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We present and discuss a series of radio tomographic images of electron density distributions in the high- and midlatitude ionosphere during different phases of the 23rd and 24th solar cycles. The images were obtained using the methods of low orbiting and high orbiting radio tomography which employ the signals from the low-orbiting navigational satellite systems (Tsikada, Parus, Transit) and high-orbiting global navigation satellite systems GPS/GLONASS. The capability of the RT methods to reconstruct spatial 2D (altitude–latitude) and 3D distributions of ionospheric electron density above large spatial regions makes these methods an efficient instrument for studying irregular structure of the ionospheric plasma. The main focus of the presentation is in analyzing the RT reconstructions based on the measurements by the Russian transcontinental RT chain Moscow–Karelia–Kola Peninsula–Svalbard. The observations cover the ionospheric region from the polar cap to midlatitudes. There is a strong relationship between the high latitude ionosphere and the magnetosphere which are linked through the electric fields and currents as well as through the fluxes of energetic particles precipitating from the magnetosphere and the ascending flows of the ionospheric plasma. During the geomagnetic storms, the dynamic regime of the ionosphere changes drastically, and strong perturbations are observed in the ionospheric parameters. We present the examples and discuss structural features revealed by RT methods in the ionosphere. The RT reconstructions demonstrate a variety of ionospheric responses to the variations in the geomagnetic activity, which appear in the form of the troughs in the ionization, local irregularities, large-scale anomalies on electron density, narrow structures, multi-extremum patchy distributions, etc. The ionization gradients are steepest and have most complicated morphology during strong geomagnetic disturbances. The RT results can be used for refining the existing ionospheric models, for solving a wide range of radio communication, radio navigation, and radar location problems. The work was supported by the Russian Foundation for Basic Research (project no. 19-05-00941).