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Say for instance, a longitude and latitude? The only information available would be that it is an available wireless network in range (secured or unsecured).

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As far as off-the-shelf solutions go, many commercial 802.11 networking infrastructures support triangulation of both host computers and "rogue" APs by comparing the signal strength of the source among all the APs that can see the signal. I've used trapeze wireless systems that import autocad maps that include things like building materials (to compensate for different signal attenuations from drywall vs brick vs steel reinforced concrete). It then draws a picture that has all stations and APs. I believe cisco and aruba have similar tools.

You can't do it with one or even two observing stations, but you could probably do it with a mobile observing station and GPS. I'm not sure what software there is to do such a thing but the usual suspects such as netstumbler may well support such a feature.

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Two receivers with directional antennae would suffice but that is really getting into specialised gear. –  John Gardeniers Nov 28 '09 at 6:18

You can do some basic Radio Direction Finding to locate the signal.

At 2.4 GHz it is easy to come across antennas with small beamwidths. Sweeping one around while watching the signal strength should give you a good idea of what direction the AP is in.

Do that from a few physically separated locations and you will have the beginnings of a triangulation. It doesn't have to be super accurate to get a good idea of where the transmitter is located.

The faster your signal strength indicator, the better. On a radio with an analog meter, it's amazing how fast you can "walk down" a transmitter with a modest yagi antenna.

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By itself, there is no way to get that information from a wifi signal. Google, however, has indexed wifi access points with their locations. So they are able to tell where you are based on the wifi AP you are connected to. In a case like that, it is possible to get a location based on wifi.

http://googlemobile.blogspot.com/2008/10/my-location-now-with-wi-fi.html

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I would like to point your attention to the following project and software:

http://www.storm.net.nz/projects/5

The ghetto way of doing the same, is to use a directional antenna with netstumbler, or something that shows signal strength. Find the maximum strength with the directional antenna, mark the angle, and try again from another point or two. Triangulate, and you'll know the location of the access point.

Or spend your weekend building some insane tripod location thingy :).

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As mentioned you can use radio direction finding to locate the signal. That works by taking multiple antennas and doing an operation called beam forming by timing variance to get the general direction. It's also possible to do a timing triangulation if you have three receivers that can all pick up the signal and you know the exact location of each.

The military uses radio direction finding most of the time from mobile units. They log position, signal strength, and cut bearing and a computer lays these on a map over time and you'll get a good idea of the transmitter location.

Another method used is basically the old warm/cold game. You have a unit that logs position and signal strength and walk around until you find it. The nicer units will overlay a map to give you a general idea where to go but over a bit of time you'll get the location.

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If you've got an android phone try OpenSignalMaps, click on the wifi/cells toggle on the bottom left to see the wifi info. Shows the positions of wifi routers on a map.

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The answer is yes. You can geo-locate wifi enabled devices using a new tool WiFi Investigator. It was invented by AIS. Check it out at: www.wifi-investigator.com.

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I think the government, police, and IT people are using it. –  carol taylor May 15 '12 at 19:59

Sometimes if you plug the gateway IP into an IP to Location database you get decent results. You might need to use traceroute to find the first IP that isn't one of the RFC1918 private networks IPs.

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