SBAS test bed provides positioning by land, sea, and air to within 10cm

In SBAS, positioning data from the Global Navigation Satellite System (GNSS) is received by ground-based stations, where software corrects imperfections in the data, sends it back to the satellite system, which then broadcast the corrected, now more precise, data.

© Commonwealth of Australia (Geoscience Australia) 2018.

The SBAS test bed is being run by a consortium that includes Geoscience Australia, Land Information New Zealand (LINZ), Lockheed Martin, GMV, Inmarsat, and the Cooperative Research Centre for Spatial Information (CRCSI). Finance for the project has been provided by the Australian ($12 million) and New Zealand ($2 million) Governments.

It’s one test bed, but is a test of three separate technologies:

• Single frequency service SBAS – provides improvement over stand-alone GPS from 5 metre accuracy to better than 1 metre accuracy
• Dual frequency/Multiple Constellation SBAS – expected to provide significant performance improvements over single frequency SBAS, to within ‘several decimetres’ according to GeoScience Australia.
• Precise Point Positioning (PPP) – accuracy to around 10 centimetres. This is the first trial in the world to integrate PPP corrections into SBAS.

The three main objectives of the SBAS Test Bed are to test:

• the performance of the technology directly in a number of industries
• current industry-specific requirements and how they interact with SBAS
• future industry-specific innovations that might be borne out by SBAS

The first ovation for SBAS

In a recent test bed project, SBAS was used to guide the cruise ship Ovation of the Seas from Sydney Heads through to the berth at Circular Quay. This project was run by Acoustic Imaging in consultation with the Port Authority of New South Wales.

Outside of this test, the Philip Holliday, the Harbour Master Sydney, said that “People will probably be surprised to learn that we use GPS technology and the old traditional eyeballs in safely getting the ship from The Heads all the way through to the berth, and then back again in the evening.”

That’s a lot of pressure on the somewhat accurate GPS technology, and the human staff of the Port Authority of NSW, particularly in the case of a leviathan like the Ovation of the Seas.

“The berth box inside Circular Quay is marginally smaller than the Ovation of the Seas, so the Ovation of the Seas is actually parking with nose protruding out in front of that parking spot. We’re on a level where metres matter, and centimetres matter,” said Nicole Bergersen, lead scientist of Acoustic Imaging’s maritime program.

“What SBAS is allowing us to do is have the pilot rely just on the information on the computer screen and if we can enable instrument navigation, then the pilot no longer needs visibility to be able to steer a ship.

“That’s going to allow the Port Authority of New South Wales to bring in more ships, more frequently and in adverse conditions,” said Ms Bergersen.

“Standalone GPS positioning is giving you five to 10 metre level positioning. This is the first time we have been able to broadcast corrections at the 10 centimetre level to the entire country, in fact to the entire region, so it’s quite new,” said Geoscience Australia’s John Dawson.

All the ways that people move

The Sydney Harbour trial is but one SBAS test bed project. The consortium received over 90 applications in its first call for projects, and over 30 projects have been supported and had agreements signed. One SBAS project announced late last year involves the Bosch Highly Automated DrivingE car, and VicRoads. “I’m pleased to see automated car technology being trialled with the increased accuracy provided by SBAS, showing the broad application space technology has right across Australia,” said the then Assistant Minister for Industry, Innovation and Science, the Hon Craig Laundy.

“VicRoads’ project is an exemplar of the innovation made possible by improvements to satellite positioning accuracy in Australia from 5 to 10 metres, to less than 10 centimetres.

“Over the course of this project, VicRoads will be comparing the accuracy of SBAS technology to commercial positioning services used to facilitate automated driving.”

John Dawson touched on the breadth of projects currently lined up to take part in the SBAS trial.

“We have intelligent and automated vehicle trials going on on land, we have some rail projects, and of course the aviation sector are very interested in this SBAS technology. So in fact we’re touching all the major transport modes, but we also have projects improving the navigation of pedestrians, particularly those pedestrians with visual impairment. We think we’re touching all the major ways that people move around the country,” said Mr Dawson.