任意多次散射机理的GTD散射中心模型频率依赖因子表达  

Frequency-dependent Factor Expression of the GTD Scattering Center Model for the Arbitrary Multiple Scattering Mechanism

作　　者：闫华 张磊 陆金文 邢笑宇 李胜 殷红成 YAN Hua;ZHANG Lei;LU Jinwen;XING Xiaoyu;LI Sheng;YIN Hongcheng(Science and Technology on Electromagnetic Scattering Laboratory,Beijing 100854,China)

机构地区：[1]电磁散射重点实验室,北京100854

出　　处：《雷达学报（中英文）》2021年第3期370-381,共12页Journal of Radars

基　　金：国家重点研发计划(2018YFC0825804)。

摘　　要：几何绕射理论(GTD)模型是一种重要的散射中心模型,能准确描述雷达目标主要散射机理的频率依赖行为,但目前在频率依赖因子与散射机理类型之间尚未建立明确、一般的数学关系。该文从射线理论出发,结合几何光学(GO),GTD,物理绕射理论(PTD)和驻相法(SPM)等方法,推导了理想电导体(PEC)目标任意多次散射机理的频率依赖因子数学表达式。该表达式具有简洁、统一的解析形式,指出散射中心频率依赖因子与形成散射中心的射线反射次数、射线经过的几何元素维数以及射线场焦散情况等因素有关。一系列典型组合体目标的电磁仿真与微波暗室测量数据验证了提出公式的有效性。该文提出的频率依赖因子表达可应用于正向参数化建模中频率依赖因子的正向推算。This paper presents a derivation of a formula with a concise and uniform analytic form by the Stationary Phase Method(SPM)plus Geometrical Optics(GO),the Physical Theory of Diffraction(PTD),and Geometrical Theory of Diffraction(GTD)to calculate the frequency-dependent factor for the arbitrary multiple scattering mechanism,validated by the simulated and measured data of a series of canonical ensembles,validated by the simulated and measured data of a series of canonical ensembles.Although the GTD model,a scattering center model,can accurately describe the frequency-dependent characteristic of several main scattering mechanisms of the radar target,no explicit and general expression relates the frequency-dependent factor to the type of scattering mechanism.The derived formula relates the scattering center’s frequencydependent factor with bounce times,dimensions of all the encountered geometrical elements,and a caustic type of ray contributing to the scattering center and can be applied to determine the parameter value of frequencydependent factor of the GTD model and its derived versions in the forward parametric modeling.

关 键 词：散射中心模型 多次散射机理 GTD模型 频率依赖因子 

分 类 号：TN95[电子电信—信号与信息处理]