East-west movement of ionospheric irregularities causing equatorial radio wave scintillations

Abstract

The paper describes the results of observation of the scintillations of radio beacon on 244 MHz from geostationary satellite FLEETSAT received simultaneously at Trivandrum and Tiruchendur, both situated very close to the magnetic equator. The ionospheric cross-over point at 400 km for the two paths are separated by 105 km in east-west direction. It was observed that the scintillations at these two places were remarkably similar in pattern and duration. The E-W drift of plasma irregularity, calculated on the basis of time shift of onset or decay of identical scintillation patches at the two places, indicated a velocity of about 110 m/s eastward at 1930 hrs IST decreasing monotonously during the course of night and reaching a value of 60 m/s by 0330 hrs IST.