Viasat Showcases Satellite-Based Augmentation System for UK EGNOS

Viasat has successfully demonstrated a UK satellite-based augmentation system (UK SBAS) for the first time. This system aims to deliver more precise and reliable navigation data compared to current GPS offerings.

The test flight, conducted from Cranfield Airport using the National Flying Laboratory Centre’s Saab 340B aircraft, showcased the capabilities of the UK SBAS in an aviation context.

Following Brexit, the UK is no longer part of the EU’s European Geostationary Navigation Overlay Service (EGNOS). The UK SBAS will supplement Galileo in the future and enhance GPS by providing information on the reliability and accuracy of positioning data, along with sending out corrections.

This trial is a significant step towards establishing a UK SBAS that can be utilized for critical "safety of life" navigation services across air, land, and sea. While UK applications can still use EGNOS, its Safety-of-Life (SoL) service was officially withdrawn in June 2021.

Viasat explained that the UK SBAS has the potential to offer positioning accuracy down to a few centimeters, compared to the few meters provided by standard GPS. In aviation, this system provides pilots with greater trust in their onboard instruments, especially in situations where visibility is limited due to adverse weather conditions.

"This means improved safety and fewer missed landings because pilots – especially those flying smaller aircraft into regional airports and general aviation airfields – can get significantly closer to the ground during an approach before making the decision whether to land. Viasat’s research with one regional flight operator indicated that close to 40% of flights cancelled due to weather could have gone ahead had UK SBAS been available for its fleet. Around the UK, 19 airports had EGNOS procedures in place prior to leaving the European Union. In total, as many as 72 airports no longer have access," Viasat stated.

With the successful aviation test completed, the trial will now proceed to test the system in other transport applications, such as rail, uncrewed aerial vehicles, and autonomous road vehicles.

The UK SBAS generates an overlay test signal to the US Global Positioning System (GPS) that complies with International Civil Aviation Organization (ICAO) standards. This signal is broadcast in coordination with the US Federal Aviation Administration (FAA), the European Space Agency (ESA), and the European Union Space Programme Agency (EUSPA).

Viasat's I-3 F5 satellite is responsible for broadcasting the UK SBAS signal.

"This trial on a sovereign UK SBAS is all about delivering trust," said Todd McDonnell, President, International Government, Viasat. "Trust for pilots in their tracking systems so they can stay safe in challenging conditions. Trust for the aviation industry more broadly so it can rely on data to operate more efficiently. And, in the future, trust that we can use highly accurate tracking to develop Britain’s transport system as new technologies come into play. We’re excited to continue the trial and see how far we can take it."

The trial is funded by the Department for Transport through the European Space Agency's NAVISP programme. It is being carried out by a team led by Viasat, which includes Goonhilly Earth Station, CGI UK, GMV, Ordnance Survey, Cranfield University, the Cranfield National Flying Laboratory Centre, and Pildo Labs.

"This testbed project is vital in helping the government understand the potential benefits of a UK SBAS," said Dean Thomas, Position, Navigation and Timing Lead at the UK Space Agency. "The flight trial both demonstrates the capability of UK industry in delivering space-based PNT solutions and illustrates the benefits of delivering UK PNT projects facilitated by ESA, through the highly flexible NAVISP programme."

Viasat also highlighted the development of a similar system called SouthPAN, which is being developed for positioning, navigation, and timing services (PNT) in Australia and New Zealand. Signals for this service will be provided by Viasat's next-generation I-8 satellites, set to launch in 2027.

With various satellite-based navigation systems available globally, including the United States' Global Positioning System (GPS), the EU's Galileo system, Russia's GLONASS, China's BeiDou system, and Japan's Quasi-Zenith Satellite System (QZSS), the UK SBAS aims to enhance navigation capabilities and ensure the safety and efficiency of transportation systems.

Image: Viasat – Representatives from organizations involved in UK Sovereign Satellite-Based Augmentation System

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