Datum Modernisation


Modernising our National Datum

On the 15th of December 2017 Geoscience Australia and the Intergovernmental Committee on Survey and Mapping (ICSM) officially launched the new GDA2020 datum.

This page provides information about changes to the system that underlies Australia’s location information which is being updated to align with global satellite positioning systems. Watch the animated video below to see why and how Australia’s Datum is changing and utilise the​ Fact Sheets​ for explanations for a non-technical audience. 

Moving from GDA94 to GDA2020 in Tasmania

GDA94 is still the operational datum being used by Land Tasmania. The process of changing from using GDA94 to GDA2020 coordinates on spatial datasets is being implemented individually in each jurisdiction with national coordination facilitated by ICSM and it will take time. The first step of this process in Tasmania was the inclusion of GDA2020 datum and coordinates in the Tasmanian Survey Control Marks Database (SurCom)​ in April 2018​.

​For more details about the physical reallisations of GDA2020 and GDA94 in Tasmania see here​.

For the latest information on Datum Modernisation​

The Intergovernmental Committee for Surveying and Mapping website has all the late​st information.​ Comprehensive explanatory and techncial information about national geodetic datums GDA2020 and GDA94 is available at the ​​ICSM datum  ​pages whilst a general overview of maps, mapping and datums is available at ICSM fundamentals of mapping pages. ​

GDA2020 Datum Animation 

Do you want to receive GDA2020 news?

Land Tasmania has an Email Notification Service to keep you up to date with the implementation of the Datum Modernisation process. Updates will be sent with news and information on relevant aspects of the implementation as they occur.

Click to subscribe to the GDA2020 Email Notification Service

Click to unsubscribe to the GDA2020 Email Notification Service

GDA2020 Online Moderated Forum


An online forum has been established by the Intergovernmental Committee on Surveying and Mapping to support users with the implementation of Australia's new datum, GDA2020. The forum is a place to discuss and share experiences, and find answers to questions relating to the datum modernisation. This includes sector-specific assistance with technical aspects of the change, as well as help for spatial data novices to understand how datums work. It is moderated by members of the GDA Modernisation Implementation Working Group and other technical specialists from around Australia.

Sub–forums cater for questions relating to:
  • tools, advice, and tips for converting spatial data;
  • the implementation or use of GDA2020 in specific software or hardware products (ESRIMapinfoQGISGNSSLIDAR and aerial imagery);
  • implementation within specific states and territories, (moderated by GMIWG members from that jurisdiction); and

concerns or issues faced by specific industries, such as mapping and surveying, utilities, mining, agriculture, construction, transport, environmental management, emergency services and scientific research.​

GDA2020 Resources Available

In support of the new Australian datum, the following tools and resources have also been released by Geoscience Australia and ICSM:

 ICSM has developed two 2D national transformation grids:

  • ​Conformal: simply a grid version of the seven-parameter similarity transformation: the basic difference between GDA94 and GDA2020 coordinates primarily due to plate tectonic movement (approximately 1.7m NNE over 26 years); and
  • Conformal + Distortion: incorporates the conformal seven-parameter similarity transformation plus localised and regional distortion revealed by incorporating coordinates on ground survey control networks across the nation.​

These transformation grid files can be downloaded from the ICSM Github site


Manager (Client Services)
Todd Baker
134 Macquarie Street
Hobart TAS 7000
Phone: 03 6165 4644
Fax: 03 6233 6568
Email: Todd.Baker@dpipwe.tas.gov.au

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