DAVID LEARMOUNT / LANGEN

EGNOS offers immediate advancements and could even one day replace guide dogs

Europe's satellite navigation augmentation system sent out its first signals from three orbiting satellites on 6 June, correcting the average expected navigational accuracy derived from the global positioning system from 20m (65ft) to 5m. The European Geostationary Navigation Overlay System (EGNOS) offers immediate improvements and legally guaranteed navigational accuracy, availability and integrity for all forms of transport in due course, says director of applications Claudio Mastracci.

EGNOS has had a ground-based testbed broadcasting since 2001, but the new satellite signals cover a much wider area - from Iceland and northern Norway across Europe to North Africa. Until early 2004, the service will be officially categorised as a test, although it is at operational standard and 80% of the time can provide Category 1 airfield approach accuracy, according to EGNOS project manager Laurent Gaultier. After the test period, EGNOS will undergo another two years' operational readiness review to be completed in 2006, by which time the first satellite in Europe's Galileo global navigation satellite system (GNSS) will be on station.

EGNOS and Galileo are not military-controlled, unlike America's GPS and Russia's Glonass. The intention is to achieve a previously unobtainable level of integrity and availability, enabling location by EGNOS/Galileo to be usable as a legal definition of location. Gaultier says the signals are compatible with GPS and its wide area augmentation system (WAAS), and with Glonass.

Terrestrial and marine transport are intended to be equal beneficiaries of the European GNSS. Trans-border rail services in Europe, through a system dubbed Integrail, are able to overcome national signalling incompatibilities by using EGNOS-derived train positions accurate enough to make terrestrial signalling redundant. Trials are also under way in Valladolid, Spain, to see if satellite navigation devices can eventually replace guide dogs for the blind, according to EGNOS.

Source: Flight International