The gravimetric geoid model for the State of Goiás covers the longitude range of -43° to -56° and the latitude range of -10° to -22°, with a resolution of 5 arc minutes. A total of 32,446 gravimetric stations were utilized for the geoid modeling. The computation was performed by the Stokes-Helmert approach through the SHGEO software package developed at the University of New Brunswick. In particular, the modified Stokes integral was applied by means of the Fast Fourier Transform. Spectral decomposition was used with the long-wavelength component represented by the EIGEN-6C4 model, up to a degree and order 250. The SAM3s_v2 digital terrain model was used too. The resulting model was assessed by comparing it with 140 GNSS/leveling stations, showing differences with a standard deviation of approximately 10 cm.

The geoid model is provided in ISG format 2.0 (ISG Format Specifications), while the file in its original data format is available at the model ISG webpage.

The International Service for the Geoid (ISG) was founded in 1992 (as International Geoid Service - IGeS) and it is now an official service of the International Association of Geodesy (IAG), under the umbrella of the International Gravity Field Service (IGFS). The main activities of ISG consist in collecting, analysing and redistributing local and regional geoid models, as well as organizing international schools on the geoid determination (Reguzzoni et al., 2021).