Manfred Birk, Deutsches Zentrum fuer Luft- und Raumfahrt (DLR), remote sensing technology institute, Wessling, Germany, Georg Wagner, Deutsches Zentrum fuer Luft und Raumfahrt (DLR), Remote Sensing Technology Institute, Wessling, Germany, Didier Mondelain, Universite Grenoble Alpes, Laboratoire LIPHY, Grenoble, France, Alain Campargue, Universite Joseph Fourier, Grenoble, France, Frank Hase, Karlsruhe Institute of Technology, IMK-ASF, Karlsruhe, Germany, Johannes Orphal, Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research, Karlsruhe, Germany, Juan Cuesta, Laboratoire Inter-universitaire des Systèmes Atmosphériques (LISA), UMR CNRS 7583, Université Paris-Est Créteil, Université de Paris, Institut Pierre Simon Laplace (IPSL), Créteil, France, Maud Rotger, Universite der Reims Champagne Ardenne, Reims, France, Marie-Renée De Backer, U. Reims, GSMA, Reims, France, Alberto Bigazzi, Serco, Rome, Italy and Claus Zehner, European Space Research Institute, Frascati, Italy