Synopses & Reviews
Within the national German geoscientific research and development programme "GEOTECHNOLOGIEN", funded by the Federal Ministry of Education and Research (BMBF) and the German Research Foundation (DFG), the research theme "Observation of the System Earth from Space" was selected as one of 13 key areas in this programme. During the first research phase for this theme from 2002 to 2004 six projects were accomplished covering Earth gravity field and Earth rotation research. These six projects are related to the data exploitation and preparation of analysis techniques for the gravity field satellite missions CHAMP, GRACE and GOCE, to the integration of geodetic observation techniques for a user centre within the International Earth Rotation Service and to improvements in observation and analysis techniques for airborne gravimetry and ring lasers. This book provides a detailed summary of the obtained results, which are relevant for a broad scientific community working in gravity field and Earth rotation research.
Synopsis
In the recent years, space-based observation methods have led to a subst- tially improved understanding of Earth system. Geodesy and geophysics are contributing to this development by measuring the temporal and spatial va- ations of the Earth's shape, gravity ?eld, and magnetic ?eld, as well as at- sphere density. In the frame of the GermanR&D programmeGEOTECHNO- LOGIEN, researchprojectshavebeen launchedin2002relatedto the satellite missions CHAMP, GRACE and ESA's planned mission GOCE, to comp- mentary terrestrial and airborne sensor systems and to consistent and stable high-precision global reference systems for satellite and other techniques. In the initial 3-year phase of the research programme (2002-2004), new gravity ?eld models have been computed from CHAMP and GRACE data which outperform previous models in accuracy by up to two orders of m- nitude for the long and medium wavelengths. A special highlight is the - termination of seasonal gravity variations caused by changes in continental water masses. For GOCE, to be launched in 2006, new gravity ?eld analysis methods are under development and integrated into the ESA processing s- tem. 200,000 GPS radio occultation pro?les, observed by CHAMP, have been processed on an operational basis. They represent new and excellent inf- mation on atmospheric refractivity, temperature and water vapor. These new developments require geodetic space techniques (such as VLBI, SLR, LLR, GPS) to be combined and synchronized as if being one global instrument.
Table of Contents
Part I CHAMP - CHAllenging Minisatellite Payload.- Part II GRACE - The Gravity Recovery And Climate Experiment.- Part III GOCE - The Gravity Field and Steady-State Ocean Circulation Explorer.- Part IV IERS - The International Earth Rotation and Reference Systems Service .- Part V GEOsensor - Ring Laser for Seismology.- Part VI - Airborne Gravimetry.