Yuan Tiezhu, Wang Hongqiang, Cheng Yongqiang, Qin Yuliang
School of Electronic Science and Engineering, National University of Defense Technology, Changsha 410073, China.
Sensors (Basel). 2017 Mar 19;17(3):630. doi: 10.3390/s17030630.
Radar imaging based on electromagnetic vortex can achieve azimuth resolution without relative motion. The present paper investigates this imaging technique with the use of a single receiving antenna through theoretical analysis and experimental results. Compared with the use of multiple receiving antennas, the echoes from a single receiver cannot be used directly for image reconstruction using Fourier method. The reason is revealed by using the point spread function. An additional phase is compensated for each mode before imaging process based on the array parameters and the elevation of the targets. A proof-of-concept imaging system based on a circular phased array is created, and imaging experiments of corner-reflector targets are performed in an anechoic chamber. The azimuthal image is reconstructed by the use of Fourier transform and spectral estimation methods. The azimuth resolution of the two methods is analyzed and compared through experimental data. The experimental results verify the principle of azimuth resolution and the proposed phase compensation method.
基于电磁涡旋的雷达成像无需相对运动即可实现方位分辨率。本文通过理论分析和实验结果，对使用单个接收天线的这种成像技术进行了研究。与使用多个接收天线相比，单个接收器的回波不能直接用于采用傅里叶方法的图像重建。利用点扩散函数揭示了其原因。在成像过程之前，根据阵列参数和目标仰角，为每个模式补偿一个附加相位。构建了基于圆形相控阵的概念验证成像系统，并在消声室中对角反射器目标进行了成像实验。利用傅里叶变换和谱估计方法重建方位图像。通过实验数据对这两种方法的方位分辨率进行了分析和比较。实验结果验证了方位分辨率原理和所提出的相位补偿方法。
