Are you having issues, or just looking to measure it? GPS status will give you a ton of information about how many satelites are locked etc. etc. and you can clear your cache to make sure nothing in there is slowing you down. If you are outdoors and turn on gps and open google maps you should see a lock in a few seconds. First location you get will be based on the towers (phone), then it should lock in to exactly where you are vis gps.