Improved IR Image (TGP IR)

[Pyroflash]

Actually, more advanced physics sees thermal energy in terms of 'statistical mechanics'. An increase in entropy (disorder) in the state of the system (particles) is a result in transfer of energy by photons, and what we notice as macroscopically as 'heat'. The increased disorder may be due to mechanical energy of the system (Brownian motion) or rotational energy around molecular bonds.

 

To understand how temperature affects intensity in the infrared band of the electromagnetic spectrum you can use Planck's Law (if you assume the emitter acts as a 'black body'). Planck's Law gives the spectral radiance at each wavelength for a given temperature.

http://en.wikipedia.org/wiki/Planck%27s_law

Don't look at the equations (you'll go cross-eyed), look at the graphs of the spectral emission for temperature. Notice how hotter objects emit more overall and have distributions with peaks toward lower wavelengths (higher energies). The difference in the wavelengths of the peaks is what IIR (Imaging Infra-Red) cameras use to discriminate objects (of they emit at different temperatures). These cameras must be sensitive to notice the small wavelength changes for different objects (and also need to be cooled so that the camera itself doesn't emit at the wavelengths of interest, or its own emissions would swamp the signals of interest).

 

Objects with similar temperatures to people emit in different parts of the IR band. Cooler objects may emit with peaks at longer (lower energy) wavelengths. On a very hot day trees may have a similar temperature to the temperature of a human body, which makes it hard to distinguish between them in warm weather. In colder conditions (snow on the ground) the difference between ambient and a human is much higher and discrimination is much better.

 

Hot objects (burning vehicles) may emit in the long wavelength end of the visible spectrum. These objects are 'red hot' (visible) with additional emission past red and in the IR part of the spectrum (which we feel as the heat).

 

Even hotter objects (The Sun's photosphere) can emit with a peak at the shorter wavelength end of the visible spectrum, eg. the Sun's peak emission is in the green (which is why plants work at that wavelength and our eyes are especially sensitive to it), although it produces so much light in other colors we see them mixed together as white.

 

That's the emission spectrum. We don't need to worry about the absorption spectrum for objects in the field of view of the Litening pod. They are opaque so you can't see absorption of the spectra of objects in the background. For A-10C we don't worry about this, but in fields such as astronomy they use the fact that some non-emitting (dark) objects such as nebula can be understood by what light they absorb from emitting objects in the background rather than what they emit.

 

I think ED have done a pretty good job of IIR cameras (I have used a real one on a P3 Orion) - especially within the limits of what can be achieved on PC hardware within a reasonable development time.

 

One of the chem classes I took dealt a lot with spectroscopy as a tool for chemical analysis so what you are saying makes sense, but it doesn't mean that trees have to stand out just as well as moving tanks. I love ED and all of the hard work they put into this sim, but when things don't seem to be working right, there is no reason it shouldn't be brought out to hopefully be rectified.

[kingneptune117]

I dont care about certain parts of the vehicle being a different thermal signature. I just want them to some time soon fix the trees being all lit up. They should not be showing up that brightly on FLIR.

[asparagin]

An increase in entropy (disorder) in the state of the system (particles) is a result in transfer of energy by photons, what we notice as macroscopically as 'heat'.

 

Not necessarily. Eg.: A decomposition: out of one molecule you get two of then, no energy transfer but increase of entropy.

 

"Heat" is not the property of a system. We say a milkglass is hot. It's wrong; It is not hot until you put your cold fingers on it.

 

 

Objects with similar temperatures to people emit in different parts of the IR band. Cooler objects may emit with peaks at longer (lower energy) wavelengths. On a very hot day trees may have a similar temperature to the temperature of a human body, which makes it hard to distinguish between them in warm weather. In colder conditions (snow on the ground) the difference between ambient and a human is much higher and discrimination is much better.

 

This, and the whole part about PLank's law is on spot! It shows exactly why it is inexact to associate heat with IR.

Also, you feed energy to a molecule, it is the property of that molecule how it will give that energy back:

 

The best example is:

You give energy to a light bulb, and it gives light.

You give the same energy to the Track IR emitter on top of your screen, and it gives you IR.

Question: which one is hotter?

 

As a bottomline, a IR receiver has *nothing* (in this context) to do with heat. Yes, IR emitters are to some degree "hot" if you touch them. But saying they emit IR because they're "hot" is wrong. It is just the explanation given so that normal Joe can understand it.

