UK: BAE Systems, a UK defence firm, developed a new positioning system, Navigation via Signals of Opportunity (NAVSOP), which could complement or even replace current technologies such as GPS. NAVSOP relies on the same signals used by mobile phones, TVs, radios and wi-fi rather than navigation satellites. The firm said that NAVSOP could help find victims inside buildings during a fire and locate stolen vehicles hidden in underground car parks. It could also be used in a war if the satnav system was turned off.
For now, the prototype is a big box-like piece of hardware placed in the back of one of BAE’s cars, which sports a radio antenna on the roof.
But once out on the market, it will be as tiny as a GPS dongle is today – a bit bigger than a coin – said Ramsey Faragher, principal scientist at the BAE Advanced Technology Centre in Chelmsford, near London.
“Let’s be clear – for NAVSOP to start working, you have to have a GPS signal, to know where you are on the face of the Earth,” he said, sitting in the back of the car as it drives along Chelmsford’s streets.
“But if the GPS signal disappears, we’ll still be able to navigate,” he added, pointing to the computer screen depicting a map with a dotted line showing the vehicle’s location.
The device for use in buildings is as small as a smartphone and it works with a tiny radio receiver
The device works by picking up all the available signals nearby, heavily relying on medium wave radio frequencies.
GPS uses signals coming from satellites spinning around the Earth, some 20,000km (12,427 miles) away. By the time these signals reach the surface of our planet, they are extremely weak and unable to be picked up by receivers, for instance, inside buildings.
“Our society has now become hugely dependent on GPS. And that’s why it’s important to have back-up systems in case GPS signal is not available,” noted Faragher.
“We are not saying that our technology should necessarily replace GPS, but rather complement it. If the GPS signal is there, by all means, use it. If not, we say that with Navsop, you can determine your position anyway,” said Faragher.
It would also be useful to the military in case one side deliberately switches off GPS to prevent its adversary from locating its units.