Shutdown of AMSA’s differential global positioning system (DGPS) service
This was announced by AMSA from Canberra on 5 May.
AMSA established its radiobeacon DGPS service in the 1990s, to improve the accuracy and integrity of GPS information for ships navigating off the coast of Australia. At the time, the publicly available GPS signal was intentionally degraded, resulting in large position errors of up to 200 metres. Augmentation was necessary to correct for these errors and meet minimum requirements for maritime positioning and navigation.
In the year 2000, the intentional error in GPS positioning was removed. Since then system technology has improved and the GPS constellation has been modernised. Observed positional accuracy for unaugmented GPS now consistently meets IMO requirements for accuracy in harbour and harbour-approach navigation.