This may seem like a strange post to write after finally releasing version 1.5 of TeeShot, which contains our first version of GPS support for the iPhone, but I have been getting a lot of posts and emails about adding more locations to courses and I want to explain the current state of iPhone GPS limitations based on my experience which helps to explain how we will evolve out GPS support.
It is probably useful to state that the GPS in the iPhone was probably designed to be useful for getting directions to places within a city, and getting a reading quickly to accuracy of a few hundred meters is generally sufficient for figuring out how to get to the nearest restaurant. Golf, though, requires a much more detailed value and, while the iPhone can ultimately get you a reading that is pretty close, its GPS is not optimized for it. This goes for any application, not just TeeShot. In fact, you can generally see the exact same behavior in the Google Maps. Start it up somewhere and see how long it takes to get a very accurate (ie. small circle) response for where you are.
As part of the preview for version 1.5, I wrote a bit about the limitations of the iPhone’s GPS accuracy in a golf situation. You can read that here. After playing more rounds with it, I figured now would be a good time to write more about my experience using the GPS features of TeeShot regularly.
The earlier article was about accuracy. It said that the best result I had ever gotten was to an accuracy of 9 meters. 9 meters (~10 yards) is a big margin of error when choosing a golf club. It is almost always the difference between one club and the next. Today’s rounds on a course where I had used Google Maps to measure the center of the green showed that the number it gives you is pretty close to accurate, usually within 5 yards but it came at a price. In my experience with my test phones two things have really surfaced as limiting factors:
- It takes a LONG time for the GPS to get an accurate location. 15-30 seconds usually. This is tough when playing golf because you should be ready to hit your ball when you get to it and waiting 30 seconds for an accurate distance is pretty bad. It is also tough to tell when it has an accurate figure since it gives you a result quickly, but it is usually the last place you got a reading so you need to wait until it looks like you are about the right distance from your last shot, or to the green if you have those figures. That is a lot of waiting and focusing on the phone when you should be thinking about your shot.
- Getting GPS coordinates takes a LOT of battery power. My new iPhone 3G, which was fully charged before the round, was at 1/3 battery after nine holes. Doing regular scoring for the foursome for the rest of the round used very little battery power. It is the GPS that really drains the power.
So how does this impact the GPS features in TeeShot? I have received a lot of requests for a way to support more than just the middle of the green as a target. Users also want the front and the back of the green, front and back readings for hazards and bunkers and more. These are all terribly useful though they will also make it harder to define courses for TeeShot and they will also make using TeeShot more complicated. I am happy to continue to work on improved GPS functionality like this if this is what TeeShot users would like, but I think users’ satisfaction with these features will be limited until the iPhone itself can be tuned to get faster and more accurate readings without draining the battery.
As always, I am completely open to feedback on how you would like to see the application evolve.
See ya on the first tee!
-Chris