With 26 satellites in orbit and more than two billion receivers in use, Europe’s Galileo satellite navigation system has made a massive impact. But our continent has another satnav system that has been providing safety-of-life services for ten years now – chances are that you’ve benefited from it without noticing.

Its name is EGNOS, the European Geostationary Navigation Overlay Service. Transmitting signals from a duo of satellite transponders in geostationary orbit, EGNOS gives additional precision to US GPS signals – delivering an average precision of 1.5 metres over European territory, a tenfold improvement over un-augmented signals in the worst-case – and also confirmation of their ‘integrity’ – or reliability – through additional messaging identifying any residual errors.

While its Open Service has been in general operation since 2009, EGNOS began its EU-guaranteed safety-of-life service in March 2011.