I just upgraded my 1st gen iPhone to a 3GS which of course has GPS. When I first got the phone I tried using GPS to locate me and it seemed to do fine... it was off by about 50 yards though.
I was looking at apps this morning and I saw a geocaching app that looked interesting but before I bought it I thought I would see how well I could do with what was already on the phone (GPS, Google Maps and the compass).
I picked a cache that is in a park not far from home so I would be familiar with my location. First thing I noticed is that when I located my location it showed me about 6 blocks away. The blue radius circle was huge. I pulled up a site that told me it would help if I turn 3G off, located and then turn it back on. Made no difference.
Since I knew roughly where the cache was by looking at google maps I headed off in the right direction. I kept the phone on the entire time. What I noticed is that it would occastionally track me and then immediately jump back to the original spot.
This is a wide open city park with no obstruction of the sky. My questions are this.. Is this normal? I have never seen any kind of GPS device be this off. If this is normal how will this ever work for turn by turn? I would assume by the pictures/video clips I have seen that the location pin would move pretty much in sync with where you are. but I cant see that. I also read that it is "assisted" GPS. Does that mean, assuming it actually works, that you have to be within 3g/edge range for it to work?
I am really not trying to complain it is just that I thought that it was actual gps and not a gimmick. Am I wrong in thinking that or is there something wrong with my phone?