FLIR Technician Discusses Navy videos and claims to refute Mick's claims

yoshy

New Member
Just a few minutes in, Falch says the glare can't rotate on its own without the whole scene rotating. But the whole scene does rotate, as it's been pointed out on this forum many times. The optical noise of the entire background rotates exactly along with the glare rotating.
 

markus

Active Member
"Even if that glare existed (which it doesn't) it's going to rotate the whole scene opposed to refracting ... it's a couple mirrors like this that are going to rotate the whole scene so the object can't independently rotate on its own"

Source: https://www.youtube.com/watch?v=vwdV7x_Rmqo


Source: https://www.youtube.com/watch?v=Kb9NSdDAb5A


I don't understand why Falch continues to insist on points that are straightforwardly debunked with clear video evidence that shows incontrovertibly that 1. the ATFLIR has glare (obviously, it's a camera, not a scrying device) and 2. glares do rotate independently from the background, as they must.
 
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jarlrmai

Senior Member
"Even if that glare existed (which it doesn't) it's going to rotate the whole scene opposed to refracting ... it's a couple mirrors like this that are going to rotate the whole scene so the object can't independently rotate on its own"

Source: https://www.youtube.com/watch?v=vwdV7x_Rmqo


Source: https://www.youtube.com/watch?v=Kb9NSdDAb5A


I don't understand why Falch continues to insist on points that are straightforwardly debunked with clear video evidence that shows incontrovertibly that 1. the ATFLIR has glare (obviously, it's a camera, not a scrying device) and 2. glares do rotate independently from the background, as they must.
He's also blocked Mick on Twitter etc so there can be no conversation about his points.
 

dimebag2

Member
Well if you listen carefully he says there can be glare in a FLIR camera, but only with a wide angle of view, not with a narrow one like in the Gimbal footage. It sounds like it's really important to compare what's comparable when discussing what's going on with this type of optics (the video above is a very different situation than Gimbal).
 

markus

Active Member
Well if you listen carefully he says there can be glare in a FLIR camera, but only with a wide angle of view, not with a narrow one like in the Gimbal footage. It sounds like it's really important to compare what's comparable when discussing what's going on with this type of optics (the video above is a very different situation than Gimbal).
See this infrared image of the Monkey Head Nebula from Hubble:

https://www.nasa.gov/sites/default/files/14-076-hubble-anniversary3_0.jpg

Plenty of glare around those stars.
 

Mick West

Administrator
Staff member
Well if you listen carefully he says there can be glare in a FLIR camera, but only with a wide angle of view, not with a narrow one like in the Gimbal footage. It sounds like it's really important to compare what's comparable when discussing what's going on with this type of optics (the video above is a very different situation than Gimbal).
There's glare in the Chilean case. It covers the plane. It's a narrow field of view.2021-08-05_14-05-27.jpg
 

Amber Robot

Active Member
I could only watch about 8 minutes but neither of them speak like I would expect optics experts to. Like when his expert said that “light doesn’t go through but heat does”. What does he think an infrared optical system is doing? “Heat” is just infrared light and would obey the same basic optics rules as visible light does in these contexts. They also seem to imply that Mick believes that the sapphire window rotates and that somehow glare emanates from the window. It was very hard to follow what they were saying even for the few minutes I could listen.
 

dimebag2

Member
There's glare in the Chilean case. It covers the plane. It's a narrow field of view.

I'll have to look into the thread on this again, but do we know what is the field of view of the instrument in that case ? Is the instrument comparable to the one used in the Gimbal video ?
 

fizzBuzz

New Member
There's glare in the Chilean case. It covers the plane. It's a narrow field of view.2021-08-05_14-05-27.jpg


Mick, in your opinion, is the glare being created by "light splash" on the actual camera sensor OR is the glare being created by a dirty/smudged/scratched lens or shield that is separate from the camera sensor?

I think this is an important distinction to make (maybe?) and it seems this may be where Falch is misunderstanding..? If the glare is being created by light splash on the sensor, then I agree it would rotate separate from the image derotation mechanism. However, if the glare is a projection created by the outside shield or even a lens, then it seems the derotation mechanism would treat the glare just like it treats everything else in the image and the glare would not rotate. Am I wrong in that thinking?

ETA: I also think it matters whether the derotation mechanism is mechanical (occurs before the image) vs being a software-based post image effect.
 
