
Indoor Positioning System Tracks Your Phone Using Sound Waves - chmaynard
http://motherboard.vice.com/read/guoguo-is-a-new-indoor-smart-phone-localization-acoustic-gps
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JoeAltmaier
Interesting idea - beacons provide 3d tracking. There used to be a product
that tracked a 3d pen using three long microphone tubes in a Cartesian
arrangement. The pen sparked, the microphones received the 'tick', and the
relative timing determined the pen position. My brother used it back in the
90's to measure finger position on cadavers in a 'hand research' lab (research
used to create more useful artificial limbs).

This article gave me a notion: how about a 'sonar' app for your phone?
Transmits tics and times their return, maybe plays a tone to give you an idea
of distance to obstacle. For the blind?

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lobotryas
Interesting idea! A quick google search shows there is at least one Android
app, but they have the trouble of supporting multiple Android devices (some of
which don't have the necessary hardware).

My assumption would be that potential users need an app that would work 99% of
the time, but this might be a very interesting side project none the less.

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infogulch
Yeah this app has been around forever, iirc I used it on the original G1! (Or
N1? It was a long time ago.) One issue they have is that for optimal accuracy,
you need raw access to the multiple microphones but the manufacturer uses the
mics to perform audio scrubbing before the data gets to the app.

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lisivka
Can you point to app, please?

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infogulch
[https://play.google.com/store/apps/details?id=com.dicon.sona...](https://play.google.com/store/apps/details?id=com.dicon.sonar.ad)

Last updated in 2012...

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andrewtbham
There are several companies trying to do indoor gps with blue tooth low energy
beacons.

[http://indoo.rs/](http://indoo.rs/) and yc company
[http://estimote.com/](http://estimote.com/) also see Apple's iBeacon.

i have never been able to get these devices to work well enough for gps type
apps. so glad to see someone is trying a new approach.

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dmritard96
We are also, [https://flair.co](https://flair.co), but more room occupancy
than navigation. Navigation and trilateration with any accuracy is incredibly
difficult.

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simmons
I'd be curious to hear what the challenges are. Is it simply that signal
strength is too noisy to be used reliably? (I.e., interference, multipath,
attenuation when the subject walks behind furniture, etc.)

I was attending a theatre show a few days ago, and thought that the sound
system could deliver a better experience if the positions of mics on stage
could be tracked as cast moves around, and the mixing adjusted accordingly.
Naturally, BLE was the first thing that came to mind.

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dmritard96
There are a lot of things. The device's antenna pattern and orientation are a
big part. Metal in/around any of the devices. Signal/Noise. etc. You can try
to improve with a lot of calibration but it will also be subject to noise from
every audience members bluetooth radio too.

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jrcii
Wasn't this in the Batman movie?

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murbard2
This has existed for at least a decade
[http://cricket.csail.mit.edu/](http://cricket.csail.mit.edu/)

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dmritard96
And here
[http://www.mccormick.northwestern.edu/news/articles/archive/...](http://www.mccormick.northwestern.edu/news/articles/archive/2009-2012/article_935.html)

