1. Land Dynamics group; Wageningen University; P.O. Box 47; 6700 AA; Wageningen; The Netherlands
2. IF Technology BV; PO Box 605; 6800 AP; Arnhem; The Netherlands
3. ITC, Faculty of Geo-Information, Science and Earth Observation; University of Twente; P.O. Box 6; 7500 AA; Enschede; The Netherlands