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I am confused by the type of connection GPS requires. Some people say it requires a direct visible connection to the satellite, while others only refer to a direct connection without the specific need for a visible connection.

Basically the question is whether GPS also works in a pocket or with a case/bumper.

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GPS works fine in a case or pocket.

You do need a generally unobstructed view (from a radio perspective, not necessarily a visible perspective) of the sky (no trees/buildings/etc. in the way, but thin barriers, like say a tent, won't present a problem.) in order to pick up the GPS signals from the satellites.

Ideally, you should have as clear and as wide a view of the sky as possible. Ideal conditions would be standing in a flat empty field with visibility to the horizon in all directions.

Narrow that view of the sky by adding buildings and trees and your ability to obtain an accurate lock starts to degrade and you get more and more error in your position, until such point where you can't get an accurate lock (or in extreme cases, like being in a deep basement or similar, any lock at all) at all.

  • Thank you. So it is really a radio signal and nothing visible-like like infrared for example (it confused me as people often say for TV satellites you should have good weather, which would make me believe it requires an actual visible connection). – user32840 Apr 24 '13 at 21:57
  • @user32840 The "good weather" bit about satellite TV is due to the radio frequencies satellite TV works on (specifically, the Ka and Ku bands), which are quite suitable to rain fade, where the water absorbs the energy of the transmission, like what happens in a microwave oven. The L band used by GPS is not very susceptible to that effect. – Compro01 Apr 24 '13 at 22:07
  • AGPS tends to work better in indoor areas since it uses phone signals and wireless signals in addition to GPS signals to get a better idea of where the phone is. This also helps where there's no direct connection. I do also believe that there's some degree of inertial navigation used by some map applications, since I have seen google navigation work inside a tunnel where I know GPS dosen't work. Pockets should be trivial to get a signal through, as should bumpers, unless they are specifically made to shield signals (which is implausible) – Journeyman Geek Apr 25 '13 at 0:15

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