Johannes Böhm is Professor of Höhere Geodäsie (Higher Geodesy) at the Department of Geodesy and Geoinformation at TU Wien, Austria. In his PhD studies and thereafter he focused on atmospheric effects in space geodesy. Together with colleagues at TU Wien, he has developed the Vienna Mapping Functions (VMF) and empirical counterparts like the Global Mapping Functions (GMF) and Global Pressure and Temperature (GPT) models. The main interest now is on the analysis of Very Long Baseline Interferometry (VLBI) observations for the determination of global terrestrial and celestial reference frames and Earth orientation parameters. The VLBI group at TU Wien is covering all aspects from scheduling and correlation to the analysis of VLBI observations with the Vienna VLBI and Satellite Software (VieVS).