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Regional Models

Brazil (MAPGEO2015)

  Authors: D. Blitzkow, et al.     Created: 2015    Resp: D. Blitzkow
      Status: PUBLIC    
The official Brazilian geoid model, called MAPGEO2015, was computed as a cooperation between IBGE and EPUSP. It is a 5' x 5' grid of geoidal undulations referred to WGS84, covering the area from 35° S to 6° N in latitude and from 75° W to 30° W in longitude. The dataset consists of 947,953 terrestrial gravity points (450,589 in Brazil), a digital terrain model based on SRTM and the EIGEN-6C4 global geopotential model up to degree and order 200. The remove-compute-restore procedure was used, where the short wavelength components were computed by Stokes integration via Fast Fourier Transform technique. In areas where sufficient data were available, neural network technique was used to complete the gravity anomaly information. Through the values of normal-orthometric heights of 592 geometric levelling points (RRNN) of the Brazilian High Precision Altimetric Network, it was possible to evaluate the consistency of the geoid undulation model, observing an improvement of approximately 20% compared to the version published in 2010. In particular, the differences between MAPGEO2015 undulations and GNSS/levelling observations show an RMS of 17 cm.

D. Blitzkow, A.C.O.C. de Matos, W.C. Machado, M.A. Nunes, N.V. Lengruber, E.M.L. Xavier, L.P.S. Fortes (2017). MAPGEO2015: the New Geoidal Undulation Model of Brazil. Revista Brasileira de Cartografia, Sociedade Brasileira de Cartografia, Geodésia, Fotogrametria e Sensoriamento Remoto. ISSN: 1808-0936, in print.
IBGE (2015). O novo modelo de ondulação geoidal do Brasil MAPGEO2015. Technical report.