Determination of the Parameters of Moving Ionospheric Disturbances from Vertical Sensing Ionograms with Additional U-Shaped Tracks

The article considers as the increase in critical frequency that is recorded on vertical sounding ionograms a result of the movement of an additional, U-shaped track. This corresponds to the appearance of a region with an increased electron concentration above the probing point. A technique is presented for the study of the characteristics of traveling ionospheric disturbances from ionograms in the framework of a two-dimensional disturbance model. The article also examines changes that occur in the shape of the additional ionogram track due to variation in the disturbance parameters. It is shown that the characteristics of moving ionospheric disturbances, e.g., the intensity, localization scale, horizontal drift velocity, can be determined.