Singularity-free Green’s function for EM sources embedded in a stratified medium

Weng, Aihua; Liu, Yunhe; Yin, Changchun; Jia, D.

doi:10.1007/s11770-016-0549-x

Cited by 6 publications

(2 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The primary field, as described by Weng et al (2016), employs a virtual interface technique (Das and De Hoop, 1995) to solve the whole-space EM fields in a 1D layer model for different types of sources (Figure 2). These sources include vertical and horizontal electric dipoles (VED and HED) as well as vertical and horizontal magnetic dipoles (VMD and HMD).…”

Section: Background Models For Primary Fieldsmentioning

confidence: 99%

A general forward solver for 3D CSEMs with multitype sources and operating environments

Wang

et al. 2023

Front. Earth Sci.

View full text Add to dashboard Cite

To determine the electromagnetic (EM) fields of different three-dimensional (3D) controlled-source electromagnetic methods (CSEMs) using the same parameters of the forward solution, by explicitly considering the commonalities, we present a general 3D forward modeling solver for CSEMs with multitype sources and operating environments. The commonality of the solver is reflected in two aspects. First, the solver is based on a frequency-domain (FD) vector Helmholtz equation for determining the scattered electric field. The different types of sources are imposed on the right-hand term of the equation, expressed as background Green’s function. Second, sources of any CSEM can be composed of electric dipole (ED) or magnetic dipole (MD) superposition. Thus, the focus of the 3D forward modeling of CSEMs is reduced to determining the EM fields of ED or MD sources for the background medium. The quasi-minimal residual (QMR) method is used to solve the large sparse complex linear system. Once the FD EM fields have been calculated, the time-domain (TD) response can be obtained using the cosine/sine transformation. The numerical results show that the relative error is less than 5% between the 3D numerical and analytical solutions, which verifies the accuracy of the solver. We further study the difference between the real (bent) and theoretical (straight) wires. We suggest that the shape of the source must be considered for TD and FD CSEMs with a wire source during data processing and inversion. The last example investigated the characteristics of FD EM fields from a finite-length wire and TD EM fields from a rectangular fixed loop on the same conductive tilted disk model buried in resistive sediments. According to the numerical results, we recommend FD CSEMs with a wire source for detecting deep anomalies.

show abstract

Section: Background Models For Primary Fieldsmentioning

confidence: 99%

A general forward solver for 3D CSEMs with multitype sources and operating environments

Wang

et al. 2023

Front. Earth Sci.

View full text Add to dashboard Cite

show abstract

“…The 3D CSAMT program was based on a finite-difference technique (Alumbaugh et al 1996). A virtual interface was added at the source location parallel to the layer interfaces, and the Green's functions were calculated for electromagnetic sources (Weng et al 2016). We decomposed the electric field Helmholtz equation for a staggered grid, with the medium divided into hexahedron to calculate the anomalous field.…”

Section: Three-dimensional Controlled-source Audiomagnetotelluric Invmentioning

confidence: 99%

Three‐dimensional electrical exploration methods for the mapping of polymetallic targets in Gansu Province, China

Gong

Yang²,

Lin³

et al. 2019

Geophysical Prospecting

View full text Add to dashboard Cite

We describe a three‐dimensional electrical exploration system, and its use in carrying out a three‐dimensional survey on a polymetallic deposit located in China's Gansu Province. A time‐domain‐induced polarization method, along with a controlled‐source audiomagnetotelluric method, was used to survey the same station points for comparison. Then, a three‐dimensional inversion based on the incomplete Gauss–Newton method (for time‐domain‐induced polarization) and a nonlinear conjugate gradient (for controlled‐source audiomagnetotelluric) method were developed and applied in order to model the data sets. Four subsurface targets were mapped by the three‐dimensional electrical exploration method. A strong correlation was found between the zones of the revealed ore‐bearing anomalies and the geological setting. Using the results of the three‐dimensional electrical exploration, we revealed the spatial distribution of the ore‐bearing stratum, as well as the relationship between the ore bodies and the stratum. The results potentially provided evidence for future interpretations of deep geological structures, along with evaluations of mineral resources.

show abstract

Applying three-dimensional inversion to the frequency-domain response converted from transient electromagnetic data for a rectangular fixed loop

Shan

Weng

2022

Journal of Applied Geophysics

View full text Add to dashboard Cite

Singularity-free Green’s function for EM sources embedded in a stratified medium

Cited by 6 publications

References 20 publications

A general forward solver for 3D CSEMs with multitype sources and operating environments

A general forward solver for 3D CSEMs with multitype sources and operating environments

Three‐dimensional electrical exploration methods for the mapping of polymetallic targets in Gansu Province, China

Applying three-dimensional inversion to the frequency-domain response converted from transient electromagnetic data for a rectangular fixed loop

Contact Info

Product

Resources

About