Possibilities of Satellite Radio Tomography and Related Products for Studying the Ionospheric Structures in Various Geophysical Conditions

Abstract

Ionospheric satellite radio tomography (RT) is an effective method for studying the structure of the ionosphere during the periods of strong geomagnetic storms when other common methods of ionospheric sounding are inapplicable or unreliable. In this work, we used two modifications of the radio tomographic methods. One is low orbiting radio tomography (LORT). LORT is based on the coherent transmissions of radio signals of the previous generation navigational satellites such as Parus/TRANSIT received at the chains of the ground receivers installed along the satellite trajectories. Another modification is the high orbiting radio tomography (HORT) based on the processing of GNSS signals recorded by the global and regional receiving networks. We present the results of RT (LORT and HORT) imaging of the ionosphere in the different regions of the world for the periods of strong geomagnetic disturbances during 23rd and 24th solar cycles. RT methods revealed multi-extrema structures, wall-like gradients of electron density, variations in the position and depth of the ionization troughs, wavelike disturbances, and a variety of local features. RT methods allow to reconstruct not only the ionospheric irregularities of natural origin but also artificial disturbances induced by various anthropogenic sources (industrial explosions, rocket launches, high power HF heating). We also discuss the application of RT reconstructions for studying HF propagation in artificially disturbed ionosphere.