iPhone GPS is 1500 miles off (in Texas)

[saturniphone]

I just got my iPhone 3G a few days ago and periodically when I use the GPS feature on the maps it puts me in Texas (I get the circle, not the true GPS dot in case you were wondering). Only problem is I live in Delaware, about 1500 miles away.

I found two instances of other people making a mention of this online and actually met someone today that was experiencing the problem. Usually it works fine, but maybe 30% of the time I'm in Texas. I've had this problem with 2.0.0 and 2.0.1.

Anyone else in this boat?

 

[DreamPod]

That has nothing to do with GPS. It generally means you are only getting a wireless signal and your internet provider is reporting that as its location.

 

[Van Wildonher]

GPS would have to be broken for it to be that far off... sometimes it takes a while to get signal... 10+ minutes, also doesn't work in airplane mode.

 

[shinenjk]

I just got my iPhone 3G a few days ago and periodically when I use the GPS feature on the maps it puts me in Texas (I get the circle, not the true GPS dot in case you were wondering). Only problem is I live in Delaware, about 1500 miles away.

I found two instances of other people making a mention of this online and actually met someone today that was experiencing the problem. Usually it works fine, but maybe 30% of the time I'm in Texas. I've had this problem with 2.0.0 and 2.0.1.

Anyone else in this boat?

One time my friend's iPhone located him to be in Atlanta when we live in Boston. It sometimes happens for whatever reason. No biggie.

 

[admanimal]

The GPS itself will never put you that far off. When this happens you are almost always getting WiFi-based localization. The reason this can put you so far off is that it is based on the names of the Wifi networks in your area. As we all know there are some common names for Wifi networks that you see all over the place, which is why it can get so confused sometimes.

For example, suppose you have a very unique name for your personal Wifi router and you normally get good Wifi-based localization when you are at home. If you were to move across the country to an area that had a bunch of other Wifi networks with generic names like linksys or dlink, the Wifi localization would place you back at the location of your previous home.

 

[saturniphone]

It may be the cell triangulation (obviously -- the thread title was for shock and awe), but I've been outside on a sunny day when this has happened. No reason the actual GPS shouldn't come into play and correct things.

I don't think it has much to do with WiFi either as in both cases I wasn't connected to a hotspot. If it solely uses the names and ignores the cell triangulation information then someone at Apple should be shot.

I never had this happen once with the original iPhone and it's happening relatively frequently with the iPhone 3G. In fact, speaking of 3G, I can always fix the problem by going in and turning off 3G. So, it seems to me the problem has to do with the 3G component somehow.

I'm somewhat amazed people think it's "no biggie". I guess if it doesn't happen to you maybe it isn't.

 

[joeconvert]

The GPS itself will never put you that far off. When this happens you are almost always getting WiFi-based localization. The reason this can put you so far off is that it is based on the names of the Wifi networks in your area. As we all know there are some common names for Wifi networks that you see all over the place, which is why it can get so confused sometimes.

For example, suppose you have a very unique name for your personal Wifi router and you normally get good Wifi-based localization when you are at home. If you were to move across the country to an area that had a bunch of other Wifi networks with generic names like linksys or dlink, the Wifi localization would place you back at the location of your previous home.

I seriously doubt it is using the SSIDs. More than likely it is using the MAC address of the wireless router or access point, which is unique (for the most part - many rogue producers out there) I would bet that a router has recently moved from Texas and this is why you are seeing that.

Although, I would think Apple would use the A-GPS before the skyhook database, that is somewhat disappointing.

 

[ski2moro]

I was in an Apple Store in Ohio and the phone kept locating me in Garden City, New Jersey. Another iPhone user standing next to me with the same network settings was getting our correct location in Ohio. (We were both on the Apple store WiFi and 3G was on, too.)

I re-started the phone and it worked properly again, finding me in Cincinnati.

I was in too much of a hurry to deal with the genius bar, but if the problem continues, I will make time to see them.

