Evaluation of Geoid Models with GPS/Levelling Points in Sweden and Finland

Five different geoid models are analysed to estimate the possible error budget of new global geoids based on the data from the gravity satellites CHAMP, GRACE and GOCE. We used the global models OSU91A and EGM96, the European model EGG97, the Nordic model NKG96 and the newest model for Finland FIN2000. FIN2000 is fitted to the Finnish height system and is the most accurate of the five. A total of 245 points in Finland and Sweden was used in the analysis. For all points, GPS-determined heights were avail-able as well as orthometric or normal heights based on spirit levelling. From these heights the geoid height was calculated and compared with corresponding geoid heights obtained from the geoid models, allowing us to estimate the geoid model error and its spatial variation.