当您使用CoreLocation时，您会收到答案越来越好。我注意到***的答案几乎总是精确到100米以内，所以理论上你可能会减少你通常给的缓冲区。但真正知道的唯一方法就是测试测试测试。查找所有世代的iphones和ipod，并查看您获得的准确性类型以及您获得的结果类型。从很多方面来看，这取决于您制作的应用类型，但是如果您想根据用户的位置提供敏感或重要的信息，则应该等待框架为您提供几乎精确的位置。

I'd like to use reliable locations, even on an old iphone. However, many readings (particularly from cell towers) are too inaccurate. I think.

When I plot my position + accuracy radius (or look at google maps app), I notice the center of the estimated circle is generally close to my physical location. I'm guessing that if I cut the "accuracy" number in half, I'll still be in the circle 99% of the time.

I believe this is a probabilistic game - the location manager is trying to provide an estimate that's correct 99.99999% of the time, so they give a deliberately wide margin. Any thoughts/info?

When you're using CoreLocation, you're getting back "answers" that get better and better. I've noticed that the "best" answer is almost always accurate to within 100m, so theoretically you could probably cut down on the "buffer" that you're normally given. The only way to really know, though, and this is what I would do, is to test test test. Find iphones and ipods from all generations and see what types of accuracies you're getting and what types of results you're getting. In a lot of ways, it depends on the type of app you're making, but if you want to deliver sensitive or important information based on where the user is, you should really wait for the framework to give you a nearly exact location.