

Using wireless network signals to see through walls - bhousel
http://www.wired.com/threatlevel/2009/10/see-through-walls/

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billswift
Bruce Schneier linked to this article, the comments are here
[http://www.schneier.com/blog/archives/2009/10/using_wi-
fi_to...](http://www.schneier.com/blog/archives/2009/10/using_wi-
fi_to.html#comments) .

This is pretty obviously an outgrowth of the old body capacitance sensors used
in monitoring secure areas. It would be pretty easy to spoof since it would
also detect moving pieces of any conductors or electronic devices. For SAR
they would only detect a person (or electronic device) that was moving; if you
are pinned down, tough luck.

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johannchiang
Honestly, it is not as useful as ultrawideband handheld radar under
prototyping. Surrounding antenna array is just too excessive.

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futuremint
Cool technology, thought the editorialization is a little lame. Really? SWAT?
Because anything that can track movement will be immediately useful to SWAT?
Wouldn't the base-station have to be _inside_ the building? The author could
have tried just a little bit harder to envision a use.

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bhousel
I don't see why the base station needs to be inside the building. Radio waves
go _everywhere_.

That is, as long as the building isn't a Faraday cage.

~~~
futuremint
Seems to me though that the radiowaves would have to go in the general
direction of the person moving, right? I suppose you could surround the entire
building and go from there...

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tocomment
It would be awesome if you could use the wifi on the iPhone to do this and
sell it as an app. I'm guessing you don't get that low level of control over
the iPhone's wifi though?

