Accession Number : ADP006528

Title :   Electrojet Modulation ELF Communications,

Corporate Author : ARCO POWER TECHNOLOGIES INC WASHINGTON DC

Personal Author(s) : Papadopoulos, K. ; Shanny, R. A. ; Susman, L. ; Machina, M. ; Stamboulis, P.

Report Date : OCT 1990

Pagination or Media Count : 9

Abstract : Me causes for the inefficient conversion of HF to ELF waves by ionospheric heating observe in recent experiments are examined. It is found that for the low frequency HF range 2.5-4 MHz used in the present experiments the modified conductance saturates during a fraction of the HF irradiation cycle. As a result most of the HF energy is transferred to processes that do not affect the conductance significantly. This was experimentally confirmed using the HIPAS facility. Techniques relying on fast HF antenna sweeping by which the efficiency can increase by more than two orders of magnitude are presented.

Descriptors :   *IONOSPHERIC PROPAGATION, *FREQUENCY CONVERSION, *IONOSPHERIC DISTURBANCES, CYCLES, EFFICIENCY, ENERGY, HEATING, IRRADIATION, ELECTROJETS, COMMUNICATION AND RADIO SYSTEMS, EXTREMELY LOW FREQUENCY.

Subject Categories : Atmospheric Physics
      Radiofrequency Wave Propagation
      Radio Communications

Distribution Statement : APPROVED FOR PUBLIC RELEASE