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You should take your phone in to the Apple Store. Not only is my GPS much more accurate, it's MUCH faster. It locates me in seconds (instead of a minute or so with the old 3G).

And all of this in NYC, where I can hardly see the sky and there is a ton of radio and magnetic interference.

I think there's something wrong with your phone.
 
Most consumer GPS devices have software that 'sticks' you to a road. My HTC Touch had Google Maps also, and it would show my position as around 100 ft off of the road when driving down a highway. I tried TomTom and I was always on a road, unless I was sitting in a parking lot or something.

Also are you waiting for it to find satellites? The iPhone will lock on quickly but it is only using triangulation, you need to wait longer for it to get enough signal from the satellites (Just like any other GPS). My parents have a Garmin standalone unit and it can take up to 5 minutes to actually get a satellite lock. The quick positioning is an advantage of A-GPS I guess.
 
True. Except the iPhone doesn't use satellites.

Ha ha, brilliant post. How does it work then? Does the iPhone communicate with birds flying above?

My GPS works brilliantly, even in the house the little blue dot is spot on.
 
i do not have a 3G S...however i've noticed that ever since i upgraded to 3.0 i have had the same problem...beforehand gps would locate me even indoors with pinpoint accuracy...now its generally a half mile off
not really sure what happened but it makes me weary of purchasing any turn-by-turn applications that come out
 
In defense of the OP, I had a similar confusion as well. Several years ago prior of the introduction of GPS Enhanced in cell phones it was reported that the system would triangulate the location of the user using cell towers and not satellites as the GPS chips and receivers would add to much additional bulk and power usage. This was not dissimilar to how some applications used Wi-Fi to accomplish the same feat.

This did not turn out to be the case. The iPhone and other phones with GPS use true GPS. I believe they also utilize cell towers to increase the accuracy and decrease the power required to lock in to a position.
 
If you are in a building (your home or wherever) and NOT using wi-fi, then the GPS will not be very accurate. However, if you are using wi-fi, then you should register your wireless routers MAC address with Skyhook ( http://www.skyhookwireless.com/howitworks/submit_ap.php ). They might already have it in their systems, but it couldn't hurt to verify it for them. Once their system is updated (they say it can take a few weeks), then your GPS will be much more accurate when inside you home. By the way, Skyhook is in partnership with Apple to provide just this sort of hybrid GPS support.
 
Ah, you guys are getting too mean to the OP :)

With all the verbal and written handwaving that Apple's done over the years to excuse their lack of this or that, it's no wonder people get confused.

Because of Apple, there are tons of people who mistakenly think that A-GPS is somehow defined by using cell tower triangulation or WiFi hotspots.
 
The GPS on both the 3G and 3GS for me have been extremely accurate. Sure there have been sometimes it might show me in the wrong location but I’ve noticed it will correct itself after you start driving – at least it did in my case.
 
You're phone's just messed up, OP. My GPS, on a bad day, when I'm inside, throws the dot a horrible, scary 15 feet away from my exact location. OH NO! I can't tell where I am, cause the GPS is saying I'm the length of a limo away from where I am!
 
priorities

The apple iphone CERTAINLY uses GPS satellites for a location fix,

THEN it will use the aGPS and cell tower/wifi triangulation data to either confirm or GET A fix if the GPS cannot get an accurate reading, or ANY reading for that matter.

So, indoors but with a cell/data signal, the phone will attempt to use the cell tower triangulation which can be VERY GROSS indeed.

Also, remember that GPS accuracy is a combination of somewhat gross LAT/LON data, like with 3 square meters or worse, and then a software refinement that hopefully gets the data more precise.

true PND devices for mapping, routing, driving use the logic that if it THINKS you are on road A (even though the data accuracy MIGHT have you off by 20 feet or so) AND you are travelling at 25 MPH, then it will SNAP you to the road it thinks you are on.

When roads are close to each other, like alleys and such, I have OFTEN been on the main road and not the ALLEY even with the best PND's out there.

IMHO, the GPS on the iphone when it CAN GET a signal from the SKY, it is pretty spot on
 
The apple iphone CERTAINLY uses GPS satellites for a location fix,

THEN it will use the aGPS and cell tower/wifi triangulation data to either confirm or GET A fix if the GPS cannot get an accurate reading, or ANY reading for that matter.

So, indoors but with a cell/data signal, the phone will attempt to use the cell tower triangulation which can be VERY GROSS indeed.

Actually, it first uses cell triangulation to grab a general area, then attempts to whittle it down if WiFi is available, THEN uses that general location to lock onto satellites for a more exact fix. Sometimes people never get past the first couple of stages, and they're left with a big 'location circle' on their map.
 
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