Evaluating Global Geopotential Models Using GNSS/Levelling Observations: An Integrated Statistical and MCDA Framework
DOI:
https://doi.org/10.55779/ng62633Keywords:
gravity field modelling, MATLAB, regional geoid evaluation, vertical control networksAbstract
Accurate orthometric height determination is essential for engineering geodesy, route surveying, and vertical datum modernization. This study evaluated selected Global Geopotential Models (GGMs) for orthometric height determination using GNSS/levelling observations within an integrated statistical and Multi-Criteria Decision Analysis (MCDA) framework. Residuals between GGM-derived and observed orthometric heights were computed and analysed before and after local bias adjustment to assess model compatibility under local geodetic conditions. Performance was evaluated using bias, standard deviation (SD), root mean square error (RMSE), mean absolute error (MAE), and corrected RMSE, while statistical significance was assessed using non-parametric inferential procedures. Normality tests showed that the residual datasets were not normally distributed (p < 0.05), thereby justifying the use of non-parametric analyses. The results showed that residual adjustment improved agreement between the GGMs and GNSS/levelling observations, confirming the importance of local correction before practical implementation. RMSE values ranged from approximately 28.57 m to 29.73 m among the evaluated models. EGM2008 produced the best overall performance and achieved the highest MCDA score (0.9981), whereas TUMS2 showed the weakest performance. Sensitivity analysis further revealed stable ranking behaviour under varying weighting scenarios, indicating robustness of the adopted framework. The study demonstrates that integrated statistical-MCDA evaluation provides a transparent, reproducible, and reliable basis for GGM selection in regional orthometric height determination applications.
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