How does google maps tracking work?

WelshBloke

Lifer
Jan 12, 2005
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I've got a device (ipaq 210) that has no phone radio and no GPS but if I install Google maps on it it can still locate me.

How the hell does that work?

The only active connection is wifi. The device has been recently flashed so there's no old data on it either.

The only think I can think of is its somehow finding me from my IP address, but I cant see that being very accurate.
 

TheStu

Moderator<br>Mobile Devices & Gadgets
Moderator
Sep 15, 2004
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It uses information from the cell towers to derive an approximate location for you.

From the OP: 'that has no phone radio'

WiFi triangulation is possible, if the coordinates of several hotspots are known, and it can calculate signal strength of those hotspots it can then extrapolate a position. It is even less precise than cell triangulation, and nothing compared to A-GPS or GPS.
 
Feb 19, 2001
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I've got a device (ipaq 210) that has no phone radio and no GPS but if I install Google maps on it it can still locate me.

How the hell does that work?

The only active connection is wifi. The device has been recently flashed so there's no old data on it either.

The only think I can think of is its somehow finding me from my IP address, but I cant see that being very accurate.

WiFi. There's data from companies like Skyhook that drive a van (think Google Street View) around and map out all the wifi networks. Since you have wifi connection, it looks at where the hotspot is and maps you approximately.

I was thinking this when I used my iPod Touch 1G back in the day. It's pretty darn accurate. I first thought they IP traced, but IP traces go to your ISP's office which is just a local thing.. usually down to the city only (worse than cell tower triangulation), but the accuracy is amazing, so yes I read up and it is Skyhook Wireless.
 

WelshBloke

Lifer
Jan 12, 2005
32,905
11,040
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Thanks guys, that makes sense, we had the google van up here in the summer.
So does this only work until someone changes their home router? I live in a fairly rural area so theres not that many wifi routers broadcasting.
Its amazing the amount of data google must store just for locaion based services.
 

vshah

Lifer
Sep 20, 2003
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24
81
From the OP: 'that has no phone radio'

WiFi triangulation is possible, if the coordinates of several hotspots are known, and it can calculate signal strength of those hotspots it can then extrapolate a position. It is even less precise than cell triangulation, and nothing compared to A-GPS or GPS.


actually, it's much more precise. think of the range of a wifi hotspot vs that of a cell tower.
 

TheStu

Moderator<br>Mobile Devices & Gadgets
Moderator
Sep 15, 2004
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actually, it's much more precise. think of the range of a wifi hotspot vs that of a cell tower.

Right, but the location of the cell tower is better known, whereas the location of the router is a little fuzzier unless Google went into each person's house and recorded the coordinates.

Do you have links to back up your statement? I am having trouble finding some myself, I just remember reading (years ago) that the Wifi option was crap compared to everything else out there.
 

vshah

Lifer
Sep 20, 2003
19,003
24
81
Right, but the location of the cell tower is better known, whereas the location of the router is a little fuzzier unless Google went into each person's house and recorded the coordinates.

Do you have links to back up your statement? I am having trouble finding some myself, I just remember reading (years ago) that the Wifi option was crap compared to everything else out there.


i'm pretty sure that when you are running google maps w/ a gps lock, and there are wifi points in the area, google also records your phone's exact gps coordinates, along with the mac/ssid of the wifi ap. the next time someone sees that ssid/mac combo, even with gps turned off, they'll know you are within ~100ft of that AP.

try walking around a downtown area with gps off and wifi location enabled. you'll usually get placed on google maps within ~100 ft.
you can even try it at home. disable gps, enable network location, and see your location on gmaps. then, unplug your wifi router so you only have cell networks to rely on, and see how your location compares.

with only cell triangulation i rarely get better than a few hundred feet accuracy
 
Feb 19, 2001
20,155
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Right, but the location of the cell tower is better known, whereas the location of the router is a little fuzzier unless Google went into each person's house and recorded the coordinates.

Do you have links to back up your statement? I am having trouble finding some myself, I just remember reading (years ago) that the Wifi option was crap compared to everything else out there.

http://www.skyhookwireless.com/

It's not fuzzy. They drove around mapping everyone. I do wonder how it would be if you moved..... Too bad I've already graduated 3 years ago, but if I just graduated from college, I'd love to see where it would put my router at...
 

TheStu

Moderator<br>Mobile Devices & Gadgets
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Sep 15, 2004
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http://www.skyhookwireless.com/

It's not fuzzy. They drove around mapping everyone. I do wonder how it would be if you moved..... Too bad I've already graduated 3 years ago, but if I just graduated from college, I'd love to see where it would put my router at...

It looks like the accuracy has gotten much higher than it was a few years ago. I sometimes forget how much can change in a few years sometimes. (Example, my current cell phone is roughly equivalent, at least in terms of raw numbers, to my 6 year old PowerBook.)
 
Feb 19, 2001
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To pinpoint location, Skyhook's Core Engine uses a massive reference network comprised of the known locations of over 250 million Wi-Fi access points and cellular towers. To develop this database, Skyhook has deployed drivers to survey every single street, highway, and alley in tens of thousands of cities and towns worldwide, scanning for Wi-Fi access points and cell towers plotting their precise geographic locations. Skyhook's extensive coverage area includes most major metro areas in North America, Europe, Asia, and Australia.

http://www.skyhookwireless.com/howitworks/coverage.php

That's just crazy. I wonder if they could've just teamed up with Google and done it with the street view vans. But at the same time this is interesting. They must have very high power antennas to pick up every signal.