IR Missile Heads

My question to you, Sup Forums, purveyors of all knowledge tech related, is how does an IR missile track its target? Specifically, given that the IR tracking head can receive the heat from the target in front of it, how does the missile head know to turn right with the target or left with the target? If tracking a plane, and the plane veers left, wouldn't that just appear as the IR signal getting weaker to the missile? how does the missile head know to turn left?

Other urls found in this thread:

youtube.com/watch?v=3Bby5pOVZJ0
youtube.com/watch?v=bZe5J8SVCYQ
mediafire.com/file/nq6i1ja0ds9gqi4/Histoy of the Electro-Optical Guided Missiles.pdf
twitter.com/SFWRedditGifs

You're sadly on the wrong board. If its not a smartphone question or a dodgy CPU/GPU graph, nobody cares.

tl;dr it holds a constant angle to the target

this means instead of tracking and chasing it, the missile tries to follow a collision course

It's tracking it.

The simplest explanation I can come up with is, it sees the IR images as a grid with heat being white, it locks onto the target it's told to fly to and after that if the target moves, for example, left, the white spot on the grid will go to left, another previously not white spot will be white and it knows what direction it goes, now it's programmed turn it's head and body to the left too because it has to keep the white heat spot in the center.

but how would that be achieved? Through multiple Ir sensors? ie. if the difference in two sensors outputs is such and such the cam shifts by so many degrees in some direction? Or is it all done with a special variable ir sensor?

>how does an IR missile track its target?
>If tracking a plane, and the plane veers left, wouldn't that just appear as the IR signal getting weaker to the missile? how does the missile head know to turn left?

I don't know if the obvious needs to be pointed out, but IR radiation is light, and so therefore travels at the speed of light.

The missile is tracking a light source, not a heat source. It just so happens that the band of light it tracks is radiated by heat.

>given that the IR tracking head can receive the heat from the target in front of it
No, it can receive the LIGHT from anything in it's sensor's range of vision.

It keeps the target in the center, if the target goes up, it's realizing the picture rapidly and the pixels on the upper side of it's image activate it to go up and keep it in the center again, until it moves.

sensor grid you fucking moron.
you know how your phone has 8 nigga pixels, well that IR dong has a MANY sensors

but it is essentially light emitted from a source of heat. I am not unclear on what IR light is, but regardless of whether it is light or heat, that does not change my question.

stay in school

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c a n c e r t h r e a d a b o r t

>cancer thread abort

CANCER THREAD ABORT

c a n c e r t h r e a d a b o r t

>cancer thread abort

CANCER THREAD ABORT

c a n c e r t h r e a d a b o r t

>cancer thread abort

CANCER THREAD ABORT

c a n c e r t h r e a d a b o r t

>cancer thread abort

I figured, but that raises several other questions. If IR light travels at the speed of light, and if focusing on a target outputting an extreme amount of IR light, how do the sensors differentiate?
Not a helpful comment, but thanks for wasting energy typing that out and hitting post.

>that does not change my question
So you're aware that IR is a light source, you're aware that the missile can sense it, and you're aware that the missile has the ability to change course...so where is your confusion?

It tracks it's target in exactly the same way that a human visually tracks a target, by looking at it, and following it.

it tracks the fucking light source this isnt fucking hard to understand. what is wrong with your brain?

you obviously have no idea how infrared works, not to mention obviously do not have the slightest fucking clue on how software could interact with it.

fuck off back to wherever you came from kid

This is the autistic simple version, the grid would be way more detailed in real.

It doesn't have to differentiate, it's tracking it at full speed.

It's not fool proof, we have decoys for that exact reason that can confuse it and make it follow something else.

FUCKING ANGLES HOW DO THEY WORK
LOOK AT THE NUB ITS A HEMISPHERE

>fuck off you fucking cancer faggot
fuck off you fucking cancer faggot
>fuck off you fucking cancer faggot
fuck off you fucking cancer faggot

Reported
>Deported
Reported
>Deported

whats with Sup Forums posters and being assholes? You could have literally posted nothing, and ignored the thread, but you didn't. You even took the time to pick out pictures to post. Truly the most cancerous board.
Thank You

You're better off asking /k/.

They actually know about applied technology, instead of just shitposting about obscure linux distros and cell phones.

