Assoc. Prof. Dr. E. Georgieva
National Institute of Meteorology and Hydrology 
66, Tsarigradsko shose, blvd 
1784 Sofia, BULGARIA 
E-mail: emilia.georgieva@meteo.bg

Prof. Dr. Roumen Nedkov Dipl. eng.
Space Research and Technology Institute
Bulgarian Academy of Sciences
Acad. Georgi Bonchev Str, Bl. 1
1113 Sofia, BULGARIA
E-mail: rnedkov@space.bas.bg

Prof. Dr. Dimiter Atanassov
National Institute of Meteorology and Hydrology
66, Tsarigradsko shose, blvd
1784 Sofia, BULGARIA
E-mail: dimiter.atanassov@meteo.bg
 
Assoc. Prof. Dr. Tatiana Spassova
National Institute of Meteorology and Hydrology
66, Tsarigradsko shose, blvd
1784 Sofia, BULGARIA
E-mail: Tatiana.Spassova@meteo.bg