Researchers Track Cell Phones Indoors By Listening In

starzia writes "Researchers at Northwestern University and the University of Michigan have developed a technique which aims to extend the reach of mobile phone location tracking. Their free iPhone app, Batphone, extracts a location 'fingerprint' from a short recording of ambient sound. This software-only approach allows the device to determine its location with high accuracy using its built-in microphone. Unlike prior indoor tracking techniques, Batphone does not rely on the presence of Wi-Fi access points to serve as landmarks, although these can be used to assist the system when available. They also posted a web game which allows you to test your own ability to recognize rooms by listening. Technical details are in a paper which was presented at the MobiSys conference on Thursday. This is from the same people who brought you laptop sonar."

Comments

They're not alone in this effort

[r_jensen11]

Nokia has been working on this since at least 2009, just search for their Kamppi trial. I know that it's fashionable to knock Nokia on many things, but they do (or is it did?) work on some very fore-front things.

Somebody else created a similar application for his Nokia phones:
http://www.techalps.com/nokia/any-minnesota-readers-please-give-this-mall-of-america-app-a-try.html