Learning iBeacon

Understanding distance

When we range beacons using the locationManager:didRangeBeacons:inRegion method of CLLocationManager, we're given a collection of beacons (CLBeacon). In order to understand the distance of the beacon from our device, the CLBeacon class gives us two properties:

• proximity: The proximity property gives you the distance from the device using the CLProximity enum, giving one of four values CLProximityUnknown, CLProximityFar, CLProximityNear, and CLProximityImmediate.
• accuracy: The accuracy property gives you the distance from the device as a double value, which is the distance measured in meters. If the distance cannot be determined, the value is returned as negative.

The CLProximity enum values represent the approximate distance ...