Where Am I? Finding Your Way with Core Location and Map Kit
Every iOS device has the ability to determine where in the world it is using a framework called Core Location. iOS also includes a framework called Map Kit that lets you easily create a live interactive map showing any locations you like, including, of course, the user’s location. In this chapter, we’ll get you started using both of these frameworks. Core Location can actually leverage three technologies to do this: GPS, cell ID location, and Wi-Fi Positioning Service (WPS). . GPS is the mo st 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.