1. Institute of Surveying, Remote Sensing and Land Information, University of Natural Resources and Life Sciences (BOKU), 1190 Vienna, Austria
2. Instituto Nacional de Pesquisas Espaciais (INPE), São José dos Campos (S.P.) CEP 12.227-010, Brazil
3. Remote Sensing & Geoinformatics Department, University of Trier, 54296 Trier, Germany