The files in this package can be unpacked in the PROJ data directory. For an installed PROJ this may be /usr/local/share/proj or /usr/share/proj on unix style operating systems.

Note that this package includes "CTable2" format grid shift files for NAD27 in the USA and require PROJ 4.8.0 or newer. On the plus side there is no need to compile ascii files into binary files with this version as CTable2 files are not system dependent (as distinct from the CTable files produced in PROJ 4.7.0 and older).

The datum grid package for PROJ is maintained on the OSGeo proj-datumgrid repository on GitHub. All grids in the package are released under permissive licenses. New grids are accepted into the package as long as they are released under a license that is compatible with the Open Source Definition and the source of the grid is clearly stated and verifiable. Suitable licenses include:

• Public domain
• X/MIT
• BSD 2/3/4 clause
• CC0
• CC-BY (v3.0 or later)
• CC-BY-SA (v3.0 or later)

2-dimensional transformation grids for horizontal datum shifts.

Source: Natural Resources Canada
Format NTv1
License: Public Domain

• ntv1_can.dat

Grid conversion from NAD27 to NAD83 in Canada

Grid transformation from NTF to RGF93 in France.

Source: IGN
Format: NTv2
License: Public Domain

• ntf_r93.gsb

Source: BKG
Format: NTv2
License: Free redistribution is allowed and welcome

Grid transformation from DE_DHDN to ETRS89 in Germany.

• BETA2007.gsb

Source: LINZ
Format: NTv2
License: Creative Commons Attribution 3.0 New Zealand

This grid file was computed by Land Information New Zealand at approximately a 20 km interval for the conversion between NZGD49 and NZGD2000.

• nzgd2kgrid0005.gsb

Source: USGS
Format: CTable2
License: Public Domain

• alaska - Alaska
• conus - Conterminous U.S.
• hawaii - Hawaii
• prvi - Puerto Rico, Virgin Is.
• stgeorge - St. George Is, Alaska
• stlrnc - St. Lawrence Is., Alaska
• stpaul - St. Paul Is., Alaska

Source: USGS
Format: CTable2
License: Public Domain

Grid data for high precision conversion of geographic coordinates from NAD83 to NAD83.

• FL - Florida
• MD - Maryland
• TN - Tennessee
• WI - Wisconsin
• WO - Washington, Oregon, N. California

1-dimensional transformation grids for vertical datum shifts.

Source: NGA
Format: GTX
License: Public Domain

15 minute worldwide geoid undulation grid that transforms WGS84 ellipsoidal heights to physical heights.

• egm96_15.gtx

In addition to the core proj-datumgrid package, regional collections of grids and init-files also exist. These includes grids and init-files that are not essential for the functionality of PROJ but still of general interest to PROJ-users in the package-specific regions.

The regional packages can be downloaded from the OSGeo download server.

The regional package for Europe includes resources for the following countries:

• Denmark
• The Faroe Islands
• The Nordic+Baltic countries

More information about the included grids and init files can be found in README.EUROPE

The regional package for North America includes resources for the following countries:

• Greenland

More information about the included grids and init files can be found in README.NORTHAMERICA

The regional package for Oceania includes resources for the following countries:

• Australia

More information about the included grids can be found in README.OCEANIA