Themal Imaging vs. Night Vision vs. X-RAY

J

Jamie Young

New member
Thermal Imaging vs. Night Vision vs. X-Ray

I noticed the Philadelphia Police Department is getting a few new toys now for raiding houses. They have some kind of xray or thermal imaging device that tells them how many people are in a house and where in the house they are. Wasn't there some movie called "Eraser" with Arnold Schwarzzahoweveryaspellit where somebody has some gun that had an xray scope on it?

I was wondering if the US Military has any form of Portable Thermal Imaging scope for snipers? Thermal Imaging seems just as practical for military purposes as night vision, and maybe more. Also, do they have night vision scopes that are in color and not all greened out? To me night vision doesn't help you at night unless a target is moving.
 
The first "night vision", AFIK, was immediately after WWII and involved IR imaging using an IR illuminator. With the illuminator off, it was great for spotting warm-blooded creatures hidden behind vegetation.

It was also a rather short-range, low-resolution proposition.

Most available NV devices remain rather sensitive to IR, but getting a clear image is difficult. Think of a glowing object--you have no shadows to define the texture and details of the object.

I've seen many images from higher-resolution IR thermal imaging. To "see" through walls, you must have some way to imprint a temperature gradient on the OUTSIDE surface. People leaning on the wall *can* leave such an imprint, but it lingers and takes a while to transmit through the wall. EPA "energy star" insulation kills almost all chances of getting these images. You can, however, frequently get useful images through cloth/window barriers.

X-ray requires a receiving plate on the opposite end. It's like shining a flashlight through your hand--it requires straight-line particles and density differences that cast the functional equivalent of a shadow. Too hard to do.

Radar and/or sonar/ultrasound are better possibilities. That's more like shining a light and seeing what gets reflected back.

It's far easier to just toss in a few tear gas grenades and wait for the fire to start. Official doctrines notwithstanding, the law enforcement brass seems to like that "defensible" and "restrained" approach better than doing an Entebbe-style shoot-em-up raid.

And before anyone praises the Brits for their antiterrorist resolve, remember that they used to search anyone's home at the drop of a hat. The also used to execute petty thieves.
 
Thermal imaging is great, but can be defeated by something as simple as window glass where the temperature inside a structure is different than outside the structure. I saw a thermal imaging demonstration where they showed what a guy looked like under IR, then turned on the AC in the back of an big truck trailer. I think the truck was designed to carry fish, so you know the AC was freezer quality. Even though you could see the guy with your eyes, he effectively disappeared on the IR because he was 'blanketed' by very cold air that hid is IR radiance.

Have you ever watched episodes of COPS where they use FLIR? The choppers lose bad guys under trees because the leaves radiate their own IR signatures and hide or blanket the suspect. If you have a complete canopy, then you have complete concealment.

IR has been used by cops to note houses that have unusually high heat signatures and those houses are then targeted for investigation as marijuana home growing setups. All those lights produce a lot of heat.

IR has also been used by firemen to locate hot spots of fires. Fire makes a lot of IR radiation and a fire concealed behind the wall of a room will make the wall hot and this will be detectable on IR. It is one way in which fires can be located between the walls without having to run your hands over every square inch until you find a warm spot.

One way to hide airplanes that have just landed from overflying spy planes with IR capabilities is to simply move them into a hanger, close the doors, and crank up the AC. The AC will high the heat signature of the planes. If all the hangers have on their ACs, then all the hangers look the same on IR.

Given the relative ease of defeating thermal imaging, I don't think you can look through walls or windows with it to count people.
 
I have a Tom Clancy book here "Armored Cavalry" and it talks about one of our tanks losing an IRAQI tank behind a sand dune until they could see heat rising from behind the dune. They ended up firing some kind of round threw the sand dune and blew the IRAQI tank to bits. SUCKS TO BE AN IRAQI!
 
The type of round they used was a uranium depleted rod round (not exact title). Yeah when it comes down to it the M1A2 Abrams is the best. But as always a tank is only as good as the crew behind it.
 
You must log in or register to reply here.
Back
Top