Characteristics of travelling ionospheric perturbations over Waltair using phase path technique

Abstract

The phase path technique is a very sensitive experimental method for detecting travelling ionospheric perturbations in the FZ-region and is capable of giving much information on the various characteristics of the perturbations. The travelling wave perturbations over Waltair, scaled from phase path records of 'O' and 'X' components in the F2-region echoes on 5.6 MHz were found to have periods in the range 3-39 min. Smaller periods were of more frequent occurrence than larger periods and the most frequently observed period was about 9 min. An average wave perturbation in the F2-region could be represented by the equation A = 46.49 K sin 2πt/K where 'A' is in meters, K the period of the disturbances in the general range 3-39 min and 't' is the time in minutes. The phase speed of the perturbations was in the range 2.5-14 km/min. Perturbations with shorter periods were found to travel faster than larger periods. It was shown that the above variation of the speed of the perturbations with period leads to the conclusion that the group speed of the perturbations is twice their phase speed.