Electromagnetic Soil Properties in the VHF/UHF Range (Phase I)

摘要

The report describes measurements of the electromagnetic parameters of soil samples in the VHF/UHF range the purpose of which was to accumulate basic data on the properties that limit subsurface target detection by EM methods. A section of coaxial waveguide filled with soil is treated as a length of lossy transmission line. Classical transmission-line theory is used in determining the complex propagation constant of the soil sample from measurements on the electrical phase and the VSWR. These data are fed into classical equations which were programmed for computer solution. Also included in the report for completeness and comparison are the results of two other techniques for measuring the real part of the complex propagation constant. The first of these techniques requires electrical phase and VSWR measurements and the solution is obtained graphically. The second technique requires the measurement of a power ratio under matched conditions of the line under test. (Author)