How accurate is the reading for GPS in iPhone's SDK?

Question

Using iPhone's SDK GPS API, how accurate can I get? Is it within a few meters or kilometers? I'm interested in the accuracy when it is indoor. My software will only be used in door.

Answer 1

The best possible accuracy seems to be 9 meters. Common values (outdoor, good coverage) is 17 m, 23 m and 49 meters. With trees covering the sky you'll probably stay under a hundred meters, but hardly accurate enough for GIS or anything like that.