Fast Multipole Algorithm For Parallel Multi-layer, A Number Of Key Technology Research

The problem of electromagnetic scattering from large-scale target has been being the focus of public for long time because of its strong engineering application requirement. It has very important use in the Radar system design, target identify, remote sensing and measuring.On one hand, although the traditional methods to solve the electromagnetic scattering form the target by the so called high frequency methods such as PO (Physical Optics), GO(Geometry Optics), have the less memory and computational requirement, they also have the fatal defection that the accuracy of these methods are too poor to use in real applications.On the other hand, the Multi-Level Fast Mutipole Algorithm (MLFMA) which based on the integral equation method can obtain the result with great accuracy, but this method accounts in all the couplings between every sub-scatter objects, it needs much more to store all of the information, and because of the rigorous integral on the spectrum space the computational complexity is also enormous. While the real applications usually need to solve the scattering problem form very large-scale target, even the recent computer can hardly satisfy the huge memory requirement and the enormous computational requirement.In order to solve this problem, some scholars presented the idea by utilizing the parallel techniques to provide the large accessible physical memory and by reasonable decomposition the whole problem to every compute node then making all the compute nodes work together to solve the whole problem. In the 90s last century the Syracuse University first implemented the parallel technique in the Moment of Method (MOM), and then Prof. W.C.Chew in UIUC successfully implemented this techniques into MLFMA, and with their code they solved the scattering problem with 10 million unknowns.In this paper, several key techniques in parallel MLFMA will be discussed.Firstly the development and the numerical implementation of Integral Equation Method are simply introduced, then the deduction of the MLFMA and some of the general difficulties in the MLFMA are discussed, several techniques to solve these difficulties are also presented.