Methodology for the determination of the ground´s electric conductivity in rural environments trough measurements of the surface wave

The conductivity is an important parameter for the prediction of AM radio broadcasting coverage area and becomes critical, in special, when it comes to the digitalization of this service, currently in discussion. In this paper, a methodology is presented to estimate the electric conductivity of the ground, from the theoretical and practical determination of the surface wave field attenuation. With this objective, the measurement of the electric field intensity had been carried through the central region of Brazil, in the medium waves band, for a distance superior to 1000 km. The value of the ground conductivity obtain for the region where the measures had been carried through is superior to the available value specified in the ITU-R P.832-2 recommendation. This information must be considered in the planning of the digital system, mainly when on-channel simulcast technique will be used.