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 – says 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 says, sitting in the back of the car as it drives along Chelmsford’s streets.BAES_GPS

“But if the GPS signal disappears, we’ll still be able to navigate,” he adds, pointing to the computer screen depicting a map with a dotted line showing the vehicle’s location.

The device works by picking up all the available signals nearby, heavily relying on medium wave radio frequencies.

This is the same part of the spectrum used by radio pioneer Guglielmo Marconi more than a 100 years ago, who opened the world’s first telegraph in the same city.

Source: BBC