Aeronomy and Radiopropagation Laboratory of ICTP, Italy.
Faculty Regional Tucuman, National Technological University, Arg.
Instituto Nacional de Pesquizas Espaciais, Brasil
Istituto Nazionale di Geofísica e Vulcanología (INGV), Italy.
Institute of Atmospheric Physics, AS, Czech. Rep.
Instituto Superior de Correlación Geológica, CONICET-UNT, Arg.