I think you may be a bit surprised at this but I don't think the IPad has a built in GPS, at least my wife's does not and I don't recall seeing it as an option. I don't think it is capable of giving a precise location. My Samsung pad does have a GPS however, along with maps but I have not used it for that purpose yet. Although it is a wifi only unit, it can be used much as a normal GPS unit is. Since it has built-in mapping and the GPS it does not require an online outside data source.
Most phones and pads seem to rely on maps being downloaded a bit at a time as required, probably because of memory requirements, by using cell phone data facilities. Location is established using known sources of Cell signals (AFIK). Many regard the purpose built GPS unit such as Garmin as a better choise especially since they can be purchased with free map updates (and traffic prediction in larger cities) or by using a PC with mapping software and a GPS receiver input, the USB GPS dongle mentioned above.
I prefer my Garmin for that purpose!!