STUDY OF SPORADIC-E CLOUDS BY BACKSCATTER RADAR

It is shown that swept-frequency backscatter ionograms covering a rang e of azimuths can be used to study the dynamics of sporadic-E clouds. A simple technique based on analytic ray tracing can be used to simula te the observed narrow traces associated with E(s) patches. This enabl es the location and extent of the sporadic-E clouds to be determined. The motion of clouds can then be determined from a time sequence of re cords. In order to demonstrate the method, results are presented from an initial study of 5 days of backscatter ionograms from the Jindalee Stage B data base obtained during March-April 1990. Usually 2-3 clouds were observed each day, mainly during the evening and up to midnight. The clouds lasted from 1-4 h and extended between 30 degrees-80 degre es in azimuth and 150-800 km in range. The clouds were mostly stationa ry or drifted generally westward with velocities of up to 80 m s(-1). Only one cloud was observed moving eastward.