Edited March 18, 2011 by asparagin

[Pyroflash]

They emit IR because they radiate heat in the form of photons when the particles in the system drop an energy level. This is the same explanation for almost all light, it is just IR happens to be located right below the visible spectrum. Though it is also true that the more energy that is bled, the hotter the object will look through FLIR.

 

If you want proof of this, try setting up a couple of incandescent light bulbs right behind you while you are using a TrackIR and see how well that works. Hot things radiate in IR, as they start to get warmer, the heat is radiated in shorter and shorter wavelengths until eventually the heat is being radiated in the visible spectrum, and then tops off around the 500 nanometer(green if I remember correctly) area. However most things you will(hopefully) encounter in life only get to the red part of the spectrum, and that is hot enough. You want proof? just go wave your hand around an electrical stove on high(don't touch it though).

[asparagin]

They emit IR because they radiate heat in the form of photons ..

 

I stopped reading here.

 

Can you find "heat" in the next picture?

 

[stormrider]

I stopped reading here.

 

Can you find "heat" in the next picture?

 

 

What´s that for? It doesnt really matters all these physics... What matters is that some trees are burning as hot as a running Hummvee and soldiers pants warmed than his face!!! I dont think the game calculates the FLIR image, it´s probably just a texture or a image filter which was half done.

[Pyroflash]

I stopped reading here.

 

Can you find "heat" in the next picture?

 

 

You want to be all technical with me, fine. But I really was only trying to prove a point about the emission of energy. And no, I can't find heat in that picture. Want to know why? It might have something to do with the fact that it is a graph of the electromagnetic spectrum, and not of energy as a whole. Kinetic energy stored as "heat" would not be in there because it is not electromagnetic energy. But what do I know right? I only fly planes, what could I possibly know about science?

 

I mean come on, at this point, what are you even trying to prove anyways, that I am wrong? Fine, I might be wrong, I might have said something that wasn't 100% correct. I admit I am no physicist. But you should at least have the common decency as a human being to give me the same respect that I show you. Saying things like "I stopped reading here" just says that you don't really care what I have to say, and fine, but to be honest I am sort of disappointed with you. I hold this community and each of its members in the highest regard; and when we stop showing each other mutual respect, we might as well be posting on /b/ for all it matters.

 

All I ask is that you please stop posting disrespectful comments. I'm pretty sure I am 100% correct in assuming that I or anybody else here for that matter doesn't deserve that.

Edited March 19, 2011 by Pyroflash

[ФрогФут]

They emit IR because they radiate heat in the form of photons ..

The objects emit if they have temperature above 0K according to Planck Law.

But in IR emission index(e) is much higher than reflection index®(e+r = 1 for non transparent bodies), and in visible part of spectrum r is higher than e. That's why it IR is used for devices working with the objects own radiation.

[Kuky]

IR is described as heat and is simply mater emiting EM waves of certain frequency or wavelenght and its freq.

 

Sun radiates energy and it hits all mater. When certain amount of energy is suplied to the atom the electrons jump from lower state of energy to higer and they absorb energy in process. Since ambient temperature is lower those electrons will release extra energy and jump back to lower energy state... the difference in energy between many different energy states where atoms reside are quantatized and when electron goes from one level to another that exact same quantity of energy is released or absorbed.

 

IR or heat is just particular amount of energy released and the EM is of particular wavelenght and freq... now going back to FLIR, it is only made to pick op that particular part of the EM specturm so it can see matter that is hotter then ambient ad in game this is not well done. Trees can absorb more heat then concrete or metal and ground without any plants is hotter then ground covered in grass... people are warmer then trees and leaves but cars on the sun are hotter then people :) and this is not well presented in game as I think textures for the FLIR are same textures slightly redone in B&W where colour of the texture is replaced with heat signature and I agree with others that think FLIR needs a new set of textures

Edited March 19, 2011 by Kuky

[asparagin]

I mean come on, at this point, what are you even trying to prove anyways, that I am wrong? Fine, I might be wrong, I might have said something that wasn't 100% correct. I admit I am no physicist. But you should at least have the common decency as a human being to give me the same respect that I show you. Saying things like "I stopped reading here" just says that you don't really care what I have to say, and fine, but to be honest I am sort of disappointed with you. I hold this community and each of its members in the highest regard; and when we stop showing each other mutual respect, we might as well be posting on /b/ for all it matters.

