I thought that the Smithsonian was working with ... someone on this. Maybe Google since they are mapping the insides of some of our museums. The process they used goes something like this:

They send a person to walk around the building with a laptop measuring the varying strengths of signal from all of the wifi access points from many physical locations in the building and record that info into a database. Then as a person walks around the building, they know where they are based on the relative strengths of the various devices. If a device moves or is replaced, then you have to measure again to get a new database. 

You don't actually need to connect to the access point to know the strength of signal from it. Retail stores are also starting to use this technology to track what parts of the store people spend time in. They can track the location of a particular wifi device even if it's not connected to the network. So the tech exists, to work both ways. :) 

--Joel


Joel Richard
Lead Web Developer, Web Services Department
Smithsonian Libraries | http://library.si.edu/
(202) 633-1706 | [log in to unmask]

________________________________________
From: Code for Libraries [[log in to unmask]] on behalf of Cary Gordon [[log in to unmask]]
Sent: Sunday, January 18, 2015 11:52 PM
To: [log in to unmask]
Subject: Re: [CODE4LIB] Wi-Fi location triangulation

It shouldn’t be impossible, but it would be tricky. Normally, users connect to one access point at a time. To locate a user would require connecting to two or three. I am sure that there is some utility library to do this, but it would need to be incorporated in an app and loaded on the user side.

Cary

> On Jan 18, 2015, at 7:24 AM, Fleming, Jason <[log in to unmask]> wrote:
>
> Has anyone used Wi-Fi to determine a user's position within the library to help them zero in on a book's location using their mobile browser?
>
> I've seen a number of interesting articles and posts, but haven't come across any actual use cases. I'm wondering if all the metal shelving in a library would make this impossible?
>
> Jason Fleming
> University of North Carolina Wilmington
> [log in to unmask]