03 October 2009

European Geostationary Navigation
Overlay Service Boosts GPS Accuracy To 2m!

The European Union launched a free global positioning system that it claims is almost five times more accurate than the U.S. system currently in use use and could help pilots, drivers and blind people by fine-tuning the accuracy of the global positioning network to around 2 meters.

Called the European Geostationary Navigation Overlay Service (EGNOS), system uses three satellites and 34 ground stations to narrow the horizontal accuracy of GPS from around 7 meters previously and improve its vertical accuracy to help pilots during landings.

The U.S. military-run GPS system, in widespread use across the globe, offers a 10-meter (32 feet) accuracy level, but EGNOS promises to fine-tune this experience and deliver accuracy levels to around 2 meters (6 feet).

EGNOS only covers the 27 member-states of the EU at the moment, but it is expected to expand to neighbouring nations and Northern Africa in the near future. The service is free for use by anyone within the coverage area with a GPS/SBAS compatible receiver.

The EU sees various uses for its more-accurate GPS system, which was in testing mode since 2006. Farmers would benefit from precision spraying fertilizers, and blind people could have personal guides. It could automatically charge road tolls or pay-per-use car insurance.

It is also expected that the next generation of GPS-enabled smarptohones such as Nokia’s Symbian and Maemo based devices, Windows mobile or Google Android devices, will benefit from the improved accuracy of EGNOS. Some standalone GPS devices might soon use EGNOS as well, given that the manufacturers release firmware updates to support the system.

EGNOS is mainly the precursor of EU's Galileo project, Europe's own GPS system, which has been plagued with delays in the last years and is expected to begin operating in 2014.

Meanwhile, American users have had their EGNOS equivalent for some tine now, called Wide Area Augmentation Service (WAAS) and the Japanese are working on a similar system called Multi-Functional Satellite Augmentation System (MFAS).

A Crucial Enhancement

The space component of the EGNOS system consists of two-way communications channels called "transponders" installed aboard three satellites occupying geostationary orbits over the equator. These extraterrestrial relay stations are designed to communicate with a ground-based network of four control centers and 40 ground stations.

"In simple terms, the ground stations measure the GPS signal and send the data to the computing centers where the correcting GPS signals are calculated," Tajani said. "And then the computing centers send out the corrective signals to the EGNOS satellites," which then relay the more accurate signals to users' GPS receivers.

Improving the accuracy of GPS signals to two meters is crucial for many applications related to safety, said Hans Fromm, retired deputy head of the navigation department at the European Space Research and Technology Centre. For example, the EGNOS system provides a navigation signal for aircraft, ships, trains and other forms of transport.

"A train needs to know which rail it's traveling on," Fromm said. "It's important for safety -- especially where life could be at risk."