基于图拉普拉斯嵌入的合成孔径雷达时变窄带干扰抑制算法

Time-varying narrow-band interference suppression algorithm for SAR based on graph Laplacian embedding

合成孔径雷达(synthetic aperture radar,SAR)作为一种宽带系统,常与同频段内其他有源电磁系统发生冲突,这些信号相较于宽带SAR系统而言,大部分是窄带干扰(narrow-band interference,NBI),会对高分辨SAR成像系统产生严重干扰。早期关于NBI抑制问题的研究中,很少有人注意到NBIs在不同脉冲之间可能具有局部时变特性,这削弱了某些经典方法在干扰抑制上的性能。因此,本文提出了一种图拉普拉斯嵌入(graph Laplacian embedding,GLE)算法,通过在不同脉冲信号之间构建拉普拉斯嵌入关系来抑制NBIs。这使得局部时变的干扰能够被嵌入到非线性低维流形中,并被有效去除。对实测受NBI干扰的SAR数据进行处理,处理后的结果证明了所提方法的有效性。

As a wideband radar system,the synthetic aperture radar(SAR)usually conflicts with other electromagnetic systems working in the same frequency bands.These signals,most of which are narrow-band interference(NBI)for SAR systems,severely interfere SAR systems to generate a high-resolution image.Many previous research results focused on the NBI suppression problem,however,few of them noticed that the NBIs may be time-varying in a local region among different pulses,which restricts the suppression performance of some classic methods.Hence,in this paper,a graph Laplacian embedding(GLE)algorithm is proposed to suppress NBIs by constructing the Laplacian embedding connections between different pulses of signals.As a result,locally time-varying interferences are embedded in a non-linear low-dimensional manifold and can be effectively mitigated.The real SAR data measured with NBI are processed,and the results show the efficiency of the proposed algorithm.