[HN Gopher] Non-line-of-sight imaging over 1.43km [pdf]
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Non-line-of-sight imaging over 1.43km [pdf]
Author : walterbell
Score : 74 points
Date : 2021-03-22 07:59 UTC (1 days ago)
(HTM) web link (www.pnas.org)
(TXT) w3m dump (www.pnas.org)
| drjasonharrison wrote:
| 2s exposure time, 64x64 raster grid, looking behind a barrier
| 1.43km away.
|
| Summary: by bouncing light off of a target barrier and having the
| light scatter around the barrier, you can compute an image of
| objects behind the barrier.
| patentatt wrote:
| Isn't this just using the 'visible wall' as a really dull
| mirror? Or am I not getting something here.
| rzzzt wrote:
| I was immediately reminded of the Dual Photography paper (well,
| I had to look it up first; I only remembered the "photographing
| a playing card that is facing away" demo at the end):
|
| - http://graphics.stanford.edu/papers/dual_photography/
|
| - https://youtu.be/p5_tpq5ejFQ
| phildenhoff wrote:
| That's an absolutely science-fiction-esque paper. I can't
| believe that's real, and I'm surprised to see such little
| follow-up research. I assume it's not practical to generate
| the light transport data with any reasonable speed?
| cs702 wrote:
| So these guys successfully got images of objects sitting behind a
| solid barrier from nearly a mile away by analyzing photons
| scattered around the barrier.
|
| I imagine the only way to hide objects from this technology is to
| enclose them well enough to prevent most photons that bounce off
| the objects from leaving the enclosure.
|
| And this is just an early-stage proof-of-concept. There's a good
| chance the technology can and will improve significantly over
| time.
|
| Just saying.
| buro9 wrote:
| This is neat. Assuming the usual things about costs going down
| and capabilities increasing, both exponentially of course... then
| one can imagine some novel and non-military applications.
|
| For example, vehicles seeing around corners to avoid collisions
| or being able to see further into damaged industrial sites than
| robots can go today (i.e. Fukushima), or for cave explorations
| (especially if they improve significantly and start building
| images from multiple reflections - see around the corners that
| themselves are around corners).
| yourself92 wrote:
| What are some of the applications of this technology?
|
| Edit: I'm also wondering if anyone has any idea as to the
| estimated cost of such a technology? Thousands, tens/hundred of
| thousands, millions? A quick search of lidar sensors seem to be
| in the range of $2500 - ~$10000 for ranges of sub 30 meters.
|
| This technology seems similar(?) to lidar from what I can tell.
| tyingq wrote:
| First one that comes to mind is military. Where to aim (or not
| aim) your high powered weapon that can shoot through a wall.
| j-pb wrote:
| Military, police, surveillance. The usual suspects when it
| comes to oppressive regimes like china.
|
| On a more upbeat note though, imagine the possibility of
| producing a 3d image of your internals during keyhole surgery
| or inspecting remote structures like solar panels and dams via
| satellite.
| EarthIsHome wrote:
| My local police department would be really interested in this
| tech. They've been using automated license plate readers,
| facial recognition tech, drones, predictive policing, and
| have a Ring doorbell partnership.
| titzer wrote:
| Where do you live? Remind me not to visit.
| MsMowz wrote:
| Any major city in the United States has all of these
| features
| titzer wrote:
| It's really incredible that we just let ourselves slide
| into this surveillance dystopia, isn't it? I yearn for
| the halcyon days of August 2001.
| EarthIsHome wrote:
| [0]: https://atlasofsurveillance.org/
|
| [1]: https://www.eff.org/issues/street-level-surveillance
| MPSimmons wrote:
| In a very real way, American police departments are
| functioning in roles that the military serves in most
| dystopian societies.
| twobitshifter wrote:
| Teslas have been shown to prevent accidents by braking based on
| things drivers can't see.
| https://www.mobilescout.com/tech/news/n77946/tesla-autopilot...
|
| I imagine that idea could be improved more with this
| technology, but Tesla is very anti lidar so it's have to be
| someone else.
| mlyle wrote:
| Dirt cheap. Laser with galvo (like many laser projectors for
| light shows have), plus 3 photodiode detectors and optics.
|
| Most of the cost will be in the telescopes.
|
| If you don't count personnel time integrating/fiddling around,
| maybe $1000 at qty 1?
| IshKebab wrote:
| Realistically there aren't any practical applications. It's a
| very cool demo though.
| mlyle wrote:
| Seeing inside a building has no practical applications?
|
| Or other non-line-of-sight things, like sensing through an
| aperture in a body?
| baybal2 wrote:
| Electro-optical reconnaisance spacecrafts
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