用射线法研究复杂目标的电磁散射特征

应用计算机图形学中的曲面造型方法给出目标精确的数学外形,将之离散为三角面元,并采用拓扑结构来描述几何元素之间的关系;利用射线追踪法模拟射线束的多次反射,同时求出扩散因子、磁场方向和相位差;在最终反射点处采用物理光学积分求远场散射,叠加每一射线束的贡献,进而得出耦合雷达散射截面值.为减小射线追踪过程中的计算量,采用了加速算法.给出了作为特例的翼身组合体的计算结果.

Study on Electromagnetic Scattering Characteristics for Complex Target Using Shooting and Bouncing Rays

The accurate mathematical externality of the target was established with surface generation method in computer graphics, which was dispersed into triangular facets. Relationships between the geometrical elements were described with topological structure. The method of shooting and bouncing rays was used to simulate the multiple-reflection of ray beam. The divergence factor, magnetic field direction and phase difference were educed. The far field scattering was solved with physical optics integration at the final reflection point. Summing up the contribution from each ray beam, the value of coupled radar cross section was obtained. In order to reduce the calculation amount in the process of ray shooting and bouncing, an acceleration arithmetic was adopted. The calculation results of a wing body combination were presented as a specific example.