The Argentinian gravimetric geoid: GEOIDE-Ar16

The GEOIDE-Ar16 Argentinian gravimetric geoid model covers the area from 57° S to 20° S in latitude and from 76° W to 52° W in longitude, with a grid resolution of 1' × 1'. It was developed using the remove-compute-restore technique and incorporating the GOCO05S satellite-only global geopotential model up to degree and order 280, together with about 650,000 land and marine gravity measurements. Terrain corrections were calculated for all gravity observations using a combination of the SRTM_v4.1 and SRTM30_Plus_v10 digital elevation models. For the regions that lacked of gravity observations, the DTU13 gravity model was utilised. The residual gravity anomalies were gridded using the tensioned spline algorithm. The resultant gravity anomaly grid was applied in the Stokes' integral using the spherical multi-band FFT approach and the deterministic kernel modification proposed by Wong and Gore. The accuracy of GEOIDE-Ar16 was assessed by comparing it with GPS-levelling derived geoid undulations at 1,904 locations and the EGM2008 model. Results show that the GEOIDE-Ar16 geoid model has an accuracy of less than 10 centimetres. 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.