NTv2 National Transformation version 2

NTv2 stands for National Transformation version 2, and describes a binary grid format, used to perform high accuracy datum conversions between coordinates.

The National Transformation format has been developed by Canada's Geodetic Survey Division (GCS). The format has been adapted to several other countries, including Australia.

A single NTv2 file can contain various grids with different accuracies. Software has to be designed in a way that a coordinate is converted using the most accurate grid available. To get the actual datum shift for a coordinate, the 4 closest known coordinates are retrieved from a grid file, and then interpolated using bi-linear interpolation. The default extension for NTv2 grid files is .GSB (Grid Shift Binary). There is also an ASCII variant of this file, which is using the extension .GSA (Grid Shift ASCII).

NTv2 in Hydromagic

Eye4Software Hydromagic fully supports NTv2 datum transformations. A collection of NTv2 transformation files is shipped with the product.

In case a NTv2 file for your country is missing, you can download it here. After downloading, extract the .gsb file(s) from the archive, and copy them in the NTv2 folder:

To use NTv2 files in Hydromagic, place the .gsb file(s) in the Hydromagic NTv2 folder.

To open the "NTv2" folder, select the "Open Program Data Folder..." option from the "Help" menu in Hydromagic and a Windows Explorer window will open.
Locate the "NTv2" folder and double click. Now you can drag .gsb files here.

For more information on how to add a new map datum with NTv2 transformation, refer to the "Manage Datums" manual page.

NTv2 in Australia

Usage

NTv2 is used in Australia to convert coordinates between:

• the AGD66 (Australian Geodetic Datum 1966) and GDA94 (Geocentric Datum of Australia 1994) datums;
• the AGD84 (Australian Geodetic Datum 1984) and GDA94 (Geocentric Datum of Australia 1994) datums;
• the GDA94 (Geocentric Datum of Australia 1994) and GDA2020 (Geocentric Datum of Australia 2020) datums.

Grid File(s)

A66 National (13.09.01).gsb
National 84 (02.07.01).gsb
GDA94_GDA2020_conformal.gsb

Download

click to download the AGD66 <> GDA94 NTv2 grid file (A66 National (13.09.01).gsb)
click to download the AGD84 <> GDA94 NTv2 grid file (National 84 (02.07.01).gsb)
click to download the GDA94 <> GDA2020 NTv2 grid file (GDA94_GDA2020_conformal.gsb)

Source

ICSM GDA Technical Manual

NTv2 in Belgium

Usage

NTv2 is used in Belgium to convert coordinates between the ETRS89 and BD72 datums.

Grid File(s)

bd72lb72_etrs89lb08.gsb

Download

click to download the BD72 <> ETRS89 NTv2 grid file (bd72lb72_etrs89lb08.gsb)

Source

Nationaal Geografisch Instituut (NGI)

NTv2 in Brazil

Usage

NTv2 is used in Brazil to convert coordinates between the Corrego Alegre 1961, Corrego Alegre 1970-72, SIRGAS 2000 and WGS84 datums.

Grid File(s)

CA61_003.gsb
CA7072_003.gsb

Download

click to download the Corrego Alegre 1961 <> SIRGAS 2000 / WGS84 NTv2 grid file (CA61_003.gsb)
click to download the Corrego Alegre 1970-72 <> SIRGAS 2000 / WGS84 NTv2 grid file (CA7072_003.gsb)

Source

Instituto Brasileiro de Geografia e Estatística

NTv2 in Canada

Usage

NTv2 is used in Canada to convert coordinates between the NAD27 (North American Datum 1927) and NAD83 (North American Datum 1983) datums.

Grid File(s)

ntv2_0.gsb

Download

click to download the NAD27 <> NAD83 NTv2 grid file (ntv2_0.gsb)

Source

Natural Resources Canada / Canadian Spatial Reference System

NTv2 in France

Usage

NTv2 is used in France to convert coordinates between the NTF (Nouvelle triangulation de la France) and RGF93 (Réseau géodésique français 1993) datums.

