ANALYSIS OF FADING-SIGNAL RECORDS TO DETERMINE IONOSPHERIC MOVEMENT OVER SINGAPORE

Abstract

In this work the fading of pulsed signals reflected from the F-region of the ionosphere over Singapore is investigated. Some 12 records received on three spaced aerials have been analysed fully to determine the parameters relating to the horizontal drift in the ionosphere, Complete auto- and cross-correlation functions have been computed for each record and these have been analysed using methods described by Yerg and by Briggs, Phillips and Shinn, with correction for anisometry of the pattern. An analysis of the amplitude distribution in the fading signals has also been performed. The correlogram results suggest that the Cambridge method of analysis is to be preferred to that of Yerg; anisometry is not very marked for the records chosen, an average axial ratio of 2 being found, with no marked orientation of the elongations along the magnetic field. Drift velocities appear to be small, with relatively large random movements evident in the records selected, but more work is required to substantiate these findings. The distribution of amplitude in the fading signals follows a Rayleigh law and a mean r.m.s, line of sight velocity of 5 metres per second is found for the scattering centres.