People with Visual Disabilities Benefit from Satellite Guidance

The prototype of an assistive technology solution that involves a satellite navigation system capable of guiding pedestrians with visual disability to their destination was demonstrated in Madrid.

Thanks to the directions dictated through a headset, a visually impaired person walking down a street with his can now be very sure about his way. Using a mobile phone fitted with a position receiver and voice, the user is safely guided to his destination by a satellite.  

The device, developed by ESA with the Spanish firm GMV Sistemas, gives a sense of self-sufficiency and accessibility to people with visual disabilities. It does not replace the white cane or guide dog but complements them with an ‘audible map.’ The person no longer needs to seek frequent guidance from other pedestrians as each move is based on guidance and advice from the equipment.

The system was developed based on advice from the Spanish National Organization for the Blind and uses EGNOS - a positioning system to process GPS data to ensure better accuracy. This development means a lot to a visually impaired person because it could mean the difference between being on the sidewalk or on the road.

EGNOS, which is a preparatory program for Galileo, comes with a guarantee of quality of service. Another system called SISNeT (Signal in Space via Internet) is currently being developed that overcomes the problem of interference in reception caused by buildings, by providing data via Internet.

A central computer processes the positional data and sends back information to the user. A person receives directions to reach his destination after programming his or her destination into the device.

Presently, the project is in demonstration phase and there is just a prototype of the receiver. Efforts are on to develop a single device that integrates all three technologies: an EGNOS/SISNeT receiver, a pocket computer and a mobile phone.

EGNOS has a network of around 40 ground stations scattered throughout Europe that are designed to record, adjust and improve data from the American GPS system. Geostationary satellites relay modified signals to the receivers of the system users. Compared to the 15-20 meter accuracy that GPS offers, the European system is accurate to less than two meters and also comes with a guarantee on signal quality.