Research Information System
The 3rd International Association of Geodesy (IAG) Commission 4 Symposium, Positioning And Applications, 13 - 15 May 2025, pp.1-10, (Summary Text)
The geoid is
a closed surface representing the Earth's true shape, coinciding with mean sea
level. It is used in geodesy to determine the orthometric heights of points. In
this study, the effect of Global Geopotential Models (GGMs) on the gravimetric
geoid was investigated using the 4 different GGMs. The selected models were
based on GOCE data, GRACE data, a combination of both satellite missions and combine
models. The GGM files used in this study were downloaded from the International
Centre for Global Earth Models (ICGEM) website. The SRTM model with a 1
arc-second resolution was employed as the digital elevation model. Additional
terrestrial data were sourced from the Colorado region in the western United
States. The geoid model was computed using the Least Squares Modification of
Stokes' Formula, based on the KTH (Royal Institute of Technology) method.
Multiple gravimetric geoid models were generated using different global
geopotential models and supplementary data. These models were subsequently
evaluated against the GNSS/Levelling geoid. To mitigate systematic errors
during model comparison, a 5-parameter corrective surface was applied.