I did, not very many responses. Figured I would deal with the assholes here to try for a better response. Every interaction I have had with Sup Forums has been a bad one.

...

then take the hint and fuck off kid

Sup Forums is among the worst boards on Sup Forums. I only come here because it's the only place you can post about PC hardware and distributed computing without getting your threads pruned.

This is one way to make the sensor go apeshit, it will notice several big sources of heat (light for it) come off the target and follow the biggest one, for the same reasons it does not get sidetracked by other sources near the target.

Obviously there goes shitloads of programming into it to make the algorithms as good as possible so they won't fuck up.

youtube.com/watch?v=3Bby5pOVZJ0
this should get you on the right track

>tfw current gen short range A2A missiles have killed dogfighting forever

Note that the 'nub' behind the sensor is riding in a gimbal. That eyeball can move to keep the target in frame even if the missle cannot orient itself at the same rate.

That inner window/lens must be ir transparent, but opaque to visible light - the opposite to normal camera lenses.

Good to see our tax dollars at work.

This makes actually perfect sense once you already know how it works.

Also, To all the Sup Forumseniuses here, since this is such an easy question, can you clarify this section of the wikipedia article on IR seekers?

"The detector in early seekers was barely directional, accepting light from a very wide field of view (FOV), perhaps 100 degrees across or more. A target located anywhere within that FOV produces the same output signal. Since the goal of the seeker is to bring the missile within the lethal radius of its warhead, the detector must be equipped with some system to narrow the FOV to a smaller angle. This is normally accomplished by placing the detector at the focal point of a telescope of some sort.

This leads to a catch-22 situation. As the FOV is reduced, the seeker becomes more accurate, and this also helps eliminate background sources which helps improve tracking. However, limiting it too much allows the target to move out of the FOV and be lost to the seeker. To be effective for guidance to the lethal radius, tracking angles of perhaps one degree are ideal, but to be able to continually track the target safely, FOVs on the order of 10 degrees or more are desired."

This portion is primarily what confused me on IR seeker designs.

Guidance missiles detect velocity and position at the very least. It's a basic system dynamics problem solved by solving a set of differential equations via linear algebra. Nowadays at least, the missile takes the shortest path to engage the target and it does not track directly behind it. Missile guidance systems are very sophisticated inside and particularly good firmware and powerful controllers are needed to do the image processing live and distinguish between flares, the sun, and the target.

That is perhaps the most worthless description of a control system that I have ever heard.

Not bitching at you, just saying.

Actually, let me specify what confused me here. I understand reducing FOV would reduce the number of potential targets, but the wikipedia article implies that reducing the FOV makes the missile more accurate in other ways. Is that true?

Making its field of view smaller makes it more accurate, consider all it can see is the colored part in posts picture, it can easily follow it by just keeping it very closely in the center, if it would see more, than it could easily get confused and start following something else, but if you make the field of view too small, the target could quickly disappear from its field of vision and it would lose it.

The missile knows where it is at all times. It knows this, because it knows where it isn't.

increase the FOV and it smooths out noise
decrease the FOV does the opposite resulting in more corrections.
not fucking difficult.

PLEASE understand children like you bring down the standard on this board.
PLEASE leave immediately.
THANKYOU :)

It can track it more accurately because it's the only thing it sees, it can process the information faster and with simpler algorithms.

I have shot a heat seeking missile, when you first target the target, you yourself see the world in a much bigger picture, the target being a white object, but once you shoot, the system I used actually flashed the missile's own view of the target in the viewfinder and all I saw was a box with the white object in the middle, almost taking up the whole screen, so when it's flying after that target, it simply, very quickly, moves in the direction the target is leaning in it's field of vision, if it touches the left side of it's field of vision, it will turn left, until it's in the center again and it will do that until it hits it.

I think the key in that statement is "in early seekers". If you have only say 16 sensing elements over which to do your calculation of error and just enough computing power to do that, there are some serious trade-offs to make.

If you have a multi-megapixel sensor, I'd guess you could stick a fisheye lens on it.

When I look at the front page all I see are generals on fucking pc hardware. What a high standard!

Decrease it too much and it won't be able to keep up (keep the target centered or in it's field of vision) with the target and lose it.

