各向异性分层介质电磁场并矢Green函数的混合算法

A Hybrid Algorithm for Calculating of Dyadic Green's Function in Layered Anisotropic Medium

提出一种兼顾精度与效率且不受参数范围限制的各向异性分层介质电磁场并矢Green函数的混合算法,并研究其在求解层状介质电磁响应中的应用。首先给出四种场型并矢Green函数在均匀各向异性介质中的闭合解析解以及在层状各向异性介质中的Sommerfeld积分表示,并重点考察了场源横向距离为零时的解;然后通过对比分析Sommerfeld积分的各种计算方法的优缺点及适用条件,得到一种根据参数范围自动选配最优计算方案的混合算法,并研究了特殊几何模型情况下全空间上并矢Green函数的高效计算问题;最后利用所提出的算法考察了层状各向异性介质背景下偶极子的辐射等实际问题。

In this paper, a hybrid algorithm is developed, which is not only compatible for precision and efficiency but also independent of bound of arguments for calculating of dyadic Green＇s function in a layered anisotropic earth; and its applications for computation of electromagnetic response in layered earth are studied. Firstly, entire analytic solutions in homogeneous anisotropic earth and expression of Sommerfeld integrals in layered anisotropic earth for four kinds of field dyadic Green＇s functions are given. Especially, the solution for the case of the distance of receiver and transmitter being zero is investigated. Characteristic and suited conditions of some usual computational methods of Sommerfeld inte- grals are analyzed and contrasted. Then a hybrid algorithm of matching optimal methods is obtained due to the range of arguments, and the efficient method of calculating dyadic Green＇s functions for whole space in special geometrical model is studied. Furthermore, the radiation of dipole in a layered anisotropic earth is investigated.