Europe's Answer to GPS Could Be a Boon for Research
On 26 December, a European satellite is set to
lift off from Baikonur cosmodrome in Kazakhstan and, once in orbit 23,000
kilometers above Earth's surface, start transmitting time signals...The craft is
the first test bed for Europe's answer to the U.S. Global Positioning System
(GPS) satellites.
On 26 December, a European satellite is set to lift off from Baikonur cosmodrome in Kazakhstan and, once in orbit 23,000 kilometers above Earth's surface, start transmitting time signals. Although small--roughly the size of a freezer--the satellite GIOVE-A is the start of something big.
The craft is the first test bed for Europe's answer to the U.S. Global Positioning System (GPS) satellites. Dubbed Galileo, the European system, like GPS, will consist of a constellation of satellites carrying atomic clocks. A receiver can use their signals to calculate its position to an accuracy of a few meters. Combining Galileo with GPS will double the number of transmitters, and with Galileo's updated technology, researchers expect it to bring a sharp improvement in quality and reliability, which in turn will enable new studies of the atmosphere and oceans. The system might even provide a way of watching for tsunamis.
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GPS receivers have become so cheap that they're widely used by hikers and drivers. But GPS remains a military system, and the Pentagon can degrade or even turn off the signal in times of crisis. Galileo, in contrast, has been designed with business in mind. "Guarantee of service is the basic difference," says Dominique Detain of the European Space Agency, which is developing Galileo jointly with the European Union.
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Researchers are also excited about a technique that detects satellite navigation signals bounced off the ocean surface. A team from the University of Surrey in Guildford, U.K., demonstrated the technique earlier this year, deriving sea surface roughness from reflected GPS signals. But the Galileo signal has extra features that may also allow researchers to measure wave height and the height of the ocean surface.
Galileo has sort of become "the rest of the world" vs. the Pentagon. At least in the minds of folk who think the Master of the Universe should live on Pennsylvania Avenue. Fortunately, the rest of the world considers the project to be mutually beneficial.
Posted: Sun - December 25, 2005 at 06:42 AM