Fast algorithm for electromagnetic scattering by buried 3-D dielectric objects of large size

作     者：Cui, TJ Chew, WC 

作者机构：Univ Illinois Dept Elect & Comp Engn Ctr Computat Electromagnet Urbana IL 61801 USA 

出 版 物：《IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING》 (IEEE Trans Geosci Remote Sens)

年 卷 期：1999年第37卷第5期

页      面：2597-2608页

核心收录：

学科分类：0808[工学-电气工程] 1002[医学-临床医学] 08[工学] 0708[理学-地球物理学] 0816[工学-测绘科学与技术] 

基　　金：National Science Foundation, NSF, (NSF ECS93-02145) National Science Foundation, NSF Office of Naval Research, ONR, (N00014-95-1-0872) Office of Naval Research, ONR U.S. Department of Energy, USDOE, (DEFG07-97ER 14835) U.S. Department of Energy, USDOE Air Force Office of Scientific Research, AFOSR, (F49620-96-1-0025) Air Force Office of Scientific Research, AFOSR 

主　　题：buried objects CG-FFT fast algorithm Sommerfeld integrals 

摘      要：A fast algorithm for electromagnetic scattering by buried three dimensional (3-D) dielectric objects of large size is presented by using the conjugate gradient (CG) method and fast Fourier transform (FFT), In this algorithm, tbe Galerkin method is utilized to discretize the electric field integral equations, where rooftop functions are chosen as both basis and testing functions. Different from the 3-D objects in homogeneous space, the resulting matrix equation for the buried objects contains both cyclic convolution and correlation terms, either of which can be Solved rapidly by the CG-FFT method. The near-scattered field on the observation plane in the upper space has been expressed by two-dimensional (2-D) discrete Fourier transforms (DFT s), which also can be rapidly computed. Because of the use of FFT s to handle the Toeplitz matrix, the Sommerfeld integrals evaluation which is time consuming yet essential for the buried object problem, has been reduced to a minimum. The memory required in this algorithm is of order N (the number of unknowns), and the computational complexity is of order NiterN log N, in which N-iter is the iteration number, and N-iter N is usually true far a large problem.