This open access volume contains selected papers of the 2021 Scientific Assembly of the International Association of Geodesy – IAG2021. The Assembly was hosted by the Chinese Society for Geodesy, Photogrammetry and Cartography (CSGPC) in Beijing, China from June 28 to July 2, 2021. It was a hybrid conference with in-person and online attendants. In total, the Assembly was attended by 146 in-person participants and 1,123 online participants. The theme of the Assembly was . 613 contributions (255 oral presentations and 358 poster presentations) covered all topics of the broad spectrum considered by the IAG:  All published papers were peer-reviewed, and we warmly recognize the contributions and support of the Associate Editors and Reviewers. weiterlesen