方位多波束弧形阵列SAR成像方法研究  

Research on Azimuth Multi-beam Arc Array SAR Imaging Method

作　　者：徐伟 刘凡 黄平平[1,2] 谭维贤 乞耀龙[1,2] XU Wei;LIU Fan;HUANG Pingping;TAN Weixian;QI Yaoong(College of Information Engineering,Inner Mongolia University of Technology,Hohhot,Inner Mongolia 010051,China;Inner Mongolia Key Laboratory of Radar Technology and Application,Hohhot,Inner Mongolia 010051,China)

机构地区：[1]内蒙古工业大学信息工程学院,内蒙古呼和浩特010051 [2]内蒙古自治区雷达技术与应用重点实验室,内蒙古呼和浩特010051

出　　处：《信号处理》2024年第5期922-931,共10页Journal of Signal Processing

基　　金：国家自然科学基金(62071258,U22A2010,61971246)。

摘　　要：弧形阵列合成孔径雷达(Synthetic Aperture Radar,简称SAR)是一种广域观测的新体制微波成像系统,相比于线性阵列合成孔径雷达,弧形阵列SAR能够有效克服常规成像雷达前视、侧视、下视等观测视角单一的问题,弥补了常规成像模式的不足。方位多波束技术是星载合成孔径雷达系统获取高分辨宽覆盖测绘能力的重要技术途径。本文首先构建了多波束弧形阵列SAR系统的方位向多通道信号模型,并通过传统的方位多通道重建方法进行成像仿真,成像结果出现虚假目标,由于传统的多通道重建方法适用于大多数线性阵列,所以通过分析回波斜距的数学几何模型推导出了多波束弧形阵列SAR相比于线性阵列SAR多了一个附加相位,与弧形阵列天线结构相结合,附加相位由子孔径角度引起,因此方位多通道回波数据中相位误差是由多通道弧形阵列SAR的子孔径角度引起,从而导致多通道不均衡,所以传统的多通道重建方法不能够直接用于弧形阵列SAR的成像处理中,为了实现弧形阵列SAR系统的静止目标聚焦成像,提出了适用于弧形阵列SAR系统的方位多通道重建方法,在进行多通道重构和合并之前,对方位通道间的附加相位进行补偿,避免方位欠采样,然后根据弧形阵列方位多通道脉冲响应重构方位多通道数据,该方法可以很好的抑制了虚假目标,最后通过仿真实验验证了该方法的可行性。Arc array synthetic aperture radar(SAR)is a new microwave imaging system used for wide-area observation.Unlike linear array SAR,arc array SAR effectively addresses the limitation of a single observation angle inherent in conventional imaging radars,including forward-looking,side-looking,and downward-looking modes.This advancement overcomes the drawbacks of traditional imaging methods,positioning arc array SAR as a technology with wide-ranging application potential.The curved array SAR system is applied to the carrier platform,which can realize the imaging perception of the large field of view and high spatial and temporal resolution of the terrain information around the platform.It has important development potential and application prospects in military reconnaissance,disaster relief,and other fields.Azimuth multi-beam technology is an important technology that can be used to improve the mapping performance of spaceborne SAR systems,including the ability to achieve high resolution and wide coverage.Due to the equiangular sampling of the arc array SAR in the azimuth direction,the azimuth is non-uniformly sampled,and multi-channel reconstruction must be performed before imaging.In this study,we construct the azimuth multi-channel signal model of the multi-beam arc array SAR system,and the imaging simulation is carried out by the traditional multi-channel reconstruction method.The imaging results show false targets.Since the traditional multi-channel reconstruction method is suitable for most linear arrays,by analyzing the mathematical geometric model of the echo slant range,it is deduced that the multi-beam arc array SAR has an additional phase compared with the linear array synthetic aperture radar.Combined with the arc array antenna structure,the additional phase is caused by the sub-aperture angle.Therefore,the phase error in the azimuth multi-channel echo data is caused by the sub-aperture angle of the multi-channel arc array SAR.The traditional multi-channel reconstruction method cannot be directly used in th

关 键 词：弧形阵列SAR 多通道重建 相位误差 方位多波束 

分 类 号：TN958[电子电信—信号与信息处理]