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Posted: 1/25/2014 9:19:45 AM EDT
I saw on one of the Discovery Channel shows yesterday where the guy held up a pane of clear glass in front of himself  at night and said the glass will defeat the thermal imaging on the chopper that was looking for him. is this true ? Sorry, can't remember the shows name.
Link Posted: 1/25/2014 9:22:46 AM EDT
[#1]
Bro, it depends on the thermal. Newer ones I believe can see through the glass, older ones not so much. A cold blanket can defeat a thermal...
Link Posted: 1/25/2014 9:23:40 AM EDT
[#2]
Yup. All thermal imagers at my fire dept could not see through glass.
Link Posted: 1/25/2014 9:24:13 AM EDT
[#3]
The TICs that I have used all had glass act like a mirror.
Link Posted: 1/25/2014 9:26:59 AM EDT
[#4]
Imagine a line of M1A1's facing a German 23 story apartment building.  After a boring day spent sweeping the motorpool it wasn't uncommon to see 8 or 10 tank tubes pointed at the apartment building and hear the hum of the thermal sights as guys tried to be voyeurs.

Never saw a thing.  

And the laser range finder will kill birds on telephone wires.
Link Posted: 1/25/2014 9:29:10 AM EDT
[#5]
Mythbusters showed this as well. Glass acts as enough of a insulator.
Link Posted: 1/25/2014 9:40:32 AM EDT
[#6]
Glass, or any shiny surface, will act as a mirror and reflect thermal energy.
Link Posted: 1/25/2014 9:40:39 AM EDT
[#7]
Hell, I had no idea. just figured if the enemyhad thermal, flir, and all,  you were just screwed. Good to know.
Link Posted: 1/25/2014 9:46:26 AM EDT
[#8]

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Quoted:


Imagine a line of M1A1's facing a German 23 story apartment building.  After a boring day spent sweeping the motorpool it wasn't uncommon to see 8 or 10 tank tubes pointed at the apartment building and hear the hum of the thermal sights as guys tried to be voyeurs.



Never saw a thing.  



And the laser range finder will kill birds on telephone wires.
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I rost.



 
Link Posted: 1/25/2014 9:53:24 AM EDT
[#9]
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Quoted:
I rost.
 
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Quoted:
Quoted:
Imagine a line of M1A1's facing a German 23 story apartment building.  After a boring day spent sweeping the motorpool it wasn't uncommon to see 8 or 10 tank tubes pointed at the apartment building and hear the hum of the thermal sights as guys tried to be voyeurs.

Never saw a thing.  

And the laser range finder will kill birds on telephone wires.
I rost.
 

The xenon searchlight on a M60 worked better/faster
Link Posted: 1/25/2014 9:54:07 AM EDT
[#10]
Glass (Silicone) is opaque to infrared.  That is why infrared imagers use Germanium lenses.
Link Posted: 1/25/2014 9:55:55 AM EDT
[#11]

Link Posted: 1/25/2014 9:59:36 AM EDT
[#12]
Thermal imaging systems generally operate in the MWIR/LWIR realm, between 5 and 10 micron wavelength; glass has very low transmittance at these bands. Add in the fact that most window coatings are designed to block heat, and, well...
Link Posted: 1/25/2014 9:59:52 AM EDT
[#13]
Glass is opaque to the wavelengths of light you are interested in:










 
Link Posted: 1/25/2014 10:01:54 AM EDT
[#14]
Yep, I wanted to cry after buying mine and trying to pick up people through glass. Unless they are close enough to heat the glass it doesn't work.
Link Posted: 1/25/2014 10:03:33 AM EDT
[#15]
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Quoted:
Glass, or any shiny surface, will act as a mirror and reflect thermal energy.
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Link Posted: 1/25/2014 10:03:36 AM EDT
[#16]
I would just shoot at the big blue rectangle in the middle of the field........
Link Posted: 1/25/2014 10:03:59 AM EDT
[#17]
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Quoted:
Yup. All thermal imagers at my fire dept could not see through glass.
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Yep. and water'

Ever look at downed power lines, easy to see where the voltage is going to ground by following the heat signature, pretty cool looking at a trace down though a tree trunk to the ground, or along a fence to a post.....
Link Posted: 1/25/2014 10:04:24 AM EDT
[#18]
Sure does
Link Posted: 1/25/2014 10:09:39 AM EDT
[#19]
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Quoted:


Lol
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Quoted:
Quoted:
Glass, or any shiny surface, will act as a mirror and reflect thermal energy.


Lol


People are going "lol" and , but he's actually not 100% wrong. Shiny surfaces with low thermal emissivities do produce a mirror-like effect when viewed with a thermal imaging system.

