Evaluation of EGM2008 Within Geopotential Space from GPS, Tide Gauges and Altimetry

  • N. DayoubEmail author
  • P. Moore
  • N. T. Penna
  • S. J. Edwards
Conference paper
Part of the International Association of Geodesy Symposia book series (IAG SYMPOSIA, volume 136)


The new global Earth gravitational model EGM2008 has been evaluated within geopotential space by comparison with its predecessor EGM96 and the GRACE combination model EIGEN-GL04C. The methodology comprises establishing geodetic coordinates of mean sea level (MSL) from GPS observations, tide gauge (TG) time series and levelling. The gravity potential at MSL was estimated at each TG location by utilising the ellipsoidal harmonic coefficients of the adopted gravity field models to their maximum degree and order. This study uses data from 23 TGs around the Baltic Sea, nine in the UK and one in France. Comparison involves testing the agreement between geopotential values for each country as gravity potentials at MSL are supposed to be consistent for regions where mean dynamic topography (MDT) does not differ significantly. Results show significant improvement with the EGM2008 model compared against its counterparts. The study shows the effect of omission errors on the solution by limiting the EGM2008 model to maximum degree and order 360 in the regional study. In addition to the regional study, EGM2008 was also evaluated globally using MSL derived from altimetric data. The global study shows that W 0 , the potential value on the geoid, is not affected by high degree terms of the EGM2008.


Tide Gauge Omission Error Gravity Field Model Tropospheric Zenith Delay Mean Dynamic Topography 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



The authors would like to thank the following institutions for supplying data for this study: NASA JPL for GIPSY software and the provision of orbital products, NERC BIGF for GPS data at UK tide gauge sites and EUREF/IGS for Brest GPS data.


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Copyright information

© Springer-Verlag Berlin Heidelberg 2012

Authors and Affiliations

  • N. Dayoub
    • 1
    Email author
  • P. Moore
    • 1
  • N. T. Penna
    • 1
  • S. J. Edwards
    • 1
  1. 1.School of Civil Engineering and GeosciencesNewcastle UniversityNewcastleUK

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