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LilWabbit

Active Member
The problem with Chris's videos as encapsulated by Siddharta Gautama Buddha (Dhammapada, 5:63):

"A fool who knows he is a fool is that much wiser, but a fool who thinks he is wise is a fool indeed."
 
The comments in the YouTube section are infuriating. Suddenly, arguments and coherent explanations no longer count against the weight of the simple word of an expert that doesn't go beyond "only people such as myself have access to these devices, therefore anyone else wouldn't understand them".
 

Itsme

Active Member
I haven't had the patience to watch the full videos, but to all the scientists out here with a passion for the truth: The rotating glare hypothesis is a convincing story qualitatively, but does it fit quantitatively as well? If you really have a passion for the truth you'll want to check this.

And you can:

1. A mirror based TMA is a near diffraction limited design so you can get a good estimate of the size of its point spread function using the Airy Disc approximation.

2. The FLIR1 video also contains a fragment where the Gimbal rotates, this should give you an impression of the point spread function of the rotating part of the optics in an ATFLIR.

The effects of dirt on the front window have already been discussed.
 

LilWabbit

Active Member
I haven't had the patience to watch the full videos, but to all the scientists out here with a passion for the truth:

Snark won't get you very far.

The rotating glare hypothesis is a convincing story qualitatively, but does it fit quantitatively as well?

Why don't you demonstrate it doesn't fit rather than offer vague references to airy disc formulae, impressions of point break functions and convoluted discussions.
 

Daniel F

Member
If the de rotation device is a mirror like device; comparable to the one Dave shows at 45 deg angles would it not create the attached effect ? See drawing. If the image is observed through a 'direct line of sight' , for lack of better description, then the potential glare on lens would remain whilst image rotates. However, if the image is observed through that de rotation device, effectively an indirect image- effectively like holding and spinning a photograph. Then would it not spin the glare as well ? As we are no longer observing directly through the offending lens. We are looking at an image being mirrored. Mick's example video; observing directly through his iPhone shows the glare remain stable. What if two rotatable mirrors were set up at 45 deg behind iPhone and Mick observed the resulting image through these. Would it not rotate the glare? We are no longer just spinning the iPhone lens in front of source, we are spinning a completely separate picture using the angled mirrors. As in the attached drawing. This is how understand both Dave Falch and that Ernhart technician describing that the glare could not rotate independently. Using the special mirrors you are effectively spinning a wholly separate image.
 

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JarJar

Member
I thought about it and decided am going to say it anyway.

This latest video confirms Chris Lehto's mission to prove Mick wrong surpasses his scientific competence and passion for truth.
Chris seems quick to resort to internet drama as needed to get attention. He knows a percentage of his viewers are going to accept whatever supports their preconceived notions, and takes full advantage of that. I assume Dave is using a similar tactic.

I have said the same thing about FE channels for years. The majority of them seem to be interested in viral attention, rather than presenting sound arguments. I'd go a step further and assert many of them team up with their 'opposition' to hurl insults back and forth to fuel the drama views for both sides.

Dunning-Kruger goes both directions.
Assuming you are an expert without merit, or being an actual expert, but assuming non-experts can't understand.
 

Itsme

Active Member
Watched both videos. I think Dave raises some good points.

1. The shimmering/spiking you typically see in FLIR footage of a jet engine is indeed absent in the gimbal case.

2. Dave tries to understand what Mick thinks is the cause of the glare in the ATFLIR optical path up to and including the de-rotation device. The effects of dirt on the front window have already been discussed earlier, and Dave basically supports my conclusion. The rest of the optical path is mirror based so Dave is at a loss what could cause the glare. He assumes Mick must think that the de-rotation device is a lens for that reason, yet it is mirror based as well. If I remember correctly, the first lens in the ATFLIR optical path comes after the de-rotation device.
Mick now simply refers to the 'point spread function' of an optical system but fails to demonstrate that the optical design of the ATFLIR (which is diffraction limited) has a point spread function this large. I gave the mathematical formula for this in my previous post.

3. Their argument that demonstrations with consumer grade equipment are not representative for sophisticated military grade sensors is of course valid as well.

4. As is their argument that thermal imaging is much less susceptible to glare than visual imaging, and they themselves never witnessed a glare like the one in the gimbal video using professional FLIR equipment.
To what extend the jet engine glare you see in the many FLIR recordings Dave made is really optical glare or the effect of looking head-on into a long stream of hot/warm gas is still open.
 

