FLIR camera

[ucorky]

I am looking to rent/buy a FLIR camera for a very low budget experiement.
I know they run about 6K to buy but any suggestions on obtaining one to use for a week would be appreciated.

PM me please.:o

[Hirudinea]

FLIR stands for Forward Looking Infra Red I assume, so do you just want an infrared camera? If so look up "infra red cam mod" or words to that effect on Google, modern (cheap) digital cameras can see in infrared, they have a filter put over the lens to stop them from seeing it though, all you have to do is take the filter off and you have IR, point it so it looks forward and I assume it would be FLIR.

[stupid939]

I believe that ucorky is talking about thermal imaging cameras. A quick search showed that he was right, and the cheap models went for around 6K. He was probably searching for something like this (http://www.imaging1.com/thermal/IR_250.html), but all of the sites that I visited, stated that you would need to call in order to negotiate rentals.

I am guessing that you are testing masking heat techniques or camouflage, and I am pretty sure that you can find the results that you are looking for on the net. If you inform us on what you are doing, I'm sure that someone can help you and save you a few hundred/thousand dollars.

[Jacks Complete]

FLIR tends to have two modes, it can be active or passive. Active uses the same camera as passive, but a tight beam of IR is used for illumination. Pretty much the same as NVG. FLIR tends to be thermal wavelengths (long IR), rather than shorter NIR as found with NVGs.

Often found on aircraft and things that move forwards at high speeds, as it is useful for seeing in the dark and through fog, etc. and often integrated into a digital sighting system that covers multiple spectrum ranges, including NIR and visible, and often microwave and radar.

Feel free to ask any questions.

[bigbhoy]

I am guessing that you are testing masking heat techniques or camouflage, and I am pretty sure that you can find the results that you are looking for on the net. If you inform us on what you are doing, I'm sure that someone can help you and save you a few hundred/thousand dollars.

I was also wondering about what exactly they could see through. I'm sure you've seen those police shows on tv, in which the helicopter has tracked some kid in a neighbor's backyard. They think they're safe, but the camera has caught their heat signature despite them hiding in a wheelie bin.

Also I caught a repeat of a Mythbusters episode last months on Sky & they used one a thermal camera to test the various ways of how it was bypassed in the movies. A way that they got around it was by using a fire suit (the silvery metallic looking one), which concealed all the body heat.

This got me wondering about those 'Rescue Blankets' that you see people getting draped around them after getting rescued from whatever dangerous situation on tv. Just how effective would they be against a thermal imaging camera!

Sample Pic (http://i6.ebayimg.com/06/i/000/95/26/59f9_1.JPG)

I doubt one would block all the heat if you were hidden under it, but do you think a few layers of them would prove adequate in blocking all the body heat from being detected?

[Jacks Complete]

If you touch it, you will be seen after a few seconds due to conduction. However, if it is above you, to reflect the IR radiation, you will be fine for much longer. You should probably use two layers, spaced a few inches apart, just to be on the safe side.

[Hirudinea]

This got me wondering about those 'Rescue Blankets' that you see people getting draped around them after getting rescued from whatever dangerous situation on tv. Just how effective would they be against a thermal imaging camera!

If you touch it, you will be seen after a few seconds due to conduction. However, if it is above you, to reflect the IR radiation, you will be fine for much longer. You should probably use two layers, spaced a few inches apart, just to be on the safe side.

A thermal blanket might also protect you longer if you wraped yourself in a regular blanket first, then the thermal blanket, this would insulate your body heat from the thermal blanket for a sometime longer, just like a winter coat stays warm on the inside and cold on the outside.

[LibertyOrDeath]

Thermal imaging is a subject that I've been very concerned about for several years. If in the future it ever becomes necessary to resist a tyrannical government, thermal imaging will be one of the guerrilla's worst enemies (and best friends, if he can afford it or otherwise obtain it).

Here's a post I found on another board years ago (bold emphasis added):

I was in Search & Rescue for many years, and we used various "thermo" devices for searches, including aircraft-mounted devices. It's not uncommon for folks who've been lost for a couple days or more to actually hide from the searchers; this is especially common in kids, but it often happens with adults, too.

The thing to remember is that you want to "break up" your heat signature so that it doesn't come off as an identifiable shape or blob. They can't really see your outline; only the concentration of your heat signature shows up on their monitor. On cold days the device works much better; the cooler the surrounding area, the better you show up. Even so, if it's warm and sunny during the day, then rocks can store enough heat to give them false readings.

