Formulation and super-efficient solution of large-scale inverse equivalent surface-source problems with consideration of various side constraints

考虑各种侧面约束的大规模反等效面源问题的公式化和超高效求解

• 批准号: 429949501
• 负责人: Professor Dr.-Ing. Thomas Eibert
• 金额: --
• 依托单位: Lehrstuhl für Hochfrequenztechnik (HFT)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/429949501?language=en
• 关键词: Formulation; super; efficient; solution; large

Inverse equivalent source solutions determine equivalent source distributions such that they are able to reproduce radiation or scattering fields observed in a collection of sample locations. Once the sources are available, diagnostic information about the radiation or scattering object(s) can be obtained and it is also possible to compute the radiation or scattering fields in new observation locations, in particular also in the far field. In the first part of this project, a variety of super-efficient solution techniques for inverse equivalent surface source problems (IESSPs) have been investigated and realized, which are based on the concepts of hierarchical propagating plane wave representations, as known from the multilevel fast multipole method (MLFMM), and on meshless field expansions via distributed spherical harmonics expansions. In particular, it was possible to realize very directive Gaussian-beam based translation operators for the plane-wave spectra without any loss of accuracy and it was possible to generate reduced sets of spherical harmonics with directive radiation toward the solution domain, which lead to a more robust, more flexible, and more efficient solution approach. On top of these very powerful techniques, new preconditioning and start vector estimation techniques for the iterative solution process could be realized. In this continuation proposal, some of these techniques shall be further pursued, but the major focus shall be on super-efficient solution techniques for IESSP solvers with observation data above multilayered planar ground. Such scenarios are, e.g., important for automotive antenna and scattering measurements, but the super-efficient solution techniques have also great potential toward the solution of integral equations of radiation and scattering problems. The presence of multilayered planar ground imposes new challenges on the algorithms, in particular with respect to efficiency, since the successful free-space methods are not directly transferable to this scenario. In particular, it will be necessary to work with plane-wave representations which are more suitable for the multilayered ground environment, such as those based on the Weyl-identity.

逆等效源解决方案确定等效源分布，使得它们能够再现在样品位置的集合中观察到的辐射或散射场。一旦源可用，就可以获得关于辐射或散射对象的诊断信息，并且还可以计算新的观察位置中的辐射或散射场，特别是还可以计算远场中的辐射或散射场。在这个项目的第一部分，各种超高效的解决方案的逆等效面源问题（IESSP）的技术进行了研究和实现，这是基于分层传播的平面波表示的概念，从多层快速多极子方法（MLFMM），和无网格场扩展通过分布球谐函数展开。特别地，可以实现用于平面波谱的非常定向的基于高斯束的平移算子而没有任何精度损失，并且可以生成具有朝向解域的定向辐射的球谐函数的缩减集合，这导致更鲁棒、更灵活和更有效的解方法。在这些非常强大的技术之上，可以实现用于迭代求解过程的新的预处理和起始向量估计技术。在这个延续的建议，其中一些技术将进一步追求，但主要的重点应是超高效的解决方案技术，IESSP求解器与观测数据以上多层平面地面。这样的场景是，例如，超高效求解技术对于汽车天线和散射测量非常重要，但是超高效求解技术对于辐射和散射问题的积分方程的求解也具有很大的潜力。多层平面地面的存在对算法提出了新的挑战，特别是在效率方面，因为成功的自由空间方法不能直接转移到这种情况下。特别是，有必要使用更适合多层地面环境的平面波表示，例如基于外尔恒等式的平面波表示。