Ravi

Active Member
I could only watch about 8 minutes but neither of them speak like I would expect optics experts to. Like when his expert said that “light doesn’t go through but heat does”. What does he think an infrared optical system is doing? “Heat” is just infrared light and would obey the same basic optics rules as visible light does in these contexts. They also seem to imply that Mick believes that the sapphire window rotates and that somehow glare emanates from the window. It was very hard to follow what they were saying even for the few minutes I could listen.
I had the exact same impression.

Dave is an expert. Well, not in my book. And Chris is a pilot who does not understand optics (ok, as a pilot I cannot expect you to be).
 

markus

Active Member
Watched both videos. I think Dave raises some good points.

1. The shimmering/spiking you typically see in FLIR footage of a jet engine is indeed absent in the gimbal case.
That shimmering is atmospheric turbulence. You can tell because the same effect can be seen in Falch's visible light images with the same camera. The air at 25,000 feet doesn't churn as much, so Falch's videos are not indicative of what this stuff would look like. This is: Source: https://www.youtube.com/watch?v=K6cSoBE770Q


Notice how there's no shimmering or 'pulsing', etc.
2. Dave tries to understand what Mick thinks is the cause of the glare in the ATFLIR optical path up to and including the de-rotation device. The effects of dirt on the front window have already been discussed earlier, and Dave basically supports my conclusion.
Smearing something on the front lens absolutely would affect the point spread function. You can test this with a pair of glasses. It's not a simple image, it wouldn't be "in focus". That's the wrong way to think about it.
The rest of the optical path is mirror based so Dave is at a loss what could cause the glare. He assumes Mick must think that the de-rotation device is a lens for that reason, yet it is mirror based as well. If I remember correctly, the first lens in the ATFLIR optical path comes after the de-rotation device.
Mick now simply refers to the 'point spread function' of an optical system but fails to demonstrate that the optical design of the ATFLIR (which is diffraction limited) has a point spread function this large. I gave the mathematical formula for this in my previous post.
How large? Can you actually provide the details of this demonstration?
3. Their argument that demonstrations with consumer grade equipment are not representative for sophisticated military grade sensors is of course valid as well.
The fundamental principles of optics are the same.
4. As is their argument that thermal imaging is much less susceptible to glare than visual imaging, and they themselves never witnessed a glare like the one in the gimbal video using professional FLIR equipment.
We see that in the Chilean navy case.
To what extend the jet engine glare you see in the many FLIR recordings Dave made is really optical glare or the effect of looking head-on into a long stream of hot/warm gas is still open.
The air coming out of a jet engine comes out hot, but cools very rapidly. E.g.: Source: https://www.youtube.com/watch?v=GqVjD3nBSQg
. You'd only see air that's directly behind the engine, and it would most certainly not be a giant blob covering the whole plane. That's glare.
 

Agent K

Senior Member
Watched both videos. I think Dave raises some good points.

1. The shimmering/spiking you typically see in FLIR footage of a jet engine is indeed absent in the gimbal case.

2. Dave tries to understand what Mick thinks is the cause of the glare in the ATFLIR optical path up to and including the de-rotation device. The effects of dirt on the front window have already been discussed earlier, and Dave basically supports my conclusion. The rest of the optical path is mirror based so Dave is at a loss what could cause the glare. He assumes Mick must think that the de-rotation device is a lens for that reason, yet it is mirror based as well. If I remember correctly, the first lens in the ATFLIR optical path comes after the de-rotation device.
Mick now simply refers to the 'point spread function' of an optical system but fails to demonstrate that the optical design of the ATFLIR (which is diffraction limited) has a point spread function this large. I gave the mathematical formula for this in my previous post.

3. Their argument that demonstrations with consumer grade equipment are not representative for sophisticated military grade sensors is of course valid as well.

4. As is their argument that thermal imaging is much less susceptible to glare than visual imaging, and they themselves never witnessed a glare like the one in the gimbal video using professional FLIR equipment.
To what extend the jet engine glare you see in the many FLIR recordings Dave made is really optical glare or the effect of looking head-on into a long stream of hot/warm gas is still open.
Mick refuted most of that with the Chilean Navy UFO, which was recorded with a military grade IR sensor and didn't shimmer.
Source: https://www.youtube.com/watch?v=iEK3YC_BKTI
 

Mechanik

Active Member
3. Their argument that demonstrations with consumer grade equipment are not representative for sophisticated military grade sensors is of course valid as well.
It’s a common misperception that military equipment is better than commercial gear. Having supplied equipment to government for many years, military equipment is always several years behind the state of the art due to lengthy procurement cycles, extremely detailed specifications, and lengthy backwards-compatibility requirements.

