Researchers develop innovative method of indoor tracking

Researchers at the McCormick School of Engineering and Applied Science determined one way of figuring out one’s location inside: by letting their phone listen. Their new mobile phone app, called Batphone, allows users to record ambient noise in a room and tag it with an acoustic fingerprint, which allows future users to use that database of fingerprints to determine their location.

The app developer Stephen Tarzia, a computer engineering graduate student in the Empathic Systems Project headed by electrical engineering and computer science professors Peter Dinda and Gokhan Memik and adjunct professor Robert Dick, presented their work at MobiSys, an International Conference on Mobile Systems, Applications, and Services.

The Batphone app records 10 seconds of noises that humans often ignore: vents, computers, lights, and appliances. The program then looks at how the sound energy is distributed over various frequencies, and after filtering out transient, short-lived sounds (like someone talking), it creates a sound fingerprint for the room.

Tarzia is currently refining the app so it could work in hallways. Right now the app is just a proof-of-concept for the technique; in the future, it could help provide indoor navigation or help determine indoor locations for users of social applications like FourSquare, where users “check-in” at businesses to both let their friends know where they are and to earn points from the business.

An acoustic fingerprint is just one way of determining location indoors; other possibilities include Wi-Fi signals and radio signals from cellular towers. “Ideally future technology would combine two sources to get better accuracy,” Tarzia said.

Source: McCormick