Ionospheric Structure Specifications and Systems Effects
BOSTON COLL CHESTNUT HILL MA INST FOR SPACE RESEARCH
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Ionospheric scintillation measurements are examined in relation to the satellite in-situ measurements of electron density structures in the ionosphere and the plasma processes responsible for the generation of these structures. Radio waves from satellites are scattered and ionospheric scintillation is recorded on the ground in the presence of a relative motion between the satellite, the ionosphere and the observer. The electron density irregularity spectrum of extended equatorial spread F structures, generated by Rayleigh-Taylor instability process, is found to be compatible with multi- frequency satellite scintilation measurements. In the case of equatorial bottomside sinusoidal irregularities, however, the power-law spectral index of scintillations is found to be considerably shallower than that expected. At high latitudes, two distinct classes of plasma instabilities, namely, the gradient- drift and shear-driven instability processes are identified. The observed difference of 0.5 between the spectral indices of high latitude scintillation and in-situ irregularity spectra has been explained in the context of anistropic irregularity spectrum as postulated, by Wernik et al. 1990.... Ionospheric scintillations, VHF, GHz, Plasma instabilities, HF Heaters, IMF, Electron density.
- Atmospheric Physics
- Radiofrequency Wave Propagation