Summary of the Wisconsin test facility effective earth conductivity measurements

摘要

The effective conductivity of the geoelectrically complex Wisconsin Test Facility area has been measured by a number of different methods during the past few years. These methods include the H/I induction method, the wave impedance measurement technique (employing lightning discharges as the source), and two direct current methods (the four-terminal-array in-line dipole and Schlumberger techniques). The principal results obtained from these measurements were: (1) The pattern of the EW antenna is skewed clockwise, while the pattern of the NS antenna is skewed counterclockwise. (2) The effective conductivity under the EW antenna is greater than that under the NS antenna. (3) The minimum distance for determining the effective earth conductivity by the H/I method is seven effective earth skin depths. (4) The method of measuring each half-antenna in order to predict the effective conductivity of the whole antenna is correct within a factor of 1.22.