Does GPS need Replacing
Professor Gordon Povey and Wired magazine pin-up Professor Harald Haas believe that visible light communication – or li-fi – can challenge the dominance of GPS, or the Global Positioning System. They believe they can use the light emitted from LED lightbulbs placed in buildings to transmit data, not only to download the latest film to a laptop, but also to tell us where we are with pinpoint accuracy. Just so long as we are in the line of sight of the light source.
Whatever the technology, these real-time locating systems (RTLS) are all about “triangulation”, explains Professor Ajay Malik, former head of engineering for Motorola and author of RTLS for Dummies. In the case of GPS, this means your position is worked out to within a few metres’ accuracy (depending on your handset), relative to four or more of the GPS navigation satellites visible to your device at a given time, out of about 30 satellites in total. Assisted GPS or A-GPS on mobile phones uses the computer power of the phone networks to help make these same calculations – if more slowly – when the radio signal from the satellites is poor.
Global positioning: A timeline
1940s Development of long range navigational systems like LORAN based on earlier British technology
1973 Global Positioning System first imagined
1978 First GPS satellite is launched
1983 Ronald Reagan decides to make GPS free-of-charge
1994 Initial network of 24 GPS satellites completed
1996 Clinton signs order formally recognising the dual use of GPS by civilians and the military
2000 Civilians get access to the higher-quality military signal
2001 First mobile phone with embedded GPS
2002 First TomTom product is released
2010 LORAN is turned off
2012 GPS on mobile phones to become standard
2014 First GPS III satellite is scheduled to launch
Both China and Russia (with Glonass) have their own navigation systems. Expected to go global by 2020.
An update to the US GPS system will be a major advance on the previous GPS… if budgets allow
Boeing timing and location
Boeing’s own systemsends a powerful signal from a low altitude
The European Union and Space Agency’s precise system features a “search and rescue” beacon
A Wi-Fi triangulation system could work out where you’re located between different Wi-Fi routers
Scientists believe that they can use the light emitted from LEDs to define locations
Full article at: http://www.independent.co.uk/life-style/gadgets-and-tech/features/does-gps-need-replacing-6298076.html