 

[shinenjk]

I'm somewhat amazed people think it's "no biggie". I guess if it doesn't happen to you maybe it isn't.

It happened ONCE to my friend, it got fixed in a couple hours. It most likely has to do with the buggy GPS software. But why should you even be worried if it works 95%+ of the time? You should only be worried if it happens frequently. Stop being so picky.

 

[Geckotek]

It happened ONCE to my friend, it got fixed in a couple hours. It most likely has to do with the buggy GPS software. But why should you even be worried if it works 95%+ of the time? You should only be worried if it happens frequently. Stop being so picky.

Because he said it works 70% of the time. Stop being so.....

 

[Geckotek]

The GPS itself will never put you that far off. When this happens you are almost always getting WiFi-based localization. The reason this can put you so far off is that it is based on the names of the Wifi networks in your area. As we all know there are some common names for Wifi networks that you see all over the place, which is why it can get so confused sometimes.

For example, suppose you have a very unique name for your personal Wifi router and you normally get good Wifi-based localization when you are at home. If you were to move across the country to an area that had a bunch of other Wifi networks with generic names like linksys or dlink, the Wifi localization would place you back at the location of your previous home.

It doesn't use the SSID, it uses the MAC address.

 

[illutionz]

The way that the aGPS works is that first, it retrieves data using Wifi and cellular network about your whereabout, then it finds the nearest GPS satellite and lastly, it locked you in.

When you see that you're in texas, probably because your wifi was used in texas and registered by skyhook while it was there. I just moved apartment couple days ago and everytime I use my maps location, it always firstly go to my old address and after hovering on top of it, they took another huge swing to my current address when the real GPS location took charge.

Now, the OP said he didn't get the DOT which means he didn't get the GPS positioning, he only got the skyhook wireless and cellular triangulation. Most likely, his router was registered back in texas

 

[kdarling]

While the cell id or hotspot methods can get confused by changes in id or location, GPS should ALWAYS get the correct location if it can find enough satellites in a good configuration.

One problem is that the methods don't seem to be integrated, perhaps because of patent issues. In other words, they don't cross check each other. Instead, they're totally separate. If there's a good GPS signal, use it... else try WiFi and then finally Cell Id.

 

[kdarling]

The way that the aGPS works is that first, it retrieves data using Wifi and cellular network about your whereabout, then it finds the nearest GPS satellite and lastly, it locked you in.

What you're talking about is called a hybrid locating system, where multiple methods are used.

A-GPS is only about assisting GPS, by having a server aid the phone with updated satellite information and/or by helping with calculations.

Even if you seeded it with a bad starting location, GPS should figure that out and give back a good position. Unless the software is buggy, that is.

 

[saturniphone]

I had it happen again today and I did what someone else recommended and turned off 3G. I tried it again and it worked fine. I then turned 3G back on and things were still good. Rebooted and still fine. I'm thinking that maybe even though I rebooted maybe since I had recently acquired the location that helped the subsequent times I tried it.

I hear what some people are saying about the WiFi issues, but I'm not sure I buy that. This has happened maybe a dozen times and only in one instance was I connected to WiFi. I'm not completely dismissing this idea, but I'm just not sure how that could play into it. Maybe next time it happens I can leave 3G on and turn off WiFi and see what happens.

Also, I should mention that every time this happens even if I wait up to a minute I never get the GPS dot. I get the dot other times, but never when I get this Texas issue. I assumed that if I could get a signal it would override the circle in Texas, but I haven't seen that happen yet.

I guess the thing that's so strange is how sporadic this problem is as I can stand in the same spot on different days and get different behavior. If it were a router or a tower or something I would expect to have the same problem all the time.

In any event I appreciate the discussion. I think we're starting to see this isn't a completely isolated problem. I'll keep posting my experiences in case it helps someone else.

 

[saturniphone]

Ok, here goes my update run-on sentence:

Happened again, found more people online with the same issue, turned off WiFi and still had problem, used GPS on 100 mile trip and it worked properly for about 10 minutes total.