UBC-GIF has finished 3D modeling of resistivity gradient survey data with EH3Dinv code (http://era-max.ca/examples.html, last two examples ). EH3Dinv is a computing code developed at UBC − GIF for inverting controlled source frequency-domain EM data to recover a 3D electrical conductivity (Inversion of 3D electromagnetic data in frequency and time domain using an inexact all-at-once approach. Eldad Haber, Uri M. Ascher, and Douglas W. Oldenburg. GEOPHYSICS, VOL. 69, NO. 5, 2004; P. 1216–1228).
The ERA’s technology, in brief, is “cross-disciplinary” – between frequency-domain and direct current (DC) concepts. The technology provides high resistivity resolution by grounded, non-contact and/or combined modes of electrical field measurements at 1.22-2500Hz. In comparison with DC method ERA equipment is several times more sensitive and in comparison with frequency-domain is defined as high-resolution.