What is SBAS?

Who hasn’t had their SATNAV suddenly jump to the other side of the street? Or start in the wrong spot? This is because Australia’s current positioning system only provides accuracy of between 10 – 15 metres. Imagine if this was 1 to 2 meters or even 10 – 15 centimetres. This is what a Satellite Based Augmentation System & a Precise Point Positioning  (PPP) deliver.

And its positive impacts are profound: it enables driverless cars, trucks and buses. It means the Royal Flying Doctor Service can safely fly in and out of remote airfields at night and in all weathers, and regional airlines can do the same at small airports across Australia. Surveyors can create land-use maps and lay out buildings, roads and bridges more quickly; farmers can plan crop planting and apply fertiliser or water their paddocks with absolute precision. And miners can conduct surveys and operate unmanned equipment and vehicles with increased accuracy and therefore safety. 

Space Based Augmentation System (SBAS) is a highly accurate and reliable  Navigation Satellite System that allows to augment GNSS system like GPS. Current GNSS (like GPS) systems give users an accuracy of between 5 and 15 metres. However, an SBAS & Precise Point Positioning  (PPP) systems provide correction allowing user with a position with much greater accuracy - to a metre-level accuracy for the aviation industry and decimetre (10 to 15 cm) accuracy for other sectors like agriculture, construction, mining, freight, and, critically, defence and national security. 

Basic positioning systems require a ground-based receiver, for example in a mobile phone, to receive signals simultaneously from a number of positioning satellites. These signals are triangulated using the slight differences in their arrival time which allows the receiver to calculate its position to within a few metres. SBAS augments and upgrades the performance of this process by correcting the some of the variations like ionosphere impacts on  signal propagation  - substantially increasing the accuracy of the receiver’s position. 

A number of countries have implemented their own Satellite Based Augmentation Systems, including the USA, the European Union, Japan and India. With a number in development including China, South Korea, Russia and Africa.

Australia and New Zealand through Geoscience Australia and Land Information New Zealand are leading the development of a Satellite Based Augmentation System for Australia and New Zealand - the Southern Positioning Augmentation Network.