David Hambling in New Scientist has a good read on how a $30 GPS jammer can screw just about everything up. Everything including the serious, like airports, to the odd, like ATM machine. GPS is so intertwined in our lives today, that one of these easy to get, very low power devices can do some major hosing. The cure? Bring back LORAN! “The cost of setting [LORAN] up again would be a fraction of the cost of one GPS satellite, and there’s a total of 31 of them in orbit at the moment. So just for a, a very small extra expenditure it could make sure that that kind of catastrophe could be avoided.” [David Hambling]
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1 comment:
Problem with GPS is that we are using well outside of its original intent, which is global 3 dimension location (lat, long, altitude). Its an extremely weak signal (about -160 dBm at the surface of the earth).
There was a project a while back (sorry, can’t find a link) called the Rosen Positioning System (RPS). Rosen worked on the original GPS. This system embedded time codes in television transmissions which are much more powerful and lower frequency than GPS, so it provided pervasive (read: in building) location, though I don’t think it could do altitude.
Think of all the things indoors that need GPS: cell phones (they do OK outdoors with A-GPS), femto cells (AT&T requires they be placed near a window to receive GPS location for emergency calling), VoIP ATAs (like vonage). Having indoor location would solve the E911 problem with these services.
As a side note, GPS was spurred by Sputnik and some board engineers (at Bell Labs, I think). Listening to the ‘bings’ coming off the satellite, these guys asked their boss if they could ‘borrow’ time on the mainframe to crunch the numbers. A few months later, they could very accurately locate the satellite. The boss asked if it could be done in reverse….use satellites to locate things on earth. The engineers looked at each other and said “well, duh, that would be easier.” And so, satnav was born.
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