基于WD和时频滑窗掩膜的SAR干扰抑制算法

窄带干扰(NarrowBand Interference,NBI)和宽带干扰(WideBand Interference,WBI)的存在将会大幅度地降低合成孔径雷达(Synthetic Aperture Radar,SAR)图像的质量.本文在对NBI和WBI的时频分析基础上,提出了一种基于Wigner分布(Wigner Distribution,WD)和时频面滑窗掩膜技术的干扰抑制算法.该算法首先利用瞬时时刻重构序列与原序列之间的联系,提出了一种基于WD的高效信号重构算法.然后采用平滑伪WD分布(Smoothed Pseudo Wigner Distribution,SPWD)作为时频掩膜抑制WD的交叉项,并结合WD信号重构算法和时频平面滑窗掩膜技术提取并重构干扰信号,最后将重构的干扰信号在原始回波中对消实现干扰抑制.该算法能有效抑制SAR图像中的时变NBI和WBI,同时能够尽可能保留有用信号.仿真数据和实测数据结果分析验证了本文方法的有效性.

Interference Suppression Algorithm for SAR Based on WD and Sliding Window Masking Technique in Time-Frequency Domain

Narrowband interference (NBI) and wideband interference (WBI) are common jamming signals against synthetic aperture radar (SAR),which can degrade the imaging quality severely.According to the time-frequency characteristic of NBI and WBI,an interference suppression algorithm based on Wigner distribution (WD) and sliding window masking technique is proposed.First,a fast signal synthesis algorithm from Wigner distribution (WD) is developed using the inherent relationship between original signal and synthesized signal.Then,the smoothed pseudo Wigner distribution (SPWD) is utilized as a time-frequency mask to suppress the cross-terms.By combination of signal synthesis algorithm and time-frequency masking technique,the interference can be extracted and synthesized.Finally,the reconstructed interference is removed from the original echoes to realize the interference suppression.The proposed algorithm can not only suppress the NBI and WBI,but also preserve the useful information as much as possible.The effectiveness of the proposed algorithm is proved by processing the simulation data and measured data.