A ground-based system that uses much stronger signals than GPS can pinpoint your location in cities and indoors

GOT a smartphone or satnav but still can't get a fix on where you are? A new positioning system could compete with GPS to make sure you never lose your bearings again.

Instead of satellites, Locata uses ground-based equipment to project a radio signal over a localised area that is a million times stronger on arrival than GPS. It can work indoors as well as out, and the makers claim the receivers can be shrunk to fit inside a regular cellphone. Even the US military, which invented GPS technology, signed a contract last month agreeing to a large-scale test of Locata at the White Sands Missile Range in New Mexico.

"This is one of the most important technology developments for the future of the positioning industry," says Nunzio Gambale, CEO and co-founder of the firm Locata, based in Griffith, Australia.

Indoor positioning is the next big thing in location-tracking technology, and companies from Google to Nokia have jumped at the chance to prevent users getting lost in cavernous shopping malls, or in the concrete canyons of big cities, where GPS struggles to keep up. But their technologies typically have a short range, and location resolutions in the order of a few metres.

By contrast, Christopher Morin of the US Air Force tested Locata's accuracy recently at White Sands, and it worked to within 18 centimetres along any axis. Morin says it should be possible to get the resolution down to 5 centimetres.

Admittedly, the tests were performed in an open desert where GPS also works beautifully. But GPS signals are weak - like a car headlight from 20,000 kilometres away - and easily blocked by solid objects. Locata's signal is far stronger, though not guaranteed to work in a complex urban environment, says David Last, consultant to the UK's General Lighthouse Authorities. "In urban areas, there are multiple blockages; propagation is principally via multi-path reflections." Such reflections can confuse receivers and reduce precision.

Gambale says the company is working on the urban angle in Australia with its Sydney Satellites project - a series of tests evaluating whether Locata can provide precise positioning for police, other emergency services and courier firms as they navigate the city's streets.

Ultimately, Locata may work alongside GPS, rather than replace it. The Jigsaw Positioning System, built by the firm Leica Geosystems, uses Locata and GPS signals. The briefcase-sized devices are already increasing coverage and guiding placement of drill rigs at the Boddington gold mine in Western Australia, operated by mining firm Newmont.

Gambale says that units small and cheap enough for smartphones should be available within five years - a similar path to the one GPS took on its way towards world domination.

Locata's technology will face competition in the race to transform indoor navigation. But it could shine in specific areas, Gambale says. Robots with Locata could easily navigate inside buildings without the complex optical systems they need at the moment. And apps that harness pinpoint location data could not only guide you around a mall, railway station or airport, but take you to the exact shelf in a shop for the product you want, he says.

Source: Thenewscientist.com