基于GRECO算法的场景极化电磁散射仿真研究

发布时间：2018-05-26 15:20

本文选题：极化电磁散射 + 雷达截面积　；参考：《哈尔滨工业大学》2017年硕士论文

【摘要】：雷达目标的电磁散射特性表征目标的固有物理特性,包括几何结构和材料等信息。一般来说,雷达目标的电磁散射特性包括散射中心特征和极化特性。散射中心特征可以准确地描述目标电磁散射特性和目标物理结构。而雷达目标的极化信息可以反演目标结构,材料,形状,姿态取向等。极化特征和散射中心特征的组合可以详细地描述目标的结构和散射特性,提高雷达图像的可理解性。电磁散射特性可以通过两种方式获得:实测和仿真。实际测量需要大量的人力物力资源,并不利于大数据获取。因此,在电磁散射理论的基础上借由计算机获得仿真数据是目前研究电磁散射特性的重要手段,电磁仿真已经成为分析目标电磁散射特性的主流方法。传统图形电磁计算(GRECO)算法可以快速计算目标雷达截面(RCS),并广泛用于计算目标的电磁散射特性中。然而,RCS仅反映目标的散射特性的幅度,而没有极化信息。为了快速获得目标的极化特征,本文研究并提出了一种极化GRECO算法,以极化散射矩阵表征场景的极化电磁散射特性,从理论上推导出极化散射矩阵与RCS之间的关系。并利用计算机图形学理论获取电磁仿真计算所需的计算参数,结合分屏预处理的方法,扩大了仿真的适用范围。利用改进的物理光学法,计算场景的极化散射矩阵。并考虑到目标的二次散射情况,采用最小夹角法搜索构成二次散射的像素对,结合几何光学法和单-双站等效原理计算二次散射,提高了仿真的精度。最后,使用具有解析解的简单目标验证算法的正确性,并对典型人造目标和典型背景的极化电磁散射特性进行仿真。实验结果表明,本文所研究的场景极化电磁散射特性仿真的方法——极化GRECO算法,能够实现对目标或背景的快速极化散射特性仿真。将针对目标RCS仿真的传统GRECO算法拓展到针对场景的极化散射矩阵的仿真中,并且结合分屏处理步骤、二次散射计算,从仿真参数的文件数以及仿真情况的综合考量上,提高了算法的仿真精度。
[Abstract]:The electromagnetic scattering characteristics of radar targets represent the intrinsic physical properties of the target, including the geometric structure and material information. Generally, the electromagnetic scattering characteristics of the radar target include the scattering center characteristics and the polarization characteristics. The scattering center features can accurately describe the characteristics of the target electromagnetic scattering and the physical structure of the target, and the polarization of the radar target. Information can be used to retrieve target structure, material, shape, attitude orientation, etc. the combination of polarization characteristics and scattering center features can describe the structure and scattering characteristics of the target in detail, and improve the comprehensibility of the radar image. The electromagnetic scattering characteristics can be obtained by two ways: Measurement and simulation. Practical measurement requires a large number of manpower and material resources. It is not conducive to the acquisition of large data. Therefore, using the computer to obtain the simulation data on the basis of the electromagnetic scattering theory is an important means to study the electromagnetic scattering characteristics at present. Electromagnetic simulation has become the main method to analyze the characteristics of the target electromagnetic scattering. The traditional graphic electromagnetic computing (GRECO) algorithm can quickly calculate the target radar cross section (RCS). It is widely used to calculate the electromagnetic scattering characteristics of the target. However, RCS only reflects the amplitude of the scattering characteristics of the target, but there is no polarization information. In order to obtain the polarization characteristics of the target quickly, a polarization GRECO algorithm is proposed in this paper to characterize the polarization electromagnetic scattering characteristics of the field scene with the polarization scattering matrix. The relation between the scattering matrix and the RCS. And using the computer graphics theory to obtain the calculated parameters of the electromagnetic simulation calculation and the application of the split screen preprocessing method, the application range of the simulation is enlarged. The polarization scattering matrix of the scene is calculated by the improved physical optics method, and the two scattering conditions of the target are taken into account, and the minimum clip is used. Corner method is used to form two scattering pixel pairs. Combining geometric optics and single bistatic equivalence principle, two scattering is calculated, and the accuracy of the simulation is improved. Finally, the correctness of the algorithm is verified by a simple target with analytical solution, and the simulation of the characteristic electromagnetic scattering characteristics of typical artificial targets and typical backgrounds is simulated. The experimental results show that The polarization GRECO algorithm, the polarization GRECO algorithm, can be used to simulate the fast polarization scattering characteristics of the target or the background. The traditional GRECO algorithm aimed at the target RCS simulation is extended to the simulation of the polarization scattering matrix for the scene, and the two scattering calculation is combined with the split screen processing step. The simulation accuracy of the algorithm is improved by considering the number of files in the simulation parameters and the comprehensive consideration of the simulation.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN958

【参考文献】