You got to remember they are probably going at least 100 mph — that's why the device has to "look" forward. Whatever shows up on the screen ain't there long. Keep that in mind, and make your heat signature very vague and confusing. Stay the hell out of the open, and avoid objects that will contrast you: e.g., walking up a creek would be a mistake. We found a fellow in just such a manner; he showed up like a turd in a punch bowl. On the other hand, you could hardly get a signature from a man standing on pavement during the summer at all.

So think in terms of overhead cover for aircraft evasion; be thinking brush "screens," rocks, ledges, and deep little valleys, etc. In rougher country it's not really much of a problem, since those are the kind of "covered" routes you're likely to be using anyway.

On all the aircraft I dealt with, the device "looked forward" from the nose, and there was definitely a "dead space." Also remember that when the aircraft turns, etc., large areas are missed. There were lots of times when I was coordinating the aircraft from the ground with a radio, and they would have a hard time getting my signature for "calibration" if I was on a hillside or deep valley, or if they came in on the "off" side of a steep canyon where I was. If I had wanted to "evade" them, they would have had a hell of time.

We also had some very nice hand-held units that we played with quite a bit. They are probably more dangerous to the evader than aircraft-mounted units, since they function in more of a "line of sight" mode and can be manipulated more slowly and with more control. They worked well for finding kids that would squirrel into brush for shelter and not respond to their names. Of course we used them on each other as well and experimented with "fooling" them.

On most searches we would force march in at night, since most folks get reported missing real late in the day. I was on the "First Response Team" and we wanted everything as fresh and "hot" as possible. By daylight folks would be coming in to "help," so things would get all fucked up. We wanted to be long in the bush before they got there.

After interviewing the "reporter," looking at the topos for "natural lines of drifts" and taking in account age, experience, and what the individual was doing out there to begin with, we made a plan. Actually, tracking at night can work in your advantage; using a headlamp you can "shadow" sign that wouldn't show up in the daylight. Some of us would "set up" on the "natural lines of drifts" and glass the large, open parks, especially at the junction of trails and creeks. With the hand-held devices you could get a signature at 700 yards if conditions were right for it and if they were not behind rocks or a thick screen of brush. Keep that in mind if you find yourself the object of desire. As soon as they find any sign of you they will put in concealed blocking forces up in front. Anyway, that's getting off in another direction.

We tried the "space blanket" concealment gag, recommended in so many "militia" gear lists. It does and it doesn't work. This is what we found:

If you wrap yourself up in the blanket, you concentrate your heat signature and end up standing out like a whore in church. The mylar blankets themselves don't give off much of a signature, but they still allow heat to be transferred to the cooler air around you because you don't have enough dead air space. In short, they don't work worth a fuck in such conditions, and, once again, the so-called "militia" people don't have a clue about what they are suggesting.

The blankets can work if you rig them as a low "tarp shelter" with at least 24" of dead air between you and the "line of sight" of the device. We found out, however, that a simple GI poncho does just as good a job. Something else interesting is that good sleeping bags work well at hiding your signature, especially under a tarp shelter or in a bivy sack. Be thinking about lots of dead air between you and whatever overhead cover you have. If you can break up your signature to the point where they can't "read" it for what it is, they will fly right on by.

Rigging a tarp shelter at the base of a large tree with lots of branches and thick brush around and above it would fuck them up good. We also tried the classic winter "camp" of digging the snow from around the base of a big pine tree and using the overhead branches for cover. That worked well for even the handheld unit, as you were below the line of sight.

If you have to evade, just assume they are going to be using thermo devices, especially if you live somewhere near national parks, etc., where folks are recreating in the back country. These areas always have both paid and volunteer Search & Rescue teams with dogs, etc. Maybe even join S&R for a season or two — it's good outdoor experience, and you will find out exactly what they have and how well they use it. S&R also coordinates with the Sheriff's Department, so you will find out just how much those dickheads know as well. It will take a day or two for the Alphabet Thugs to get on the scene. You need to be gone before the goons get there.

When you go on the run, "locals" will of course will be the first to respond, and lots of times they use the civvie S&R folks because they are for the most part far more experienced and know the local area well. It pays to know who these folks are in your area and how a search gets conducted, especially when a time comes where you are the guest of honor.

This is a good subject. So many folks have this Che Guevara fantasy that they are going to be conducting ambushes and raids and then "fade" undetected into the wilderness. Fuck, I've brought so many so-called "woodsmen" out of the backcountry, I've lost count. If are going to survive as a guerrilla, you'd better start getting "hard" right now. You'd better be one "land-navigating SOB" and have good feet under you. There are other things that need addressing too, but this thread was about thermo detection.

