Roland Billen received his Doctor of Science degree in geomatics from the University of Liege in 2002 for his work on 3D spatial relationships and 3D data structures. He is currently working toward his Ph.D. degree at the Belgian National Scientific Foundation (FNRS). He has been a professor of geomatics in the Department of Geography at the University of Liege since 2005. He was appointed as a lecturer in the Department of Geographical and Earth Sciences (formerly Geography and Geomatics) at the University of Glasgow (Scotland, UK) in January 2003. He is active in several fields of spatial information sciences such as data acquisition techniques (photogrammetry, surveying, and GNSS/GPS), GIS and spatial databases design, and qualitative spatial reasoning. He has been involved in several projects on spatial database design and has initiated research projects on 3D urban GIS. He was a visiting researcher at the GIS technology section of the TU Delft, The Netherlands and in the Electrical Engineering Department at the University of LAquila, Italy. He has been a guest editor of journal special issues on 3D GIS and Spatial Databases and has taken part in the organization of related conferences and workshops.