TOWARDS A PAN-EU BUILDING FOOTPRINT MAP BASED ON THE HIERARCHICAL CONFLATION OF OPEN DATASETS: THE DIGITAL BUILDING STOCK MODEL - DBSM - Florio, P.; Giovando, C.; Goch, K.; Pesaresi, M.; Politis, P.; Martinez, A. (Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., 2023)