At the very end of this (sad) article are three pictures of I presume a Belgian SWAT team assaulting a suspect’s hideout in Molenbeek.
Is it an infrared camera?
Yes, if you click on the picture it gets bigger and there’s a caption that says it’s a thermal camera.
ETA, I see what your question is. A ‘thermal camera’ is an infrared/FLIR camera. Same thing.
Oh, yes, I saw the caption; but through experience I’ve grown to doubt technological information given in daily newspapers.
Now that you mention it, however, there must be something important about the “Forward” in FLIR that makes them a different refinement of the design.
Not to be rude, but have you considered just looking some of this stuff up? That’s how I made sure a thermal camera was, more or less, the same as an IR camera before I said it.
Here’s the wiki entry on the meaning of forward in FLIR
(ETA, just because I think it’s funny…it means the camera is looking forward)
No there isn’t. FLIR is an acronym that goes back to at least the early 80s. There is also a company named FLIR that makes most of the commercial IR cameras in the world.
Thank you. So did I.
I take it you found it interesting.
Correct me if I’m wrong but I thought that anything above 0 Kelvin emitted radiation. Are particular bands of the IR spectrum more linked to heat than other parts of the electromagnetic spectrum?
Is it only long-wave IR that can’t see through windows? If so, I’d expect a SWAT unit to use medium or short wave IR if those can see through glass. So if only LWIR counts as thermal vision and the Belgian SWAT wants to see through windows, they wouldn’t be considered thermal vision.
I don’t know which of SWIR, MWIR and LWIR do the best job of seeing through smoke and fog which would matter here since they used it to see in a room they’d put gas in.
The wavelength is linked to the temperature. Heat something enough and hey, you just invented lightbulbs!
So, both the frequency and the amplitude are linked to the temperature? Does the frequency increase at the inverse square root of the energy input and the amplitude linearly with the energy input?
Does that mean that, ceteris paribus, blue is brighter than red?
Does that mean that heating something only a little could be picked up by mm wave radar?
Wheh talking about the radiation itself, blue is brighter than red for certain temperatures, red is brighter than blue at others; a heated object such as a bar of iron will start displaying visible radiation in the red and go further into the visible spectrum as it heats more (a red hot iron is not as hot as a white hot one). The radiation emitted is not a single wavelength except in very specific conditions. Frequency and amplitude are always linked to each other.
When talking about “thermal imaging”, the process which turns the invisible radiation picked up by the camera into the visible image we see follows protocols using whatever color codification we wish to impose on it. Blue is normally used to mean “cooler”, but that’s human choice.
You almost have it. We are talking mostly in terms of black bodyradiators. The spectra of black bodies depends upon the temperature, and has a characteristic shape. It is more complicated than something as simple as the energy input, or its square root. To use energy you would need to work out the equilibrium temperature. The peak of the curve is however simply proportional to the inverse of the temperature. The curve has two important characteristics. 1. As the temperature increases the peak moves to shorter (bluer) wavelengths. 2. The curve always includes the entirety of the curve at lower temperatures. So even when the peak of the emission becomes bluer, there is still more light in the red being emitted than when the peak was back in the red. Clearly the integral of energy across the entire spectrum must equal the energy input, but since the shape changes it isn’t as easy as saying the amplitude goes up linearly with energy input. It depends what you mean by “amplitude”.
Not everything emits radiation as well as a black body, so there are variations in what you see with a FLIR that depend upon the material as well as its temperature. As you get to far IR you are not really detecting light in the manner we usually detect photons (ie with a process dependant upon some for to QED interaction), rather you are measuring how much the sensor heats up - and the device is really an imaging bolometer.
Any hot thing is emitting in the mm wavelengths - see above about the point about the spectrum always encompassing the entire spectrum of colder curves. The most famous millimetre thermal radiation is of course the cosmic background radiation. The trouble is that the noise in everything else makes it very very difficult to differentiate the signal.
Provided there is a temperature difference between objects and that thermal radiation makes it to the FLIR sensor you will get a reasonable image. FLIR has limitations when objects are a similar temperature to the background, the image becomes washed out.