INVESTIGATION OF HF/VHF IONOSPHERIC WAVEGUIDANCE MODES.
Abstract
The report presents the results of an experimental activity devoted to a preliminary investigation of the ''whispering gallery'' behavior of the earth's ionosphere below the F2 layer maximum, at HF and VHF. Endo-ionospheric waveguidance propagation has been investigated by using ground-based links in the band 20 to 50 mc/s; wave injection/extraction into/from the mode, otherwise impossible from the earth's surface, has been sought through a concentrated scattering center (meteor, aurora column, sporadic E patch, etc.) naturally occurring above at least one of the link terminals, with distributed ionospheric scattering as extraction/injection mechanism for the other terminal. At 23 mc/s the characteristics of the received signals, especially their duration, often exceeding one hour, did not always allow a clear-cut distinction between conventional multihop propagation and the endoionospheric waveguidance mechanism associated with long-lasting aurora and sporadic E scatterers as wave injectors/extractors. At 30 and 40 mc/s burst-type signals have been received at the Arcetri terminal, having the characteristics of meteor scattering. At 50 mc/s a link was operated between Jicamarca, Peru and Littleton, Massachusetts, but no firm evidence of reception was obtained. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 15, 1964
- Accession Number
- AD0436761
Entities
Organizations
- RTX