Full Professor at the Faculty of Geoengineering of the University of Warmia and Mazury in Olsztyn (UWM), Poland, where he earned his PhD in Geodesy in 2002. In 2002–2005, he was a Visiting Scholar at Ohio State University (OSU). His research interests cover satellite navigation, precise kinematic and static positioning, deformation monitoring, and also GNSS-based ionosphere and troposphere studies. His research achievements earned him the Heiskanen Senior Award in 2004. In the last several years, he was involved in a number of research projects funded by national and international agencies (European Space Agency, National Science Centre, etc.). He is involved in activities of major international scientific organizations, he was the Chair of the International Association of Geodesy (IAG) Sub-Commission 4.4 “Multi-constellation GNSS” (2017–2023). In 2023, he was elected the President of the IAG Commission 4 “Positioning and Applications”. Since 2015, he is a member of the Global Geodetic Observing System (GGOS) Science Panel. Since 2020, he is a member of the ESA GNSS Scientific Advisory Committee (GSAC). He has published over 60 JCR papers on GNSS.