基于多项相位变换的FMCW-ISAR微多普勒特征提取方法

主要研究了调频连续波逆合成孔径雷达(FMCW-ISAR)目标的微多普勒特征及其提取方法。在FMCW-ISAR系统中,脉冲持续时间内微动目标的连续运动将导致一维距离像产生走动和主瓣展宽,由此引入的误差将影响到后续的微多普勒特征提取以及成像,利用现有的微多普勒特征提取方法不能得到真实的目标微动特征。针对该问题,本文首先详细分析了FMCW-ISAR目标微多普勒效应的具体表现形式及其特点,应用多项相位变换的方法对导致一维距离像主瓣展宽和走动的误差相位进行了补偿,结合扩展Hough变换,提出了一种基于多项相位变换的FMCW-ISAR微多普勒特征参数提取方法。论文所提方法在微多普勒曲线产生展宽和走动的情况下,能准确提取出旋转目标的微多普勒特征参数,最后仿真实验验证了理论分析结果及所提方法的有效性。

An Extracting Method of Micro-Doppler Features in FMCW-ISAR Based on Polynomial Phase Transform

The micro-Doppler (m-D) features and extracting method based on the FMCW-ISAR is mainly studied in the paper. The target''s continuous moving in pulse repetition interval (PRI) will induce the main lobe widening and deviation of the range profile in FMCW-ISAR system. The induced error will influence the processing of the extraction of m-D features and imaging. The accurate micro motion features cannot be obtained by immediately utilizing existing method of extracting m-D features. To solve this problem, the detailed manifestation and characteristics of target''s m-D in FMCW-ISAR is analysed firstly. And then, combining with the extended Hough transform, an extracting method of m-D features parameters in FMCW-ISAR based on Polynomial Phase Transform is proposed in the paper. Finally, some results are given for validating the theoretical derivation and the effectiveness of the proposed method