Working Group Details
356_WG - Minor Revisions Working Group
|Working Group Chair||
Withdrawn Standard. Withdrawn Date: Sep 15, 1995. This guide is the result of a survey of radio techniques employed for measuring the conductivity of the earth. Results are applicable to the design of communication channels that are influenced by the electrical characteristics of the earth. Emphasized are those techniques used at frequencies where the loss tangent is large. The techniques are classed broadly into those that make use of drill holes into the earth and those that do not. Also, a distinction is made between active and passive methods. Comments and critiques on the various techniques are included. Theoretical and practical details underlying some of the methods are given in the appendixes.
" The electromagnetic properties of the earth play an important role in the design and implementationof radio communications systems, geophysical prospecting instruments, and subsurface mapping techniques.Measurement techniques include dc resistivity, surface impedance, propagation studies, wave tilt methods,probe impedance methods, mutual impedance methods, transient methods, time domain reflectometry, groundprobing radar, laboratory-based techniques, and free-space reflection measurements. The separation distancebetween the probes and the wavelength of the radiation both affect the volume of earth material measured.This guide provides a summary of current measurement techniques and, where appropriate, inversion methodsfor determining the conductivity and the relative permittivity of the volume under investigation."