Mike Schwank, Yiwen Zhou, Swiss Federal Research Institute WSL, Switzerland; Anna Kontu, Finnish Meteorological Institute, Finland; Arnaud Mialon, Centre D'Etudes Spatiales De La Biosphere CESBIO, France; Juha Lemmetyinen, Kimmo Rautiainen, Finnish Meteorological Institute, Finland; Philippe Richaume, Yann Kerr, Centre D'Etudes Spatiales De La Biosphere CESBIO, France; Christian Mätzler, GAMMA Remote Sensing, Switzerland