基于时域物理光学法的涂覆目标瞬态散射分析

为了对涂覆雷达吸波材料(RAM)的电大尺寸目标的时域瞬态散射特性和宽带RCS进行快速计算,以满足工程上对目标电磁散射特性的计算向宽频带、向时域靠拢的需求。通过引入阻抗边界条件(IBC),计算了涂覆RAM 目标表面的等效反射系数,将等效反射系数代入频域物理光学法(PO)的表达式,并进行逆傅里叶变换(IFT),推导出了适用于涂覆RAM的目标的时域物理光学法(TDPO)积分表达式。使用OpenGL 控制图形处理器(GPU)来对目标的面元模型进行消隐处理,提高了运算速度。最后通过两个仿真算例,对TDPO与频域PO计算所得的时域瞬态响应和宽带RCS 进行对比,验证了TDPO计算结果与频域PO计算结果具有同等精度。

The Analysis of Transient Scattering from Coated Target Based on Time-Domain Physical Optics Method

A new approach is proposed to accelerate the calculation of the transient scattering and wide-band RCS from electrically large target coated with radar absorption material (RAM), and to meet the engineering requirements of obtaining the scattering characteristics in wide-band and time domain. The equivalent complex reflection coefficient of RAM-coated target is calculated by introducing the impedance boundary conditions (IBC). With the substitution of the equivalent complex reflection coefficient for frequency-domain physical optics (PO), the integral expression of the time-domain physical optics (TDPO) is obtained by implementing the inverse Fourier transformation (IFT), which is suitable for RAM-coated target.The Graphics Processing Unit (GPU) is driven to accelerate the shadowing processing of the facet target model by the OpenGL. With the comparisons of the transient scattering and wide-band RCS between TDPO and frequency-PO, TDPO is proved to have the same accuracy as frequency-PO.