3 ms·

How is that possible? GPS satellites are sending the same signal out to everyone, I don't see how they could possibly target a certain area.

• a_c_s 12y ago
  I don't know how they do it, but if you drive by the Pentagon with a GPS unit you'll see it go crazy.
• kweinber 12y ago
  Gps satellites all send slightly incorrect information... A separate radio signal correction is transmitted to correct it. That way, during wartime (or in high value target areas) the US can basically mess up enemy gps enabled weapons by broadcasting misleading satellite and correction data.
  • foldr 12y ago
    That doesn't answer the question of how they could make GPs inaccurate only in a specific area.
    • sbalea 12y ago
      Low power GPS jammer at the Whitehouse, perhaps?
• markild 12y ago
  The Economist[1] had a story about the London Stock Exchange getting jammed GPS-signal 10 minutes every day. I believe they are using something similar. [1]: http://www.economist.com/news/international/21582288-satellite-positioning-data-are-vitalbut-signal-surprisingly-easy-disrupt-out http://www.economist.com/news/international/21582288-satelli...
• syncsynchalt 12y ago
  A terrestrial transmitter spoofs or overpowers the GPS signal. GPS satellites have a signal strength on par with a night light's, so it's easy to overpower in a small area using a low power transmission.