Badger network may keep humans from getting lost underground

Magnetic fields reach where GPS can't, with many fewer antennae, but more badgers

GPS systems quickly went from a luxury item to a necessity to a ubiquitous contributor to the geographic ignorance of Americans, many of whom rely on their smartphones' ability to give directions to every place they go to keep from having to learn the way themselves.

That's a problem when GPS is suddenly unavailable. When the battery dies. When you drive under a bridge and the GPS thinks you jumped to the highway above or below. When you go into a tunnel and disappear entirely.

Two biology researchers from Oxford University are trying to remedy that, using GPS technology they adapted to keep track of badgers in suburban wilderness outside the city of Oxford.

Andrew Markham and Niki Trigoni, both post-doctoral researchers and instructors at Oxford's Department of Computer Science drew quite a lot of attention to themselves and to Oxford's suburban badger population with a system designed to monitor what the badgers were up to when they were underground.

Badgers forage and do most other things above ground by themselves, for the most part, but evidently have a rich communal social life underground.

Putting a camera in the burrows would provide a picture of one room, but not a macro picture of what was going on elsewhere.

"It is quite challenging to identify badgers when they are underground," Markham told the BBC last year.

Rather than string cameras throughout the burrows, or string GPS antennas, the research team planted a series of antennas that would project magnetic fields of varying intensity to cover the whole area of the burrows.

Individual badgers got special collars with sensors capable of detecting the fields, tracking their intensity and recording it.

When each badger came aboveground the radio in its collar sync'd with servers attached to the antenna network, giving researchers detailed information about where the badger had been during its time out of sight.

Because they used very low-frequency magnetic fields, the network Markham and Trigoni built was able to penetrate far deeper underground than radio waves – the medium on which GPS depends.

The two found the data they gathered showed not only good badger-tracking capabilities, but also the ability to identify a spot in three dimensions without having to receive signals from three points to calculate location by triangulation.

The changing patterns of magnetic fields created a unique signature at each point near the transmitter.

Low-frequency magnetic fields penetrated the ground and other solid objects more deeply than radio could have and provided a good depth metric via predictable changes in field intensity.

The result was the ability to "triangulate" the position of a sensor using only one antenna and no triangulation at all.

"Our technology can work out your position in three dimensions from a single transmitter. It can even tell you which way your device is facing," Markham told Wired.

Seeing an opportunity to move out of badgers and into location services, Markham and Trigoni took their system to Isis Innovation, a company owned by Oxford University whose job it is to commercialize scientific findings generated there.

The two are looking for 1.7 million pounds in seed capital to fund their startup, OneTriax, which is working on a version of the receiver that would run on Android.

Smart phones already have magnetometers and electronic compasses they use to orient the screen and locate cell-phone towers.

With slightly more processing power and greater sensitivity, those sensors could also pick up enough magnetic data to be used as a backup location system when line-of-sight GPS radio waves just won't cut it.

Making it work will require an advance in signal processing, but not a huge leap. Badger-net pickups rely on a signal with more information in it than a typical GPS radio signal, so reception will still be a challenge, Markham said.

The two have already developed the software to process it, however, and are working on ways to improve its accuracy to less than the 30cm give or take the Badger-net was able to achieve.

Within four years, Markham predicts, smartphones will be manufactured with his and Trigoni's underground GPS capability.

Then the only problems will be extending all those GPS networks with magnetic broadcasting stations, figuring out how to hand responsibility for location from one to the other as the user's location changes and deciding whether or not they'll have to pay the badgers a royalty.

"We think it's achievable," he told Wired.

Read more of Kevin Fogarty's CoreIT blog and follow the latest IT news at ITworld. Follow Kevin on Twitter at @KevinFogarty. For the latest IT news, analysis and how-tos, follow ITworld on Twitter and Facebook.

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