About SBAS

Global Navigation Satellite Systems (GNSS) have become the primary means of obtaining Position, Navigation and Timing (PNT) information at sea.  Most ships are equipped with GNSS receivers.  A GNSS or an equivalent radio navigation receiver, is a SOLAS carriage requirement (Ch V/Reg.19.2.1.6).  The United States-operated Global Positioning System (GPS) is a prime example of a GNSS.

Traditionally, navigators have relied on the marine radio beacon DGPS (Differential GPS) augmentation service, to improve positional accuracy and provide integrity monitoring for GPS signals.  Integrity monitoring helps GPS receivers identify and discard signals from ‘unhealthy’ satellites.  However, DGPS is a 1990s technology, and its coverage is limited to medium frequency radio ranges.  AMSA discontinued its DGPS service in 2020. 

SBAS has now replaced DGPS in Australia. There is no carriage requirement for SBAS in SOLAS.

Southern Positioning Augmentation Network (SouthPAN)

The joint Australia and New Zealand government operated SBAS is named Southern Positioning Augmentation Network or SouthPAN.

SouthPAN will improve the accuracy, availability and integrity of PNT information for users in the region.  It now delivers early Open Services, free of user charges.  SouthPAN provides accurate, reliable and instant augmentation of PNT information across all of Australia and New Zealand (see diagram).  For example, the horizontal accuracy provided is several times better than the current unaugmented GNSS accuracy of about 10 metres.

With early Open Services now live, Australia and New Zealand are working towards full Open Services capability and an International Civil Aviation Organization (ICAO) certified Safety-Of-Life Services (primarily for aviation use) by 2028.