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Experimental and theoretical first approach to ƒ H plasma resonance from a relaxation sounding rocket experiment
Author(s) -
Higel B.,
Feraudy H.
Publication year - 1977
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/rs012i006p00879
Subject(s) - physics , computational physics , ionosphere , schumann resonances , resonance (particle physics) , dipole , rocket (weapon) , polarization (electrochemistry) , amplitude , plasma oscillation , plasma , atomic physics , optics , geophysics , quantum mechanics , chemistry , engineering , aerospace engineering
The various plasma resonance phenomena observed in the ionosphere as relaxation signals near the characteristic frequencies ƒ N , ƒ T (plasma and upper hybrid frequencies), and n ƒ H (electron gyrofrequency harmonics) have been correctly interpreted as oblique echoes. However, the ƒ H case is not yet understood. The EIDI 3 relaxation sounding rocket experiment has provided original results regarding the plasma resonances. These results provide grounds to approach the ƒ H problem. Indeed, the spectral features of the ƒ H resonance signal look like pure sine‐wave ones; their frequency location is found to be very close to the gyrofrequency deduced from the earth's magnetic field model (relative frequency shift of the order of 10 −4 ). The duration of the ƒ H resonances is very short and their amplitude level very weak in the EIDI 3 ionospheric flight conditions. Moreover, a well‐defined dependence of this level on the orientation of the dipole antenna with respect to the earth's magnetic field has been pointed out, as well as an increase of the signal level when the antenna length is doubled. To interpret theoretically these experimental results, a brief review is made of the various modes of principal waves propagating close to ƒ H . Their frequency range, their wave vector orientation, and the EM field polarization are examined with respect to the corresponding experimental features in order to discard the disagreeing kinds of waves. The ordinary wave mode gives good agreement with the EIDI 3 results. A first‐approach study of the interest of this mode for explaining the ƒ H resonance phenomenon provides good grounds for its further study.