基于涡旋电磁波体制的三维SAR成像方法

Three-dimensional Imaging Using the Electromagnetic Vortex Synthetic Aperture Radar

涡旋电磁波得名于其传播时围绕行进轴的旋转现象,该电磁属性被称为轨道角动量。基于其在方位角上的目标分辨能力,该文将涡旋电磁波引入传统的合成孔径成像中,提出了一种新的三维成像方案。在结合轨道角动量模态域之后,将合成孔径雷达二维回波扩展到三维。首先,基于波形分集理论,获取同时多模态回波数据,并利用傅里叶变换(FT)变换到方位角维,形成距离-合成孔径方位-方位角三维数据。然后,基于Radon-FT,提出了一种联合二维方位压缩算法来生成三维目标成像。仿真结果验证了系统和算法的性能,证明了涡旋电磁三维合成孔径成像雷达系统的优越性。

The ElectroMagnetic Vortex(EMV)wave is named after the rotation around the wave propagation axis.This electromagnetic characteristic is called the Orbital Angular Momentum(OAM).Considering its azimuth angular resolution,this paper introduces the EMV wave into traditional Synthetic Aperture Radar(SAR)imaging and proposes a novel Three-Dimensional(3 D)imaging scheme called EMV-SAR.In EMV-SAR,the echo is extended into 3D after involving the OAM mode domain.Based on the waveform diversity technology,the multiOAM-mode echo is obtained and simultaneously transformed into azimuthal angular signals via Fourier Transform(FT)to form the 3D data of range-azimuth-angular.In this study,we propose a joint two-dimensional azimuthal compression algorithm to generate 3D target imaging based on Radon FT.The simulation results validate the performance of the proposed system and algorithms and demonstrate the superiority of EMV-SAR in 3D imaging.