New Zealand and Australia are working together to explore developing a regional satellite-based augmentation system (SBAS) to improve the accuracy of GPS.
GPS usually provides positioning information accurate to about 5-10 metres. This new system will improve the accuracy to less than a metre, and in some devices to 10 centimetres.
Budget 2019 set aside almost $2 million for Land Information New Zealand (LINZ) to work with our Australian counterpart, Geoscience Australia (GA), to investigate in more detail ways to deliver SBAS.
The funding will allow us to jointly develop specifications and undertake initial procurement processes. Once a preferred provider for delivering SBAS has been identified, approval to release further funding will be sought to implement the technology.
SBAS uses satellites as well as ground-based infrastructure to improve the accuracy, integrity and availability of basic Global Navigation Satellite System (GNSS) signals, like GPS.
The benefits of SBAS
SBAS will make positioning data, like GPS, even more accurate than it is now. It will allow us to identify any errors in these systems, so they can be adjusted to be more precise for New Zealand.
This will make them more useful for intelligent transport systems like driverless cars, unmanned aerial deliveries, as well as precision agriculture and smart phone-based services.
SBAS can be used for air navigation. It can help aircraft to land in poor weather at regional airports and heliports without the need for expensive ground-based landing aids. There are also potential longer-term benefits for road safety and congestion management.
SBAS in operation
SBAS is already in use in the United States, Europe, Japan and India. While New Zealand and Australia currently have good access to GPS, we do not currently have access to SBAS.
SBAS does not require information about users to operate. It will simply provide more accurate positioning for users of the system, similar to systems like GPS.
Australasian SBAS Trial
The Australasian SBAS Test-bed Demonstrator Trial was a partnership between LINZ and GA.
The 18-month trial took place from January 2017 until January 2019 and involved 27 demonstration projects across ten sectors in both countries.
The SBAS Test-bed Demonstrator Trial Economic Benefits Report completed following the trial identified economic benefits to the value of AU$7.4b to the region over 30 years, with AU$1.4 billion accruing to New Zealand.
The trial tested three SBAS signals and found they all provide benefits to both countries.
The SBAS Test-bed trial also showed general benefits including; improved GPS accuracy (from 5-10 metres to one metre or less), improved signal integrity, and reduced commercial costs and infrastructure investment.
The New Zealand Government provided AU$2 million funding for the trial on top of AU$12 million from the Australian Government. The report, as well as further information, is available on the FrontierSI website.
How the SBAS trial worked
The SBAS provided corrections to existing satellite navigation systems like GPS. This was achieved by analysing data received at LINZ and Geoscience Australia’s existing networks of GNSS tracking stations.
The data was transmitted to Geoscience Australia’s processing facility where the SBAS corrections were calculated and sent to the satellite up-link station and onto the satellite. The geostationary satellite then broadcast the corrections over the Australasian region.
The SBAS test-bed tested three technologies:
- Single frequency service SBAS, which is the equivalent of the systems used in the US (the Wide Area Augmentation System or WAAS), and Europe, (the European Geostationary Navigation Overlay Service or EGNOS). This technology will improve the accuracy of GPS from 5 metre accuracy to better than 1 metre accuracy.
- Dual frequency-Multiple Constellation SBAS. This is known as next generation SBAS and used two civil signals and two constellations (GPS and Galileo). This will provide significant performance improvements over single frequency SBAS, particularly in regions with dynamic ionosphere.
- Precise Point Positioning (PPP). PPP is a method that provides highly accurately position solutions with accuracy better than 10 centimetres.
Management of the trial
The trial was a collaborative project funded by the New Zealand and Australian governments. FrontierSI was engaged to manage and deliver the project with oversight from LINZ and GA. New Zealand government funding was provided through LINZ, New Zealand Transport Agency, Ministry of Business, Innovation and Employment and the Ministry of Transport.