Testing

[lheagy]

From @prisae on slack:
Just joined #updates and stumbled upon geoana. A random thought: How about setting up a few tests comparing simpeg/geoana with empymod.model.analytical? empymod has a couple of analytical solutions included. They should yield the same result, so comparing them to ensure they are the same could make both "stronger".

Included analytical solutions in empymod:

• Complete full-space (el, & mag, src & rec); space-frequency domain
• Diffusive half-space (el. src & rec); space-frequency and space-time domains

The diffusive half-space solution can be split into:

• Direct wave (= diffusive full-space solution)
• Reflected wave
• Airwave (semi-analytical in the case of step responses, using the Gaver-Stehfest method)

As I said, just an idea.

Just in case someone is interested, here the references I used:

Complete full-space solution uses Hunziker et al., 2015:
Hunziker, J., J. Thorbecke, and E. Slob, 2015, The electromagnetic response in a layered vertical transverse isotropic medium: A new look at an old problem: Geophysics, 80(1), F1–F18; DOI: 10.1190/geo2013-0411.1.

Diffusive half-space solution uses Slob et al., 2010:
Slob, E., J. Hunziker, and W. A. Mulder, 2010, Green’s tensors for the diffusive electric field in a VTI half-space: PIER, 107, 1–20: DOI: 10.2528/PIER10052807.

Slob et al., 2010, has, unfortunately, quite a few typos in the equations. If there is interest I can provide an updated version here. Evert Slob happily sends out updated versions as well if you ask him directly (they plan to publish an updated version at some point, I just don't know when).