Reinstating the UK’s membership of the European Geostationary Navigation Overlay Service (EGNOS)

Approximate read time: 10 minutes 

On 12 June 2025, the House of Lords will consider the following question for short debate:  

Lord Berkeley (Labour) to ask His Majesty’s Government whether they intend to apply to reinstate the United Kingdom’s membership of the European Geostationary Navigation Overlay Service. 

1. What is the European Geostationary Navigation Overlay Service?

The European Union’s space programme includes the following components: 

• the European satellite navigation programmes, Galileo and the European Geostationary Navigation Overlay Service (EGNOS) 
• the Copernicus Earth observation programme 
• the EU space surveillance and tracking (EUSST) programme 
• the governmental satellite communications (GovSatCom) programme^[1] 

EGNOS is Europe’s regional satellite-based augmentation system (SBAS). SBASs are used to augment the signals of global navigation satellite systems (GNSS), improving their accuracy so that they can be used for safety-of-life applications such as precision approaches in aviation.^[2] This is particularly important when guiding aircraft vertically as well as horizontally during landing approaches, providing greater assistance in overcoming challenging weather conditions, for example. It also has applications in other areas such as maritime navigation and helicopter emergency services.  

The UK remains a member of the European Space Agency (ESA), which is not an EU organisation. However, following the UK’s departure from the European Union, the UK no longer participates in the EU Galileo or EGNOS programmes, both of which are fully financed from the EU budget.^[3] 

1.1 How EGNOS works

Ground stations deployed around Europe acquire signals from the US GPS satellite navigation system and now the European Galileo system, which are then gathered and processed through a central computing system.^[4] Here, differential corrections and integrity messages are calculated. These messages are then broadcast back to users across Europe via a set of three geostationary satellites. 

As a result, EGNOS improves the accuracy of GNSS positioning information while also providing an integrity message which allows the user to get a reliable guarantee on its residual positioning errors (both horizontal and vertical). In addition, EGNOS signals provide the users with accurate synchronization to the UTC time (co-ordinated universal time, the primary time standard globally used to regulate clocks and time). 

1.2 Benefits 

The European Union Agency for the Space Programme (EUSPA) maintains that EGNOS is essential for applications where accuracy and integrity are critical (such as aviation). EUSPA contends that, since its certification for use in civil aviation in 2011, EGNOS has become an important aid in the European aviation sector, “increasing both the safety and accessibility of airports in general and, in particular, small and regional airports and airfields”.^[5] EUSPA suggests:  

Thanks to the accurate and safe guidance offered by the system everywhere and anytime in Europe, pilots are better positioned to land in challenging weather conditions, including poor visibility and storms, and avoid aborted landings (go-arounds).^[6] 

Maritime users are also widely using EGNOS for harbour entrances, harbour approaches and coastal waters in the EU. 

Beyond these sectors, EUSPA contends that EGNOS improves and extends the scope of GNSS applications in various areas, including road, rail, surveying, mapping, location-based services and agriculture. 

1.3 Infrastructure 

The EGNOS infrastructure is comprised of: 

• a ground network of around 40 ranging and integrity monitoring stations (RIMS) 
• six navigation land earth stations (NLES) 
• two mission control centres 
• an operations coordination centre and a service centre 
• signal transponders on three geostationary satellites operated by SATCOM service providers^[7] 

2. Calls for the UK to rejoin EGNOS

The All-Party Parliamentary Group for Aviation—of which Lord Berkeley is a former vice-chair (and is still a member) and Lord Davies of Gower (Conservative) and Lord Kirkhope of Harrogate (Conservative) are current vice-chairs—issued a report in 2022 calling for EGNOS to be temporarily reinstated in the UK.^[8] The APPG contended that this would have several benefits, including improved reliability of search and rescue (SAR) and helicopter emergency medical services (HEMS), and improved flight safety, and wider uses such as precision farming and providing better services for those in remote locations such as the Hebridean islands. The group also contended that this temporary reinstatement would not preclude the development of a UK alternative to EGNOS.  

Other stakeholders have also expressed a desire for the UK to rejoin EGNOS. Martin Robinson, head of the UK branch of the Aircraft Owners and Pilots Association (AOPA), has contended that the loss of EGNOS has “crippled the rollout of satellite-based instrument approaches, locking hundreds of aerodromes out of safer, more resilient flight options”.^[9] 

3. The UK government perspective

When questioned on the issue in May 2025, Lord Vallance of Balham, minister of state in the Department for Science, Innovation and Technology, said that the government was considering options for UK access to a satellite-based augmentation system following its withdrawal from EGNOS and that “work is ongoing and no decision has yet been made”.^[10] 

Ministers have acknowledged that systems such as EGNOS are beneficial for smaller, regional airports in particular, but have said that flights that are taking place continue to do so safely, following alternative Civil Aviation Authority approved procedures:  

Larger UK airports and many regional airports have instrument landing systems in place and therefore a satellite-based augmentation system, such as European Geostationary Navigation Overlay Service (EGNOS), is primarily beneficial at smaller regional airports and general aviation aerodromes during periods of poor weather resulting in restricted visibility. Flights that are taking place continue to do so safely, following alternative Civil Aviation Authority approved procedures. 

Helicopter emergency medical services (HEMS) will, in the UK, be supported through a GNSS point in space ‘PinS’ approach to helicopter landing sites at trauma hospitals which will greatly assist in increasing the utility of air ambulance helicopters in poor visibility conditions.^[11] 

UK-based infrastructure continues to support the operation of EGNOS. When questioned by Lord Berkeley in February 2025 about the future of this provision, Lord Vallance reiterated that the UK was considering options for the future:  

The UK continues to host two ranging integrity monitoring stations, in Glasgow and Swanwick, that support European Geostationary Navigation Overlay Service (EGNOS) services. The government is considering options for future UK access to a satellite based augmentation system such as EGNOS, and no decision has been taken. The government has not had any discussions with European counterparts on the restoration of EGNOS services.^[12] 

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Cover image by NASA on Unsplash.