Current Satellite-Based Augmentation Systems (SBASs) improve the positioning accuracy and integrity of GPS satellites and provide safe civil aviation navigation services for procedures from en-route to LPV-200 precision approach over specific regions. SBAS Systems already operate, such as WAAS, EGNOS, GAGAN and MSAS.

The development of operational SBAS systems is in transition due to the extension of L1 SBAS services to new regions and the improvements expected by the introduction of Dual Frequency Multi-Constellation (DFMC) services, which allow the use of more core constellations such as Galileo and the use of the ionosphere-free L1/L5 signal combination.

Following the UK's withdrawal from the European Union (EU), the use of EGNOS's Safety of Life (SoL) services in UK airspace ended. The UKSBAS testbed is a demonstration and feasibility project in the framework of ESA's Navigation Innovation Support Programme (NAVISP) sponsored by the UK's HMG with the participation of the Department for Transport and the UK Space Agency. UKSBAS main objective is to deliver a new L1 SBAS signal in space (SiS) from May 2022 in the UK region using Inmarsat's 3F5 geostationary (GEO) satellite and Goonhilly Earth Station as signal uplink over PRN 158, as well as L1 SBAS and DFMC SBAS services through the Internet. SBAS messages are generated by GMV's magicSBAS software fed with data from Ordnace Survey's stations network.

This paper provides an assessment of the performance achieved by UKSBAS services during the last two years of operations at SiS and user level, including a number of experimentation campaigns performed in the aviation and maritime domains comprising ground tests at airports, flight tests on aircraft and sea trials on a vessel. This assessment includes, among others, service availability (e.g.: APV-I, LPV-200), Protection Levels (PL) and Position Errors (PE) statistics over the service area and in a network of receivers.