Final question, are there any consumer grade electronics that us IR seekers? things such as motion cameras and whatnot? Know of any cheap ones?

It's not hard to make one yourself, all you need is an IR camera a few servos and an arduino and Pi.

There is a raspberry pi camera that has the IR filter removed for 'night vision'. It might have a relevant IR response (I don't know).

IIRC there are actually laws against engineering a missile guidance system outside of the MIC. Seems bullshit to me, but I think Uncle Sam does not want some egghead writing code for this and sticking it on a website someplace just for kicks.

There's a difference between tracking a target and guiding to a target. There's also a difference between "IR sensor" and "imaging infrared seeker". Most modern IR seeking missiles use an imaging infrared seeker which is essentially an IR camera on a gimbal. Since you have an array of pixels to work with, you can do image processing to detect movements of a target and identify a target from background clutter, countermeasures, etc. So in your "plane turning left" example, the seeker would run its onboard image processing and determine that its target is moving left and command the missile to steer accordingly.

There's usually a designator that paints the target with IR on the ground

C'mon bruh, are you telling me that you've always been as super smart as you are today? You've never had to ask a simple question to something that may have been above your capacity to grasp on your own..?

Imagine you have an array of infrared pixels comprising your seeker. If the total field of view is large, then each pixel's FOV is presumably large. There could be an entire airplane in that one pixel and you probably wouldn't guide to it because there's no way of knowing if it's your target or some sort of background source, etc. But if the FOV is narrow, each pixel's FOV is small so your airplane now shows up as a pixelly-looking airplane shape which your image processing algorithms should be able to identify as an airplane. The tradeoff is that a narrow FOV means that if the target is very nimble it can jump out of your FOV before you can compensate.

Think you're confusing laser guided with heat-seeking there user.

There's toys and consumer products that use IR sensors, but the kind of stuff you see on missiles is very different, very classified, and very expensive. You could maybe get one of those FLIR cameras for your smartphone for fairly cheap...

The missile knows where it is at all times. It knows this because it knows where it isn't. By subtracting where it is from where it isn't, or where it isn't from where it is (whichever is greater), it obtains a difference, or deviation. The guidance subsystem uses deviations to generate corrective commands to drive the missile from a position where it is to a position where it isn't, and arriving at a position where it wasn't, it now is. Consequently, the position where it is, is now the position that it wasn't, and it follows that the position that it was, is now the position that it isn't.

In the event that the position that it is in is not the position that it wasn't, the system has acquired a variation, the variation being the difference between where the missile is, and where it wasn't. If variation is considered to be a significant factor, it too may be corrected by the GEA. However, the missile must also know where it was.

The missile guidance computer scenario works as follows. Because a variation has modified some of the information the missile has obtained, it is not sure just where it is. However, it is sure where it isn't, within reason, and it knows where it was. It now subtracts where it should be from where it wasn't, or vice-versa, and by differentiating this from the algebraic sum of where it shouldn't be, and where it was, it is able to obtain the deviation and its variation, which is called error.

>tfw jet engines killed dogfighting forever

user said IR, which is what that produces for tracking. It's a Lightweight Laser Designator and Rangefinder. It uses a laser to "paint" a target with IR light, and the missile tracks to the target.

Laser targeting is LIDAR, "heat-seeking" is a missile that homes in on multiple IR wavelengths without external assistance, and IR is exactly what I posted above.

Source: I build this shit.

And this, good people of Sup Forums, is an example of weaponized autism.

May your post become the next meme with power over 9000.

>Source: I build this shit.
nah

There are also ones that don't need guidance.
Once shot it will guide itself to the target/heat source.

also there are ones that can do both

I'm convinced that you don't "build this shit", because LIDAR is exactly what infra-red guidance systems are not. LIDAR is essentially a scanning laser rangefinder, and totally irrelevant to passive targeting.

Stop talking out your ass faggot.

Well, learn Calculus and this will suddenly all make a lot more sense. Even if the IR camera inputs a 2-dimensional image, it is able to establish metrics from the movement of its target by analyzing the 2D image over time, IE, predicting where it will be.

>passive targeting

Please quote OP on where he says passive.

>faggot

Projecting much?

The missile knows where it is at all times. It knows this because it knows where it isn't.

