Guenther Retscher is an Associate Professor at the Department of Geodesy and Geoinformation at TU Wien, Vienna, Austria. He received his Venia Docendi in the field of Applied Geodesy from the same university in 2009 and his Ph.D. in 1995. His main research and teaching interests are in the fields of engineering geodesy, satellite positioning and navigation, and indoor and pedestrian positioning, as well as the applications of multi-sensor systems in geodesy and navigation.