航空学报 > 2004, Vol. 25 Issue (5): 495-498

基于修正离散Chirp-Fourier变换的高速目标ISAR距离像补偿

刘爱芳, 朱晓华, 刘中   

  1. 南京理工大学电子工程系 江苏南京 210094
  • 收稿日期:2003-08-21 修回日期:2004-03-15 出版日期:2004-10-25 发布日期:2004-10-25

ISAR Range Profile Compensation of Fast-moving Target Using Modified Discrete Chirp-Fourier Transform

LIU Ai-fang, ZHU Xiao-hua, LIU Zhong   

  1. Department of Electronic Engineering, Nanjing University of Science and Technology, Nanjing210094, China
  • Received:2003-08-21 Revised:2004-03-15 Online:2004-10-25 Published:2004-10-25

摘要: 分析了高速运动目标的逆合成孔径雷达(ISAR)回波信号模型和高速运动对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。为此,提出了一种基于修正离散Chirp Fourier变换(MDCFT)的高速运动目标距离像补偿算法,采用MDCFT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。仿真结果表明了该距离像补偿算法的有效性。

关键词: 逆合成孔径雷达, 修正离散ChirpFourier变换, 线性调频信号, 距离像

Abstract: The inverse synthetic aperture radar (ISAR) echo signal model of fast-moving target and the effect of fast-moving character on ISAR signal processing are analyzed. The analysis results show that the fast-moving character will result in ISAR range profile aberration and two-dimensional image blurring. To resolve this problem, a range profile compensation algorithm based on the modified discrete Chirp-Fourier transform is proposed. In the algorithm, the spectrum envelope entropy minimizing criterion is applied for Chirp rate estimation to overcome the parameter estimation difficulty under amplitude maximum criterion. The simulation results prove the effectiveness of the proposed algorithm.

Key words: inverse synthetic aperture radar, modified discrete Chirp-Fourier transform, LFM signal, range profile