MIMO-SAR回波分离方法分析

Analysis of Echo Separation in MIMO-SAR

MIMO-SAR(Multiple input multiple output synthetic aperture radar)是近年来提出的一种新的SAR体制。通过多个发射天线和接收天线的组合,可以形成更多等效相位中心,提高系统自由度,进一步扩展SAR的模式,提高其性能。但是,SAR回波对应分布场景,匹配滤波后互相关噪声叠加,相互干扰造成图像下降,通常MIMO雷达中正交波形分集方法在MIMO-SAR体制中是无效的。因此,回波分离成为MIMO-SAR实现的关键问题。本文介绍了MIMO-SAR的工作原理及其应用,对目前已有的回波分离方法进行分析,指出其原理和约束条件,最后针对回波分离问题,探讨了一些新的解决方法。

MIMO-SAR （multiple input multiple output synthetic aperture radar） is a new kind of SAR system,which combines multiple transmitters and multiple receivers to acquire more equivalent phase centers and more degrees of freedom.By this way,MIMO-SAR extends system working mode and improves the performance.However,SAR echo is scattered from a distributed scene.Cross-correlation noise will overlap and interferences will degrade the image.That will make the separation methods used in MIMO radar fail in MIMO-SAR.Therefore,separation is a key problem to the implementation of MIMO-SAR.This paper introduces the principle of MIMO-SAR and its applications,then reviews the methods proposed in current literatures.The principles and constrains of every separation method are pointed out.Some new approaches to the problem are proposed and discussed.