The direction of movement of F2 region perturbations

A new method is described for measuring the direction of movement of F2 region perturbations from the changes of phase path due to travelling ionospheric perturbations recorded at three closely-spaced aerials. The results of the analysis using this method for 151 perturbations are presented. It is found that the direction of movement of perturbations with quasi-periods of about 15 minutes and maximum height changes of about 2¿3 km is within 230 to 250° to the east of north at a low-latitude station, Waltair. The direction of movement of these perturbations was found to be independent of the time of the day.