The gravimetric geoid of São Paulo State based on Fast Fourier Transformation with modified Stokes kernel: GEOID-SP-2014-FFT

This gravimetric geoid model of São Paulo State, Brazil, has been computed by remove-restore technique using Stokes integration through Fast Fourier Transform (FFT) with spheroidal Molodenskii-Meissl kernel modification. The reference geopotential model is GO_CONS_GCF_2_DIR_R5 up to degree and order 200. The SAM3s_v2 DTM has been used for the computation of terrain correction and other topographic and atmospheric effects. The mean free-air gravity anomaly (FA) in a 5'x5' grid over continent has been derived from the complete Bouguer anomalies (FA over the ocean has been obtained from the DTU10 satellite gravity model). Geoidal heights, referred to the GRS80 ellipsoid, have been computed on a grid of 5'x5' covering the area from 17°S to 28°S in latitude and from 56°W to 42°W in longitude. The resulting model has been verified by comparing them with 363 GPS/leveling points distributed all over the area, showing differences with a root mean square of 0.22 m. 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.