Regional assessment of recent high-degree global geoid models for Türkiye

Abstract

The validation of recent global geoid models is essential for improving the accuracy and reliability of geodetic applications in T & uuml;rkiye. This study aims to assess the performance of global geoid models, such as the Earth Gravitational Model 2008 (EGM2008) and other satellite-based models by comparing them with regional and national geoid models constructed using high-precision local GNSS and levelling data. The geoid undulations from global models are compared with those obtained from the Turkish national geoid model, developed from gravity measurements and geodetic surveys conducted by national agencies. The analysis involves statistical evaluation using Root Mean Square Error (RMSE) and standard deviations to quantify discrepancies. The results show significant variations in geoid heights, especially in tectonically active regions, highlighting the limitations of global models in accurately representing local geoid features. Based on the validation results, suggestions for improving the global models by incorporating local geophysical data are discussed. The findings emphasize the importance of region-specific geoid models for precise height transformations and geodetic applications in T & uuml;rkiye.