Link Posted: 1/25/2014 10:11:38 AM EDT
[#20]
Visible spectrum is about 280nm to 750nm

Very near infrared light that is used in infrared lasers, camcorder night vision and IR remote controls is in the 800-900nm range.  This very short wavelength infrared energy can go through glass.

Most thermal IR cameras operate between 3um and 14um.  

The longer wavelengths of infrared are associated with heat energy. Glass is specifically designed to pass visible wavelengths and most glass is also designed to block infrared energy for efficiency. At infrared wavelengths glass becomes a mirror.
Link Posted: 1/25/2014 10:16:00 AM EDT
[#21]
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Quoted:
Imagine a line of M1A1's facing a German 23 story apartment building.  After a boring day spent sweeping the motorpool it wasn't uncommon to see 8 or 10 tank tubes pointed at the apartment building and hear the hum of the thermal sights as guys tried to be voyeurs.

Never saw a thing.  

And the laser range finder will kill birds on telephone wires.  
View Quote


Sounds like guys working the newer F-4Es at Ramstein AB in Germany.  Whenever a plane in a certain group of shelters needed to be worked on there were almost fights to see who got the job.  Those newer planes had TISEO (Target Identification System, Electro Optical) similar to the F-14's TADS/PNVS and from that set of shelters there was a clear view into the womens' barracks shower room.  TISEO allowed the Phantom's crew to visually identify and aircraft from almost 40 miles away and to read identification markings on a plane at 10 miles.  The view of the gals in that shower room from one mile were said to be "intimate".
Link Posted: 1/25/2014 10:19:42 AM EDT
[#22]
Our helos' night vision cannot see through auto glass.
Link Posted: 1/25/2014 10:21:57 AM EDT
[#23]
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Quoted:
Yup. All thermal imagers at my fire dept could not see through glass.
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You guys needed thermal to help you find the fire
Link Posted: 1/25/2014 10:29:23 AM EDT
[#24]
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Quoted:



You guys needed thermal to help you find the fire
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Quoted:
Quoted:
Yup. All thermal imagers at my fire dept could not see through glass.



You guys needed thermal to help you find the fire


They had too many worker's comp cases from the old technique of licking an object on fire to see if it was hot.
Link Posted: 1/25/2014 10:30:57 AM EDT
[#25]
We used a big handheld bastard in the service called the Talon, and it could see through glass. The FLIR could not. As for finding the fire, thermals were used for finding people and hot spots, and generally seeing where the hell you're going.
Link Posted: 1/25/2014 10:33:03 AM EDT
[#26]
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Quoted:
Glass, or any shiny surface, will act as a mirror and reflect thermal energy.
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good to know, my glass in my car is defective, the glass gets hot due to the sun
Link Posted: 1/25/2014 10:35:23 AM EDT
[#27]
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Quoted:



You guys needed thermal to help you find the fire
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Quoted:
Quoted:
Yup. All thermal imagers at my fire dept could not see through glass.



You guys needed thermal to help you find the fire



Nope. But it sure helped with not crashing into things.
Link Posted: 1/25/2014 10:39:55 AM EDT
[#28]
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Quoted:
Glass, or any shiny surface, will act as a mirror and reflect thermal energy.
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The lenses used in thermal IR sensors are typically Germanium, Chalcogenide glass, Zinc Selenide, and Zinc Sulfide.  They are very smooth and appear shiny when viewed at visible wavelengths.  But, they are transparent at long wave IR.
Link Posted: 1/25/2014 10:40:54 AM EDT
[#29]
Glass will not allow IR wavelength to pass through, that is why the fancy fireplace doors jump so much in price, they are quartz and not glass.
Link Posted: 1/25/2014 10:43:10 AM EDT
[#30]
Just don't think you're going to carry around a large sheet of glass on your way in to sneek up on or away from anything that's using IR or thermal.

You'll just look like a big square in the middle of a natural back ground.

Like wearing a cardboard box over your body and thinking no one can see you.

You're right, they can't see "you" but they can see the big box in the middle of the road/feild/roof/parking lot.


And that won't attract attention to yourself, NOOOO not at allllll.
Link Posted: 1/25/2014 10:59:18 AM EDT
[#31]

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Quoted:


Just don't think you're going to carry around a large sheet of glass on your way in to sneek up on or away from anything that's using IR or thermal.



You'll just look like a big square in the middle of a natural back ground.



Like wearing a cardboard box over your body and thinking no one can see you.



You're right, they can't see "you" but they can see the big box in the middle of the road/feild/roof/parking lot.





