O.V. Mitin1, I.V. Krasheninnikov2

1 South Ural State University (Chelyabinsk, Russian)
1,2 Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation Russian Academy of Sciences (IZMIRAN) (Moscow, Troitsk, Russia)
1 mitin@izmiran.ru, 2 krash@izmiran.ru