1. Institut de Ciències de l’Espai (ICE, CSIC), Campus UAB, C/ de Can Magrans s/n, E-08193 Cerdanyola del Vallès, Catalonia, Spain
2. Departament de Química, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Catalonia, Spain
3. Institut d’Estudis Espacials de Catalunya (IEEC), E-08034 Barcelona, Catalonia, Spain
4. Finnish Geospatial Research Institute (FGI), Geodeetinrinne 2, FI-02430 Masala, Finland
5. Department of Physics, University of Helsinki, Gustaf Hällströmin katu 2a, PO Box 64, FI-00014 Helsinki, Finland
6. Institute of Physics and Technology, Ural Federal University, Mira str 19. 620002 Ekaterinburg, Russia