Preface

Observing the Earth from space has undergone rapid developments in recent years and has a prominent position in geo-related scientific research today. Research satellites are indispensable tools for studying processes on the Earth’s surface and within the System Earth. The view from space allows the observation of the entire planet uniformly in near-real-time. At the same time the resulting time series of measurements allow the detection and monitoring of changes in this very complex system. Satellites like Challenging Mini-satellite Payload (CHAMP), Gravity Recovery and Climate Experiment (GRACE) and Gravity Field and steady state Ocean Circulation Explorer (GOCE) measure the gravity and magnetic fields of the Earth with unprecedented accuracy and resolution (in time and space) and provide the metrological basis for oceanography, climatology, glaciology, global change and geophysics in general. These missions have been—and continue to be—instrumental to establish a new segment of the Earth system science. Based on these data it is possible to explore and monitor changes related to the Earth’s surface, the boundary layer between atmosphere and solid Earth, oceans and ice shields. This boundary layer is our habitat and therefore in the focus of our interests. The Earth’s surface is exposed to anthropogenic changes, to changes driven by Sun, Moon and planets, and to processes in the Earth system. The state parameters and their changes are best monitored from space. The theme ‘‘Observation of the System Earth from Space’’ offers comprehensive insights into a broad range of research topics relevant to geodesy, oceanography, atmosphere science (from meteorology to climatology), hydrology and glaciology, and to society as a whole. The volume Observation of the System Earth from Space-CHAMP, GRACE, GOCE and Future Missions documents the third phase of the topic Observation of the system Earth from space. As opposed to the first two phases the range of topics was narrowed down to the projects LOTSE-CHAMP/GRACE (led by Frank Flechtner), REAL GOCE (led by Wolf-Dieter Schuh) and Future Gravity Field Satellite Missions (led by Nico Sneeuw). This structure is also mirrored by the table of contents in the volume. Three seminars, the status seminars at the University of Bonn in October 2010 and at the University of Stuttgart in October 2011 and the final presentations at the GFZ, German Research Centre for Geosciences in Potsdam in May 2012 were