Even though GPS navigation is not always accurate, the errors in satellite navigation are even more apparent if you live in Australia. If you are using GPS to find your way around the continent, you may end up 5 feet (around 1.5 meters) off the mark.
The Australian government has recently initiated a project to fix the problem by updating the datum used for the satellite navigation coordinates. The updates will account for the tectonic shifts that have literally driven everything five feet off its mark.
A satellite navigation system uses the datum, i.e. the latitude and longitude grids to find the exact location on Earth. However, all the system do not use the same datum to update the maps. While the US NAVSTAR relies on the Earth’s core-based datum, most of the US maps use the tectonic plate-based datum. Dru Smith from NSG explains the significance of the plate-based datum:
“Most surveyors and mapmakers would be happy to live in a world where the plates don’t move. We can’t fix that, but we can fix the datum so that the effect is not felt by the predominant number of users.”
Geoscience Australia has launched the AuScope Global Navigation Satellite System (GNSS) network. The GDA2020 effort to update geocentric datum is driven by the same project.
The GDA94 datum specifically developed for Australia in 1994 is being used in the country. The eastern fragment of the Indo-Australian tectonic plate annually shifts around 2.2 inches thus, resulting in datum inaccuracy during the past twenty years.
The new datum will point out the location of the continent in 2020. It will come in use next year and will be 20 centimetres off. The second phase of this project will start in 2020 to synchronise the date with GNSS, thus allowing it to update datum in real time.