Alternative Methods to Obtain Ground Conductivity

The radio planning of systems in lower frequency bands, such as LF and MF, makes use of ground conductivity at these frequencies, as it determines the attenuation of the surface wave, characteristic of the propagation in these bands. In this paper, three alternative methods to obtain an estimation of the conductivity are presented and compared. The first one is based on measurements of the electric field strength generated by AM transmitters. Although it is considered the most accurate, it is also the most expensive as it requires extensive and detailed measurements that are not always feasible. The second method relies on several terrain characteristics that are known to be related to the conductivity, and uses reference conductivity values from similar areas. The third method makes use of remote sensing data, information that is readily available worldwide at low cost. The methods are compared through their application in a research work carried out in Mexico. The results show that these approximate methods can yield results with reasonable accuracy, when compared with the results obtained from field strength measurements.