Accession Number : AD0701017

Title :   LITHOSPHERIC RADIO PROPAGATION. A REVIEW,

Corporate Author : ARMY ELECTRONICS COMMAND FORT MONMOUTH N J INST FOR EXPLORATORY RESEARCH

Personal Author(s) : Levin,S. Benedict

Report Date : 1966

Pagination or Media Count : 51

Abstract : The feasibility of linking sub-surface stations by radio propagation entirely thru the rocks of the earth's crust, over paths several hundred to thousands of kilometers long, depends upon several sets of critical geophysical factors. Among these are: (1) the geologic structure of the crust; (2) the compositional variations of the major rock facies, both laterally and in depth; (3) the electrical conductivity, dielectric permittivity, and intrinsic attenuation of these rock facies as a function of temperature, frequency, and pressure; (4) the temperatures and temperature gradients in the crust. Little is known about these properties of the crust by direct observation below a depth of about 3 Km, but (by extrapolation and inference) if any favorable zone does exist, it will be found between depths of about 6 to 25 Km. Current knowledge does not rule out the probability of achieving radio communication thru the crust, but several unfavorable aspects are revealed by careful analysis of the geophysical factors. Some recent experiments in shallow boreholes (less than 3 Km deep) have yielded results which are at best ambiguous, but not conclusive. (Author)

Descriptors :   (*LITHOSPHERE, *RADIO TRANSMISSION), REVIEWS, COMMUNICATION AND RADIO SYSTEMS, ROCK, ELECTRICAL PROPERTIES, UNDERGROUND

Subject Categories : Geology, Geochemistry and Mineralogy
      Radio Communications

Distribution Statement : APPROVED FOR PUBLIC RELEASE