Sebastian Hahn was born in Vienna, Austria, in 1985. He received the B.Sc. degree in geodesy and geomatic engineering, and the M.Sc. in geodesy and geophysics from the Vienna University of Technology, in 2009 and 2011, respectively. Since April 2010 he has been a Project Assistant at the Vienna University of Technology Department of Geodesy and Geoinformation Research Group Remote Sensing. He is currently one of the key-developers for the software package WARP (Soil Water Retrieval Package), which represents the implementation of the TU Wien soil moisture retrieval model. As a developer he is focused on software design, multi-processing, model calibration and algorithmic improvements, also in light of his PhD studies started in 2011. His main research interests include remote sensing over land using active microwave instruments, active soil moisture retrieval algorithms, software development and validation of soil moisture products.