Countering Aerial Thermal Surveillance

I have moved this post up from its October 2012 date due to the number of questions I have received about the ‘Thermal Ponchos’ that feature in ‘Patriot Dawn’ and Contact!’ I will be putting up a post about the ponchos themselves shortly.

Following on from my comment in the previous post about having to hide from Drones, I thought it would be a good interest topic to write about the threat of aerial thermal surveillance. A few ‘open source’ comments and facts about this threat, should you ever have to face it.

Here is a video that shows this in action. WARNING: not for the faint hearted, this is real kill cam video from Afghanistan. Think you can get out of this one? If as a survivor you find yourself in a situation where some enemy has a FLIR capability and they are hunting you, it is a complete game changer and you would have to totally adapt your TTPs to take account of this threat. Darkness is no cover. You would have to live under hard cover preferably under a deep tree canopy and preferably only move using defiles and in areas of dense overhead canopy.


Thermal Imaging is a different thing than normal image intensifying, which magnifies available light. FLIR or thermal imaging picks up heat, and really it is about heat differentials, which allows it to create an image. It can be seen as white (hot) on a black (cooler) background, or the color view can be flipped. You can also be seen as a cooler spot on a hotter background. The thing about FLIR is that it can be blocked by some form of cover. In a similar way to cover from view and cover from fire, the best form of protection is hard cover, and things like foliage, if you have enough, will also protect your from view by the operator. That is why FLIR is so useful in places like the desert where there is not a lot of cover, and you get almost perfect images of people.

What you have to watch out for is your body heat starting to heat up the thing you are taking cover behind. So, if you want to hide from FLIR, you want to block the image of your body heat, and also the view of any non-environmental heat that you may generate into your cover. It has been talked about that you can use blankets to help with this, but eventually you will heat up the blanket so that can only be a short term fix. A good idea, if you were mobile and had no choice, would be to carry a combination of a space blanket sandwiched in something like a normal blanket or better a military camo poncho liner blanket. Be aware that you also have to be camo against normal non-IR naked eye, so you still need to be camouflaged. A flip problem is appearing as a hole in the background, so you want to think about your cover being the same temperature as the background if possible.

Movement is always a problem, and will attract the eye of an operator. So, if you think you may be under observation, don’t move. But unless you can disguise your human shape, you will be seen anyway. Best thing: get in a cave!

It’s a big topic, but basically your night vision type goggles (NODS/NVGs) are image intensifiers, which simply help you to see via available light at light, such as moonlight. They can also use active infrared light in the near infrared spectrum, which is like a spotlight that you can’t see with the naked eye. So, image intensifiers can be passive or active. Active is a problem if someone else has one, then they can see your light like daylight to them, even though it is dark to the naked eye. That is why US technology works well at night against low tech insurgents who don’t have the gear.

Thermal imaging is the system where you see the heat differential, such as in the clip above or a police tracking helicopter. That uses IR technology, but IR is a big spectrum so has a lot of uses. Basic stuff, the thermal/IR imaging cameras see the thermal signature.

Military BDUs are usually designed to be IR retardant, which reduces IR signature. Often, this comes with specific care and washing instructions, and you can ruin the capability. There are also issues of how a material matches the background in terms of emissivity/reflectivity, and I would beware use of a tarp due to the way the surface reflects. That is why something like a Mylar blanket could be used but to line something with less reflectivity, such as some kind of camo material or a blanket type thing. So, wearing IR retardant gear will help, you will be “less white” on the imager, but you will still be seen.

Thermal imaging is just that, it is not an x-ray machine, but it will see radiated heat and if you warm the object you are under or behind it will be able to see you. Bottom line is you need some way to block the heat signature but also have that material matching the background in a decent way. For instance, something like a ghillie suit would probably work well. Maybe you could create a “ghillie blanket” with an inside Mylar space blanket that would be bulky but that you could pull over you, hopefully the ghillie material side would match the background a bit better and would not reflect. Carried on the outside of a ruck you would hope that it would adapt to the background temperature and then be ready to deploy and get under as necessary. Only if you hear the chopper in time. If you don’t hear it (i.e. Drone) you won’t know it’s up there….be afraid, very afraid…

The whole IR thing is a little confusing because “IR” or infrared is basically a non-visible part of the light spectrum that has lots of uses *(ask a science teacher….). The confusion comes in when we talk about Image Intensifiers and Thermal Imaging. They both actually use IR technology, but in different ways. Image intensifiers just amplify ambient light. Thermal images see the heat differentials, but they both use IR. I went on the net and found this on Wikipedia to help describe it:

“Active infrared night vision: the camera illuminates the scene at infrared wavelengths invisible to the human eye. Despite a dark back-lit scene, active-infrared night vision delivers identifying details, as seen on the display monitor. Infrared is used in night vision equipment when there is insufficient visible light to see. Night vision devices operate through a process involving the conversion of ambient light photons into electrons which are then amplified by a chemical and electrical process and then converted back into visible light. Infrared light sources can be used to augment the available ambient light for conversion by night vision devices, increasing in-the-dark visibility without actually using a visible light source. The use of infrared light and night vision devices should not be confused with thermal imaging which creates images based on differences in surface temperature by detecting infrared radiation (heat) that emanates from objects and their surrounding environment.”

“Thermography: infrared radiation can be used to remotely determine the temperature of objects (if the emissivity is known). This is termed thermography, or in the case of very hot objects in the NIR or visible it is termed pyrometry. Thermography (thermal imaging) is mainly used in military and industrial applications but the technology is reaching the public market in the form of infrared cameras on cars due to the massively reduced production costs. Thermographic cameras detect radiation in the infrared range of the electromagnetic spectrum (roughly 900–14,000 nanometers or 0.9–14 μm) and produce images of that radiation. Since infrared radiation is emitted by all objects based on their temperatures, according to the black body radiation law, thermography makes it possible to “see” one’s environment with or without visible illumination. The amount of radiation emitted by an object increases with temperature, therefore thermography allows one to see variations in temperature (hence the name).”

Much as I would not like to contemplate our own assets being used against citizens, there are theoretical situations where such knowledge could be useful. However, never assume an enemy has an all seeing ability and just give up. Friction, assets and battlefield clutter, plus human error, comes into play. We survive in those gaps.

For instance, often people do not give enough thought to the full scope of a collapse, beyond stocking up and having a couple of weapons. What if in a post collapse power vacuum another power moved in? What about China? Then, rather than a civil war you may be fighting as insurgents/partisans/freedom fighters, if you so choose. The foreign invader may not have, or perhaps be left with after some combat, full all seeing capability. Perhaps the main threat is Chinese FLIR equipped hunter killer helicopters?

For an interest discussion, that is something that may be considered and you may need emergency counter measures in case you are caught out. Also, you can amend your operating procedures to have camps in suitable defiles in densely forested areas, or even ratlines on urban areas, to counter the threat. Hell, think of it like the resistance in the first terminator movie if you like!

Food for thought…..