 

All I ask is that you please stop posting disrespectful comments. I'm pretty sure I am 100% correct in assuming that I or anybody else here for that matter doesn't deserve that.

 

I'm sorry for that. You are right I lost my patience at that point, comes with age.

 

My point was that one should differentiate between "heat" as thermodynamical process in which thermal energy is transferred from point to the other and whatever form of radiation, might it be IR, or thermal radiation. Thermal radiation is not thermal energy is not heat.

 

Sorry again if my comment was disrespectful.

[Pyroflash]

It's fine, people trip up every now and again, I should know...

 

Anyways, I agree fully with Kuky on this one. Something needs to be done.

[Druid_]

Is there some way that vehicles can be identified as seperate to the surrounding terrain in the post processing IR effect? I know it can be done in other graphics engines, surely there is some way of doing so in the DCS engine.

[Ptroinks]

Trees can absorb more heat then concrete or metal and ground without any plants is hotter then ground covered in grass... people are warmer then trees and leaves but cars on the sun are hotter then people :) and this is not well presented in game.

 

Excellent post! The IR needs some work! When rivers show up as hotter than anything else in the IR image (including vehicles and people), something is very wrong!

[aaron886]

I don't have any problem with a "pseudo" IR... but dark trees would be nice.

[Bucic]

Heat isnt the molecular dancing, heat is transfer of energy. Im pretty sure, do we have a chemist here that can clear this out?

Correct.

There's a special video I've prepared for such occasions :P

 

 

 

 

Just asking here... Is it that IR image in Warthog should show different levels of IR spectrum on hot parts of vehicles?

 

BTW, here's s thermo imagery done in a primitive graphics engine of Steel Beasts Pro Pe.

 

 

Here's how it would look like in B/W:

Edited March 21, 2011 by Bucic

[Thermal]

You guys are funny.

 

You cant even decide on a complete definition of heat, yet your insisting that ED "do something" about how they have modeled a FLIR, within the confines of an existing 3d engine.

 

IR is tricky to model. More tricky than normal visual wavelengths, because the IR emitted is both temporal (time) based and physics based. You want ED to not only model IR based on the running time of a tank, but also store those textures in memory, and modify and map then in real time as well as the visual textures?

 

Wow. I'd like to have your systems :)

[Pyroflash]

Obviously the guys behind ArmA 2 at Bohemia interactive found a good way to do this using their pre-existing engine.

[stormrider]

You guys are funny.

 

You cant even decide on a complete definition of heat, yet your insisting that ED "do something" about how they have modeled a FLIR, within the confines of an existing 3d engine.

 

IR is tricky to model. More tricky than normal visual wavelengths, because the IR emitted is both temporal (time) based and physics based. You want ED to not only model IR based on the running time of a tank, but also store those textures in memory, and modify and map then in real time as well as the visual textures?

 

Wow. I'd like to have your systems :)

 

Not really! We just want the correct FLIR textures.

[RichardG]

Arma2 guys do it. Its even "dynamic" IR. A tank thats been sitting a long time is cold. Fire the main gun or mgs and they get hot. Drive around awhile and the engine compartment and tracks gets hot. Park for awhile and the tank gets cold. HDR/Bloom effect even washes out your image if you see something too hot from too close, like a hot mg barrel too close to your IR camera or scope.

[Ptroinks]

If I'm flying a mission and my TGP gets hit, my IR mavericks are pretty much useless to me. Unless I know EXACTLY where to look, finding a tank with the Mav seeker is next to impossible. It depends a lot on what sort of ground texture the tank is on, but if it's not in the middle of a field or something, I can't find it...

 

ED could at least make the contrast between ground textures and vehicles\units a little higher, as a temporary fix.

[miguelaco]

I don't have any problem with a "pseudo" IR... but dark trees would be nice.

 

+1

 

I don't think we need a revamp of the IR display just some tweaking on the textures will work for me and could make a great difference.

[G00dnight]

so whats heat then ? lol

[Bucic]

:D

[Slayer]

This arguement is very educational but I think some people need to look up the definition of "feature creep" and read "The parabale of Janes A-10".

[Pyroflash]

Yeah, but we already have A-10C, so we can bitch all we want without fear of feature logging the product so much that it will never get released :D