺寸凸体粗糙目标雷达回波散射建模与成像仿真

doi: 10.12000/JR17086

国防科技大学电子科学学院长沙 410073

基金项目: 国家自然科学基金(61701513, 61571011)

详细信息

作者简介:
高敬坤(1992–)，男，山东梁山人，国防科技大学电子科学学院博士生，主要研究方向为雷达成像与信号处理

邓　彬(1981–)，男，山东邹城人，国防科技大学电子科学学院副研究员，主要研究方向为合成孔径雷达、太赫兹雷达微动与成像

秦玉亮(1980–)，男，山东潍坊人，国防科技大学电子科学学院副研究员，主要研究方向为太赫兹雷达、雷达关联成像与电磁涡旋

王宏强(1970–)，男，陕西宝鸡人，国防科技大学电子科学学院研究员，973技术首席，原863太赫兹专家，主要研究方向为太赫兹雷达、雷达信号处理与自动目标识别等

黎　湘(1967–)，男，湖南浏阳人，国防科技大学电子科学学院教授，长江学者特聘教授，主要研究方向为目标探测识别与雷达成像等

通讯作者:
王宏强 oliverwhq@tom.com

中图分类号: TN95
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出版历程
- 收稿日期: 2017-10-09
- 修回日期: 2018-01-15
- 网络出版日期: 2018-02-28

Radar Echo Scattering Modeling and Image Simulations of Full-scale Convex Rough Targets at Terahertz Frequencies

College of Electronic Science and Engineering, National University of Defense Technology, Changsha 410073, China

Funds: The National Natural Science Foundation of China (61701513, 61571011)

摘要

摘要: 回波仿真是研究雷达成像体制、算法及后续应用的前提条件，目标散射建模又是回波仿真的重要一环。在THz频段，目标常常具有超电大尺寸，这使得利用经典电磁计算方法面临现实困难。而波长的减小使得目标表面粗糙起伏成为不能忽略的因素，这使得传统基于点散射模型的回波生成手段难以适用。如何对目标进行THz散射建模及高效的雷达回波生成成为亟待解决的问题。该文提出了基于面片分级的半确定性建模方法，采用粗糙面全波法计算面片的散射场，再将各面片散射场转换至目标坐标系并相干叠加得到带有相位信息的雷达回波。利用小尺寸粗糙模型，通过与高频数值方法进行对比，验证了该文方法的有效性，并给出了全尺寸锥体的成像结果。初步解决了THz频段全尺寸凸体粗糙目标散射建模及回波生成问题，为后续成像体制和算法研发打下了基础。
- THz /
- 回波仿真 /
- 粗糙表面 /
- 超电大
Abstract: Echo simulation is a precondition for developing radar imaging systems, algorithms, and subsequent applications. Electromagnetic scattering modeling of the target is key to echo simulation. At terahertz (THz) frequencies, targets are usually of ultra-large electrical size that makes applying classical electromagnetic calculation methods unpractical. In contrast, the short wavelength makes the surface roughness of targets a factor that cannot be ignored, and this makes the traditional echo simulation methods based on point scattering hypothesis in applicable. Modeling the scattering characteristics of targets and efficiently generating its radar echoes in THz bands has become a problem that must be solved. In this paper, a hierarchical semi-deterministic modeling method is proposed. A full-wave algorithm of rough surfaces is used to calculate the scattered field of facets. Then, the scattered fields of all facets are transformed into the target coordinate system and coherently summed. Finally, the radar echo containing phase information can be obtained. Using small-scale rough models, our method is compared with the standard high-frequency numerical method, which verifies the effectiveness of the proposed method. Imaging results of a full-scale cone-shape target is presented, and the scattering model and echo generation problem of the full-scale convex targets with rough surfaces in THz bands are preliminary solved; this lays the foundation for future research on imaging regimes and algorithms.
- Terahertz waves /
- Echo simulation /
- Rough surface /
- Electric-Large

HTML全文

图 1 全尺寸目标一级面片建模示意图

Figure 1. Illustration of the first-level-facets modeling of full-scale targets

下载: 全尺寸图片幻灯片

图 2 二级面片建模过程示意图

Figure 2. Illustration of the second-level-facets modeling

下载: 全尺寸图片幻灯片

图 3 一级面片坐标系定义

Figure 3. Definition of the first-level-facet coordinate system

下载: 全尺寸图片幻灯片

图 4 THz全尺寸凸体粗糙目标回波仿真流程

Figure 4. Flowchart of radar echo simulation for THz full-scale convex rough targets

下载: 全尺寸图片幻灯片

图 5 粗糙矩形板RCS随俯仰角变化曲线

Figure 5. Calculated RCS vs. elevation angle of the rough rectangular plate

下载: 全尺寸图片幻灯片

图 6 粗糙平板成像结果，粗糙度250 μm( $\lambda /4$ )

Figure 6. Imaging results of the rough plate with 250 μm surface roughness

下载: 全尺寸图片幻灯片

图 8 粗糙锥体成像结果，粗糙度250 μm( $\lambda /4$ )

Figure 8. Imaging results of the full-scale cone with 250 μm surface roughness

下载: 全尺寸图片幻灯片

图 7 粗糙锥体成像结果，粗糙度125 μm( $\lambda /8$ )

Figure 7. Imaging results of the full-scale cone with 125 μm surface roughness

下载: 全尺寸图片幻灯片

表 1 小尺寸粗糙矩形板回波生成及成像仿真参数

Table 1. Parameters of echo generation and image simulation for the rough rectangular plate

参数	数值
方位向转角(°)	10
方位向采样间隔(°)	0.25
俯仰向转角(°)	10
俯仰向采样间隔(°)	0.25
中心方位角(°)	45
方位向分辨率(cm)	0.29
方位向不混叠距离(cm)	11.5
俯仰向分辨率(cm)	0.29
俯仰向不混叠距离(cm)	11.5
中心俯仰角(°)	45

下载: 导出CSV

表 2 小尺寸粗糙矩形板回波生成资源消耗

Table 2. Memory costs and time needs of echo simulation for the rough plate

计算方法	计算内存消耗(MB)	计算耗时(s)
CST软件	156	≈58900
本文方法	143	489

下载: 导出CSV

表 3 全尺寸锥体回波生成及成像仿真参数

Table 3. Parameters of echo generation and image simulation for the full-scale cone

参数	数值
方位向转角(°)	1
方位向采样间隔(°)	0.04
俯仰向转角(°)	1
俯仰向采样间隔(°)	0.025
中心方位角(°)	45
方位向分辨率(cm)	2.86
方位向不混叠距离(cm)	0.72
俯仰向分辨率(cm)	2.86
俯仰向不混叠距离(cm)	1.15
中心俯仰角(°)	55

下载: 导出CSV

表 4 全尺寸锥体回波生成资源消耗

Table 4. Memory costs and time needs of echo simulation for the full-scale cone

计算方法	计算内存消耗(MB)	计算耗时(s)
CST软件	—	—
本文方法	2969	≈317000

下载: 导出CSV

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