旋翼叶片回波建模与闪烁现象机理分析  

Rotor blades echo modeling and mechanism analysis of flashes phenomena

作　　者：陈永彬[1] 李少东[1] 杨军[1] 曹芙蓉[1] 

机构地区：[1]空军预警学院三系,武汉430019

出　　处：《物理学报》2016年第13期281-291,共11页Acta Physica Sinica

摘　　要：对旋翼叶片回波建模与闪烁现象进行了综合研究.基于散射点散射系数和分布情况,构建了旋翼叶片回波的散射点模型,并分析了散射点分布对回波的影响;在此基础上研究了回波时域闪烁现象的物理散射机理,并结合时频分析和横向分辨率分析了微多普勒特征及时频域闪烁现象;对两类不同分布间隔的散射点模型进行了仿真,并与积分模型进行对比性实验,结果验证了闪烁现象物理分析的合理性.该研究成果在旋翼目标的探测识别领域具有一定的理论与应用价值.Since the rotorcraft can easily be recognized by using the micro-Doppler（m-D） signature of rotor blades, the m-D effect induced by micro-motion dynamics plays an important role in target recognition and classification. However, the existing researches on the rotor blades pay little attention to the mechanism of the time-domain and time-frequencydomain flash phenomena. To comprehensively explain the flash phenomena from physics, the modeling of the rotor blades and the mechanism of the flash phenomena are studied in this paper. Firstly, for the rotor blades, the target cannot be represented as a rigid, homogeneous line nor several points. Taking the scattering coefficients and the interval of adjacent scattering points（the scattering point distribution on the blade） into consideration, the scattering point model of the rotor blade echo is established, and the influence of the scattering point distribution on the radar echo is analyzed as well. The detailed mathematic analysis and comparison results show that the conventional integral model of the rotor blade is only a special case of the scattering point model. Furthermore, in the case where the scattering point model is approximately equivalent to the conventional integral model, the critical interval of adjacent scattering points is deduced by mathematic analysis. Secondly, on the basis of the proposed model above, the physical mechanism of the time-domain and time-frequency-domain flash phenomena is studied from the viewpoint of the electromagnetic（EM） scattering. On the one hand, considering the EM scattering and scattering point distribution, the mechanism of the time-domain flashes is analyzed. Ideally, when the rotor blade is at the vertical position relative to the radar line of sight, i.e., at the flash time, the blade has the strongest echo. At this moment, the radar echo consists of echoes of all scattering points, thus inducing the time-domain flashes. At the non-flash time, the scattering points at the tip of blade and hub of rotor have st

关 键 词：闪烁 电磁散射 微多普勒 散射点模型 

分 类 号：V275.1[航空宇航科学与技术—飞行器设计]