1. Doctoral School of Earth Sciences, ELTE Eötvös Loránd University, Pázmány P. sétány 1/C, H-1117 Budapest, Hungary
2. Institute of Cartography and Geoinformatics, ELTE Eötvös Loránd University, H-1117 Budapest, Hungary
3. Research Division Cartography, Department of Geodesy and Geoinformation, Technical University Vienna, 1040 Vienna, Austria
4. Department of Geography and Geology, University of Nebraska at Omaha, Omaha, NE 68182, USA