二维频率域电磁测深反演中偏导数的计算  

Calculating the Sensitivities of Two-dimension Frequency-domain Electromagnetic Sounding Inversion

作　　者：高远 申建平 

机构地区：[1]湖南省煤炭地质勘查院,湖南长沙410014

出　　处：《工程地球物理学报》2013年第6期757-762,共6页Chinese Journal of Engineering Geophysics

基　　金：湖南省科技计划项目(编号:2011SK3195)资助

摘　　要：在有限单元法进行正演模拟的前提下,本文介绍了利用辅助场求解二维频率域电磁测深反演问题中观测响应对模型参数的偏导数的方法。文中以无限长线电流源为例,通过在测点上引入辅助场源,求出辅助场值,再与原始场值经过一系列数学变换和计算,求出测点处的原始场对电导率的偏导数。最后通过实际算例与差分法计算得到的结果对比可知,该方法计算速度快、精度高。This paper introduces a method for calculating the sensitivities of two--dimension frequency--domain electromagnetic sounding inversion using auxiliary fields, while using finite element method to solve the forward problem. In this paper, we use an infinite line current source for example. Putting an auxiliary source in the measuring point, the auxilia- ry fields can be calculated. Through a series of mathematical transformations and calcula- tions using the auxiliary fields and the primal fields, the partial derivatives of the primal fields in the measuring points to the conductivity can be calculated. Finally, through a practical example and the comparison of the results calculated by difference methods, it shows that the calculation method is fast and precise.

关 键 词：辅助场 偏导数 电磁法 反演 

分 类 号：P631.3[天文地球—地质矿产勘探]