Institute of Terrestrial Magnetism, Ionosphere, and Radio Propagation, Russian Academy of Sciences, 142190 Troitsk, Moskovskaya obl., Russia 5 Institute of Atmospheric Physics ASCR, 14131 Prague, Czech Republic 6 Institute of Communications and Navigation, German Aerospace Center, 51147 Cologne, Germany 7 Ebro Observatory, University Ramon Llull, CSIC, E-43520 Roquetes, Spain 8 Dipartimento di Fisica, Universita` degli Studi di Roma, 00185 Rome, Italy 9 Atmospheric Sounding Station

Organization name
Institute of Terrestrial Magnetism, Ionosphere, and Radio Propagation, Russian Academy of Sciences, 142190 Troitsk, Moskovskaya obl., Russia 5 Institute of Atmospheric Physics ASCR, 14131 Prague, Czech Republic 6 Institute of Communications and Navigation, German Aerospace Center, 51147 Cologne, Germany 7 Ebro Observatory, University Ramon Llull, CSIC, E-43520 Roquetes, Spain 8 Dipartimento di Fisica, Universita` degli Studi di Roma, 00185 Rome, Italy 9 Atmospheric Sounding Station