by Bernhard Friedrichs
Metronix has carried out several measurements with high frequency MT systems called Radio Magnetotelluric Sounding. The goal was to reach frequencies at 250 kHz as well as to use a gradiometer for the magnetic z component: using dB/dz would allow to skip the measurement of the electric fields at high frequencies which might be distorted and influenced by coupling effects.
This work was founded by the German VDI under 13N6453A.
The sections are calculated automatically by the system. An algorithm by Laust Pedersen (Uppsala) is used for the inversion. It is easy to see that at the Northern end (right) of the profile a thick resistive area at 5 m depth exists which is thinning out from West (profile 1) to East (profile 5).
The plan views are derived form the rhoa and phase values. Different frequencies indicate different depths.