2026-07-26T04:41:29Zhttp://doidb.wdc-terra.org/oaip/oai

oai:doidb.wdc-terra.org:73712026-06-10T10:17:34ZDOIDBDOIDB.ISG

false4DOIDB.ISG 10.5880/isg.2021.005 de Matos, Ana Cristina Oliveira Cancoro Ana Cristina Oliveira Cancoro de Matos 0000-0002-0040-588X Centro de Estudos de Geodesia (CENEGEO), São Paulo, Brazil Blitzkow, Denizar Denizar Blitzkow 0000-0003-1412-3063 Escola Politécnica da Universidade de São Paulo (EPUSP) and Centro de Estudos de Geodesia (CENEGEO), São Paulo, Brazil Guimarães, Gabriel do Nascimento Gabriel do Nascimento Guimarães 0000-0003-4380-4650 Instituto de Geografia, Universidade Federal de Uberlândia (UFU), Uberlândia, Brazil Silva, Valéria Cristina Valéria Cristina Silva 0000-0003-1499-6956 Escola Politécnica da Universidade de São Paulo (EPUSP), São Paulo, Brazil GFZ Data Services 2021 Geodesy Geoid model ISG Fast Fourier Transform South America EARTH SCIENCE > SOLID EARTH > GEODETICS > GEOID CHARACTERISTICS EARTH SCIENCE > SOLID EARTH > GRAVITY/GRAVITATIONAL FIELD > GRAVITY Reguzzoni, Mirko Mirko Reguzzoni 0000-0002-4027-9347 International Service for the Geoid (ISG), Politecnico di Milano, Italy Carrion, Daniela Daniela Carrion 0000-0003-1262-9394 International Service for the Geoid (ISG), Politecnico di Milano, Italy Rossi, Lorenzo Lorenzo Rossi 0000-0001-6050-1972 International Service for the Geoid (ISG), Politecnico di Milano, Italy de Matos, Ana Cristina Oliveira Cancoro Centro de Estudos de Geodesia (CENEGEO), São Paulo, Brazil ISG Staff International Service for the Geoid (ISG) 2021 Dataset https://www.isgeoid.polimi.it/Geoid/America/Southamerica/SIRGAS2021_sesion3_martes_geoid2021_Matos.pdf http://www2.unb.ca/gge/Research/GRL/GeodesyGroup/SHGeo/1_Stokes-Helmert_Technique/1987_Vanicek_et_al.pdf https://dx.doi.org/10.1017/S0016756800048834 10.5194/essd-13-1653-2021 http://www.isgeoid.polimi.it/ 10.5880/isg.2021.006 1.0 CC BY 4.0 The South American gravimetric quasi-geoid model, named QGEOID2021, was computed thanks to a collaboration of several institutions, companies and universities of South America. The model covers the area between 15°N and 60°S in latitude and 100°W and 30°W in longitude, with a grid resolution of 5' x 5'. It is based on 959,404 terrestrial gravimetric points, the XGM2019 global geopotential model up to degree and order 200 and the SRTMv3 digital terrain model. The short wavelengths of the solution were estimated via Fast Fourier Transform (FFT) with the modified Stokes kernel proposed by Vaníček and Kleusberg (1987). On the other hand, long and medium wavelengths were removed and replaced in the framework of a remove-compute-restore procedure. Regions without gravimetric observations were completed using XGM2019 to its full degree. The calculation of the geoid model was performed by the Canadian package SHGEO (Stokes-Helmert Geoid Software). The quasi-geoid model was obtained by the classical geoid/quasi-geoid separation term (Heiskanen and Moritz, 1967). The comparison between height anomalies and GPS/levelling data at 1108 points in Brazil shows differences with an RMS of 41 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).
Gravimetric quasi-geoid model QGEOID2021 -99.9583 -30.0417 -59.9583 14.9583