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Open Access

Spectral characteristics of scintillations producing ionospheric irregularities in the Indian region

Earth, Planets and Space201457:BF03351805

Received: 4 February 2004

Accepted: 4 January 2005

Published: 20 June 2014


VHF amplitude scintillations were recorded at Tirunelveli (8.7°N, 77.7°E; 0.6°N dip Latitude), Pondicherry (12°N, 79.1°E; 4.4°N dip Latitude) and Mumbai, (19°N, 73°E; 13.5°N dip Latitude) for the years 1992–1996 using the 250 MHz radio beacon from the geostationary satellite FLEETSAT (73°E). The recorded digital scintillation data for few nights are analyzed to estimate scintillation index (S4), fade rates, auto-correlation functions and power spectral densities for every 2.5 minute sample during the period of the scintillation activity. The power spectral slopes are shallower for the scintillation at the generation phase and steeper towards the decay phase, which indicates the erosion of smaller scale sizes towards the decay phase.

Key words

Equatorial ionosphereionospheric irregularitiesVHF Scintillationfade rate