Accession Number : AD0665007

Title :   PROPAGATION OF ELF AND VLF WAVES BELOW A GENERALLY ANISOTROPIC IONOSPHERE.

Descriptive Note : Research rept.,

Corporate Author : SYLVANIA ELECTRONIC SYSTEMS-EAST WALTHAM MASS APPLIED RESEARCH LAB

Personal Author(s) : Galejs,Janis

Report Date : JAN 1968

Pagination or Media Count : 17

Abstract : The mode analysis of ELF and VLF waves has been generalized to allow arbitrary directions of propagation below a curved stratified ionosphere with a dipping static magnetic field. In the ELF range, the propagation parameters are changed almost linearly with the azimuthal angle phi by varying the direction of propagation from East to West. In the VLF range, the phase velocity exhibits its maximum value for propagation in South and North direction; and minimum values occur for propagation towards West. Also, maximum attenuation rates occur for propagation towards West. Measured interference distances D of the two lowest wave-guide modes have been explained using nighttime ionosphere models which exhibit sharp density gradients in the height range from 80 to 85 km. (Author)

Descriptors :   (*IONOSPHERIC PROPAGATION, WAVE PROPAGATION), UPPER ATMOSPHERE, ATMOSPHERE MODELS, ELECTRON DENSITY, GEOMAGNETISM, ELECTROMAGNETIC WAVE REFLECTIONS, ATTENUATION, SUNSPOTS, VERY LOW FREQUENCY, EXTREMELY LOW FREQUENCY

Subject Categories : Radiofrequency Wave Propagation

Distribution Statement : APPROVED FOR PUBLIC RELEASE