Diego Valsesia, Andrea Grippi, Enrico Magli, Politecnico di Torino, Italy; Roberto Susino, Daniele Telloni, Gianalfredo Nicolini, National Institute for Astrophysics - Astrophysical Observatory of Torino, Italy; Marta Casti, Angelo Fabio Mulone, Rosario Messineo, ALTEC SpA, Italy