iPhone - Native App GeoLocation VS Web App GeoLocation

Question

Here's my situation; I've built a very simple web app that looks up a users location and plots it on a Google map. Here's my code: http://pastebin.com/d3a185efd

When I test it, my location is detected as being >= 500 meters from where I actually stand.

BUT

When I open up Google Maps or Gowalla my location is correct to within <20 meters?

So my question is: Do native iPhone apps benefit from a higher accuracy rate than web apps?

If so, why?

Answer 1

According to the specification, webapp geolocation should use whatever positioning method works best in any situation - so in theory, one would assume it uses GPS when available. The discussion linked in the "best answer" by rohit doesn't seem conclusive to me - here is another one, with someone reporting a similar problem to yours and other users professing to getting accurate gps data (scroll down to comments 26-28 Sept):

http://www.thecssninja.com/javascript/geolocation-iphone

But it does seem like the geolocation stuff is buggy still. I'd suspect your problem is basically that, some bug.

Answer 2

Based on the following link, I believe you are getting coordinates in web app through tower triangulation and not using GPS. I really doubt if GeoIP can give coordinates within 500 meters.

http://phonegap.lighthouseapp.com/projects/20116/tickets/16-navigatorgeolocation-does-not-make-use-of-gps-data

Answer 3

The geolocation API allows for a high accuracy parameter.
http://dev.w3.org/geo/api/spec-source.html#position_options_interface
(But uses extra battery, so probably best use sparsely)
Have you tested that?

Boolean: enableHighAccuracy