基于切趾滤波的线性调频步进信号栅瓣抑制方法  

Grafting Lobe Suppression for Frequency-stepped LFM Signal by Apodization Filtering

作　　者：仲利华[1,2,3] 韩冰[1,2] 胡东辉[1,2] 丁赤飚[1,2] 

机构地区：[1]中国科学院空间信息处理与应用系统技术重点实验室,北京100190 [2]中国科学院电子学研究所,北京100190 [3]中国科学院研究生院,北京100039

出　　处：《电子与信息学报》2013年第3期545-551,共7页Journal of Electronics & Information Technology

基　　金：国家部委基金资助课题

摘　　要：在线性调频步进信号中,相邻子脉冲间的频谱重叠将导致脉冲压缩后出现较强的栅瓣,弱小目标可能被强目标的栅瓣所遮掩。为此,该文通过分析线性调频步进信号自相关函数的组成,提出一种新的对子脉冲加权后信号进行切趾滤波的栅瓣抑制方法。通过对子脉冲频谱采用不同的窗函数加权,改变子脉冲信号自相关函数旁瓣符号,进而改变调频步进信号栅瓣位置处的符号,通过多组不同加权结果的对比,利用切趾滤波的思想实现栅瓣的识别与抑制。数值仿真和实际图像处理证实了该方法的有效性。In the frequency-stepped chirp signal, the frequency spectrum overlap between the neighboring sub pulses would lead to grating lobes in the result of range compression. The weaker points may be masked or distorted by the grating lobes of strong points. In this paper, a grating lobe suppression algorithm is proposed based on apodization filtering. By weighting the spectrum of sub pulse signals with different functions, the apodization could be done through the results and the grating lobes could be eliminated. Numerical simulations and real data experiment confirm the effectiveness of the proposed algorithm.

关 键 词：SAR图像处理 频谱重叠 栅瓣抑制 子脉冲加权 切趾滤波 

分 类 号：TN957.52[电子电信—信号与信息处理]