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Australian Geospatial Reference System (AGRS) Modernisation

Australia is in the process of modernising the Australian Geospatial Reference System (AGRS) to support advancements in precise positioning and enhance alignment with underlying spatial information.

This national program is being delivered through the Intergovernmental Committee on Surveying and Mapping (ICSM) and involves updating fundamental components of the national coordinate reference system:

  • GDA2020 – Geocentric Datum of Australian 2020 (GDA2020)
  • ATRF2014 – Australian Terrestrial Reference Frame
  • AVWS – Australian Vertical Working Surface

More information on the AGRS is available on the ICSM webpage.

The Surveyor-General of Victoria (SGV) Geodesy is leading the development and implementation of the AGRS modernisation program in Victoria.


The Geocentric Datum of Australia 2020 (GDA2020) and the Map Grid of Australia 2020 (MGA2020) are the official datum and map projection for Australia. GDA2020 is a conventional static datum based on ITRF2014 at the reference epoch of 1 January 2020.

The Surveyor-General of Victoria (SGV) has led the implementation of GDA2020 in Victoria.  We are actively encouraging and supporting organisations in the transition of their spatial information and applications to the new national datum. Drivers for the transition to GDA2020 in Victoria are detailed in the fact sheet.

To support organisations in planning and implementing the transition to GDA2020 the following guidance notes have been prepared.

Technical guidance and information for the transformation of spatial information between GDA94 and GDA2020 is available in the GDA2020 transformation in Victoria fact sheet.

Technical summary of essential datum or Coordinate Reference System (CRS) requirements for the development of modern spatial software, applications, and Web mapping services in Victoria.


The Geocentric Datum of Australia 1994 (GDA94) and Map Grid of Australia 1994 (MGA94) are still supported in Victoria. GDA94 is a static coordinate datum based on the International Terrestrial Reference Frame 1992 (ITRF92) at the reference epoch of 1 January 1994.

The coordinates of features on maps based on GDA94 are no longer aligned with Global Navigation Satellite System (GNSS), such as GPS. To enable seamless interaction between precise positioning technology and spatial information, users are encouraged to transition to GDA2020.

GDA2020 support

Further technical information, manuals, software and tools to support the transition from GDA94 to GDA2020 are available on the ICSM website.

Tools to support legacy coordinate conversion and scale factor calculations

GDAit transformation software

The GDAit software is a Windows-based application that transforms coordinates between datums AGD66 (AMG66) and GDA94 (MGA94).

The transformation grid file (A66_National_13_09_01.gsb) required for the transformation is included in the zip file.

Once downloaded, please unzip the contents and select the transformation grid file during the initial execution.

GDAit Version 2.02 October 2001 (ZIP, 3.2 MB)
GDAit User Guide (PDF, 136.8 KB)

AMGVG conversion software

The AMGVG software is a command line-based application that performs coordinate conversions and transformation between AGD66 (AMG66) and VicGrid (VicGrid94).

Note this software does not transform coordinate information between AGD66 and GDA94. Please use GDAit software for this transformation.

Download AMGVG.exe Version 3.2 June 2010 (ZIP, 58.1 KB)

Scale factor calculations

A spreadsheet to assist with computing Point Scale Factor, Height Factor and Grid Convergence calculations is available for download.

Download scale/Height Factor Calculations and Grid Convergence (Excel, 190.0 KB)

Page last updated: 11/07/23