1. German Remote Sensing Data Center (DFD), German Aerospace Center (DLR), Oberpfaffenhofen, Germany
2. Remote Sensing Research Group, Department of Geodesy and Geoinformation, TU Wien, Vienna, Austria
3. Environmental Research and Innovation Department, Luxembourg Institute of Science and Technology, Esch-sur-Alzette, Luxembourg
4. Joint Research Centre (JRC) of the European Commission, Ispra, Italy