频率步进雷达ISAR成像包络对齐新方法  

New Method for Range Alignment of Stepped Frequency ISAR Imaging

作　　者：罗贤全[1] 尚朝轩[1] 何强[1] 于久恩[1] 

机构地区：[1]军械工程学院光学与电子工程系,石家庄050003

出　　处：《数据采集与处理》2008年第3期259-264,共6页Journal of Data Acquisition and Processing

摘　　要：逆合成孔径雷达成像常用的运动补偿方法是利用距离像的相关性进行包络对齐。但当目标速度或加速度较大时,散射点走动较大且距离像发散程度严重,此时直接利用距离像的相关性进行包络对齐会有较大的误差。本文分析了频率步进雷达运动目标的回波信号模型,讨论了目标的速度和加速度对距离像的影响,提出了当目标速度和加速度较大时,先用高斯包络线性调频信号自适应分解估计出目标运动的加速度和速度,粗补偿后再用距离像最小熵准则进行精补偿的包络对齐方法。该方法计算量小,估计精度高,且无测速模糊的缺点,仿真结果验证了它能较精确地估计出目标的运动参数,运动补偿效果好。The common method use for motion compensation on inverse synthetic aperture radar （ISAR） imaging is studied to use the correlation of range profiles to align range. But when the target has high velocity and acceleration, scatters walk out of the range cell and profiles have bad aberrance, and traditional range alignment method cannot perform well. This paper analyzes the echoed signal model for moving targets of stepped frequency ISAR and disscusses the influence of the speed and the acceleration of the moving target on ISAR imaging. A new method for the range alignment based on adaptive Gauss chirplet decomposition and minimal entropy of high resolution range profile is proposed. The method estimates the acceleration and velocity by obtaining echoed signal chirprate decomposed from adaptive Gauss chirplet method. After rough compensation, range profiles are aligned based on minimal entropy criterion. The method has advantages of fast computation speed and high accuracy. The numerical simulation proves the good efficiency of the method.

关 键 词：频率步进雷达 自适应分解 包络对齐 距离像最小熵准则 

分 类 号：TN958[电子电信—信号与信息处理]