合成孔径雷达容易受到射频干扰的影响,严重影响成像质量。本文针对合成孔径雷达面临的射频干扰问题,分析了射频干扰(RFI)的信号特性和信号模型,根据RFI信号功率高、频带窄的特点,提出了基于特征分解的干扰抑制方法。其基本思想是:通过对观测数据矩阵进行特征分解,根据特征值分布构造干扰子空间和信号子空间,利用二者的正交性抑制干扰信号。本文首先介绍了特征分解方法的基本原理,在此基础上,基于MDL准则判断主特征值的个数,提出了基于特征值分布的RFI检测方法,并进一步,利用特征向量构造相应的干扰子空间和信号子空间,给出了基于特征分解的RFI抑制方法。基于SAR实测数据的仿真实验表明该方法可以有效的抑制RFI,且尽可能的保留目标回波。
The performance of synthetic aperture radar(SAR) may be affected by all kinds of radio frequency interference (RFI).Based on the RFI characteristics of high power and narrow band,a novel RFI suppression method based on eigen-decomposition is proposed for SAR.This method decomposes the eigenvectors of the received signal with RFI into interference subspace and signal subspace,and the orthogonality of the two subspaces is used to suppress the RFI signals.This paper describes the characteristics of the basic principles of eigen-decomposition,and proposes a new RFI detection method based on the MDL criterion to determine the number of main eigenvalues,and further,the eigenvectors are used to construct the corresponding interference subspace and signal subspace, and the eigen-decomposition based method for RFI suppression are proposed.The experimental results based on SAR real data shows that are also shown to verify the proposed algorithm.