Preliminary results of clay soils state monitoring using transient electromagnetic sounding apparatus

The background for creating an electromagnetic soil sounding apparatus with receiving and transmitting antennas separated by a distance of up to 100 meters is considered in this paper. The temperature and frequency dependences of the complex dielectric permittivity of multilayer clay soil are studied in conjunction with the results of numerical simulation of ultra-wideband log-periodic antennas immersed in the soil to a depth of 1.5 m. The choice of a high-voltage generator and pulse receiver is studied, and a structure of apparatus prototype is given. Based on the results of oscillograms’ and signal spectra measurements with 30 m antennas separation, and with reference to the soil temperature, estimates of the possible limits of change in the electrophysical parameters of the clay soil at a geophysical site are provided. Conclusions are drawn about ways to improve the apparatus in order to create a new technology for transient electromagnetic monitoring of permafrost.