At a unit level (like a FLIR pod), it’s going to be more rugged than commercial and specifically designed to work with the radar and other onboard systems, but the unit itself only rarely outperforms what your local police force or news helicopter can buy today.
 

Agent K

Senior Member
It’s a common misperception that military equipment is better than commercial gear. Having supplied equipment to government for many years, military equipment is always several years behind the state of the art due to lengthy procurement cycles, extremely detailed specifications, and lengthy backwards-compatibility requirements.

At a unit level (like a FLIR pod), it’s going to be more rugged than commercial and specifically designed to work with the radar and other onboard systems, but the unit itself only rarely outperforms what your local police force or news helicopter can buy today.
He was talking about comparing ATFLIR with a $300 FLIR ONE thermal camera. By the way, Raytheon partnered with Seek Thermal to make a competing $300 thermal camera.
 

JarJar

Member
2. Dave tries to understand what Mick thinks is the cause of the glare in the ATFLIR optical path up to and including the de-rotation device. The effects of dirt on the front window have already been discussed earlier, and Dave basically supports my conclusion.
Dave discussed a particle or bugs stuck to the front window, but what about condensation or fog completely covering the window?
 

Amber Robot

Active Member
2. Dave tries to understand what Mick thinks is the cause of the glare in the ATFLIR optical path up to and including the de-rotation device. The effects of dirt on the front window have already been discussed earlier, and Dave basically supports my conclusion. The rest of the optical path is mirror based so Dave is at a loss what could cause the glare. He assumes Mick must think that the de-rotation device is a lens for that reason, yet it is mirror based as well. If I remember correctly, the first lens in the ATFLIR optical path comes after the de-rotation device.
it would be very useful to know the exact optical layout (if not the prescription) of the system in question. I could easily see the derotator occurring after the primary telescope but prior to the detector.
Mirrors can scatter light too, not just lenses.
i also don’t know what a lens-based derotator would look like — I’m familiar with K-mirror systems, used in a few astronomical systems I know of.

Mick now simply refers to the 'point spread function' of an optical system but fails to demonstrate that the optical design of the ATFLIR (which is diffraction limited) has a point spread function this large. I gave the mathematical formula for this in my previous post.
Even if we know the PSF we don’t know how saturated the source is and thus how far down the PSF we might be seeing. If the core is saturated then most of the shape being seen could be sampling the wings of the PSF, which would be more sensitive to things like defects and scattered light.
The Airy distribution would be appropriate for a diffraction-limited system but we don’t know if this particular system is operating at the diffraction limit and multiple kinds of errors (like alignment and fabrication errors) will impact the wavefront and ultimately the image quality.
There is likely just not enough quantitative information available to assess most of the images.
 
Very interesting. A question. If what we see rotating at the end is the glare of the exhaust gases of the engines placed in front of the viewer, why is this exhaust, evidently very visible in the IR, not seen at all at the beginning when the object was showing a side view?
 

Itsme

Active Member
That shimmering is atmospheric turbulence. You can tell because the same effect can be seen in Falch's visible light images with the same camera. The air at 25,000 feet doesn't churn as much, so Falch's videos are not indicative of what this stuff would look like. This is: Source: https://www.youtube.com/watch?v=K6cSoBE770Q


Notice how there's no shimmering or 'pulsing', etc.

Smearing something on the front lens absolutely would affect the point spread function. You can test this with a pair of glasses. It's not a simple image, it wouldn't be "in focus". That's the wrong way to think about it.

How large? Can you actually provide the details of this demonstration?

The fundamental principles of optics are the same.

We see that in the Chilean navy case.

The air coming out of a jet engine comes out hot, but cools very rapidly. E.g.: Source: https://www.youtube.com/watch?v=GqVjD3nBSQg
. You'd only see air that's directly behind the engine, and it would most certainly not be a giant blob covering the whole plane. That's glare.
People tend to forget that thermal imaging translates temperature differences into visual images. Small temperature differences can be translated into high contrast at will. So even a relatively small temperature difference between the jet exhaust cloud and the surrounding air can be translated into high contrast.

In the FLIR images of jet engines, the 'glare' does not typically rotate independently except for the often used Sukhoi example but this jet has thrust vectoring, i.e. it can point the exhaust stream of its engines in different directions. My guess is that the glare in this example is the actual jet exhaust stream.