Pretty sure they measure heat intensity in multiple directions, so that if the strongest heat signals are to the left, it knows to turn to bring those heat signals directly in front of it.

It doesn't, it keeps the heat source always at it's tip

>tripcancer
Delete your account.

It actually turns out though that flares are higher heat intensity than jet fighter exist, so the newer missiles are actually programmed to ignore anomalously high heat readings so they won't be tricked by them. Though I imagine the algorithms must be complex, since the recieved heat intensity of jet exhaust would vary depending on how far it is away.

I think what they're saying is that the early sensors only had one "signal" that they sent to the guidance controller, it's not like modern ones where they can independently measure heat from different directions. So they had no understanding of where the heat was coming from, just whether it was "in arc" or not. Meaning, a large arc would make it easier to lock on and stay locked, but a smaller arc would increase the accuracy when the lock is maintained, but also make it easy to lose the lock with sharp maneuvering.

fuck off ammo, go back to your hole

That missile's head is worth more than 99% of Sup Forums.

The missile knows where it is by knowing where it isnt

The real question is which algorithm in computer science will allow the next smart missiles to be created which can actually dodge counter fire?

So this is how these missiles get so expensive, each of them needs a fucking computer inside

fucking hell couldn't you just stay after class and ask your fucking middle school science teacher this shit if you were daydreaming about fucking missles you fuck

AI would have done it anyway

magazine.uc.edu/editors_picks/recent_features/alpha.html

wrong, there were dogfights in korea and vietnam, and haven't you ever seen top gun, highway to the danger zone?

>ITT
>a bunch of faggots autistically trying to outsmart each other while none of them has actually even seen a missile like that in real life yet alone touched it

>the last word faggot thinks he's getting the last word
wrong kiddo

I only watched it for the volleyball scene

The sensors on missiles are actually really low resolution at least on the older ones. They're only like 8x8 pixels. Where they will be less like consumer devices is speed, the seeker probably refreshes hundreds of times per second, while consumer FLIR are limited to some low framerate. High resolution may not be an advantage either lower pixel counts with higher sensitivity would be more suitable.

With a 8x8 seeker you can probably just make a look up table with 64 possible positions for the control surfaces.

as a fighter jet mechanic i literally see and touch aim-9Ms every day.

youtube.com/watch?v=bZe5J8SVCYQ

This video explains how ir missiles work.

The missile knows where it is at all times. It knows this because it knows where it isn't. By subtracting where it is from where it isn't, or where it isn't from where it is - whichever is greater - it obtains a difference or deviation. The guidance subsystem uses deviation to generate corrective commands to drive the missile from a position where it is to a position where it isn't, and arriving at a position that it wasn't, it now is. Consequently, the position where it is is now the position that it wasn't, and if follows that the position that it was is now the position that it isn't. In the event that the position that the position that it is in is not the position that it wasn't, the system has acquired a variation. The variation being the difference between where the missile is and where it wasn't. If variation is considered to be a significant factor, it too may be corrected by the GEA. However, the missile must also know where it was. The missile guidance computer scenario works as follows: Because a variation has modified some of the information that the missile has obtained, it is not sure just where it is. However, it is sure where it isn't, within reason, and it know where it was. It now subtracts where it should be from where it wasn't, or vice versa. And by differentiating this from the algebraic sum of where it shouldn't be and where it was, it is able to obtain the deviation and its variation, which is called error.

>IR
>Laser
>paint a target with IR
>paint a target with IR that is very hot on it's own anyway
>paint a target that is flying with some 320 KIAS
>paint it manually
>track a flying object from ground level where trees and building cut your LOS to target
>Laser emitting IR
>you building that

I do believe you are building these things. You're probably a dumb spic working in an assembly line with instructional pamphlets in front of you telling you how to tighten those 5 screws. But you have no idea how a heat-seeking missile works.

>Please quote OP on where he says passive.
Not that user, but please show me an active painted air to air missile.

Try to understand context without being all autistic about semantics.

Call of Duty does not count silly

Lurk the thread before you get a spam warning

thank you, i was getting a little worried no one was going to say it and i would have to say it myself.

I was looking for this. It all makes sense now.
Thank you.

>being this new

mediafire.com/file/nq6i1ja0ds9gqi4/Histoy of the Electro-Optical Guided Missiles.pdf