Historically, location differences of a metre or so have not been an issue, because GNSS has traditionally only provided accuracy of 5 – 10 m. Global Navigation Satellite Systems, like GPS, base their coordinates on a framework that is fixed to the centre of the Earth around which satellites are orbiting. These frameworks are called ‘time-dependent reference frames / earth fixed’ in which the positions of features change with time due to plate tectonic motion. In contrast, Global Navigation Satellite Systems (GNSS) base their coordinates on a framework that is fixed to the centre of the Earth around which satellites are orbiting. This is beneficial for many applications where it is easier if the coordinates of features do not change (e.g. roads, buildings and property boundaries), do not change over time despite the ongoing changes in the Earth’s surface (e.g. A ‘static’ datum means that the positions of features (e.g.
#GEODETIC DATUM UPGRADE#
In anticipation for the growing use and reliance on positioning technology, the Permanent Committee on Geodesy led the development of the upgrade of Australia’s ‘static / plate fixed’ datum from the Geocentric Datum of Australia 1994 (GDA94) to GDA2020 which was released in 2017.
A ‘static’ datum means that the coordinates of features (e.g.GDA2020 is a static datum – just like GDA94.In anticipation for the growing use and reliance on positioning technology, the Permanent Committee on Geodesy is leading the upgrade of a number of elements of Australia’s Geospatial Reference System including the static datum from GDA94 to GDA2020. This is a significant improvement from the 5-10 m accuracy you can currently achieve using GPS enabled devices.
The Australian Government has committed $225m to provide 10 cm (or better) accurate positioning to anyone, anytime, anywhere in Australia in the near future.