Evaluation Results of the Earth Gravitational Model EGM08 over the Baltic Countries
Newton's Bulletin Issue 2009
Artu Ellmann, Jānis Kaminskis, Eimuntas Paršeliūnas, Harli Jurgenson, Tonis Oja

Earth’s geopotential model (EGM) in conjunction with regional terrestrial gravity data are often used in regional geoid determination. Thus, significant enhancements are expected due to release of the new high resolution Earth Gravitational Model EGM08. Accordingly, this study evaluates the performance of the EGM08 model over the Baltic Sea region with emphasis to Estonia, Latvia and Lithuania. Several different sets of the “ground truth” data are used in the comparisons. First, the EGM08-derived height anomalies are compared with an existing regional geoid model. The detected discrepancies range within ± 0.3 m with a mean of - 0.02 m, whereas the standard deviation (STD) of the discrepancies amounts to 0.08 m. The largest discrepancies occur in the areas where only a few data points were available either for the regional geoid modeling or at the EGM08 compilation, or both. Second, the free-air gravity anomalies at the terrestrial data-points are compared with the EGM08-derived anomalies. The STD of the anomaly discrepancies is 2.6 mGal. Finally, the EGM08 model is validated with respect to GPSlevelling data. The STD of detected discrepancies is 0.06 m, with a mean of 0.49 m. Thus, the EGM08 based quantities agree reasonably well with the tested datasets. Evidently, most of the available gravity data in the Baltic Sea region appear to be utilised at the EGM08 construction.


Atslēgas vārdi
geopotential model, geoid, GPS-levelling

Ellmann, A., Kaminskis, J., Paršeliūnas, E., Jurgenson, H., Oja, T. Evaluation Results of the Earth Gravitational Model EGM08 over the Baltic Countries. Newton's Bulletin Issue, 2009, No.4, 110.-121.lpp. ISSN 1810-8555.

Publikācijas valoda
English (en)
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