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iphoneiosgpsproximity

iOS proximity & GPS measure the distance

I am developing an app where I require to alert user if he move more than 20 meters from his checking location. I am planning to use proximity sensor for this development. However I found this document.

http://developer.apple.com/library/ios/#documentation/userexperience/conceptual/LocationAwarenessPG/CoreLocation/CoreLocation.html

It says

"The specific threshold distances are determined by the hardware and the location technologies that are currently available. For example, if Wi-Fi is disabled, region monitoring is significantly less accurate. However, for testing purposes, you can assume that the minimum distance is approximately 200 meters."

If I use GPS distance it will take considerable power utilization. Am I developing on wrong path? Appriciate your kind sugesstions.

Solution

  • For your task the only way is using GPS in best quality mode (CLLocationAcuracyBest).
    Check loaction.getAcuracy() to see if the location came from GPS or cell Tower/wifi.