基于小波伽辽金法的大地电磁二维数值模拟
Two-dimensional forward modeling of magnetotelluric using a Wavelet-Galerkin method
程子煜 1熊彬 1陈汉波 1陆裕国 1韩钰 1刘浩1
作者信息
- 1. 桂林理工大学地球科学学院,桂林 541004
- 折叠
摘要
大地电磁法因其勘探深度大、成本较低,广泛运用于深部地质构造、矿产、水文地质等勘查活动中.为了实现快速、稳定的大地电磁反演,采取高效的正演技术是关键.本文利用Daubechies小波的性质,介绍了一种以Daubechies小波尺度函数作为伽辽金法基函数的大地电磁二维正演算法,并应用不完全LU分解的双稳定共轭梯度算法求解方程组,提高了求解的效率.通过设计典型的地电模型进行正演计算,与有限元法数值解对比.对比结果表明,采用小波伽辽金法进行大地电磁二维正演是可行、有效的.本文所提出的算法具有良好的通用性,可推广应用于求解其他电磁法数值模拟问题.
Abstract
Magnetotelluric method is widely used in the exploration of deep geological structure,mineral resources,hydrogeology and so on because of its large exploration depth and low cost.Efficient forward modeling is the key to fast and stable magnetotelluric inversion.Therefore,based on the properties of Daubechies wavelet and the scale function of Daubechies wavelet as the basis function of Galerkin method,a two-dimensional forward algorithm for magnetotellurics based on wavelet is constructed in this paper.Firstly,based on the partial differential equations satisfying the magnetotelluric field,the wavelet Galerkin method equations for two-dimensional forward magnetotelluric field are derived in detail,and the bistable conjugate gradient algorithm of incomplete LU decomposition is used to solve the equations,which improves the efficiency of solution.Finally,a typical geoelectric model is designed for forward calculation and compared with the finite element method.The comparison results show that the wavelet Galerkin method is feasible and effective for two-dimensional magnetotelluric forward modeling.The algorithm presented in this paper has good universality and can be extended to other electromagnetic numerical simulation problems.
关键词
大地电磁/小波伽辽金法/Daubechies小波/尺度函数/正演Key words
Magnetotelluric/Wavelet-Galerkin method/Daubechies wavelet/Scaling function/Forward modeling引用本文复制引用
基金项目
广西科技基地和人才专项基金(桂科AD23026231)
中国博士后科学基金项目(2021MD703820)
桂林理工大学科研启动基金项目(RD2100002165)
出版年
2024
NETL
NSTL
万方数据