Three-dimensional anisotropic radio frequency magneto telluric adaptive finite element forward modeling method

Abstract

The invention discloses a three-dimensional anisotropic radio frequency magneto telluric adaptive finite element forward modeling method. The three-dimensional anisotropic radio frequency magneto telluric adaptive finite element forward modeling method comprises the steps that a three-dimensional geoelectric geometric model representing a solution region is constructed, and control parameters of different regions are acquired; the three-dimensional geoelectric geometric model is divided into a plurality of mutually disjoint tetrahedral elements; the integration weak form corresponding to the three-dimensional anisotropic radio frequency magneto telluric is acquired, sparse linear equation sets are constructed, then incident fields with two different polarization directions are introduced to the earth surface so as to obtain different right-end items in the two sparse linear equation sets, and the two sparse linear equation sets are solved to obtain approximate electric field tangentialcomponent on each edge in the two polarization directions; based on the approximate electric field tangential component on each edge in the two polarization directions, and a combination of parameters of one or more of an electric field, a magnetic field, impedance tensor, magnetic inclination sub vector, apparent resistivity, and phase response at a measuring point is acquired. According to thethree-dimensional anisotropic radio frequency magneto telluric adaptive finite element forward modeling method, 3D RMT anisotropic forward modeling simulation is realized based on an adaptive finite element method.

Description

technical field [0001] The invention belongs to the technical field of forward modeling of geophysical electromagnetic prospecting methods, and in particular relates to a three-dimensional anisotropic radio frequency magnetotelluric self-adaptive finite element forward modeling method. Background technique [0002] Radio-magnetotelluric (RMT) is a shallow frequency domain electromagnetic prospecting method developed on the basis of geophysical methods such as magnetotelluric, controlled source audio magnetotelluric and bottom-penetrating radar. It generally uses high-frequency electromagnetic waves emitted by submarines and radio stations as the signal source, and calculates parameters such as apparent resistivity and phase through the electromagnetic field collected in the far area, so as to study the electrical structure of the shallow surface. The detection frequency is about 10k-300kHz , The detection depth is generally within 100m. Because the RMT method has a high det...

AI Technical Summary

Problems solved by technology

[0004] In the existing technology, although the 3D magnetotelluric anisotropy forward modeling technology that only considers the conductivity anisotropy has become mature, it does not need to consider the influence of the dielectric constant and the influence of the magnetotelluric and radio frequency due to the low detection frequency of this method. There are essential differences in the magnetotelluric method, so it cannot be applied to 3DRMT radio frequency magnetotelluric forward modeling

Images