Satellite and Internet combine to create receiver providing precise geographical location
Paving the way for Galileo, the European space agency (ESA) has developed a receiver enabling drivers to know their exact position through a combination of satellite navigation and the Internet. In tests, the SisNet receiver has given position information with an accuracy of less than two metres. The technology uses data from the European geostationary navigation overlay service (EGNOS) together with the Internet. EGNOS is an augmentation signal: it corrects and improves the signals sent by the American GPS constellation using geostationary satellites and improves the accuracy to within one or two metres, as opposed to the 15 to 20 metres available with GPS signals. 'This is the first time we demonstrate both the accuracy of EGNOS and the possibility to obtain, in real time, EGNOS navigation data by using the Internet,' said Dr Javier Ventura-Traveset, principal system engineer for EGNOS and responsible for the development of SisNet at ESA. As the receiver is a hand held device, it can be used in many environments, not only in cars. Access to the satellite data via the Internet also allows the user to continue navigating when out of the range of a geostationary satellite. This could be useful when travelling in towns where buildings interfere with signal reception. 'The use of SisNet is only limited by our imagination,' says Dr Ventura-Traveset. The receiver is currently made out of existing technology which was designed for other purposes. Commercially viable receivers are however now being developed in cooperation with several European industries.