Satellite radiosounding of the polar ionosphere: Results of the experiments of the XX century and hopes of the XXI century

It is proposed to conduct an topside radio sounding of the Arctic ionosphere from highly elliptical satellites. This allows for a continuous study of the ionosphere, including ionospheric irregularities, for many hours. Continuous and long-term recording of ionograms and transionograms makes it possible to study all the phases of the onset, life, and decay of large irregularities. As an example, the possibility of recording quasi-vertical irregularities is considered. As a result of the modeling of transionograms, the emergence of a new multifrequency trace is shown through the main zones of the Arctic from various altitudes of the satellites. It, on the one hand, reliably determines the existence of irregularities, on the other hand, carries information about the plasma of heterogeneity and space next to it.