水平层状介质中三维异常体电磁波散射模拟的混合DTA-BCGS算法  

Hybrid DTA-BCGS algorithm for simulating electromagnetic scattering of 3-D inhomogeneous objects in horizontally stratified medium

作　　者：魏宝君[1] 宋殿光[1] LIU Q H 

机构地区：[1]中国石油大学物理科学与技术学院,山东东营257061 [2]Department of Electrical ＆ Computer Engineering, Duke University, Durhan, NC 27708, USA

出　　处：《中国石油大学学报（自然科学版）》2008年第1期156-161,共6页Journal of China University of Petroleum(Edition of Natural Science)

基　　金：美国国家科学基金(CCR-0219528);中国石油大学基础科研基金(Y061814)

摘　　要：为提高水平层状介质中三维异常体的电磁波散射精确数值模拟的效率,提出了一种将求解积分方程的对角张量近似(DTA)和稳定型双共轭梯度快速Fourier变换(BCGS-FFT)混合应用的算法。根据不同回代方式得到了两种近似,即DTA1和DTA2,二者均可以通过快速Fourier变换技术加速。DTA既可以作为BCGS-FFT算法的初始猜测值也可以作为它的预条件因子,从而使得这种混合算法能以比传统的BCGS-FFT算法更少的迭代次数精确求解电磁波散射场。对DTA、混合DTA-BCGS以及BCGS-FFT的精度和收敛性进行了对比,结果表明,DTA2改进型的对角张量近似可使计算精度进一步提高,而混合DTA-BCGS能以更少的迭代次数达到与传统的BCGS-FFT完全相同的精度。A hybrid implementation of a novel scattering approximation-diagonal tensor approximation （DTA） with the stabilized biconjugate-gradient fast Fourier transform （BCGS-FFT） algorithm for integral equations was developed to improve the efficiency for accurate simulating electromagnetic scattering of 3-D inhomogeneous objects in horizontally stratified medium. Two kinds of approximation were obtained, which can be accelerated by the fast Fourier transform technique. The DTA solution is used as both the initial estimate and the pre-conditioner in the BCGS-FFT algorithm in order to solve the scattered electromagnetic fields accurately with fewer iterations than conventional BCGS-FFT. The accuracy and convergence of DTA, the hybrid DTA-BCGS and BCGS-FFT were compared with several numerical examples. The numerical results show that the second kind of improved diagonal tensor approximation （DTA2） is greatly superior in the accuracy and that the hybrid DTABCGS algorithm can produce results as accurate as the conventional BCGS-FFT but with fewer iterations.

关 键 词：积分方程 对角张量近似(DTA) 稳定型双共轭梯度 快速FOURIER变换 水平层状介质 并矢Green函数 

分 类 号：P631.811[天文地球—地质矿产勘探] O441.4[天文地球—地质学]