So… technically you can’t calibrate your iPhones GPS. What you can do is force it to rethink how it figures out where you are. I created this post because I recently ran into this exact issue. The issue being that my iPhone for no apparent reason was extremely inaccurate when showing my current location through google maps. When looking at Google maps my current location was off by roughly 4 miles. Yes MILES!!!
So on to the fix. I was able to get my gps position refreshed to within 500-1000 feet of what it should have been by doing all of the following in no specific order.
- Switch the network from 3G to Edge or vise versa (Settings -> General -> Network -> 3G ON/OFF)
- Open google maps and click the “location” option found within the lower left corner of the screen.
- Wait for your location to shift… then close Google Maps.
- Disable data services (Settings -> General -> Network -> Cellular Data ON/OFF)
- Perform Step 2 again… and wait, then close Google Maps.
- At this point you may have to perform step 1 and 2 again if your position has not corrected itself.