The European Space Agency just released this video to show how its Galileo satellite navigation system works. I love the part about how a nanosecond error in the onboard clocks would translate to a 30m error on the ground – but if that error were a second, the position error would amount to 300,000km, enough to leave driver wondering whether they were approaching the house or cruising on the Moon.
The first two spacecraft are due for launch on 20 October, and then ESA will be making a fast-track push to provide near-global coverage in 2014 and, in 2019, a full constellation of 27 spacecraft and three orbiting spares.
Unlike the USA’s GPS system, Galileo will be fully under civilian control. The idea is to ensure that Europe is self-sufficient in a technology that is becomming increasingly indispensible. Galileo will also do a better job than GPS at high latitudes, so Nordic Europeans should really notice the difference. Everybody else can be sure sure of continuous service – no worries about the US military degrading the signal in an emergency – and, combined with the ground-based signal enhancement system called EGNOS that went live earlier this year, can get position information accurate to less than 1m. EGNOS signals are free, too, and Brussels is encouraging companies to develop receivers and services to exploit them.
Budget wrangles will have delayed Galileo by seven years by the time coverage goes global in 2014, but it should be well worth the wait. Satnav services are already coming down in price, so the combination of an added layer of reliability and better geographic coverage should make them cheap and easy to use for any conceivable application.