Where Am I? Finding Your Way with Core Location
Your iPhone has the ability to determine where in the world it is using a framework called Core Location. There are actually three technologies that Core Location can leverage to do this: GPS, cell tower triangulation, and Wi-Fi Positioning Service (WPS). GPS is the most accurate of the three but is not available on first-generation iPhones. GPS reads microwave signals from multiple satellites to determine the current location. Cell tower triangulation determines the current location by doing a calculation based on the locations of the cell towers in the phone’s range. Cell tower triangulation can be fairly accurate in cities and other areas with a high cell tower density but becomes less accurate in areas where there is a greater distance between towers. The last option, WPS, uses the IP address from iPhone’s Wi-Fi connection to make a guess at your location by referencing a large database of known service providers and the areas they service. WPS is imprecise and can be off by many miles.
KeywordsLocation Manager Blue Circle Core Location Previous Location Vertical Accuracy
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