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ElectroMagnetic Simulation in Geophysics#

emsig are open-source codes to simulate electromagnetic data. Their main targets are geophysical applications (exploration and monitoring, engineering, environmental), but they are by no means limited to that. Currently there are two main codes, empymod and emg3d. The former is a 3D code for layered media, the latter is a low-memory multigrid solver for 3D media. Both are written in Python and released under the permissive Apache-2.0 license.

3D EM modeller for 1D VTI media


The modeller empymod can compute electric or magnetic responses due to a 3D electric or magnetic source in a layered-earth model with vertical transverse isotropic (VTI) resistivity, VTI electric permittivity, and VTI magnetic permeability, from very low frequencies (DC) to very high frequencies (GPR). The computation is carried out in the wavenumber-frequency domain, and various Hankel- and Fourier-transform methods are included to transform the responses into the space-frequency and space-time domains.

Multigrid solver for 3D EM diffusion


The modeller emg3d is a multigrid solver for 3D EM diffusion with tri-axial electrical anisotropy. The matrix-free solver can be used as main solver or as preconditioner for Krylov subspace methods, and the governing equations are discretized on a staggered Yee grid.

Contributing & Contact#

emsig are community codes, please help to shape their future!

Join the #emsig-channel either on SWUNG or on SimPEG.

If you prefer personal email you can contact me through my website werthmuller.org.