On Modelling the Regional Distortions of the European Gravimetric Geoid EGG97 in Romania

Abstract

We analyze and model the regional distortions of the European Gravimetric Geoid 1997 (EGG97) in Romania using GPS-levelling data. A comparison of the EGG97 gravimetric quasi-geoid with the GPS-levelling data indicates the presence of significant regional distortions in particular areas along the border of the country. To model the regional distortions, we apply two methods: (i) the recently proposed innovation function approach by Prutkin and Klees (J. Geod. 82(3), 147-156, 2007), which is based on a mathematical formulation of the differences between gravimetric quasi-geoid and GPS-levelling data in terms of a Cauchy boundary-value problem for the Laplace equation. (ii) the conventional approach of a low-degree polynomial correction surface. The results reveal that the innovation function approach gives more options to model a more complex trend of the regional gravimetric quasi-geoid distortions than the correction surface approach. © Springer-Verlag Berlin Heidelberg 2010.