Accession Number : AD0744868

Title :   Theoretical and Experimental Studies of VLF and LF Waves.

Descriptive Note : Final rept. 1 Jan-31 Dec 71,

Corporate Author : INNSBRUCK UNIV (AUSTRIA) ELECTRONICS LAB

Personal Author(s) : Nessler,Norbert

Report Date : 29 FEB 1972

Pagination or Media Count : 79

Abstract : A new helical antenna was built with low resonant frequency for use in dissipative media. A theoretical foundation is given for the local periods found by experiment when measuring an incoming radio signal in a gallery of the mine. The measuring device with automatic range selector which was built for quick and accurate measurements in the mine is described in detail. A new method is discussed for measuring the electric rock parameters in an inhomogeneous and anisotropic medium by means of two frequencies. The distortion of an electromagnetic field at 1000 kHz penetrating a fairly good conductive boundary layer is explained by using the theory of images. Detailed studies were made on receiving elliptically polarized VLF and LF waves. A new method of phase measurement facilitates considerably the measurement of elliptically polarized fields. (Author)

Descriptors :   (*ELECTROMAGNETIC RADIATION, PROPAGATION), (*RADIO TRANSMISSION, UNDERGROUND), ELECTRICAL CONDUCTIVITY, VERY LOW FREQUENCY, LOW FREQUENCY, ROCK, POLARIZATION, HELICAL ANTENNAS, AUSTRIA

Subject Categories : Radiofrequency Wave Propagation

Distribution Statement : APPROVED FOR PUBLIC RELEASE