Other IR countermeasures I've read about include ghillie suits made of natural vegetation. This is supposed to work quite well. Even plain old ghillie suits may do the trick, although they're hot to wear.

An umbrella covered with natural vegetation has also been used by some military snipers as portable concealment (not just from IR, either). The stand-off distance between you and the vegetation provided by the umbrella's "stem" prevents your body heat from being transferred effectively to the umbrella's "dome."

It's also worth noting that in urban areas, IR wavelengths do not penetrate glass well. This is why IR imagers need to use special material for the lenses (sapphire is one, if memory serves).

The following link also provides very good information:

http://www.snipercountry.com/Articles/IRDetection.asp

Of course, for an IR imager to be effective, the user has to know generally where to look. These units were certainly available when Eric Robert Rudolph was on the run and when everyone was looking for the "DC snipers." So they don't provide the pigs with godlike awareness of everything. It's still very good to know how to defeat these devices, though.

[Jacks Complete]

Not sapphire, but Selenium Oxide is used for longer IR wavelengths. It appears black and opaque to the eye, and is a toxic material that is water damaged easily. Therefore it is always coated with something, usually an AR (anti-reflective) coating.

That article by the SAR guy pretty much backs up what I said.

I recall an interesting cold war story. The West German side dug a tunnel under the border somewhere, for some reason. One day they looked over the ground above it, and the snow had been cleared, all the way along it. Looking over the other side, it was also clear! They paniced, then someone realised that the heat of the men digging and the heaters had simply melted the snow on the ground in the marginal conditions for the snow. They shut down the heaters and the problem disappeared.
Obviously, a modern thermal imager would have found the tunnel in a few seconds.

[imported__Jim]

A little background information, if I may, as to why FLIR is called FLIR (it's historical background) as opposed to other obscure IR systems like IRLS and SLIR.

http://www.wat.edu.pl/review/optor/10(2)111.pdf

(If the link above does not work this paper can be found by doing a google search on: "10(2)111.pdf")

Infrared devices and techniques (This is a good paper BTW)
A. Rogalski and K. Chrzanowski
Opto-Electronis Review 10(2), 111-136 (2002)

"FLIR" is archaic sixties jargon for forward-looking infrared
to distinguish these systems from [aircraft "belly"-mounted]
IR line scanners, which look down rather than forward. Conversely,
most sensors that do look forward are not considered to be FLIRs
(e.g. [InfraRed] cameras and astronomical instruments). The term
"FLIR" should be eliminated from IR techno-speak, but is
still used and is likely to remain in the jargon for a while.

- - - - - - - -

And this -

IRLS SLIR FLIR

http://student.bton.ac.uk/engineering/msc_de/DGM01_MSc_CV/CHAPTER9.PDF

The Tornado reconnaissance aircraft carries three scanners, an IRLS (IR linescan) slung under the fuselage and two sideways-looking IR (SLIR). The IRLS scans across the track of the aircraft from horizon to horizon and thus allows a two-dimensional swath to be captured as the aircraft flies forward. The imagery is corrected for the geometric 'bow-tie' distortion which results from the variable 'footprint' of a sensor photosite as it is scanned from directly beneath the aircraft's track to the horizon. Therefore a pixel captured from near the horizon should not be displayed with an area equal to one captured from near the aircraft track. This is particularly important because it is often impossible (or unwise) to fly directly over the suspected hostile territory, meaning that much of the useful information is contained in the relatively low resolution pixels towards the horizon.

The SLIRs are framing sensors that look out from either side of the aircraft. Their imagery is arranged to scroll from left to right on the navigator's monitor whilst the IRLS imagery scrolls from top to bottom. All imagery is electronically annotated with the aircraft's height, velocity, position and heading at regular intervals. When the data is returned to the ground either by radio link, or physically, it can be further enhanced by a ground-based image processing workstation. This reconnaissance system proved itself to be a great asset to the allies during the Gulf War of 1991.

A third type of IR scanner is used by other aircraft, helicopters and civilian agencies. It is called FLIR (forward-looking IR). Like, the SLIR it is a framing sensor but it may be mounted in the nose of an aircraft or slung on a gimbal mount underneath a helicopter or in ground-based surveillance applications.

