A prototype satellite navigation system known as MOMO, accurate enough to direct vision-impaired pedestrians to their destination, has been successfully demonstrated in Madrid. It is based on the European Geostationary Navigation Overlay Service (EGNOS), a joint project of ESA, the European Commission and Eurocontrol.
EGNOS consists of a network of around 40 ground stations scattered throughout Europe designed to record, adjust and improve data from the American GPS system. Geostationary satellites relay the modified signals to the receivers of system users. In contrast to the 15–20 metre accuracy offered by GPS, the European system is accurate to better than two metres.
Seen from a distance, a blind man guided by his dog in the streets of Madrid seems quite sure of his way. He is receiving directions to his destination through his headphones: “turn to the right, turn to the left, continue straight ahead…” Thanks to a mobile phone combined with a position receiver and a voice synthesizer, he can travel confidently through the city while being guided by satellite.
Developed by ESA, with the Spanish firm GMV Sistemas, this device offers greater autonomy for the visually impaired. The system is not intended to replace a white cane or a guide dog but to complement them with an ‘audible map’.
This system, designed with the advice of the Spanish National Organisation for the Blind (Organisacion Nacional de los Ciegos de España – ONCE), relies on the increased accuracy of EGNOS. This is rather important for a blind person, since a localisation accuracy of one metre makes the difference between being on the pathway or in the road.
The MOMO system also makes use of another ESA-developed system: SISNeT (Signal In Space via Internet). In an urban environment, buildings often prevent or interfere with reception of satellite signals. SISNeT overcomes this problem by providing EGNOS data via the Internet, enabling users like the person in the film to access it via a mobile data service.
EGNOS is Europe’s first venture in the field of satellite navigation and is the precursor to Galileo, a civilian Global Navigation Satellite System (GNSS).