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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.

Information to assist with transition to GDA2020 is available in the GDA2020 Factsheet (DOCX, 2.2 MB).


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.

GDA 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

AMGVG conversion software

Download 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.

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: 09/12/20