The AGEMA "Thermovision 1000" is a FLIR operating in the 8-12 µm band. It has a 12-bit 'luminance' resolution and a spatial resolution that allows it to detect a human on land at 3 km, a 30-foot boat at 10 km or an aircraft at 60 km [43]. It employs a electromechanical scanning system to focus radiation onto a five element SPRITE (signal processing in the element) array [44]. This type of detector allows very good signal to noise performance to be achieved from a scanning system.

[imported__Jim]

Thermal imaging is a subject that I've been very concerned about for several It's also worth noting that in urban areas, IR wavelengths do not penetrate glass well. This is why IR imagers need to use special material for the lenses (sapphire is one, if memory serves).


Prowling around in the paper titled "Infrared devices and techniques (link above) paragraph 2.7 is about "Infrared Optics" and mentions the materials used for refractive optics include Germanium (2-15 um transmission range), Silicon (1-7 um and 25-300 um ranges), fused silica (.3 - 3 um), glass BK-7 (no lower than 2.5 um), Zinc Selenide (2 - 22 um) and Zinc Sulfide 2 - 12 um).

A radiator at ambient temperature (a little cooler than the human body) would radiate most effectively in the 8 - 14 um band whereas a hotter object such as a furnace would emit the greater amount of its radiation in the 3 - 5 um band

[anonymous411]

If you're looking for 24 inches of dead air to diffuse your signature, might a 42" Balcar metalized photography umbrella work? And if so, could you construct an improvised shield from a space-blanket-lined normal umbrella?

This topic is way outside my area of expertise, but it seems like an interesting possibility.

http://www.calumetphoto.com/resources/images/prod_tnlg/bf20203-1.jpg

[LibertyOrDeath]

Jacks Complete and Jim: Thanks for that further information.

anonymous411:

I'm not sure the metal lining or space-blanket lining would even be necessary.

The real advantage of the umbrella is simply that it creates space for airflow between you and a barrier that stands between you and the IR imager. Thus, you don't transfer any appreciable heat to the barrier. But that barrier still needs to be camouflaged -- an umbrella can still be seen for what it is through an IR camera! Natural vegetation should do the trick in appropriate surroundings.

------------

To get an idea of the capability of IR imaging devices, I looked up some videos on YouTube. By observing how certain barriers block the bright thermal signature of the people in the videos, we can see that thermal devices are far from invincible:

http://www.youtube.com/watch?v=0jwlwENJnlg

In the above video, we see at 0:22 that even heavy clothing can GREATLY reduce thermal signature relative to uncovered areas (such as the face and hands).

The thermal signature at 0:57 looks a lot brighter for some reason (gain turned up?), but the car in front of the person blocks his thermal signature completely -- just as an umbrella or similar screening device might.

At about 1:38, we see that the jacket worn by the guy on the left has reduced the IR signature from his torso enormously. Being covered head-to-toe with similar material (or something like a ghillie suit) might make him nearly invisible to a thermal scan -- especially a cursory one.

Here's a similar video:

http://www.youtube.com/watch?v=e34kiSgr8l0

Note at 0:12 how the man's jacket appears cooler toward the bottom, where the jacket "hugs" him less and fits more loosely. That's to be expected: heavy but loose-fitting clothing that allows more air circulation between the skin and the cloth should present a lower IR profile. Note the comment in my first post on this thread where the search & rescue veteran said that a simple GI poncho does a good job of masking IR.

Note also around the 1:00 mark how the IR system doesn't see through foliage itself -- only through the darkness created by the foliage. A person completely covered with foliage would not be seen. This is very well demonstated in the same video around 2:17.

[Jacks Complete]

Basically, it's not a FLIR unless it is on a vehicle. An IR thermal imager is just a thermal imager.

The YouTube videos are quite interesting.

One thing to point out is that the difference in the temperatures that can be picked up are very, very small on high-end cameras. Less than 1/10th of a degree will show up well on a high end camera. In a fast scan, these tiny differences would be missed if there were something else warm in the picture, as the cameras tend to auto-adjust the scale, so the hottest thing is always white, and the coldest is always black (or perhaps colours) so a 800 degree ciggie butt will mask you at 35 degrees, until the camera pans so the butt is out the frame, then it will re-scale so you are the brightest thing visible.

http://www.youtube.com/watch?v=6mV4ecEbV1s&mode=related&search= shows a few more tricks, like the fact that garbage bags are see-through - hence the "X-ray" specs you can buy for near IR cameras.

As an aside, you can use a thermal scan to check for heat loss in your house (it's on YouTube) and you can also use them to find hidden cameras and microphones, due to the heat residue from the CCD and batteries.