Brazilian Coordinate Reference Systems

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This page discusses the Coordinate Reference Systems used in Brazil. It started as an attempt to reach a consensus on the transformation parameters that should be submitted to the "upstream" of open source programs such as proj4, libgeotiff and gdal.

The discussion was held mostly on the mailing list starting April 25, 2012 (

Note: Some parts of this document are in Brazilian Portuguese.

The following references are a substancial source of information (in Portuguese), as well as others below:

Coordinate Reference Systems used in Brazil

Brazil has used various reference systems. Brazilian law # XXXX determines that, starting from XXXX, the SIRGAS 2000 sistem will be used exclusively.

( O Brasil já utilizou diversos sistemas de referência. A lei XXXX determina que, a partir de XXXX, será adotado unicamente o sistema SIRGAS 2000 )


Reference:          ???
Note:               Considered identical to WGS84

SAD69 (SAD69 a partir de 1995)

Projection:         longlat
EPSG code:           4618
PROJ string:        '+proj=longlat +ellps=aust_SA +towgs84=-67.35,+3.88,-38.22'
PROJ string (ntv2): '+proj=longlat +ellps=aust_SA +nadgrids=sad96_003.gsb +nodefs'
Reference:          RPR 01/2005 - 25/02/2005 - IBGE 

SAD69 before 1995 (SAD69 antes de 1995)

Projection:         longlat
EPSG code:          4291
PROJ string:        '+proj=longlat +ellps=aust_SA +towgs84=-66.87,+4.37,-38.52'
PROJ string (ntv2): '+proj=longlat +ellps=aust_SA +nadgrids=sad69_003.gsb +nodefs'
Reference:          Resolução da Presidência do IBGE n° 23, de 21/02/89 (R.PR 23/89) 

SICAD (Sistema Cartográfico do Distrito Federal)

Projection:         longlat
EPSG code:          ???
PROJ string:        '+proj=longlat +ellps=intl +towgs84=-144.35,+242.88,-33.22'
Reference:          GDF DECRETO 32.575-2010_SICAD-SIRGAS
Note:               only valid in UTM 23s zone

Corrego Alegre 1961 (Córrego Alegre 1961)

Projection:         longlat
EPSG code:          5524
PROJ string:        ???
PROJ string (ntv2): '+proj=longlat +ellps=intl +nadgrids=ca61_003.gsb +nodefs'
Reference:          ???

Corrego Alegre 1970-72 (Córrego Alegre 1970-72)

Projection:         longlat
EPSG code:          4225
PROJ string:        '+proj=longlat +ellps=intl +towgs84=-205.57,+168.77,-4.12'
PROJ string (ntv2): '+proj=longlat +ellps=intl +nadgrids=ca7072_003.gsb +nodefs'
Reference: (calculated by composing the transformations in the two following documents)

Chua (Astro Chuá)

Projection:         longlat
EPSG code:          4224
PROJ string:        '+proj=longlat +ellps=intl +towgs84=-143.87,+243.37,-33.52'
Reference: (unofficial reference)

Summary Table

Name EPSG towgs84 towgs84 currently in use by gdal (incorrect) ntv2 grid from IBGE
SAD69 4618 -67.35,+3.88,-38.22 -57,1,-41 sad96_003.gsb
SAD69 before 1995 4291 -66.87,+4.37,-38.52 -57,1,-41 sad69_003.gsb
SICAD ??? -144.35,+242.88,-33.22 ??? -
Corrego Alegre 1961 5524 ??? - ca61_003.gsb
Corrego Alegre 1970-72 4225 -205.57,+168.77,-4.12 -206,172,-6 ca7072_003.gsb
Chua 4224 -143.87,+243.37,-33.52 -134,229,-29 -

Ellipsoids in use


PROJ name:         Australian Natl &  S. Amer. 1969
PROJ string:       '+ellps=aust_SA'
Semimajor radius   a=6378160.0
Flattening         rf=298.25
EPSG name:         GRS 1967 Modified 
EPSG code:         7050


PROJ name:         International 1909 (Hayford)
PROJ string:       '+ellps=intl'
Semimajor radius   a=6378388.0
Flattening         rf=297.0
EPSG name:         International 1924
EPSG code:         7022


To use the UTM projection, substitute "+proj=longlat" with the desired projection parameter, zone and units for the area of interest For example:

"+proj=utm +zone=23 +south +units=m" for zone 23s


"+proj=utm +zone=21 +north +units=m" for zone 21n

NTV2 grids (*.gsb files) are distributed with the Progrid software package from IBGE (


Para utilizar a projeção UTM, substitua "+proj=longlat" pelos parâmetros de projeção, zona e unidades para a zona de interesse.

Por exemplo, a string do SAD69:

+proj=longlat +ellps=aust_SA +towgs84=-67.35,+3.88,-38.22

Pode ser transformada em

+proj=utm +zone=23 +south +units=m +ellps=aust_SA +towgs84=-67.35,+3.88,-38.22

para uso na zona UTM 23s ou em

+proj=utm +zone=21 +north +units=m +ellps=aust_SA +towgs84=-67.35,+3.88,-38.22

para uso na zona UTM 21n

Comparação entre o método grid (ntv2) e parâmetros towgs84: SAD69 para SIRGAS2000

Os arquivos *.gsb são distribuídos junto com o software progrid do IBGE ( e devem ser copiados para a pasta "/usr/share/proj" para esses parâmetros funcionarem com o proj.

AVISO: o proj não dá erro se você esquecer de copiar o arquivo ou errar o nome do arquivo na string de conversão. Cheque os resultados antes de utilizá-los.


  • testar as transformações do tipo grid (ntv2)
  • preencher os campos marcados com XXXX
  • completar a documentação dos sistemas de coordenadas
  • atingir consenso na lista antes de mandar pedidos de correção ou complementação para os desenvolvedores upstream ou para a EPSG.