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Night Vision Thermal vs NV?

FailureToStart

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Minuteman
Feb 2, 2012
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OK so my search-fu is busted and I didn't find enough answers to my questions. I understand that the systems are vastly different, but I don't understand their strengths and weaknesses relative to each-other. This is a situation where I absolutely don't know what I don't know and I may end up asking all the wrong questions. If I miss anything important, help out please. My experience is limited to a shitty set of gen2 binoculars that can't see across my back yard with a full moon.

I'm looking for a straight image comparison between the two technologies. I'll take the time to consider mounting options and versatility (seems to be a HUGE plus for NV). In this case, I'd be looking at something like a Raytheon W1000-9 or a PVS-14 + TNVC Torch Pro or similar. Hand-held thermal units are pretty much out, which limits me to weapon mounted thermals or extremely versatile NV systems like the PVS-14.


Anyway lets start with what I assume are pretty good conditions for NV - clear sky and a full moon with no other lighting. What kind of useful detection range would a PVS-14 unit have in an open field? What about the range at which you can clearly ID an individual and what they have in their hands?

What about with total overcast or a blacked out building with zero ambient light?

And for my nightmare - the real reason I've started on this quest. There is a field with a road running along it. At one end of the field is a slight bend in the road, and a tree line that runs parallel to the road. A street light opposite the tree line over-shoots the road a bit and casts a shadow onto the field, however the edge of the tree line runs right up against the edge of the corona and only light side-spill hits the field. Just past the end of the tree line is another street light, but on the same side as the field/tree line. The main illumination of bot street lights overlap to form a very well illuminated section of road that has a very high contrast with the field, especially the section which has a shadow cast on it. You could park a bus in this shadow and no one would ever see it. It isn't possible to be sky-lined in this field unless you are roughly 45 degrees to the left of the tree line from my point of view, where you might get some back-lighting from some apartments nearly a mile away. My point of view is from across the street from the field/trees, roughly at the bend in the road and maybe 80 feet from the road.

Under those conditions, would a NV unit work well, or would the street lights cause problems?

Are there any of the above situations where a thermal unit would really shine? Do thermal units require ambient light, or are they helped in any way by it? If the ambient temperature is ~100F - or roughly the temperature of what you are trying to observe -, are thermal units less able to resolve images?

Ultimately what I'd really like is something like a quality thermal unit compared side by side with the images in the TNVC NV Generation comparison guide under the same circumstances - especially the warehouse and loading dock scenarios. Any help and information would be greatly appreciated.

Are there companies that rent thermal or NV units? That is one hell of an investment for something that may not work out as intended.
 
I might (probably) be retarded, but I can't wrap my head around the picture you are trying to paint.

There are a lot of questions there, but I'll try my best to answer them or offer solutions.

Generally the lights themselves are the thing that blooms, it they are above the treeline you might be able to resolve what is hidden in the shadows, the automatic brightness control might make that a little more difficult though. In situations like that I use my DBAL-D2 illuminator to just shower that area with IR and never have problems. So if you are planning on getting a torch you'll probably be alright.

No idea about useful detection range - good gen 3 allows you to see pretty far. How far depends on lighting conditions. Zero ambient light on an overcast night or inside an unlit building won't allow you to see a thing. You'll need supplemental IR for that situation. Torch might be too much for indoors. If you've never used it, and IR light is a hell of a lot more efficient than a normal flashlight. My DBAL's illuminator (same one as the SIPR (I think)) will hit out to 700-800yards no prob, and it's small. If I use it indoors it blooms to a level that makes it unusable.

Thermal is a WHOLE different story. You'll find it almost useless indoors unless you're looking for someone, the temperature resolution just can't detect differences in temp between surfaces in a normal climate controlled room to be able to display enough of an image to walk around with (and I have a good one). Outdoors it shines for DETECTION. Using it to navigate isn't all that easy. It is extremely dependent on the conditions - not just temp, but wind, humidity as well. On a 100 degree day (or night) you'll find that people tend to lend in with surroundings, the colder it is outside the better. You'll be able to see someone from FAR away in the right conditions. Identifying weapons or if it's even a person or not is a different story.
 
Mr_Happyface - likely that I am retarded here. Your bit on thermal is pretty much exactly what I'm looking for. From what I'm understanding, it seems like thermal is exceptional under certain conditions and possibly damn near worthless under others. Whereas the deficiencies with NV can be fixed to an extent with supplemental IR.

A hand held thermal may have a place in my world after all - a different form of detection which might be able to see things that NV flat out can't see. Lets say that NV relies on your natural visual ability, like moving objects being easier to see, hard outlines, things like that. We won't get into IR reflectivity for simplicity. If an individual is hidden stationary in fairly dense foliage, they may not be "visible" with NV - as in they are for sure there, but you can't see them because they haven't done anything to get your attention. On the other hand with a thermal unit, you could possibly see there was SOMETHING there and maneuver accordingly.

