Esa Jukka Kallio¹, Markku Alho¹, Riku Jarvinen^1,2, Tomi Kärkkäinen³, Cyril Simon Wedlund⁴ and Valtteri Harmainen⁵, (1)Aalto University, School of Electrical Engineering, Department of Electronics and Nanoengineering, Espoo, Finland, (2)Finnish Meteorological Inst, Helsinki, Finland, (3)Reaktor Space Lab, Helsinki, Finland, (4)Institut für Weltraumforschung (IWF), Graz, Austria, (5)University of Jyväskylä, Jyväskylä, Finland