Calculations of Radar Cross Section of Complex-shaped 3D Objects

在目前的雷达截面计算研究中，很多情况下都是对二维目标进行计算。即使对于3D物体，RCS也只对简单形状的3D物体进行了计算，通常是近似计算。本文采用高可靠性数值分析技术Yasuura法精确计算了任意形状三维物体的RCS，并研究了电磁波散射特性。此外，我们还分析了由各种材料和/或复杂结构组成的光学器件和光波导的特性，将FD-TD方法作为并行计算的一种较好的数值分析技术。本研究的主要成果如下：1.研究结果表明：本文提出了引入广义多极技术的Yasuura方法，该方法可以准确地计算复杂形状三维物体的RCS，由于其解的收敛速度快，是求解散射问题的一种有效的数值分析方法。实际中，我们计算了各种形状复杂的三维物体的RCS，如花生壳形、甜甜圈形等。结果表明，以完全匹配层（PML）作为吸收边界条件的FD-TD方法广泛适用于任意复杂形状三维物体的电磁波散射问题。此外，我们还表明，它可能是一种强大的技术，用于分析政治器件和/或光波导。我们制作了一个由计算机和个人计算机组成的小型并行计算机系统供实验室使用，使两种方法的并行计算成为可能。

Up to now in researches of radar cross section (RCS) calculations, the RCS have been calculated for 2D objects in many cases. Even though for 3D objects, the RCS have been calculated only for simple-shaped 3D objects, of calculated with approximation quiteoften. In this research we calculated the RCS of arbitrary-shaped 3D objects accurately using the Yasuura method which was a high-reliable numerical analysis technique, and studied about characteristics of electromagnetic wave scattering. And also, we analyzed characteristics of optical devices and optical waveguides, which are composed of various materials and/or complex structures, using the FD-TD method as a preferable numerical analysis technique for the parallel computation. The main results of this research are as follows :1.We offered the Yasuura method introducing the Generalized Multipole Technique (GMT) , that could calculate the RCS of complex-shaped 3D objects accurately, and could be a effective numerical analysis technique for the scattering problems on account of fast convergence of the solutions. Practically, we calculated the RCS of various complex-shaped 3D objects, such as peanutshell-shaped, doughnut-shaped and so on.2.We showed that the FD-TD method using Perfectly Matched Layr (PML) as the absorbing boundary condition is widely applicable to electromagnetic wave scattering problems with arbitrary complex-shaped 3D objects. Furthermore we also showed that it could be a powerful technique for the analysis of potical devices and/or optical waveguides.3.We made up a small-scaled parallel computer system composed of transputers and personal computers for laboratory use, which enabling the parallel computation of the both methods.