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Ionospheric heater beam scanning: A mobile source of ELF radiation
Author(s) -
Barr R.,
Rietveld M. T.,
Stubbe P.,
Kopka H.
Publication year - 1987
Publication title -
radio science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.371
H-Index - 84
eISSN - 1944-799X
pISSN - 0048-6604
DOI - 10.1029/rs022i006p01073
Subject(s) - ionosphere , zenith , electrojet , beam (structure) , physics , radio wave , radiation , optics , ionospheric heater , amplitude , geophysics , earth's magnetic field , quantum mechanics , magnetic field
The heating facility at Ramfjordmoen near Tromsø, Norway, is used to modulate the auroral electrojet at extremely low frequencies (ELF) and the radiation of low‐frequency waves by the system is now well documented. In most reports the heater has been operated with a stationary heating beam, modulated at ELF, directed toward the zenith. This paper describes the signals recorded at Lycksele, 500 km from the heating site, when the HF heating beam was modulated at an ELF frequency and simultaneously scanned up to 37° from the zenith in the north‐south direction. ELF phase measurements at Lycksele confirm that the moving heated patch of ionosphere acts as a mobile source of ELF radio waves in the Earth‐ionosphere‐waveguide and that this mobile source may be used to determine the propagation parameters of the waveguide. Using square wave modulation of the beam position, of a constant amplitude HF beam, two simultaneous sources of ELF radiation have been produced in the ionosphere and a directional ionospheric ELF radio source synthesized.