mmW seekers for AAMs?

Very interesting info, Mercurius, I hadn’t known about that. And welcome back.

This original post was in fact purely from the gut-derived as it seemed plausible, especially when potentially coupled with a dual-mode seeker. Timing was lucky I guess. Well, for one thing this tech will certainly rise in cost per round relative to counter-balancing the high-value avg unit cost of new age jets, it would seem. The counter-measures will get extreme in 15 yrs for sure too. Crazy game. 🙂

Type – active-radar

Wavelength – 8 mm.

Antenna diameter – 135 mm

Range – 5-7 km with a detection probability of 0.9 and a false-alarm probability of 10-3.
(For a front-hemisphere head-on target against a target with an RCS of 3 sq m)

According to Jane’s Missiles & Rockets, Agat’s chief designer says the move to millimetric wavelength gives better accuracy, but “does little to help with the problem of attacking stealth aircraft…since it is likely that radar cross-section of such targets at millimetric wavelength will show only a slight increase from that at centimetric wavelengths.”

Nor was it been of much help in creating a seeker able to offer the sort of aim-point selection possible with infrared and other electro-optical seekers. A move to 3 mm wavelength might help in this regard, Agat stated, but in practice would be impractical due to atmospheric absorption.

I’m not long back from ‘parts foreign’, so have only now had a chance to respond to the original poster’s question. Earlier this year Russia’s Agat design bureau revealed that it had developed a MM-wave seeker for air-to-air missiles. I’ll post the details as soon as I get a free moment. It will take me a while to dig them out.

If you’re going to design a new AAM in this day and age I think it’s prudent to optimize it for being carried underwing it’s entire lifespan. Many companies out there can field missiles that can accurately strike targets. How many can shave off fuel burn costs lugging said missile around? This is why I feel the smaller AMRAAM-derived LR-AAM has a future over an ESSM-derived design.

How ’bout an ESSM with an AMRAAM seeker?

– Sferrin, nov. 2005.

Point —-> sferrin… lol. I’ll correct my statement: sferrin and Dwightlooi were ahead of their time in discussing this alternative concept.

And yes, if a 6.5″ or 7″ body can effectively accomodate a next-gen dual-mode seeker configuration (possibly including a mmW) into an extended range+ AAM (beyond 120D class ranged system), then credit due to that design.

WW – fair point.. imho though, a more asymmetrical 620lb class AAM such as an ESSM-based one, would more likely be a supplemental high-end system (perhaps with 50% greater NEZ then 120D?) to a next-gen JDRADM/120D-class and not necessarily a substitute. And the suggested ESSM-based IOC date as being achieved prior to (and cheaper than) an hypothetical 2018-2019 JDRADM IOC date, was furthermore only for perspective. And… fwiw, I didn’t intend to highlight the ESSM ‘what if’ development in this thread despite my apparent bias for it… rather was more interested in viability of the mmW ‘dual-mode’ or stand-alone seeker.

I guess my incremental-approach, motivating this thread to begin with, was on integrating a dual-mode IIR/mmW on an air launched ESSM, to be possibly IOC 4-5 yrs ahead of JDRADM (and at a much cheaper dev cost). Such an existing airframe class would seem to be large enough to support dual-mode development, while also increasing the range substantially over AMRAAM?

First, if the USAF/USN felt that the -120D was deficient, the JDRADM would have much higher priority. The necessity for upgrades(i.e. D, D+, JDRADM), are based upon assessments of enemy weapons. I’ve yet to hear complaints about the range of the C7/D AMRAAMS(from the users anyhow). Secondly, what’s a substantial increase? 50%? I don’t see how an ESSM based weapon could reach IOC and be in the inventory significantly faster than the JDRADM, and if it were, would that push the IOC for the JDRADM to the right?

Sferrin,

LoL, that exchange between you and Abe was hilarious..

Anyway, taking a trip down memory lane… I just now returned to the old March/April 08 F16net threads (two inter-linked threads) on this topic which was a pretty interesting convo – one in which Dwightlooi elaborated on well and in which you also extensively contributed.

Even further back in sept07, dwightlooi first explored this air launched concept (via an ESSM airframe) on stratpage I see. That guy was always ahead of the time on multiple aspects.

