GDA94 useful tools
The Department of Sustainability and Environment has developed software called GDAit for users to transform between AGD and GDA using geographical coordinates (AGD66 – GDA94) and UTM grid coordinates and zones (AMG66 – MGA94).
The transformation process uses a grid of Latitude and Longitude shifts. The shifts are a combination of a 7-parameter conformal transformation and the modelled distortion between AGD and GDA.
GDAit (release version 2.02 22/11/01) has been updated for national use with grid data stored in the NTv2 format (Canadian Binary Format).
On this page:
GDAit transformation software
GDAit User Guide
GDAit DLL for software developers
AMGVG conversion software
GDAit transformation softwarePlease note that while every effort has been made to ensure the accuracy and currency of GDAit and the Victorian grid data, the State of Victoria does not accept responsibility for any actions arising from the use of the software or data.
Download the latest national version of GDAit v2.02.
Files included in the download:
- Install Instructions – how to install the software and grid on your computer, as well as a history LOG showing the changes that have occurred with the GDAit software and grid files during its development. Note the latest grid file is downloaded separately from the GDAit software. Please read below for further instructions regarding the grid file and its download.
Instructions for downloading GDAit
- GDAit v2.02 (32 Bit for Windows 95 / 98 / 2000 / NT / ME) – download and then execute to automatically install GDAit onto your computer. The current grid file will have to be manually imported into GDAit once the GDAit software has been installed.
A National Transformation Grid File is available from the ICSM website and replaces all previous versions of the grid files (Victorian, south-east Australia, etc.).
The complete national coverage from AGD to GDA is 3.2MB. This coverage was generated using the latest algorithms with data from the previous AGD state and territory grid files and AGD and GDA data from the National Geodetic Data Base.
The national file also covers the offshore areas out to the Exclusive Economic Zone (EEZ). The grid is supplied in the NTv2 format and a simple conformal (7-parameter) transformation was used to generate the shifts in these offshore areas.
GDAit User Guide
GDAit User Guide Download the GDAit User Guide – same as the online help included in the software download.
Download GDAit Software Documentation – explains the GDAit software architecture, including the bi-linear interpolation technique used to interpolate the transformation grid file.
GDAit DLL for software developersGDAit DLL is the Dynamic Link Library version of GDAit that transforms coordinates between AGD (66/84) and GDA and vice versa. The DLL is freely available for download and use by developers to incorporate into their software (provided appropriate acknowledgement of Land Victoria is included).
Download GDAit Dynamic Link Library with accompanying documentation describing the functions contained in the DLL and how to call them from C or Visual Basic. For detailed information on the transformation process please refer to the GDAit user guide and software documentation above.
AMGVG conversion softwareDownload and then execute the program to perform calculations with coordinates. Note this software does not transform coordinate information between AGD and GDA, either geographical or UTM grid coordinates.
- To change between AMG and MGA input screens, enter either A or M respectively at Select Option.
- When in the MGA mode calculations for Vicgrid are performed relating to Vicgrid94 specifications.
- AMGVG.exe Version 3.2 June 2010