Navigate by Wi-Fi and TV signals with GPS rival Navsop

GPS could drop off the map as British boffins work on a new location technology that navigates by signals from mobile phones and Wi-Fi. Defence firm BAE is testing Navsop, a navigation system that goes where others can't.

Navsop figures out where it is from a GPS signal, then learns about different signals including medium-wave radio frequencies, mobile phones, TVs and Wi-Fi to find its way about.

Unlike GPS, Navsop doesn't need satellites once it's got going, so it doesn't rely on a signal coming from the sky. That means it can be used indoors and even underground, both places that GPS can't go because the signals are too weak, having journeyed all the way from space. By contrast, radio, TV and mobile signals are much stronger.

Examples of possible uses include finding people trapped in burning or collapsed buildings, or nabbing stolen cars stashed away in underground car parks. And if the sat-nav signals fail because of solar flares or human interference -- even if they're turned off during a war -- Navsop should still work.

BAE reckons the technology will be the size of a coin -- but it isn't quite ready to fit in your phone just yet. The prototype is a box that has to be carried in a car, with a big radio antenna sticking out of the top.

Anything that improves your ability to find where you are earns a thumbs-up from me. Having a map on my phone is one of my favourite aspects of the smart phone revolution -- and there are few things worse than being stuck without a signal when you're stuck somewhere unfamiliar.

Until this new technology turns up, finding our way without a data connection requires a bit of forward planning. While you have a Wi-Fi or 3G connection, download a map of the place you're going and cache it on your phone, so you can consult the map without needing to connect to the web. The new Android Maps app offers offline caching, among others.