IR missile defence.

Pendekar

New Member
As i understand, IR missile use dual-color seeker that sense both IR and UV radiation to prevent the missile from being fool into targeting other heat source like a sun and cloud edges. The system work by rejecting the source that emit both IR and UV and only lock on to a source that emit IR only. So my question is, if we can place UV lamps around the part of aircraft that emit IR emission, like engines and leading edges, can this measure prevent an IR missile from targeting the aircraft?
 

Lobos82

New Member
As i understand, IR missile use dual-color seeker that sense both IR and UV radiation to prevent the missile from being fool into targeting other heat source like a sun and cloud edges. The system work by rejecting the source that emit both IR and UV and only lock on to a source that emit IR only. So my question is, if we can place UV lamps around the part of aircraft that emit IR emission, like engines and leading edges, can this measure prevent an IR missile from targeting the aircraft?
What missile are you talking about? If it was this simple to trick the missile, I doubt it would ever be produced. I've heard of missiles that track IR and RF, but not IR and UV.
 

Gremlin29

Super Moderator
Staff member
Verified Defense Pro
IR missiles look for a specific frequency range. Sensitivity ie the seekers ability to discrmininate a very narrow range within the frequency spectrum is driven by the ability/quality of the cooling within the seeker. This is important for it to resolve smaller bands and thus the ability to reject heat sources that are naturally occuring (sun) or man made (flare countermeasures). For every measure, there is a counter measure, and a counter counter measure and so on.
 

Lobos82

New Member
IR missiles look for a specific frequency range. Sensitivity ie the seekers ability to discrmininate a very narrow range within the frequency spectrum is driven by the ability/quality of the cooling within the seeker. This is important for it to resolve smaller bands and thus the ability to reject heat sources that are naturally occuring (sun) or man made (flare countermeasures). For every measure, there is a counter measure, and a counter counter measure and so on.
I'm not a missile expert, but this just doesn't sound right. The cooling within a seeker should have nothing to do with what spectrum it is detecting. The heat from the target will not heat up the seeker because it is not actually making the seeker hot, it is just a heat signature that the seeker is detecting. I have heard of all kinds of counter-counter-counters, and they will keep happening as long as there is war and hostility. IR seems to be a primitive homing method in my opinion, it is much easier to fool than other missiles.
 

Bonza

Super Moderator
Staff member
I'm not a missile expert, but this just doesn't sound right. The cooling within a seeker should have nothing to do with what spectrum it is detecting. The heat from the target will not heat up the seeker because it is not actually making the seeker hot, it is just a heat signature that the seeker is detecting.
What about the missile being launched at potentially supersonic speeds and accelerating to Mach 4ish itself? That's bound to heat up the seeker a bit, don't you think?

IR seems to be a primitive homing method in my opinion, it is much easier to fool than other missiles.
You're welcome to your opinion of course, but given the most advanced militaries in the world all use IR homing on a variety of guided weapons, it seems they disagree with you.
 

Lobos82

New Member
What about the missile being launched at potentially supersonic speeds and accelerating to Mach 4ish itself? That's bound to heat up the seeker a bit, don't you think?



You're welcome to your opinion of course, but given the most advanced militaries in the world all use IR homing on a variety of guided weapons, it seems they disagree with you.
Who uses these IR capabilities? And at mach 4, the target should already be acquired.... If you're going mach 4 and need to change your detonation point, there are bigger problems you need to address....
 

Gremlin29

Super Moderator
Staff member
Verified Defense Pro
Cooling the seeker makes it more sensitive/receptive to wavelength. FLIR systems are cooled for the same reason. The latest gen seekers home on a very small bandwidth of IR, making them harder to defeat. That's why old IR seekers could be spoofed by the sun, they couldn't discriminate. They aren't actually looking for heat, they are looking for a very specific range of IR. The narrower the range, the better the seeker and the harder it is to counter. This can be easily seen by the generation of manpads, their lethality improved with their ability to super cool (among other things like the life of the battery that provides power for cooling). We think of them as heat seeking because hot objects radiate IR but it's all about wavelength.
 

gf0012-aust

Grumpy Old Man
Staff member
Verified Defense Pro
I'm not a missile expert, but this just doesn't sound right. The cooling within a seeker should have nothing to do with what spectrum it is detecting.
I've been involved in evaluating thermal imaging and detection systems

the cryo is used to assist in extending the range of detection -

it makes a significant difference
 

Bonza

Super Moderator
Staff member
Who uses these IR capabilities? And at mach 4, the target should already be acquired.... If you're going mach 4 and need to change your detonation point, there are bigger problems you need to address....
Well, there are many missiles that use IR homing. Along with the MANPADS type weapons Gremlin mentioned, all the current iterations of short range air to air missile, for example (AIM-9X, ASRAAM, IRIS-T, one of the Mica variants, the Vympel R-73), use IR homing.

The C variant of the JSOW, intended to engage moving targets, uses IR homing for terminal guidance, and that's a relatively recent development. Several anti-ship missiles use IR for terminal guidance as well, among them the Kongsberg NSM, which is another recent development.

I'm surprised you aren't aware of this as I thought it was common knowledge that IR guidance was a relatively common method of guiding a weapon onto a target. Or are you distinguishing between IR guidance in general and IIR, or imaging infra-red? If that's the case then my mistake, and I'm not sufficiently aware of the differences between various IR guidance methods to really comment.

I'm not sure I understand your second statement. A missile like ASRAAM accelerates to Mach 4 (at least that's the number I hear thrown around, but I am not a military man and so rely on open source information) and is guided onto the target via an IR sensor. As it is intended to engage high performance fighter aircraft, of course there is a need to constantly update the point at which the missile will detonate, based on the movement of the target. But maybe I misunderstood something you said?

Happy to stand corrected on any of the above, as I said maybe I misunderstood you. But I don't know why modern missiles, and even missiles still in development, would be employing IR seekers if they were ineffective at guiding a weapon onto a target, particularly as some weapons are intended to engage high performance aerial targets.
 
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