PARIS — Thales Alenia Space of France and Italy on April 21 said it will upgrade Europe’s regional EGNOS GPS-verification network under a contract with the European Commission and the European Space Agency (ESA) valued at 54.5 million euros ($79 million).

Under the 28-month contract, Thales Alenia Space will change out both the hardware and the software at the 38 reference stations and six uplink stations that, along with a data-processing center, form the European Geostationary Navigation Overlay System.

The EGNOS ground network is linked to two satellites in geostationary orbit that, after verification by the ground stations, relays GPS data to users, offering both greater positioning, timing and navigation accuracy, and providing verification that the GPS signals are accurate.

“When EGNOS was first commissioned in the late 1990s it was with aeronautical and safety-of-life applications in mind, meaning we used only tested equipment and technology that, at this point, is more than 20 years old,” said Simon Acarier, navigation sales manager at Thales Alenia Space.

“For some of the equipment in the current EGNOS, it is now impossible to find spare parts on the market,” Acarier said in an interview. “And since we have to change the hardware, we will also be obliged to change the software that EGNOS uses.”

Acarier said the two satellites now used for EGNOS — navigation payloads attached to ESA’s Artemis data-relay spacecraft and to an Inmarsat mobile-communications satellite — are scheduled to be retired in three years or so. The European Commission has selected two commercial telecommunications satellites under construction by fleet operator SES of Luxembourg to host the next-generation EGNOS payloads. The existing EGNOS ground system would have trouble operating with the new EGNOS space segment, a fact that argues for a replacement of EGNOS ground gear starting now, Acarier said.

The United States and Japan have similar regional navigation systems, also using commercial telecommunications satellites in geostationary orbit to verify data from the GPS constellation, which flies in medium Earth orbit. Russia is planning a similar system for its Glonass global navigation constellation.

EGNOS is financed by the executive commission of the 27-nation European Union, which is also managing Europe’s future Galileo global navigation network. The commission has assigned ESA as contracting authority for both programs.