摘要
带有轨道角动量(OAM)的涡旋电磁波理论上可以产生无穷多种相互正交的调制模式,为MIMO-SAR系统带来了新的自由度。根据MIMO-SAR的特点,研究了电磁涡旋雷达成像的理论基础,建立了正侧视下的OAM-SAR成像模型,针对涡旋信号采用了改进的BP算法进行双波段成像,利用低波段成像结果确定目标大致范围,利用高波段成像结果获得目标清晰细节,最后将两幅图像进行融合。仿真和实际数据处理结果表明,BP-OAM-SAR系统可以大幅度提高方位向分辨率,而双波段SAR图像融合可以降低成像的计算量,有效排除高波段下虚像的干扰,进一步提高图像分辨率。
Theoretical research has shown that electromagnetic waves with Orbital Angular Momentum(OAM)can generate an infinite number of mutually orthogonal modulation modes.This property brings new degrees of freedom to MIMO-SAR systems.Based on the characteristics of MIMO-SAR,the theoretical foundations of electromagnetic vortex radar imaging is studied,and the OAM-SAR imaging model is established for side-looking geometries.An improved back-projection(BP)algorithm is employed for dual-band imaging using vortex signals.The low-band imaging result is utilized to determine the approximate range of the target,while the high-band imaging result provides clear and detailed information about the target.Finally,the two images are fused together.Simulation and image evaluation results demonstrate that the BP-OAM-SAR system significantly enhances azimuth resolution.Moreover,the dual-band SAR image fusion technique reduces computational complexity and effectively eliminates the interference of virtual images in the high-band,and further improve the image resolution.
作者
潘夏叶
胡俊
李黄炎
高晓松
吴文
PAN Xia-ye;HU Jun;LI Huang-yan;GAO Xiao-song;WU Wen(Key Laboratory of Near-Range RF Sensing ICs&Microsystems(NJUST),Ministry of Education,School of Electronic and Optical Engineering,Nanjing University of Science and Technology,NanJing 210094,China)
出处
《微波学报》
CSCD
北大核心
2023年第S01期328-332,共5页
Journal of Microwaves
作者简介
通信作者:吴文,男,1968年生,研究员。主要研究方向:射频电路理论与技术、毫米波天线理论与技术、毫米波近程探测理论与技术、多模复合探测理论与技术。E-mail:wuwen@njust.edu.cn
