1. Institute for Environment and Sustainability, Joint Research Centre of the European Commission, 21027 Ispra (VA), Italy
2. AGIV, Agentschap voor Geografische Informatie Vlaanderen, 9000 Ghent, Belgium
3. Terrestrial Ecosystems Monitoring Laboratory, Space Research Institute (IKI), Russian Academy of Sciences, 117997 Moscow, Russia
4. Reggiani SpA, Institute for Environment and Sustainability, Joint Research Centre of the European Commission, I-21027 Ispra (VA), Italy