Software and plugins

GDA94 ⇔ GDA2020 transformation and conversion tools


GDAy 3.0 is available to download from the ICSM Australia GitHub Repository. GDAy 3.0 transforms coordinates between GDA94 and GDA2020 datums. GDAy supports conformal and non-conformal (i.e. conformal plus distortion) transformations via bi-linear interpolation from a grid of coordinate shifts, and conformal datum transformations via seven-parameter similarity (Helmert) transformation. GDAy may be used anywhere throughout Australia provided an appropriate grid is selected.

With GDAy, users can perform datum transformations and coordinate conversions using geographical coordinates (ie. latitude and longitude) or Map Grid of Australia projected coordinates (ie. Easting, Northing and Zone), whether working on one datum or between GDA94 and GDA2020. Coordinates may be transformed by entering individual values in the main GDAy dialog or multiple coordinates by file input.

QGIS Plugins

ICSM has developed two plugins for the free and open source QGIS software to perform transformations using the national NTv2 grids.

An existing NTv2 transformation plugin, accesses from the processing toolbox, now incorporates the NTv2 grids to transform between AGD66 / 84 and GDA94. Please note that as of April 2018, this plugin is not yet available in QGIS 3.0.

An ICSM branded plugin dealing only with NTv2 transformations between Australian datums has also been developed.

Image of Plugin manager from QGIS version 2.18.9

The plugins cater for the GDA94⇔GDA2020 conformal and GDA94⇔GDA2020 conformal and distortion transformation cases.


GDA94 ⇔ AGD66/84 Transformation and Conversion Tools

QGIS plugins will support NTv2 grid transformations using the national transformation grids.

The following software, which supports the NTv2 transformation grids, is freely available from the named jurisdiction.

ICSM also developed the following resources:

NOTE: Online versions of Vincenty’s and Redfearns Formulae are also available on the Geoscience Australia website. The online calculators provide the same results as the spreadsheets in the Technical Manual.

AUSGeoid Products and Tools

AUSGeoid files enable GDA94 and GDA2020 ellipsoidal heights to be transformed to Australian Height Datum (AHD) heights. Information about AUSGeoid as well as the products and tools are available from Geoscience Australia :

Downloadable interpolation software, developed by Dr Roger Fraser from Victoria, is also available:

Latest version of geoid interpolation program. Requires geoid grid file in either WINTER DAT format or NTv2 gsb format. Offers interactive and file interpolation modes and the ability to create a single NTv2 file from a grid file in the legacy AUSGeoid DAT file format. Software documentation is provided.
(Users who experience problems running this software for the first time should install the Microsoft Visual C++ 2008 Libraries.)