Evaluation and selection of an appropriate Global Geopotential Model over the Territory of Vietnam

Abstract

The purpose of this study is to evaluate and select the most suitable Global Geopotential
Model (GGM) for the territory of Vietnam. Over the past two decades, many GGMs have been
developed worldwide. Based on comparisons with GPS/levelling data in various countries, six of
the best-performing models were selected for testing. These models were compared with
GPS/levelling data from 818 points across Vietnam. The results show that the deviations follow a
normal distribution and that the correlation between model-derived height anomalies and
GPS/levelling data is very strong. The accuracy of the six models ranges from ±0.298 m to ±0.159
m. Among them, the XGM2019e model is the most suitable for Vietnam, exhibiting the smallest
standard deviation and the best correlation with GPS/levelling data. Large deviations are mainly
found in the northwestern mountainous region, where levelling measurements are difficult to
obtain. The findings of this study can serve as a reference for selecting an appropriate GGM for
geodesy applications.