摘要
微动特征是当前学术界公认的弹道中段目标雷达识别的有效特征之一,目前的特征提取与识别研究通常假定散射中心与目标自身的微动规律一致,其微Doppler效应为正弦调频信号.但这种假设忽视了随着观测视角的改变,散射中心将在目标体上滑动这一事实.文中对弹体不同位置散射中心的微运动特性进行了完整建模,首次得到了滑动型散射中心微Doppler的数学表达式,并针对导弹攻防对抗条件导出其Taylor近似,指出并非文献上通常假定的正弦规律.设计了进动目标暗室动态测量实验,生动揭示了散射中心的这种滑动特性,实验现象与文中的理论分析结果相一致.文中揭示的微Doppler机理为弹头类目标微动特性模拟及特征反演等应用领域提供了更为准确的物理基础和数学模型.
The feature of micro-motion is one of the most effective features used for radar recognition in midcourse phase. At present, the study of feature extraction and recognition is usually based on the assumption that the micro-motion of the scattering center and warhead itself is the same, and the radar echo is sinusoid-FM signal. However this assumption ignores the fact that the scattering center would slide on the warhead with the change of the aspect angle. In this paper, a complete micro-motion model is set for the scattering centers of different positions on the warhead, and the mathematical expression of the micro-Doppler of the sliding-type scattering center is obtained for the first time. The approximation of Taylor expansion under the background of missile confrontation is studied subsequently. The curve of this micro-Doppler is not the generally assumed sinusoid. Dynamic measurement of a precessional target in microwave anechoic chamber is done to vividly observe the sliding feature of the scattering center. The measurement results agree with the theoretic analysis in this paper. This research on micro-Doppler characteristics of sliding-type scattering center provides a more accurate model for the micro-motion simulation and feature extraction of precessional warheads.
出处
《中国科学：信息科学》
CSCD
2011年第5期605-616,共12页
Scientia Sinica(Informationis)
基金
国家自然科学基金(批准号:60672033
60875019)资助项目
关键词
旋转对称目标
滑动型散射中心
进动
微Doppler
rotationally symmetric target
sliding-type scattering center
precession
micro-Doppler