Yeah, guess where he got the idea:

http://www.f-16.net/index.php?name=PNphpBB2&file=viewtopic&p=46731&highlight=essm#46731

2005

😉

P.S. Abe is a cranky old ba$tard but I do like reading his posts. 🙂

Sferrin,

LoL, that exchange between you and Abe was hilarious..

Anyway, taking a trip down memory lane… I just now returned to the old March/April 08 F16net threads (two inter-linked threads) on this topic which was a pretty interesting convo – one in which Dwightlooi elaborated on well and in which you also extensively contributed.

Even further back in sept07, dwightlooi first explored this air launched concept (via an ESSM airframe) on stratpage I see. That guy was always ahead of the time on multiple aspects.

Interesting that he was contemplating, go figure, an air launched mmW guided pac-3 too. Anyway, whether one calls it an airlaunched ESSM (maybe call it an EASM ‘active’ Sparrow?) or SLAMRAAM-ER, my example was indeed including the ESSM’s basic airframe/booster/control fins as a starting point. I was contemplating the 8″ front end of the ESSM however, in order to better accomodate dual seekers (e.g., IIR+mmW), plus a bigger WH for potentially bigger targets and maybe the insanely high closing speeds? In this regard maybe they’d have to adjust the boost/sustain motor grains in part to keep a max speed in the mach 5 zone, not sure.

But the generic AAM mmW-seeker question out of pure curiosity would then seem to be touched on with regards to a possible pac-3 variant example which I hadn’t thought of, and maybe practical. Or maybe not, in which case I can write this thread off 🙂

Thanks for reply, madrat et al..

Regarding mmW susceptibility to bad weather… well, that was my initial thought too, until I had read somewhere (can’t remember where) that improvements in various EHF wavelength seekers, e.g., the AGM-88E’s mmW seeker perhaps, can improve the performance in relatively poor conditions.

And Erkokite –

Bingo. Thanks for that interesting info, which I guess is what I was looking for as a confirmation… for a starting point. My gut feeling was indeed actually pondering a future concept including a dual-moded main IIR seeker + dual mode, conformally mounted mmW seeker (when the opponent’s DIRCM takes out your IIR?). I was also considering feasibility of a passive radar (ARM) seeker in combination with a dual-mode mmW? Not sure how effective in A2A, so that’s why I was asking for corresponding thoughts here.

And with regards in particular to this ‘Stunner’… wouldn’t that appear to be in direct competition to NCADE then? Or could Raytheon intend to market both munitions eventually? Interesting…

I guess my incremental-approach, motivating this thread to begin with, was on integrating a dual-mode IIR/mmW on an air launched ESSM, to be possibly IOC 4-5 yrs ahead of JDRADM (and at a much cheaper dev cost). Such an existing airframe class would seem to be large enough to support dual-mode development, while also increasing the range substantially over AMRAAM?

The idea of a dual mode seeker has been around for quite some time. (See the Westinghouse/GD AAAM.)

Speaking of an air-launched ESSM there is at least two variants of a surface-launched AMRAAM with ESSM’s 10″ booster that have been floated over the years. One of those might make a better start point than ESSM. (Go check over on Secret Projects for pics.)

Actually that is not true. These days they make them aim for the cockpit (so the pilot can’t come back with another plane). Also, the more accurate your missile is the smaller your warhead has to be.

Well yes and no. Aiming for the cockpit is always a bit of an aproximation and an AAM doesn’t have to even hit the target to achieve a kill, a grenade sized warhead going off next to a modern fighter will do serious often fatal damage. Warhead size has generally always been small on AAM targeted at single aircraft for that reason, so yes the more accurate your guidance the smaller the warhead, but with few exceptions (mainly designed for attacking large aircraft and formations) warhead size has always been pretty small. As for MMw guidance – you don’t need that level of accuracy on AAMs, you are not looking to place a missile on a particular weak spot like you are on a tank where the difference in where you hit really matters.

Yeah, I was guessing from little knowledge I have on this, an A2A oriented terminal W-band type EHF or similar to supplement a primary seeker – which apparently is the mmW seeker type on the dual-mode 88E as well. But thanks for that interesting correlation and insight.

