Affiliation: | 1.Crimean Astrophysical Observatory, Russian Academy of Sciences, 298409, Nauchny, Russia ;2.Sternberg State Astronomical Institute, Lomonosov Moscow State University, 119991, Moscow, Russia ;3.Pushkov Institute of Terrestrial Magnetism, Ionosphere, and Radio Wave Propagation, Russian Academy of Sciences, 142191, Troitsk, Russia ; |