Grid File(s)

ntf_r93.gsb

Download

click to download the NTF <> RFG93 NTv2 grid file (ntf_r93.gsb)

Source

IGN Projet Lambert 93

NTv2 in Germany

Usage

NTv2 is used in Germany to convert coordinates between the DHDN (Deutsches Hauptdreiecksnetz) and ETRS89 (European Terrestrial Reference System 1989) datums.

Grid File(s)

beta2007.gsb

Download

click to download the DHDN90 <> ETRS89 NTv2 grid file (beta2007.gsb)

Source

Beschreibung der Transformation - DE_DHDN (BeTA, 2007) nach ETRS89

NTv2 in Hungary

Usage

NTv2 is used in Hungary to convert coordinates between the HD72 (Hungarian Datum of 1972) and ETRS89 (European Terrestrial Reference System 1989) datums.

Grid File(s)

etrs2eov.gsb

Download

click to download the ETRS89 <> HD72 NTv2 grid file (etrs2eov.gsb)

Source

ETRS89 to EOV description and online calculator

NTv2 in The Netherlands

Usage

NTv2 is used in The Netherlands to convert coordinates with the RDNAPTRANS2008 method.

Grid File(s)

rdtrans2008.gsb

Download

click to download the RDNAPTRANS2008 NTv2 grid file (rdtrans2008.gsb)

Source

RDNAPTRANS description, downloads and service

NTv2 in New Zealand

Usage

NTv2 is used in New Zealand to convert coordinates between the NZGD1949 (New Zealand Geodetic Datum 1949) and NZGD2000 (New Zealand Geodetic Datum 2000) datums.

Grid File(s)

nzgd2kgrid0005.gsb

Download

click to download the NZGD1949 <> NZGD2000 NTv2 grid file (nzgd2kgrid0005.gsb)

Source

NZGD1949 - NZGD2000 Distortion Grid

NTv2 in Portugal

Usage

NTv2 is used in Portugal to convert coordinates between the Datum Lisboa, Datum 73 and ETRS89 datums.

Grid File(s)

DLx_ETRS89_geo.gsb
D73_ETRS89_geo.gsb

Download

click to download the Datum Lisboa <> ETRS89 NTv2 binary grid file (DLx_ETRS89_geo.gsb)
click to download the Datum 73 <> ETRS89 NTv2 binary grid file (D73_ETRS89_geo.gsb)

Source

Instituto Geográfico Português (IGP)

NTv2 in Spain

Usage

NTv2 is used in Spain to convert coordinates between the ED50 and ETRS89 datums on the peninsula and the Balearic islands.

Grid File(s)

PENR2009.gsb
BALR2009.gsb

Download

click to download the ED50 <> ETRS89 (peninsula) NTv2 binary grid file (PENR2009.gsb)
click to download the ED50 <> ETRS89 (Balearic islands) NTv2 binary grid file (BALR2009.gsb)

Source

El Instituto Geográfico Nacional (IGN)

NTv2 in Switzerland

Usage

NTv2 is used in Switzerland (Swiss Confederation) to convert coordinates between the CH1903 and CH1903+ datums.
The dataset used to perform the conversions is called CHENyx06.

Grid File(s)

chenyx06a.gsb

Download

click to download the CH1903 <> CH1903+ NTv2 binary grid file (chenyx06a.gsb)

Source

Swisstopo, the Federal Geo-Information center

NTv2 in United Kingdom

Usage

NTv2 is used in the United Kingdom to convert coordinates between the OSGB1936(Ordnance Survey Great Brittain 1936) and ETRS89 (European Terrestrial Reference System 1989) datums. This conversion grid is also called OSTN02.

Grid File(s)

ostn02.gsb

Download

click to download the OSGB36 <> ETRS89 NTv2 grid file (ostn02.gsb)

Source

Ordnance Survey

NTv2 in Venezuela

Usage

NTv2 is used in Venezuela to convert coordinates between the CANOA and WGS84 datums.

Grid File(s)

canoa_wgs84_mb.gsb

Download

click to download the CANOA <> WGS84 NTv2 binary grid file (canoa_wgs84_mb.gsb)

Source

PDVSA