基于离散匹配傅里叶变换的高速运动目标逆合成孔径雷达距离像补偿

INVERSE SYNTHETIC APERTURE RADAR RANGE PROFILE COMPENSATION OF FAST-MOVING TARGETS USING DISCRETE MATCH FOURIER TRANSFORM

本文分析了高速运动目标的逆合成孔径雷达 (ISAR)回波信号模型 ,讨论了目标高速运动特征对ISAR信号处理的影响。结果表明 ,高速运动特征会导致目标一维距离像的畸变和二维像的模糊。因此 ,必须对高速运动目标的距离像进行有效的补偿以消除距离像的畸变。针对高速运动目标的ISAR回波信号模型 ,本文提出了一种基于离散匹配傅里叶变换 (DMFT)的高速运动目标距离像补偿算法。该算法采用DMFT谱包络最小Shannon熵准则进行参数估计 ,可解决幅度最大准则下参数估计性能恶化的问题。

Inverse synthetic aperture radar (ISAR) echo signal model of fast-moving targets was analyzed and the impact of fast-moving character on the ISAR signal processing was discussed. The analysis indicates that the fast-moving character results in 1D range profile aberration and 2D image blurring. To resolve this problem, an effective algorithm based on discrete match Fourier transform (DMFT) was proposed for fast-moving target range profile compensation. In this algorithm, the spectrum envelope entropy minimizing criterion is applied for chirp rate estimation to overcome the difficulty of parameter estimation under the amplitude maximum criterion. The simulation results show that the algorithm of the rang profile compensation is effective.