Improved location accuracy with SouthPAN
This article by Matt Amos, SouthPAN Technical Director with Toitū Te Whenua Land Information New Zealand (LINZ), originally appeared in Professional Skipper magazine in January 2024.
SouthPAN – the Southern Positioning Augmentation Network – is a joint initiative by the New Zealand and Australian Governments to provide improved positioning services across each country’s land and maritime zones. Early open services are freely available now for users with compatible devices, and SouthPAN will be fully operational from 2028.
It is the southern hemisphere’s first satellite-based augmentation system, joining many other services that are either in place or in development across the northern hemisphere.
SouthPAN-compatible devices receive positioning data directly from satellites. The data is collected at a network of ground stations across the service area to model corrections that account for satellite orbit and clock errors and changes in the Earth’s ionosphere. Geostationary satellites are used to broadcast the corrections to users located across Australia, New Zealand and their maritime regions. The result is an improvement of location accuracy from the current 5-10m to less than a metre in most cases.
A simplified diagram showing how SouthPAN’s satellite-based augmentation system works
In a maritime context, SouthPAN offers multiple advantages over GPS, including more reliable location data for pilots guiding vessels in and out of harbours, often in adverse conditions, and a free public alternative to the subscription services used by vessels equipped with dynamic positioning.
With dynamic positioning that can identify exactly where the bottom of a vessel is in relation to the seabed, skippers will be better able to manage under-keel clearance. As new SouthPANcompatible technologies come onto the market, the innovations and benefits will mount. Combined with other technologies, SouthPAN will also enable innovation across the agriculture, forestry, construction and transport industries.
Other applications include precision farming, geofencing, stock management, worker safety, asset monitoring and autonomous vehicle use, which will only be possible with this technology. By 2028, SouthPAN will be Safety of Life certified for aviation, allowing aircraft to fly in adverse weather conditions they cannot operate in now.
MARITIME TRIAL
SouthPAN’s quantified economic benefits to New Zealand have been estimated at $864 million over the next 20 years, including$55.14 million attributed to maritime-related activities.
To demonstrate the potential for an Australasian satellite-based augmentation system, a trial service operated from 2017 to 2019 and included 27 individual projects. This included three with a maritime focus: investigating vessel navigation and tracking; hydrographic surveying and pilotage; and port operations.
The vessel navigation and tracking project was run by Maritime Industry Australia Ltd, and aimed to test the system’s accuracy and reliability over the broadest possible geographical area and with a wide range of vessels, including commercial, cruise and research. SouthPAN-compatible receiver technology was installed on 16 vessels and trialled on voyages from November 2017 to May 2018, including the Cook Strait ferries, cruise ships in Fiordland and a research trip to Antarctica.
The system was trialled on 16 vessels journeying as far south as Antarctica
The trial largely focused on under-keel clearance –the space between the bottom of a vessel and the seabed. The more accurate positioning available means the dynamic position of the vessel is known in real time, enabling better clearance monitoring in shallower waters.
Another project concentrated on the improvements SouthPAN could deliver in hydrographic surveying and professional piloting of large vessels in congested waterways. The two are linked, in that pilots rely on electronic navigation charts generated from hydrographic surveys, which map the shape and nature of the seabed. This project was done in 2018 and 2019 in Sydney Harbour, Australia’s busiest waterway, with visits from around
1200 large commercial vessels each year.
The third maritime project looked at the use of SouthPAN to improve the accuracy, efficiency and safety of container movement in port environments, given positioning technology is a key part of the automation of container handling equipment to improve productivity.
SouthPAN can help improve the accuracy, efficiency and safety of container movements in ports
Mobile port equipment, including carriers and cranes, are carefully choreographed to avoid inefficiencies, so knowing precisely where the equipment and its next load are helps to limit mistakes, unsafe deliveries and wasteful movements. This is usually achieved by using differential corrected GNSS data, which relies on a base station set up within the port to correct positioning data. This system is vulnerable to glitches and blackouts, so SouthPAN, which does not rely on cellular or radio networks, is a reliable backup option.
These three projects all showed that the satellite-based augmentation system would deliver benefits to the maritime sector. It is likely the benefit estimate is conservative, since there are many more areas not covered by the trial programme that will also be able to utilise SouthPAN as it is deployed.
The SouthPAN project is a partnership between Toitū Te Whenua Land Information New Zealand and Geoscience Australia. It represents a significant achievement in international cooperation between the two countries and will benefit multiple sectors by promoting innovation and greater productivity.
FrontierSI is supporting Geoscience Australia and Toitū Te Whenua Land Information New Zealand with community and industry engagement related to SouthPAN. For official information about SouthPAN services, please visit the government websites at www.ga.gov.au/southpan and www.linz.govt.nz/southpan.
