To paraphrase Galileo Galilei — the great Italian astronomer, philosopher, engineer, mathematician and physicist — positioning, navigation and timing (PNT) does not revolve around GPS. The European GNSS named after the father of modern science (as Albert Einstein called him) is making great strides and currently provides more accurate positioning than the United States’ GPS, Russia’s GLONASS, or China’s BeiDou-3. In fact, there are more Galileo satellites providing an L5 signal than GPS satellites.
I heard much well-earned pride about Galileo’s achievements expressed by European presenters at the Institute of Navigation’s GNSS+ conference in Denver in September; during a visit to the European Commission’s Joint Research Center in Ispra, Italy, on Oct. 7; and at the INTERGEO conference and trade show in Essen, Germany, on Oct. 18-20. (On the way, I stayed several days in Pisa, Italy — where I spent my teen years when my father taught physics at the city’s university — at a friend’s home about 100 feet away from the house where Galileo was born in 1564.)
While two more launches are required to complete the Galileo constellation so that it will have at least one spare satellite per plane, its service availability is already at 98-99% and a new ground segment has been deployed. A second generation of satellites is on its way, with expected initial operational capability in 2028 and full operational capability starting after 2031. Its features will include new signals, improved effective isotropic radiated power (EIRP), inter-satellite links, and a 15-year lifespan.
The Open Service Navigation Message Authentication (OSNMA), a free data authentication function for users of Galileo’s Open Service, has been stably transmitted worldwide for a year. It will enable users to verify the authenticity of GNSS data, thereby greatly helping to detect instances of spoofing. A declaration of initial service is foreseen for 2023, and the first OSNMA-capable receivers are already on the market.
Galileo’s High Accuracy Service (HAS) signal has been available worldwide with orbit and clock corrections and biases for Galileo and GPS since July 22. While it is still in its validation phase, it is already performing very well and an initial service declaration is expected by the end of the year, including an Internet-based correction distribution service.
Galileo is also developing an emergency warning service that will use the L1 band to broadcast alerts and guidance to populations at risk of natural disasters. It is expected to enter service in 2024 and reach any Galileo-enabled device, of which there are already about three billion. Other services will include advanced timing, space service volume (to aid in the positioning and navigation of spacecraft in high-Earth orbits), advanced receiver autonomous integrity monitoring (ARAIM), and predictions of ionospheric perturbations.
Like so much else, completion of the Galileo constellation was affected by Russia’s war in Ukraine, because two launches planned for this year from French Guyana aboard Russian Soyuz rockets were scrapped.
Finally, one of my favorite quotes from Galileo: “Measure what can be measured and make measurable what cannot yet be measured.”
