As of January 2017, Australia’s coordinates have officially moved 1.8 metres northeast, following the launch of the Geocentric Datum of Australia 2020 (GDA2020). The first update to Australia’s coordinate system in two decades, GDA2020 is a step towards modernising Australia’s spatial referencing system, and will be a key topic of discussion in Position Magazine’s forthcoming February/March issue.
Prior to the update, Australia’s coordinates were no longer in alignment with global navigation satellite systems (GNSS) such as GPS. The definition of GDA2020 officially occurred in January 2017, when coordinates on over 100 of Australian GNSS CORS stations were gazetted as a Recognised Value Standard of Measurement of Position under the National Measurement Act, replacing GDA94.
“Australia’s Datum Modernisation will ensure Australia’s spatial data sets align with GNSS locations so that the community can take full advantage of accurate location-based information in the digital age.” – Michael Giudici
Next, GDA2020 will be made available to adopt from early February 2017. The new coordinates are based on the projected position of the Australian continent in 2020, which means they are currently offset from GNSS coordinates by 21 centimetres. In the lead up to 1 January 2020, the Australian tectonic plate will move into alignment as it catches up with GDA2020 positions.
To establish just what this means for those dealing with location information, Position Magazine interviewed perhaps the most crucial member of the team behind the modernisation program, Michael Giudici. As Surveyor General of Tasmania, Chair of the Intergovernmental Committee on Surveying and Mapping (ICSM) and part of the GDA Modernisation Implementation Working Group (GMIWG), Australia’s new datum will be one of Giudici’s major priorities for 2017 and beyond. Ahead of his appearance at Locate17 in April, Giudici explained Australia’s datum modernisation program at length, and what we can expect over the coming months and years.
Giudici told Position that Australia’s datum modernisation program will “ensure Australia’s spatial data sets align with GNSS locations so that the community can take full advantage of accurate location-based information in the digital age.”
Geoscience Australia expects that professionals involved in surveying, spatial sciences and mapping will particularly benefit from the implementation of GDA2020. Others that rely on location information supported by the national geodetic datum, such as construction and mining, may also realise benefits following the update. The intricacies of these changes will be further explored in Position Magazine with two exclusive feature articles, “Dynamic Datums: An uncoordinated future,” written by Richard Stanaway and “Nation on the move – Are you ready for GDA2020?”
The February/March 2017 issue of Position Magazine will be available exclusively in print in the coming weeks.
The crucial next phase of Australia’s modernisation program will take place in January 2020, when users will be able to transition to a time dependant, or ‘dynamic’, reference frame. This ‘earth-fixed’ reference frame will provide a sustainable, traceable, high-precision geospatial reference system designed to maintain full alignment to GNSS.