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The benefit of wifi spectrum is that the parts are cheap and you generally won't get in trouble for transmitting signals without a license, which is what their
by Jach 11y ago
The benefit of wifi spectrum is that the parts are cheap and you generally won't get in trouble for transmitting signals without a license, which is what their system does. (It's not passive.) Unfortunately the wifi spectrum isn't that great for through-wall imaging in general -- you're going to lose a lot of transmission power if the wall is composed of just about anything besides drywall, glass, or wood, on top of the massive loss of power you get by default since the received signal's power is inversely proportional to the distance raised to the fourth power.
- darkmighty 11y agoIs there a range of frequencies that does better? Don't frequencies that go through walls easily also go through bodies easily, or are there frequencies where the body is particularly reflective w.r.t. concrete walls?
- dr_zoidberg 11y agoX-rays would do better, but you know, dangerous. On a less sarcastic note, yes, there are frequencies which would be better suited for a specific target material, but like Jach said, regulations and cost are what keeps this things in the WiFi spectrum. I think it also has a kind of "wow factor" when told to non-technical people.
- shalmanese 11y agoScanners designed for this purpose use X-rays and are in use by counter-terrorism and law enforcement units: http://www.pbs.org/wnet/need-to-know/opinion/google-street-view-angers-advocates-but-can-it-see-inside-your-car/3400/ http://www.pbs.org/wnet/need-to-know/opinion/google-street-v...
- darkmighty 11y agoThis is a different technology, those are not radars as far as I know, and I'm not sure it's possible to build x-ray radars due to low reflectance/scattering.