The W band at 94 GHz (were most of these mmW seekers work, e.g. the Hellfire seeker) is the last frequency that has a half decent atmospheric opacity (little bit under 60%), further up it’s in the IR spectrum with 80%, and further down it’s in the 35 GHz area with an opacity of around 80% (that is where other seekers work, e.g. the Longbow radar). Only those two frequencies work for mmW seekers in the atmosphere.

Thanks for reply, madrat et al..

Regarding mmW susceptibility to bad weather… well, that was my initial thought too, until I had read somewhere (can’t remember where) that improvements in various EHF wavelength seekers, e.g., the AGM-88E’s mmW seeker perhaps, can improve the performance in relatively poor conditions.

And Erkokite –

Bingo. Thanks for that interesting info, which I guess is what I was looking for as a confirmation… for a starting point. My gut feeling was indeed actually pondering a future concept including a dual-moded main IIR seeker + dual mode, conformally mounted mmW seeker (when the opponent’s DIRCM takes out your IIR?). I was also considering feasibility of a passive radar (ARM) seeker in combination with a dual-mode mmW? Not sure how effective in A2A, so that’s why I was asking for corresponding thoughts here.

And with regards in particular to this ‘Stunner’… wouldn’t that appear to be in direct competition to NCADE then? Or could Raytheon intend to market both munitions eventually? Interesting…

I guess my incremental-approach, motivating this thread to begin with, was on integrating a dual-mode IIR/mmW on an air launched ESSM, to be possibly IOC 4-5 yrs ahead of JDRADM (and at a much cheaper dev cost). Such an existing airframe class would seem to be large enough to support dual-mode development, while also increasing the range substantially over AMRAAM?

MMw is useful when you look at hitting tanks where the important point is often ‘where’ you hit the tank in making a kill (or not) for AA this is less important, detonate some HE on or near any part of a modern fighter and it will more than likely kill or at the very least cripple it. The important factor in AA is seaker/guidance range rather than accuracy of the strike.

Actually that is not true. These days they make them aim for the cockpit (so the pilot can’t come back with another plane). Also, the more accurate your missile is the smaller your warhead has to be.

I haven’t found much in browsing the net with regards to practical use or potential for mmW as either a stand-alone or dual-mode seeker for air intercept missiles?

I’d be interested to read any views or insight into this aspect, pros and cons. Thanks..

They don’t like rain. Big minus.

From here:
http://www.aviationweek.com/aw/generic/story.jsp?id=news/awst/2010/09/20/AW_09_20_2010_p71-253575.xml&headline=Missile-Killing%20Interceptors%20Eyed%20By%20Israel,%20U.S.&channel=defense

The Stunner interceptor, designed and built by Rafael in a cooperative program with Raytheon, is a low-cost design that targets threats such as cruise missiles, medium- and long-range artillery rockets and short-range ballistic missiles. It has two stages: The first is a solid-fuel, rocket motor booster; the second is a curious asymmetrical kill vehicle with advanced steering for increased agility. A three-pulse motor provides additional thrust at critical moments of flight. A multi-mode sensor package—electro-optical and millimeter wave, electronically scanned array radar—provides all-weather performance against small, maneuvering targets. The Stunner is larger than Raytheon’s AIM-120 medium-range air-to-air missile but smaller than the Arrow 3 interceptor.

Well, Milstar satellites use EHF, and also their successor will use EHF. If i’m reading it right, next gen datalink – MADL – will use EHF, and i’m pretty sure f-22’s internal datalink is based on EHF.

But i’m guessing it’s not the same to send relatively small amounts of data with built in redundancy packets and to recieve enough clear data from a bounced off radar beam (it travelled double the distance) to form a precise enough radar image.

Was thinking the same. Attenuation due to atmospheric conditions is an issue when it comes to higher frequencies, from what I’ve learned. Are there any current applications for EHF in aviation at all?

Isn’t the mmw range VERY susceptible to atmospheric conditions? That is basically the reason why its range is as short as it is. Simply adding more power to the emitter just won’t give corresponding returns in added range as it would in, say, X-band.

MMw is useful when you look at hitting tanks where the important point is often ‘where’ you hit the tank in making a kill (or not) for AA this is less important, detonate some HE on or near any part of a modern fighter and it will more than likely kill or at the very least cripple it. The important factor in AA is seaker/guidance range rather than accuracy of the strike.