And that won't attract attention to yourself, NOOOO not at allllll.
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Worked in the Metal Gear series.  







 
Link Posted: 1/25/2014 12:29:43 PM EDT
[#32]
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Quoted:


People are going "lol" and , but he's actually not 100% wrong. Shiny surfaces with low thermal emissivities do produce a mirror-like effect when viewed with a thermal imaging system.

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Quoted:
Quoted:
Quoted:
Glass, or any shiny surface, will act as a mirror and reflect thermal energy.


Lol


People are going "lol" and , but he's actually not 100% wrong. Shiny surfaces with low thermal emissivities do produce a mirror-like effect when viewed with a thermal imaging system.



No, it's 100% wrong. Surface diffusivity or specularity has nothing to do with reflectance. Some of the most reflective material (i.e. MgO) is also among the most diffuse.

What is at hand here is the transmittance of the glass. If the glass has low transmittance in the IR spectrum which the thermal imager is sensitive to, it will basically act the same way an opaque wall would to our eyes.

Science on ARFCOM
Link Posted: 1/25/2014 12:34:42 PM EDT
[#33]

Discussion ForumsJump to Quoted PostQuote History
Quoted:
Sounds like guys working the newer F-4Es at Ramstein AB in Germany.  Whenever a plane in a certain group of shelters needed to be worked on there were almost fights to see who got the job.  Those newer planes had TISEO (Target Identification System, Electro Optical) similar to the F-14's TADS/PNVS and from that set of shelters there was a clear view into the womens' barracks shower room.  TISEO allowed the Phantom's crew to visually identify and aircraft from almost 40 miles away and to read identification markings on a plane at 10 miles.  The view of the gals in that shower room from one mile were said to be "intimate".
View Quote View All Quotes
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Discussion ForumsJump to Quoted PostQuote History
Quoted:



Quoted:

Imagine a line of M1A1's facing a German 23 story apartment building.  After a boring day spent sweeping the motorpool it wasn't uncommon to see 8 or 10 tank tubes pointed at the apartment building and hear the hum of the thermal sights as guys tried to be voyeurs.



Never saw a thing.  



And the laser range finder will kill birds on telephone wires.  




Sounds like guys working the newer F-4Es at Ramstein AB in Germany.  Whenever a plane in a certain group of shelters needed to be worked on there were almost fights to see who got the job.  Those newer planes had TISEO (Target Identification System, Electro Optical) similar to the F-14's TADS/PNVS and from that set of shelters there was a clear view into the womens' barracks shower room.  TISEO allowed the Phantom's crew to visually identify and aircraft from almost 40 miles away and to read identification markings on a plane at 10 miles.  The view of the gals in that shower room from one mile were said to be "intimate".
It was always fun to watch all the turrets in the tank pool traverse whenever a female walked past the line...



I might have been in one, more than once.



 
Link Posted: 1/25/2014 12:59:05 PM EDT
[#34]
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Quoted:


They had too many worker's comp cases from the old technique of licking an object on fire to see if it was hot.
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Quoted:
Quoted:
Quoted:
Yup. All thermal imagers at my fire dept could not see through glass.



You guys needed thermal to help you find the fire


They had too many worker's comp cases from the old technique of licking an object on fire to see if it was hot.



I lol'd
Link Posted: 1/25/2014 1:06:05 PM EDT
[#35]
Discussion ForumsJump to Quoted PostQuote History
Quoted:


No, it's 100% wrong. Surface diffusivity or specularity has nothing to do with reflectance. Some of the most reflective material (i.e. MgO) is also among the most diffuse.

What is at hand here is the transmittance of the glass. If the glass has low transmittance in the IR spectrum which the thermal imager is sensitive to, it will basically act the same way an opaque wall would to our eyes.

Science on ARFCOM
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Quoted:
Quoted:
Quoted:
Quoted:
Glass, or any shiny surface, will act as a mirror and reflect thermal energy.


Lol


People are going "lol" and , but he's actually not 100% wrong. Shiny surfaces with low thermal emissivities do produce a mirror-like effect when viewed with a thermal imaging system.



No, it's 100% wrong. Surface diffusivity or specularity has nothing to do with reflectance. Some of the most reflective material (i.e. MgO) is also among the most diffuse.

What is at hand here is the transmittance of the glass. If the glass has low transmittance in the IR spectrum which the thermal imager is sensitive to, it will basically act the same way an opaque wall would to our eyes.