Concerning your PSF remark: The clouds and the object in the video seem to be in focus, not blurred. This remark was already made by Chris and Dave.
 

jarlrmai

Senior Member
In the FLIR images of jet engines, the 'glare' does not typically rotate independently except for the often used Sukhoi example but this jet has thrust vectoring, i.e. it can point the exhaust stream of its engines in different directions. My guess is that the glare in this example is the actual jet exhaust stream.

I doubt it is vectoring it's thrust ins all those different directions at the same time, this claim seems like a huge stretch to me.

Source: https://www.youtube.com/watch?v=cC6g1RRCpW4


The vectoring seems to point the entire engine nozzle in one direction at a time
 

Mick West

Administrator
Staff member
Nonsense. It clearly shimmers at the 0:32 mark.
The clouds also shimmer, pretty much the same. Here are two image regions of the same segment of the video, same magnification


I think that's a combination of
  1. Atmospheric Turbulence, with the low altitude helicopter looking through 50+ miles of air.
  2. Compression artifacts
  3. Motion (vibration and turbulence) from the helicopter camera, magnified by the long focal length
Consider this video of glare around the engines of Concord taking off.

Note the top edge of the glare. There's no flicker. Below the glare itself we are not seeing glare, but the actual hot gasses turbulently mixing with the atmosphere. Here we see the flickering, but that's because we can see the gas plume directly. When the glare cover that (like when it's far away and tail-on) then you won't see that mixing fluctuation. You'll see the stability seen in the top edge of the glare.
 

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  • Chilean Comparison Flicker.mov
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Ravi

Active Member
i also don’t know what a lens-based derotator would look like — I’m familiar with K-mirror systems, used in a few astronomical systems I know of.

Yes, these units are used in combination with big telescopes using the "Nasmyth" output (side). So it corrects the scene angle wrt telescope motion.

Quite certain it cannot be obtained with lenses.
 

markus

Active Member
People tend to forget that thermal imaging translates temperature differences into visual images. Small temperature differences can be translated into high contrast at will. So even a relatively small temperature difference between the jet exhaust cloud and the surrounding air can be translated into high contrast.
Nothing else would be visible in the video if that were the case. But the contrast setting is such that the whole scene is clear.
In the FLIR images of jet engines, the 'glare' does not typically rotate independently except for the often used Sukhoi example but this jet has thrust vectoring, i.e. it can point the exhaust stream of its engines in different directions. My guess is that the glare in this example is the actual jet exhaust stream.
No, it's glare. Thrust vectoring doesn't push extra air at 90 degrees from the engine, and the nozzle is clearly not moving.
Concerning your PSF remark: The clouds and the object in the video seem to be in focus, not blurred. This remark was already made by Chris and Dave.
The clouds are much less bright.
 

Itsme

Active Member
The clouds also shimmer, pretty much the same. Here are two image regions of the same segment of the video, same magnification


I think that's a combination of
  1. Atmospheric Turbulence, with the low altitude helicopter looking through 50+ miles of air.
  2. Compression artifacts
  3. Motion (vibration and turbulence) from the helicopter camera, magnified by the long focal length
Consider this video of glare around the engines of Concord taking off.

Note the top edge of the glare. There's no flicker. Below the glare itself we are not seeing glare, but the actual hot gasses turbulently mixing with the atmosphere. Here we see the flickering, but that's because we can see the gas plume directly. When the glare cover that (like when it's far away and tail-on) then you won't see that mixing fluctuation. You'll see the stability seen in the top edge of the glare.
Mick, that's not glare you see on the Concorde video, it's a big cloud of hot air. You can even see it in the normal visual footage of a concorde takeoff:

The shimmering of the jet engines in your first example is clearly more pronounced than that of the clouds.
 

Amber Robot

Active Member
It’s definitely saturating in the infrared. You can see that horizontal line of black going to the left. But I agree that there’s a large cloud of warm air being imaged, the core of which is saturated in the image.
 

Agent K

Senior Member
2. Dave tries to understand what Mick thinks is the cause of the glare in the ATFLIR optical path up to and including the de-rotation device. The effects of dirt on the front window have already been discussed earlier, and Dave basically supports my conclusion. The rest of the optical path is mirror based so Dave is at a loss what could cause the glare.
I think there are lenses before the dero, but why can't windows and mirrors cause glare? Ever drive at night with a dirty windshield?
 
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