The co-ordinates of physical locations in Australia are currently defined using the Geocentric Datum of Australia 1994 or “GDA94”. However, Australia sits on one of the Earth’s fastest moving tectonic plates and by 2020, there will be an error of approximately 1.8m between a location’s GDA94 co-ordinates and its co-ordinates from global satellite positioning systems. This is because Australia’s GDA94 datum is plate-fixed and moves with the Australian continent whereas GPS co-ordinates are fixed to the centre of the earth.
To bring Australia’s coordinates into line with those from global satellite positioning systems, Australia will soon be changing to a new official national datum called the Geocentric Datum of Australia 2020 or “GDA2020”. The change not only affects the spatial sector, such as surveyors, but applies to all users of location-based data. Industries that use location-based data may need to transition their own systems and processes to support GDA2020 data. SA Government agencies are working together to ensure a collaborative approach and are targeting a transition to GDA2020 as the operational datum for South Australia in early 2019. More information will be made available as we complete testing of our systems and databases. Current SA Government petroleum and geothermal energy legislation, policies and guidelines will be updated where they refer to an older datum or coordinate system.
The transition to GDA2020 is being facilitated by the Intergovernmental Committee on Surveying and Mapping (ICSM) and Geoscience Australia. For further information, we recommend the following useful links to their websites:
Source: ICSM Datum Matters Factsheet 3