A.V. Popov – Dr.Sc.(Phys.-Math.), Main Research Scientist, Pushkov Institute of Terrestrial Magnetism,  Ionosphere and Radio Wave Propagation of RAS (Moscow, Troitsk)

E-mail: popov@izmiran.ru

I.V. Prokopovich – Research Scientist, Pushkov Institute of Terrestrial Magnetism, 

Ionosphere and Radio Wave Propagation of RAS (Moscow, Troitsk)

E-mail: prokop@izmiran.ru

D.E. Edemsky – Ph.D.(Eng.), Senior Research Scientist, Pushkov Institute of Terrestrial Magnetism,  Ionosphere and Radio Wave Propagation of RAS (Moscow, Troitsk) E-mail: deedemsky@gmail.com