System Earth via Geodetic-Geophysical Space Techniques (Advanced Technologies in Earth Sciences)

Our planet is currently experiencing substantial changes due to natural phen- ena and direct or indirect human interactions. Observations from space are the only means to monitor and quantify these changes on a global and long-term p- spective. Continuous time series of a large set of Earth system parameters are needed in order to better understand the processes causing these changes, as well as their interactions. This knowledge is needed to build comprehensive Earth s- tem models used for analysis and prediction of the changing Earth. Geodesy and geophysics contribute to the understanding of system Earth through the observation of global parameter sets in space and time, such as tectonic motion, Earth surface deformation, sea level changes and gravity, magnetic and atmospheric elds. In the framework of the German geoscience research and development p- gramme GEOTECHNOLOGIEN, research projects related to the theme “Observing the Earth System from Space” have been funded within two consecutive phases since 2002, both covering 3 years. The projects address data analysis and model development using the satellite missions CHAMP, GRACE, GOCE and comp- mentary ground or airborne observations. The results of the rst phase projects have been published in the Springer book, titled “Observation of the Earth System from Space”, edited by Flury, Rummel, Reigber, Rothacher, Boedecker and Schreiber in 2006. The present book, titled “System Earth via Geodetic-Geophysical Space Techniques” summarizes in 40 scienti c papers the results of eight coordinated research projects funded in the second phase of this programme (2005–2008).

The Earth’s gravity and magnetic gravity fields play an important role in global and regional geodynamics. Research satellites such as CHAMP, GRACE, and GOCE apply new measurement techniques to recover gravity and magnetic fields with unprecedented accuracy and resolution in space and time. Combined with terrestrial observations and numerical models, this data will significantly improve a detailed understanding of the Earth as a coupled system of atmosphere, hydrosphere and solid Earth.

In Germany, many of the processing, modelling and interpreting methodologies for these new observation techniques have been developed under the umbrella of the R&D-programme GEOTECHNOLOGIEN. The research projects focus on a better understanding of the spatial and temporal variations in the magnetic and gravity field and their relationship to the dynmaics of the Earth's interior and global change processes close to its surface.

This volume presents the results of all multidisciplinary studies covered by this programme for the period 2005-2008, including the following topics:

- Static and time variable gravity field models from CHAMP, GRACE and GOCE
- Applications of GRACE , altimetry, GPS and other data for geophysical analyses
- Contributions to the Global Geodetic Observing System (GGOS)
- Atmospheric sounding by GPS radio occultation technique with CHAMP
  and GRACE
- Observation of the Earth's magnetic field with CHAMP

Thus, it offers an up-to-date overview for a broad scientific community working in gravity field and Earth rotation research.