1. Department of Physics and Astronomy, Faculty of Samarkand Pedagogical Institute, 734025, Samarkand, Republic of Uzbekistan
2. Department of Physics , Chirchik State Pedagogical University, 104 A.Temur str., Chirchik, 111700 , Uzbekistan
3. Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radiowave Propagation of the Russian Academy of Sciences (IZMIRAN), Moscow, Russia