Chapter 18

Where Am I? Finding Your Way with Core Location

Every iOS device has the ability to determine where in the world it is using a framework called Core Location. Core Location can actually leverage three technologies to do this: GPS, cell tower triangulation, and Wi-Fi Positioning Service (WPS).

GPS is the most accurate of the three technologies, but it is not available on first-generation iPhones, iPod touches, or Wi-Fi-only iPads. In short, any device with at least a 3G data connection also contains a GPS unit. GPS reads microwave signals from multiple satellites to determine the current location.

NOTE: Technically, Apple uses a version of GPS called Assisted GPS, also known as A-GPS. A-GPS uses network resources to help improve ...

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