Estimation of the parameters of traveling ionospheric disturbances using a chirp-ionosondes network

In this article, the results of our observations of traveling ionospheric disturbances are discussed using the data from a network of chirp stations for oblique ionospheric sounding in December 2019. All observations were made with the same type of chirp stations located in the village of Vasilsursk, as well as in the cities of Yoshkar-Ola, Kazan, and Nizhny Novgorod. The stations formed six synchronous sounding paths with a length from 120 to 320 km. The amplitude-frequency and distance-frequency characteristics were registered per minute by the stations of oblique chirp sounding. Based on the data obtained, a method for determining the parameters of traveling ionospheric disturbances using the network of three chirp ionosondes was proposed. Since the ionosonde had both a receiver and a transmitter, it was possible to get data on six radio paths while using three ionosondes and, thus, to estimate the disturbance parameters only from the experimental data, without resorting to any model concepts. From a practical perspective, our research is highly relevant: the international reference ionosphere (IRI) prognostic model is widely used to calculate the ionospheric propagation of radio waves, but variations in the ionosphere can nullify the effectiveness of such forecasting under real conditions.