All you ever see are perfect high contrast thermal videos where you can clearly see perfectly detailed animals before they get blasted. I'd love for someone to do some real world worst case scenarios which show the limitations of thermal compared to NV.

the impactzone - thanks for the additional reading, I'll make the most of it.
 
Thermal = great detection/observation capabilities.
Gen 3 night vision = Great for observation and identifying targets.

I'd go with the Gen 3 PVS-14. Helmet mounted, it basically turns night into day. Thermal imaging is a very attractive option for detection, however, target IDing is where performance is not so great. Just look at the thermal videos that are out there, white/black silhouettes with no facial characteristics.

I was spoiled with my first exposure to night vision, (Gen 3 AN AVS-6s) so that's my bias.
 
My setup isn't too bad for the price, pvs14 on the head and a D760 on the gun. soon to get a IR illuminator and a heldheld thermal mono. I think thermal to locate and NV for really seeing what your looking at is the way to go. I haven't had a chance to really test it out in the field the way I want to but it seems real promising.
 
Mr_Happyface - likely that I am retarded here. Your bit on thermal is pretty much exactly what I'm looking for. From what I'm understanding, it seems like thermal is exceptional under certain conditions and possibly damn near worthless under others. Whereas the deficiencies with NV can be fixed to an extent with supplemental IR.

A hand held thermal may have a place in my world after all - a different form of detection which might be able to see things that NV flat out can't see. Lets say that NV relies on your natural visual ability, like moving objects being easier to see, hard outlines, things like that. We won't get into IR reflectivity for simplicity. If an individual is hidden stationary in fairly dense foliage, they may not be "visible" with NV - as in they are for sure there, but you can't see them because they haven't done anything to get your attention. On the other hand with a thermal unit, you could possibly see there was SOMETHING there and maneuver accordingly.

All you ever see are perfect high contrast thermal videos where you can clearly see perfectly detailed animals before they get blasted. I'd love for someone to do some real world worst case scenarios which show the limitations of thermal compared to NV.

the impactzone - thanks for the additional reading, I'll make the most of it.


Yep, pretty much.

I was messing with it the other day, it was night and had been raining for the past few days. I went outside and might as well have had the lens cap on the image was so bad. Looked up to the trees and found a bunch of small hot spots. Looked at them through the NV and couldn't see anything - so with the help of the NV I walked closer to where they were and hit them with a flashlight, turns out it was just a bunch of birds bed down for the night. Pretty cool what you can find - although on nights like that if the image sucks it can be hard to correlate WHERE the thing you are seeing under thermal actually is in the NV. A laser on the thermal would be helpful, but I don't have one.

I've been finding that the conditions that will produce a crappy image of your surroundings (cold, uniform temps) can also be amazing for finding living things. On the other hand, I can get an INCREDIBLE image with this thing (better than $300K+ cooled thermal imagers) under the perfect conditions, but unlike those imagers the detection ability of my thermal under those conditions sucks.

I really want to do a detailed write-up of this thing but it's going to be a month or so before I can get started. There just isn't that much info on thermal out there.

You have it figured out though. I really like my setup; head mounted NV, IR illuminator & laser on your rifle, and a thermal monocular around your neck.
You can get the whole setup for less than 10K
 
Shoot something just before dark, and tell me if you can use thermal to follow a blood trail.
 
I^2 Imaging vs. Thermal Imaging

I'm looking for a straight image comparison between the two technologies ...

FailureToStart,

The following image comparisons should help you with insights to answers for some of your questions. The two images, one via i^2 (night vision) and another via thermal imaging, were taken 24 hours apart in similar conditions (as annotated).

One attribute not yet discussed in this thread are the differences between the "white hot" and "black hot" viewing modes available via thermal imaging. Black hot does not display "warm body on cool background" contrast in a manner that is as obvious to the human eye as does white hot, but can reveal highly granular (fine) details that are often washed out with white hot imaging. The thermal image on the right is black hot. Note how the warmer heat signature of the interior wood framing is visible "through" the exterior siding on the houses. The house at the center is 175 meters away from the view point. The tree-line on the far horizon is 800 meters away. Note how the thermal imager is able to discern the details of the electrical power lines at that distance.

In the comparison, you can see how the thermal imager is completely "immune" to bloom caused either by the street lights / house lights or the powerful IR illuminator beam and projection (onto the far tree line).

NOTE: the weather conditions for these images were ideal: with low humidity, no fog / mist / precipitation, and no wind. As one or all of these factors augment and combine, the resolution of the thermal imaging will substantially degrade and give up advantages to night vision.

