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Status of the European Gravity and Geoid Project EGGP

  • H. Denker
  • J.-P. Barriot
  • R. Barzaghi
  • R. Forsberg
  • J. Ihde
  • A. Kenyeres
  • U. Marti
  • I.N. Tziavos
Part of the International Association of Geodesy Symposia book series (IAG SYMPOSIA, volume 129)

Abstract

The European Gravity and Geoid Project (EGGP) is a project within IAG Commission 2, reporting to Sub-commission 2.4. The main goal of the project is to compute an improved European geoid and quasigeoid model. This appears to be possible now because significant new and improved data sets have become available since the last computation in 1997 (EGG97). These improvements include better global geopotential models from the CHAMP and GRACE missions, better digital elevation models (DEMs) in some regions (e.g., new national DEMs, SRTM3, GTOPO30), updated gravity data sets for selected regions, updated ship and altimetric gravity data including improved merging procedures, the use of GPS/levelling data, as well as improved modelling and computation techniques.

An overview is given on the project structure, the computation strategy, the available data sets, the expected accuracies, the time schedule, and the work done so far. The primary input data sets are high-resolution gravity and terrain data supplemented by a state-of-the-art global geopotential model. The general computation strategy is the remove-restore procedure. The initial computations are based on the spectral combination approach with integral formulas evaluated by 1D FFT. First results based on an updated terrestrial gravity data set and GRACE geopotential models show significant improvements (up to 60 %) as compared to GPS/-levelling. Moreover, also the tilts, existing in previous solutions, have been reduced to typically below 0.1 ppm.

Keywords

Geoid quasigeoid gravity field modelling GPS/levelling EGGP CHAMP GRACE 

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Copyright information

© Springer-Verlag Berlin Heidelberg 2005

Authors and Affiliations

  • H. Denker
    • 1
  • J.-P. Barriot
  • R. Barzaghi
  • R. Forsberg
  • J. Ihde
  • A. Kenyeres
  • U. Marti
  • I.N. Tziavos
  1. 1.Institut für ErdmessungUniversität HannoverHannoverGermany

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