摘要
逆合成孔径雷达 (ISAR)机动目标成像受到研究者的广泛重视 .在已有的机动目标成像算法中 ,通常假设在综合孔径处理期间 ,各距离单元内各散射回波是等幅线性调频信号 .在实际中 ,以上假设仅是近似成立 ,基于此假设的机动目标成像算法难以得到目标的较高质量的像 .文中采用更精确的信号模型———多分量调幅 线性调频 (AM LFM)信号表示实际机动目标的各距离单元回波 ,并提出一种瞬时幅度和调频率参数估计的快速算法 .通过这些信号参数 ,得到了机动目标的高质量的动态ISAR像序列 ,以利于目标识别 。
Most of dynamic Inverse Synthetic Aperture Radar (ISAR) imaging methods for maneuvering target are based on time-frequency distribution, and the assumption that the scatterer's echo has a constant amplitude and linear frequency modulation. In fact, when the target has dihedrals and trihedrals components, or scatterers exist in Migration Through Resolution Cells (MTRC), or the scatterer moves in or out of the analyzing range cell, all this results in the fact that the amplitude is not constant, and for a maneuvering target, the Doppler of the scatterers' echo after translational motion compensation is time varying. In order to solve this problem, we use multicomponent amplitude modulation and linear frequency modulation (AM-LFM) signals to approximate the scatterers' echoes, and we propose a fast algorithm for estimating the amplitude and chirp rate. With the algorithm, dynamic ISAR images are obtained. Images obtained by this method are better than those obtained by other methods, which helps automatic target recognition (ATR) and lead to the small computation load.
出处
《西安电子科技大学学报》
EI
CAS
CSCD
北大核心
2001年第1期22-26,共5页
Journal of Xidian University
基金
国家自然科学基金资助项目! (6 98310 40 )
国家部委预研基金! (7 4 2 1)资助项目
关键词
机动目标
动态成像
线性调频
逆合成孔径雷达
瞬时幅度
调频率估计
Algorithms
Amplitude modulation
Approximation theory
Doppler effect
Echo suppression
Electromagnetic wave scattering
Frequency modulation
Inverse synthetic aperture radar
Parameter estimation
Radar target recognition
