simpegEM Utilities

SimPEG for EM provides a few EM specific utility codes, sources, and analytic functions.

Utilities for Electromagnetics

Analytic Functions - Time

SimPEG.electromagnetics.analytics.TDEM.hzAnalyticDipoleT(r, t, sigma)

SimPEG.electromagnetics.analytics.TDEM.hzAnalyticCentLoopT(a, t, sigma)

SimPEG.electromagnetics.analytics.TDEM.TransientMagneticDipoleWholeSpace(XYZ, srcLoc, sig, t, moment, fieldType='h', mu_r=1)

Analytical solution for a dipole in a whole-space.

SimPEG.electromagnetics.analytics.TDEM.TransientElectricDipoleWholeSpace(XYZ, srcLoc, sig, t, moment, fieldType='h', mu_r=1)

Analytic Functions - Frequency

SimPEG.electromagnetics.analytics.FDEM.hzAnalyticDipoleF(r, freq, sigma, secondary=True, mu=1.25663706212e-06)

The analytical expression is given in Equation 4.56 in Ward and Hohmann, 1988, and the example reproduces their Figure 4.2.

(Source code, png, hires.png, pdf)

Reference

• Ward, S. H., and G. W. Hohmann, 1988, Electromagnetic theory for geophysical applications, Chapter 4 of Electromagnetic Methods in Applied Geophysics: SEG, Investigations in Geophysics No. 3, 130–311; DOI: 10.1190/1.9781560802631.ch4.

SimPEG.electromagnetics.analytics.FDEM.MagneticDipoleWholeSpace(XYZ, srcLoc, sig, f, moment, fieldType='b', mu_r=1, eps_r=1, **kwargs)

Analytical solution for a dipole in a whole-space.

The analytical expression is given in Equation 2.57 in Ward and Hohmann, 1988, and the example reproduces their Figure 2.2.

TODOs:

• set it up to instead take a mesh & survey

• add divide by zero safety

(Source code, png, hires.png, pdf)

Reference

• Ward, S. H., and G. W. Hohmann, 1988, Electromagnetic theory for geophysical applications, Chapter 4 of Electromagnetic Methods in Applied Geophysics: SEG, Investigations in Geophysics No. 3, 130–311; DOI: 10.1190/1.9781560802631.ch4.

SimPEG.electromagnetics.analytics.FDEM.ElectricDipoleWholeSpace(XYZ, srcLoc, sig, f, moment='X', fieldType='e', mu_r=1, eps_r=1, **kwargs)