Electrical resistivity method was used in carrying out geophysical investigations at the Centre for Energy Research and Training (CERT), Ahmadu Bello University, Zaria, with a view of determining the depth to the bedrock, thickness of the top soil and weathered basement.Vertical Electrical Sounding (VES) using Schlumberger array was carried out at forty (40) VES stations. ABEM terrameter (SAS 3...

Low frequency sub-surface radio is used for communications with miners and cavers. The signal attenuation is dependent on frequency and on the electrical conductivity of the ground. In addition, the optimum frequency for communications is dependent on depth below the surface; and on the degree of noise and cochannel interference. An adaptive communications system makes use of a channel-sounding...