Heat seeking missile experts?

Crusoe’s comments about the Laser Dazzle Sight in Incubus’s thread gave me an idea for a heat seeking missile defense, but I’m not sure how the warheads work now. And depending on the answer, I have just imagined either a cool defense, or an ENORMOUS missile beacon of death, I don’t know which!

The idea is to mount a radar/ir guided laser in the tail of a plane. If the that pours energy into the missile’s nose. Not to melt it or destroy it, just to overwhelm it’s sensors, and either give it a huge blob with a low hit probability, or trigger it’s proximity fuse while it’s a safe distance away.

The ideal way to employ this would seem to be straight and level flight, so the laser has a stable platform and target. So the consequences of it NOT working are pretty grim.

Are proximity fuses in IR missile ALSO IR based? If it’s RF based, I’m screwed. If there are NO proximity fuses, only impact, it’s also probably a worthless idea.

So, have I invented a life saver or a death machine? Or is this a case of been there, done that’s already been tried and discarded? I posted here, because someone may have the actual knowledge to tell me.

IANAAE (aeronautical engineer) but… I would think that a small spherical turret of sorts, could be mounted on the tips of vertical stabilizers. With gyrostabilization it could stay on target even with evasive manuvers. and its placement would allow it a pretty wide field of fire. This would avoid the need to maintain straight level flight.

Of course, you realize that all the would be needed to defeat your jammer would be a small shift in the frequencies for which the seeker is looking. Tuneable frequency lasers are nowhere near the stage where you’d be able to deploy them in any militarily useful capacity, while a frequency-hopping IR seeker is eaily done.

Also: A missile seeker is a small, fast target that is manuevering hard. IIRC, the latest mark of the AIM-9 Sidewinder is capable of pulling in excess of 12 G’s in a turn, and is only 7 inches wide.

Also: You’d need reliable and timely launch warning.

Or, you could mount a disposable broadband IR source on your aircraft, and jettison it in an emergency, leaving the aircraft free to evade. It’s called a decoy flare. :stuck_out_tongue:

Not a totally bad idea, but you can see that there are some very large hurdles to overcome before an IR laser jammer would be useful.

Actually, there are already IR jammers that work on something like this principle. I think they use an IR “disco ball” type of thing to project high power IR signals in random directions, confusing the missile.

This is what I was thinking of. It doesn’t explain what it does, though, really.

The “disco ball” thing I remember, I think, was from reading the rather comprehensive manual to Jane’s Longbow several years ago. :slight_smile:

Some coverage of modern and future electronic counter-measure stuff:


"One of the most revolutionary developments in electronic warfare is the ATIRCM system. Infrared countermeasures have moved towards laser-based jammers due to inherent tracking and pointing requirements. The ATIRCM functions include detection and cueing, tracking and pointing, and jamming. In operation, the system detects missile launch and decides if the missile is approaching the aircraft. If the missile is approaching, the system tracks the missile with enough accuracy to point a jamming laser at the missile seeker. "

Well, I’ll be.

Learn something new every day, around here.

The aim-9 is pretty sophisticated. The seekerhead is designed to not fly the missle into the heat source, it intentionally misses by a small margin. The proximity fuse is pairs of laser emitters and detectors behind looking to the sides, not the front. When the missle flys past the target the lateral reflection from the target sets it off. The expanding rod warhead works best when it fods the target’s engines allowing all the hot turbine blades to do the work as they go through fuel tanks. There is a reason that the aim-9 is more successful for the US than guns and all other a-a missles combined.

One problem with such a device may be that since many high-powered lasers rely upon a very high-energy chemical reaction to create the beam, the vented exhaust from such a device may create an even greater heat signature. Furthermore, the exhaust must be vented immediately, which changes flight characteristics.

It’s difficult for a fighter or an attack aircraft to mount such a device along the center line, because the engines and tail section are often in the way. Someone I know well tells me that early designs required such a device to be mounted in place of one of the fixed fuel tanks, with a ducted exhaust for the reactants. The result was an involuntary split-S, which pilots did not exactly welcome!

Thanks, SenorBeef!

Not so far fetched afterall.

Tranquilis, my idea for the best flight profile to employ this defense, straight and level flight (or nearly so), should in theory minimize hgh-g maneuvering for both missile and target.

Come to think of it, you’d have a BIG issue of pilot mistrust to overcome, even if it works. Who’d want to leave everthing to a magic box, when you can see the bullet chasing you?

Aren’t the newest ones capable of head-on atacks, seeking the hotter leading edges? I’d think with the converging speeds, blowing up next to the plane would be too late?

Yes, aim-9s have worked in head-on angle for a long time. There is enough IR in the front of a jet engine for it to lock. I don’t think the fuzing method is a problem.