UK SatNav signal generated to test future PNT capabilities

Posted on 9 June, 2022 by Advance 

An Inmarsat-led team of companies in the UK, building on national expertise and prior experience within the group, has begun broadcasting a satellite navigation signal as part of a programme to explore the creation of a sovereign national capability in resilient positioning, navigation and timing (PNT) for the aviation and maritime sectors.

Image courtesy Inmarsat

The signal, being broadcast in coordination with the US Federal Aviation Administration (FAA), the European Space Agency (ESA) and the European Union Space Programme Agency (EUSPA), is now stable and operational, enabling on-going testing and validation by industry, regulators, and users.
Inmarsat, alongside British partners Goonhilly Earth Station Limited and GMVNSL Limited, is delivering the UK Space Agency-funded tests with the European Space Agency via the latter’s Navigation Innovation and Support Programme (NAVISP).
UKSBAS – the UK Space-Based Augmentation System – generates an overlay test signal to the US Global Positioning System (GPS), fully-compliant with International Civil Aviation Organisation (ICAO) standards, to enable assessment of more precise, resilient and high integrity navigation for maritime and aviation users in UK waters and airspace. It increases accuracy in positioning to a few centimetres of accuracy rather than the few metres provided by standard GPS. This is a similar system to that already under evaluation in Australia and New Zealand, supported by Inmarsat.
Since leaving the European Union, the UK is not part of the Galileo satnav system and cannot use the European Geostationary Navigation Overlay Service (EGNOS) safety of life (SOL) services, which enable the use of GPS for airport approach and landing operations for aircraft. By repurposing the SBAS transponder on Inmarsat’s I-3 F5 satellite in geostationary orbit at 54° west, the UKSBAS signal enables testing of this potential alternative system to begin. Built by Inmarsat’s Athena partner Lockheed Martin and launched in 1998, I-3F5 covers the UK as part of its Atlantic Ocean region service overlay. This makes it an ideal candidate to participate in this test and demonstrates the commitment to sustainability of Inmarsat with a satellite that has already served the equivalent of several low Earth orbit (LEO) satellite life cycles.
Todd McDonell, President, Global Government at Inmarsat, said: “The Inmarsat team is inspired by delivering solutions to new problems through technology and innovation. Repurposing a transponder on a long-serving satellite to deliver a new capability to the UK, potentially a vital and enduring one, certainly lives up to that core Inmarsat ethos. Working with our fellow British companies at Goonhilly and GMVNSL to deliver such a capability for the country is very rewarding and we look forward to reporting on the results.”
These tests will assess whether UKSBAS can develop into a full operational capability to support safety-critical applications such as airport approach and landing operations or navigating ships through narrow channels, especially at night and in poor weather conditions. Goonhilly provides the signal uplink for the system from Cornwall and software from GMVNSL, based in Nottingham, generates the necessary navigational data.
Transport Minister Robert Courts said: “The UK's thriving space sector is developing at pace, and British-led innovations like this have the potential to deliver crucial navigation services for our aviation and maritime sectors.  
“That’s why this Government is investing millions in new technologies to make our transport network even safer while boosting high-skilled job opportunities across the nation."
UKSBAS is helping to regenerate UK strategic capabilities in this domain. The establishment of this new national platform creates the opportunity to evaluate high-integrity, resilient and precise navigation across the country, in its airspace and within surrounding waters. The project may be crucial for UK users who need accurate, high-integrity navigation capabilities to enable their operations, initially covering aviation and maritime operations but with potential extension into rail and road applications.
Paul Bate, CEO of the UK Space Agency, said: “Congratulations to Inmarsat, Goonhilly and GMVNSL on this impressive achievement. In recent years, the UK Space Agency has invested in the development of UK expertise in Positioning, Navigation and Timing (PNT), and the government’s commitment to strengthening PNT resilience is set out in both the National Space Strategy and Integrated Review, given its importance to our critical national infrastructure and economy.  
“This project is a great example of the innovation found throughout the UK space sector and demonstrates how we can work effectively with the European Space Agency to strengthen our national space capabilities.”