The images below provide some parallels to the "nightmare" scenario you described, where a dark, shadowed area is surrounded by a more brightly lit area with lots of bright, point sources of visible light. With there being essentially no moon in either image, you can see how dark the area in the foreground appears with night vision. This area is a depression with a stream running through it and heavy with brush and trees, though devoid of foliage (leaves) due to the winter season. As you can see, the thermal image presents substantially more detail of this area. A whitetail deer traversing this area would be very difficult to detect with night vision, without supplemental illumination, but would stand out clearly to the thermal scope.

In the night vision image, note how the ambient light from the IR illumination beam reveals some faint details of the trees and brush in the dark area. In your scenario, a bus parked in this dark area would probably be visible to the night vision as a result of ambient light reflecting off of it's smooth and reflective surfaces from the distant light sources. Note how brightly the sides of the houses (in the shadows) appear. Plus, in the night vision image, there are residual patches of white snow on the house at the center -- note how they are in the shadows of the visible light and yet highly visible to the night vision scope. For these types of surfaces, any supplement to the ambient light, even as indirect light reflected from a supplemental illuminator will substantially increase visibility to night vision.

Both images, by the way, were captured at unity (1x magnification). The night vision scope in this comparison, has a much broader field of view (FOV) than the thermal scope.

IR-V

2urqfde.jpg
 
Pretty crummy photo of some deer hanging around the feeder at 175 yards in black hot mode:

FLIR%20ACOG%20Deer%20Gray.jpg



Realtime image is about 10X better than this digital photo is on the web.


Hogs show up great too!

Thermal%20Pig.jpg
 
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Nice cannon for a IR lum you got there Irv!

Vic, it's a single beam test of a tri-beam PICO projection system that I adapted with IR capability. Later that evening, I took the assembly out to the mountains where I projected a video from an iPhone onto the side of a mountain 2 km away -- all visible only to viewers with i^2 night vision. Brings whole new meaning to "drive in theatre" ... LOL :)

IR-V
 
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IR-V, what imager and what size objective are you using in the thermal image you posted, it looks damn good.
 
How we look to mosquitoes

IR-V, what imager and what size objective are you using in the thermal image you posted, it looks damn good.

Mr_Happyface,

I've built a slew of custom short-range and long-range, thermal weapons scopes on DRS cores. I'm heavy into the back-end processing, and therefore prefer to collect as much "raw data" as possible on the front-end. As a result, I use 42mm objectives on my short-range builds. Honestly, I don't think they add untenable size or weight to the overall proportions or mass of the unit.

Here are some images from a long-range imager / weapons scope that I've built and am currently testing. Without going to a multi-sensor matrix / array (coming soon to my labs), the key, I've found, to gaining "eye popping" performance is to max the sensitivity on the core and interpolate to the highest resolution OLED possible. Check out the ability to discern veins on a human arm (and running along the fingers of an open hand) at 100 meters ... that was the max distance I could get in the halls of the Caesar's Palace Las Vegas convention facilities! Talk about a heat map that mosquitos would kill for! :)

As presented previously, black hot provides certain advantages to the human eye for perceiving details ...

IR-V

2ef7vif.jpg
 
The following image comparisons should help you with insights to answers for some of your questions. The two images, one via i^2 (night vision) and another via thermal imaging, were taken 24 hours apart in similar conditions (as annotated).

Wow, those images are pretty remarkable.

Any chance you'd be willing to take an image off the thermal under really horrid conditions, something like a climate controlled room?

Thanks a bunch, its starting to look like a NV is a good place to start, but thermal is a great addition.
 
Wow, I bet you can identify gang members by their tattoos with that setup!

Skypup,

"Prison Tats" made from a common "jail cell" (ad-hoc) ink show up extremely well when viewed with thermal imagers! :)

IR-V
 
The objective lens on that system has got to be 100mm plus.

Without giving away too much, it is a variable lens system - meaning I've designed it so that I can replace the objective lens and tune the mechanical and electro optics as needed! ;-)

IR-V
 
Wow, those images are pretty remarkable.

Any chance you'd be willing to take an image off the thermal under really horrid conditions, something like a climate controlled room?

Thanks a bunch, its starting to look like a NV is a good place to start, but thermal is a great addition.

Welcome, FTS. Glad to help.

"Really horrid conditions" is a relative condition. Poor thermal imaging conditions differ between outdoors and indoors. In the outdoors, where airborn moisture (humidity) tends to be higher, wind can degrade the imaging by leveling the contrast. In the indoors, which tend to have desert-like (arid) conditions, forced air (from HVAC, for example) actually improves the contrast -- the worst, indoor conditions are when heating or cooling has occured at a consistent level over a long period of time, in a well-insulated room or enclosure (such as one's wife's wardrobe closet), with lots of wood, leather, fabrics, non-reflective, and non-metal surfaces, and in the periods between when the air is forced into circulation (by HVAC fan / blower, for example).

