How does GPS work on a mobile device?
Okay, so this is really an iPhone question, but could someone tell me how GPS will work on the phone? Is it a function of software or hardware?
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Funny what info can be found on Apple’s site:
GPS (Global Positioning System) technology uses information from earth-orbiting satellites to find locations. A receiver estimates the distance to GPS satellites based on the time it takes for signals to reach it, then uses that information to identify its location. But the A-GPS (Assisted GPS) solution on iPhone 3G goes a step further, using a unique approach to find the closest satellites and more quickly identify your position. That gives you a faster fix on your location than with regular GPS.
In addition to A-GPS, iPhone 3G uses signals from GPS satellites, Wi-Fi hot spots, and cellular towers to get the most accurate location fast. If GPS is available, iPhone displays a blue GPS indicator. But if you’re inside — without a clear line of sight to a GPS satellite — iPhone finds you via Wi-Fi. If you’re not in range of a Wi-Fi hot spot, iPhone finds you using cellular towers.
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In all cases, there is indeed special hardware involved in order to talk to the various pieces. That is, something for the satellites, something else for cell towers, and another something else for wi-fi. Throw in Apple’s (and some third-party) software to make it all seamless and intelligent, and it’s greatness in a neat, little package.
@robmandu, you rock my world. Thanks for doing my leg work.
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