一种复杂分层介质中电磁探测的正演算法研究  

A method used for CSEM forward calculation in complex medium

作　　者：葛勤革 韩逍菲[2] 潘威炎[2] 罗强[3] 

机构地区：[1]海司信息化部 [2]中国电波传播研究所 [3]中国人民解放军91919部队

出　　处：《电波科学学报》2012年第6期1244-1248,1268,共6页Chinese Journal of Radio Science

摘　　要：针对海底可控源电磁法(CSEM)正演计算中所涉及到的极低频电磁波在含有目标体的不均匀分层介质中的传播问题,提出了基于"扰动"的格林函数算法。该算法将发射源在目标体内产生的初级场直接作为接收点处次级场的激励源,结合并矢格林函数的物理意义对次级场进行计算,从而避免了矩阵方程的求解。验证结果表明:当目标体相对于背景介质为"微扰"时,计算精度可接受。最后,给出了目标体位于不同位置时次级场幅值的2-D分布图,从图中可以明显看出目标体的分布位置及大小对于目标体的作用区域及大小的影响,为反演的进行提供了依据。For the problem of ELF electromagnetic wave propagation in layered me dium with target body, remaining in controued-source electromagnetic method （CSEM） forward calculation, a method based on ＂disturbance＂ and Green functions is put forward. This method regards the electromagnetic fields in target body directly as the source of the second-fields at the receiving points, and combines Dyadic Green functions to calculate the fields without solving matrix functions. Results show that if the target body can be regarded as ＂disturbance＂ compared with the background medium, the precision is acceptable. Finally, 2-D pictures about electric amplitude distribution which gained by method based on ＂disturbance＂ and Green functions are given with target body at different locations. In the pictures, the effect of body location on its work region can be seen clearly, which provids proof for inversion.

关 键 词：极低频 分层介质 并矢格林函数 可控源电磁法 电偶极子 

分 类 号：P631.3[天文地球—地质矿产勘探]