Science on ARFCOM

Are telling me what I have personally seen in regards to glass mirroring thermals didn't happen?
Link Posted: 1/25/2014 1:19:19 PM EDT
[#36]
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Quoted:

Are telling me what I have personally seen in regards to glass mirroring thermals didn't happen?
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Discussion ForumsJump to Quoted PostQuote History
Quoted:
Quoted:
Quoted:
Quoted:
Quoted:
Glass, or any shiny surface, will act as a mirror and reflect thermal energy.


Lol


People are going "lol" and , but he's actually not 100% wrong. Shiny surfaces with low thermal emissivities do produce a mirror-like effect when viewed with a thermal imaging system.



No, it's 100% wrong. Surface diffusivity or specularity has nothing to do with reflectance. Some of the most reflective material (i.e. MgO) is also among the most diffuse.

What is at hand here is the transmittance of the glass. If the glass has low transmittance in the IR spectrum which the thermal imager is sensitive to, it will basically act the same way an opaque wall would to our eyes.

Science on ARFCOM

Are telling me what I have personally seen in regards to glass mirroring thermals didn't happen?

Smooth shiny shit will generally reflect the thermal image. No, you won't see through glass with thermals.

Some of you will recite books and numbers but mirrors, glass, hell even dry erase boards, all reflect thermal images.
Link Posted: 1/25/2014 1:32:02 PM EDT
[#37]
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Quoted:
I would just shoot at the big blue rectangle in the middle of the field........
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That's why I jump in a puddle of mud before going on ops.
Link Posted: 1/25/2014 1:34:27 PM EDT
[#38]
Discussion ForumsJump to Quoted PostQuote History
Quoted:

Are telling me what I have personally seen in regards to glass mirroring thermals didn't happen?
View Quote View All Quotes
View All Quotes
Discussion ForumsJump to Quoted PostQuote History
Quoted:
Quoted:
Quoted:
Quoted:
Quoted:
Glass, or any shiny surface, will act as a mirror and reflect thermal energy.


Lol


People are going "lol" and , but he's actually not 100% wrong. Shiny surfaces with low thermal emissivities do produce a mirror-like effect when viewed with a thermal imaging system.



No, it's 100% wrong. Surface diffusivity or specularity has nothing to do with reflectance. Some of the most reflective material (i.e. MgO) is also among the most diffuse.

What is at hand here is the transmittance of the glass. If the glass has low transmittance in the IR spectrum which the thermal imager is sensitive to, it will basically act the same way an opaque wall would to our eyes.

Science on ARFCOM

Are telling me what I have personally seen in regards to glass mirroring thermals didn't happen?


You are applying causation to a simple correlation that you found.
Link Posted: 1/25/2014 1:37:59 PM EDT
[#39]
Is sure does! That's why I do all my tactical mission in this


Link Posted: 1/25/2014 1:41:35 PM EDT
[#40]
I have heard that insurgents have been known to use carpets/rugs to hide thermal signatures.  Blankets heat up too quickly.

Where I was in Afghanistan they just stepped behind trees/rocks

ETA:  It sucks when you get in sector and think you're going to dominate mountain fighting with your sweet new thermal scopes then you realize that rocks retain heat after dark and half of the fucking mountainside is glowing at you and nothing stands out from anything else.
Link Posted: 1/25/2014 1:45:31 PM EDT
[#41]
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Quoted:
Smooth shiny shit will generally reflect the thermal image. No, you won't see through glass with thermals.

Some of you will recite books and numbers but mirrors, glass, hell even dry erase boards, all reflect thermal images.
View Quote


You guys need to learn to read. Nobody said glass doesn't reflect IR. We said just because something is shiny doesn't mean it reflects IR. Anybody bother to look how shiny the dome in front of a FLIR is? How smooth and shiny is that chalkboard?

As already mentioned, most window glass is made to reflect IR for insulate reasons. Low e glass has special coatings to do just this. However you can take 2 pieces of glass that look identical to your eyes, and one will transmit IR just fine while another will completely blackout a TIC.
Link Posted: 1/25/2014 1:49:01 PM EDT
[#42]

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Quoted:


I would just shoot at the big blue rectangle in the middle of the field........
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Great minds think alike...look for what ever looks out of place.

 
Link Posted: 1/25/2014 2:06:31 PM EDT
[#43]
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Quoted:
Imagine a line of M1A1's facing a German 23 story apartment building.  After a boring day spent sweeping the motorpool it wasn't uncommon to see 8 or 10 tank tubes pointed at the apartment building and hear the hum of the thermal sights as guys tried to be voyeurs.

Never saw a thing.  

And the laser range finder will kill birds on telephone wires.
View Quote


How did it kill them, did they catch on fire?
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