A Laser Fired Through a Keyhole Can Expose Everything Inside a Room:
Being able to see inside a closed room was a skill once reserved for super heroes. But researchers at the Stanford Computational Imaging Lab have expanded on a technique called non-line-of-sight imaging so that just a single point of laser light entering a room can be used to see what physical objects might be inside.
Non-line-of-sight (NLOS, for short) imaging is by no means a new idea. It’s a clever technique that’s been refined in research labs over the years to create cameras that can remarkably see around corners and generate images of objects that otherwise aren’t in the camera’s field of view, or are blocked by a series of obstacles. Previously, the technique has leveraged flat surfaces like floors or walls that are in the line of sight of both the camera and the obstructed object. A series of light pulses originating from the camera, usually from lasers, bounce off these surfaces and then bounce off the hidden object before eventually making their way back to the camera’s sensors. Algorithms then use the information about how long it took these reflections to return to generate an image of what the camera can’t see. The results aren’t high resolution, but they’re usually detailed enough to easily determine what the object in question is.
The first link in the story is to a 3m39s YouTube video demonstrating the process in operation.
(Score: 2) by Rich on Sunday September 12 2021, @02:08PM (4 children)
There's yet another "Keyhole". One that can see about everything. It just occured to me as I happened to see one fly by just yesterday. KH-11 Block 4 Unit 1 to be precise. And to get back on topic, I wouldn't be surprised, if later blocks would have some kind of indirect laser sensing to make the headline true. :)
(Score: 2) by EvilSS on Sunday September 12 2021, @06:29PM (3 children)
(Score: 2) by Rich on Sunday September 12 2021, @08:37PM (2 children)
They just crank the laser power up a tick?
Jokes aside, they probably can use a cluster of satellites to illuminate stuff from different angles and do analysis on the reflections.
(Score: 1) by khallow on Monday September 13 2021, @10:11PM (1 child)
(Score: 2) by Rich on Tuesday September 14 2021, @11:35AM
Or you want to create the impression that you are watching from afar to distract from the fact that you have a mole on the ground. These are three-letter-agencies, after all. :)