Evaluation Orthometric Height derived from GNSS CORS network using various Geoid Model

Abstract

This study focuses on assessing the accuracy of the orthometric heights using GNSS Network-based Real Time Kinematic (NRTK) with different geoid model; the local model (TGM17) and global model (EGM2008, EGM96). And evaluate the accuracy of observed orthometric heights with the elevation information of primary benchmarks of the Royal Thai Survey Department. The lower Chao Phraya River basin was selected to be the study area and carried out in Kinematic technique; Virtual Reference Station (VRS). The results have shown, the comparison differences between the estimated orthometric heights with the geoid model from NRTK and the primary benchmarks elevation are shown the RMSE of 0.030 m, 0.841 m and 0.933 m for TGM17, EGM2008 and EGM96 respectively. From these results, orthometric height estimated from NRTK with the local geoid model (TGM17) could archive better accuracy than any global geoid model. Therefore, the potential of the CORS network with a local geoid model can be one of the better options for any survey works and also can be the shorty measurement base on mean sea level as well.