Even in these "poor" conditions for thermal imaging, when something or someone with strongly contrasting temperature range and gradient is introduced, it will appear very clear and detailed to the thermal imager, but will appear to be "floating" in a uniform cloud or mist. In fusion imaging, where i^2 and thermal images are joined into the same viewing plane, this phenomenon is actually a beneficial thing, as it helps present a thermal image (within the night vision context) that highlights only what is "hot" and prevents distraction by image artifacts from what is "not (hot)". An example, is the "outline" mode or "patrol" mode found on dual-band "fused" imaging systems.

Furthermore, all the current thermal weapons scopes at 0.3 megapixels or higher resolution collect more image detail than your eye can see without enhancement. This is where the back-end processing becomes important. There are many techniques for this, such as compressing the color range, adjusting the color midpoints for hot/cold, or setting new thresholds for "what is hot and what is not". Some makers of thermal imaging scopes use all these techniques, embedded in firmware and via on-board processors, to provide "enhanced" or "optimized" imaging under the less-than-ideal conditions previously described. This is not unlike a scientist applying stain to a specimen being viewed under a microscope. Other makers purposefully avoid these enhancements, preferring to give a pure presentation, and letting the user apply physical filters on the viewing or presentation end to improve contrast. These are akin to the makers of "audiophile" sound systems that provide as simple and direct a connection as is possible between the power amplifier and speakers ... their goal is high "fidelity" ... if the user desires more "contrast" it is up to the user to insert sound processing gear (such as equalizers, compressors, etc.) in-line with the system. Neither approach is better or worse, but is a matter of the user's preference and, for this discussion, imaging "philosophy".

IR-V
 
...Furthermore, all the current thermal weapons scopes at 0.3 megapixels or higher resolution collect more image detail than your eye can see without enhancement. This is where the back-end processing becomes important. There are many techniques for this, such as compressing the color range, adjusting the color midpoints for hot/cold, or setting new thresholds for "what is hot and what is not". Some makers of thermal imaging scopes use all these techniques, embedded in firmware and via on-board processors, to provide "enhanced" or "optimized" imaging under the less-than-ideal conditions previously described. This is not unlike a scientist applying stain to a specimen being viewed under a microscope. Other makers purposefully avoid these enhancements, preferring to give a pure presentation, and letting the user apply physical filters on the viewing or presentation end to improve contrast. These are akin to the makers of "audiophile" sound systems that provide as simple and direct a connection as is possible between the power amplifier and speakers ... their goal is high "fidelity" ... if the user desires more "contrast" it is up to the user to insert sound processing gear (such as equalizers, compressors, etc.) in-line with the system. Neither approach is better or worse, but is a matter of the user's preference and, for this discussion, imaging "philosophy".

IR-V

To simplify without giving away any prorprietary info, is this processing lookup tables, Fourier transforms, iterative reconstructions, or... ?
 
To simplify without giving away any prorprietary info, is this processing lookup tables, Fourier transforms, iterative reconstructions, or... ?

All of the above and more. The Fourier transforms are a staple for data sampling, the "more" is in the type of analysis that is applied. Lookup tables are a staple for keeping up processing speed when managing palettes and certain filters, the "more" is in how they are used to manage gradients. Iterative reconstructions and other fractal / chaos theory methods are more useful for image compression and identification of objects of interest in a target field.

IR-V
 
Thank you. Though I am an "end user" of such tools at work, not a developer, it must be a gas! If you lived closer, I'd pester you to "Let me see! Let me see!"
 
Vic, it's a single beam test of a tri-beam PICO projection system that I adapted with IR capability. Later that evening, I took the assembly out to the mountains where I projected a video from an iPhone onto the side of a mountain 2 km away -- all visible only to viewers with i^2 night vision. Brings whole new meaning to "drive in theatre" ... LOL :)

IR-V

VERY NICE IR-V. There is definitely a few other applications we've been dabbling with in this arena. PM sent.

Vic
 
Another good night vision thread that quickly turned into something that most of us cant understand.
 
Aye, and I get the feeling the budget for the PVS14 is dwarfed ever so slightly by whatever produced those thermal images.
 
Thank you. Though I am an "end user" of such tools at work, not a developer, it must be a gas! If you lived closer, I'd pester you to "Let me see! Let me see!"

Welcome, Nukes! I appreciate your interest to "look beneath the hood" -- that makes you an engineer at heart! :)

IR-V
 
VERY NICE IR-V. There is definitely a few other applications we've been dabbling with in this arena. PM sent.

Vic

Thanks, Vic. PM didn't come through. Since the format change on these forums, my PM here has been inconsistent on receiving messages.

IR-V
 
@ IR-V

I am curious. What was the outcome of your multi sensor array project?

I am further curious. <s>Are you aware of</s> Can you discuss any worthwhile "jail breaks" for the LWTS?