双通道MIMO-SAR运动目标成像  

Imaging of moving targets of dual-channel MIMO-SAR

作　　者：武其松[1] 邢孟道[1] 保铮[1] 

机构地区：[1]西安电子科技大学雷达信号处理国家重点实验室,陕西西安710071

出　　处：《系统工程与电子技术》2010年第5期921-926,共6页Systems Engineering and Electronics

基　　金：国家自然科学基金(60890072)资助课题

摘　　要：基于双通道多输入多输出合成孔径雷达(multiple-input multiple-output synthetic aperture radar,MIMO-SAR)新体制,提出一种置换相位中心天线(displaced phase center antenna,DPCA)离散调频傅里叶变换(discrete chirp-Fourier transform,DCFT)实现运动目标的检测、定位和成像的方法。提出利用DCFT方法估计运动目标径向速度,考虑到线性调频信号通过DCFT处理后的单峰值特性,给出一种估计目标运动沿航向速度的快速搜索方法。由于同一多普勒中心频率在不同载频下的脉压位置不同,因而可以利用位置的比值来确定模糊次数,从而实现了运动目标的正确定位。在解模糊过程中,给出了载频设计分析。通过将传统双通道DPCA的一发多收体制扩展到双通道MIMO体制,不仅能够实现低信噪比情况下动目标检测,还可以完成动目标速度测量、定位和成像。Based on the novel system with multiple-input multiple-output synthetic aperture radar（MIMO-SAR）,an approach combining displaced phase center antenna（DPCA） with discrete chirp-Fourier transform（DCFT） is proposed for the detection,positioning and imaging of moving targets.The DCFT method is applied to estimate the along-track velocities of moving targets.Considering the useful characteristic of a single maximum value in amplitude figure which is aroused when the DCFT is used to deal with the chirp signal,a fast arithmetic for searching their along-track velocities is presented.Since the positions after pulse compression are different under the condition that the identical Doppler centroid frenquecy lies in the different carrier frequencies,the ratio of the positions is used to resolve the times of ambiguities;thus the reposition can be achieved.In the process of resolving the ambiguities,the analysis of the choice of carrier frequencies is provided.Through extending the single-input multiple-output system to a dual-channel MIMO system,the detection of moving targets under the low signal-to-noise ratio is achieved;moreover,the motion parameters,position and imaging of moving targets can also be estimated.

关 键 词：合成孔径雷达 多发多收系统 运动参数估计 离散调频傅里叶变换 

分 类 号：TN957[电子电信—信号与信息处理]