f Analog-Scale Modelling Transient Electromagnetic Field in Dispersive Media

Most of rocks display conductivity dispersion in low and very low frequency range, i.e. in the range, where usual displacement currents may be neglected. For a long period of time, this type of dispersion was not taken into account both in theory and in practice of geophysical electromagnetics. It's second "discovery" was closely connected with revealing non-monotonous transient responses while taking time-domain electromagnetic field measurements by means of coincidental loops configuration. Reversals of the response sign were especially unexpected in this configuration and not predicted by the electromagnetic theory.