| 摘要: |
| 针对现今日益复杂的电磁环境和各种高新技术的涌现，不断出现了一些新概念、新体制雷达，来解决传统雷达成像性能瓶颈等问题。电磁涡旋雷达是近几年提出的一种新型雷达。携带轨道角动量(OAM)的涡旋电磁波具有特殊的螺旋形相位波前，可以为雷达成像带来更加丰富的自由度，以突破传统雷达成像分辨率限制，实现超高分辨率成像。根据合成孔径雷达(SAR)的特点，研究了电磁涡旋雷达成像的理论基础，重点剖析了电磁涡旋在SAR成像中的应用，建立了多收多发电磁涡旋SAR(EMV-SAR)成像模型，并对传统的反向投影(BP)算法进行了改进，提出了一种适用于涡旋电磁波的新型SAR成像方法。实验结果表明，EMV-SAR系统可以极大地提高方位向成像分辨率，随着OAM模式数的增大分辨率逐步提升，并且混合多模的涡旋电磁波可以有效地解决引入电磁涡旋后方位向旁瓣电平增高的问题。 |
| 关键词: 电磁涡旋 轨道角动量 雷达成像 电磁涡旋SAR |
| DOI：DOI:10.3969/j.issn.1672-2337.2020.05.012 |
| 分类号:TN957.52 |
| 基金项目:国家自然科学基金（No.61961033，61631044）； 内蒙古自治区自然科学基金（No.2019MS06021）； 内蒙古自治区青年科技领军人才项目（No.NJYT-19-A15）； 内蒙古科技大学创新基金项目（No.2017YQL10） |
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| Electromagnetic Vortex Imaging Method Based on Improved BP Algorithm |
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DU Yongxing， TONG Zongjun， QIN Ling， LI Chenlu， LI Baoshan
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School of Information Engineering, Inner Mongolia University of Science and Technology, Baotou 014010, China
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| Abstract: |
| In view of the increasingly complex electromagnetic environment and the emergence of various high-techs, there are some new concepts and new systems of radar to solve the problem of traditional radar imaging performance bottleneck. Electromagnetic vortex radar is a new type of radar proposed in recent years.The vortex electromagnetic wave with orbital angular momentum (OAM) has a special spiral phase wavefront, which can bring more freedom for radar imaging, so as to break through the limitation of traditional radar imaging resolution and achieve ultra-high resolution imaging.According to the characteristics of synthetic aperture radar(SAR), the theoretical basis of electromagnetic vortex radar imaging is studied in this paper,with focus on the application of electromagnetic vortex in SAR imaging. The imaging model of multi receiver multi transmitter electromagnetic vortex SAR(EMV-SAR) is established and the traditional back projection (BP) algorithm is improved. And a new SAR imaging method suitable for vortex electromagnetic wave is proposed. The experimental results show that the EMV-SAR system can greatly improve the azimuth imaging resolution. With the increase of OAM mode number, the resolution gradually increases, and the mixed multi-mode vortex electromagnetic wave can effectively solve the problem of azimuth sidelobe level increasing after introducing the electromagnetic vortex. |
| Key words: electromagnetic vortex orbital angular momentum radar imaging electromagnetic vortex SAR |
