Preface

At the XXV General Assembly of the International Union of Geodesy and Geophysics (IUGG), held from June 27 to July 8, 2011 in Melbourne, Australia, the International Association of Geodesy (IAG) also had its quadrennial General Assembly. The IAG co-organised and contributed to several Union Symposia, as well as to Joint Symposia with other Associations. It also organised seven symposia of its own, one dedicated to each of the four commissions and three dedicated to specific scientific issues. This volume contains the proceedings of 13 symposia, which are listed below with the name of their associate editor(s): Symposium JG01: Space Geodesy-based Atmospheric Remote Sensing as a Synergistic Link between Geodesy and Meteorology Editors: Marcelo Santos, Jens Wickert Symposium JG02: Application of Geodetic Techniques in Cryospheric Studies Editor: Reinhard Dietrich, Matt King Symposium JG03: History of Geosciences from Terrestrial to Spaceborne Observations Editor: Jozsef Adàm Symposium JG04: Structure and Deformation of Plate Interiors Editor: John Dawson Symposium JG05: Integrated Earth Observing Systems Editor: Markus Rothacher Symposium JG06: Tectonic Geodesy and Earthquakes Editor: Jeff Freymueller Symposium G01: Reference Frames from Regional to Global Scales Editor: Zuheir Altamimi, Athanasios Dermanis, Joao Agria Torres Symposium G02: Monitoring and Modelling of Mass Distribution and Mass Displacements by Geodetic Methods Editors: Yoichi Fukuda, Nico Sneeuw, Frank Lemoine, Richard Gross, Herbert Wilmes Symposium G03: Monitoring and Modelling Earth Rotation Editors: Richard Gross, Harald Schuh, Oleg Titov Symposium G04: Multisensor Systems for Engineering Geodesy Editors: Dorota Grejner-Brzezinska, Hanjörg Kutterer Symposium G05: Geodetic Imaging Techniques Editor: Sandra Verhagen, Xiaoli Ding Symposium G06: Towards a Unified World Height System Editors: Johannes Ihde, Laura Sanchez Symposium G07: High Precision GNSS Editors: Urs Hugentobler, Mikael Lilje, Ruth Neilan The goal of Modern Geodesy is to monitor changes in a range of physical processes in the solid Earth, the atmosphere and the oceans in order to improve our understanding of this fragile, precious and stressed planet. This is an ambitious goal, but one that all geodesists can have confidence that we are making significant progress in addressing. The range of papers presented at the IAG General Assembly is testament to the ingenuity and hard work of scientists and engineers engaged in geodetic studies and in operational geodesy. Although contributions to the so-called three pillars of geodesy—geometry,