WI: Anti-Radiation AAMs

[CalBear]

The AIM-54 had a "home on jam" mode. Since it had more range than anything else in use at the time, and the F-14's radar was able to acquire targets well beyond the weapons range, there was never really any need to come up with a specific anti-radiation mode.

The Russian, as has been mentioned, have a VLR (some estimate put it over 200 NM range) AAM (R-37/AA-13 Arrow) that the MiG-31 carries that appears to be a dedicated AWACS killer.

 

[CalBear]

Beyond countermeasures, couldn't an AWACS simply turn off its radar after detecting such a missile? In most scenarios, wouldn't the Soviets have only been able to target them at long range?

That is almost a good as a kill. The AWACS is more than just a detection platform. Its personnel control the air battle, in the case of the Hawkeye it controls the entire environment in a naval engagement beyond the sensor range of the AGEIS system.

 

[Delta Force]

That is almost a good as a kill. The AWACS is more than just a detection platform. Its personnel control the air battle, in the case of the Hawkeye it controls the entire environment in a naval engagement beyond the sensor range of the AGEIS system.

Also, aircraft are only allowed to undertake attacks with authorization from an AWACS, ground control station, or visual identification. If the AWACS has to turn off or flee BVR attacks are essentially impossible unless an electro-optical system is equipped. TISEO was one such system, allowing up to 10x magnification of whatever the radar set was tracking.

 

[SAVORYapple]

Each type of missile requires it's own type of countermeasure, towed jammers could be used against ARM and radar guided AAMs, but while they are in action the IR countermeasures may not be as effective and the IR missile in the 3-4 missile barrage gets the kill.

This type of barrage has never been tried in real life combat before. I know the Soviet Mig-23 had a two-system barrage (one heat-seeking and one radar-guided), which would force enemy pilots to simultaneously pull of two different countermeasures (and thus increase the chance of a kill). Why didn't NATO develop such systems?

 

[Delta Force]

This type of barrage has never been tried in real life combat before. I know the Soviet Mig-23 had a two-system barrage (one heat-seeking and one radar-guided), which would force enemy pilots to simultaneously pull of two different countermeasures (and thus increase the chance of a kill). Why didn't NATO develop such systems?

Aerospace Defense Command interceptors were designed to salvo the AIM-4 Falcon.

 

[Delta Force]

I found some information on the AIM-4 salvo system, including the AIM-4F (semi-active radar) and AIM-4G (IR). Both of those variants had a 0.87 kill probability ratio for a two missile salvo in the rear hemisphere against a bomber sized target. That means one missile had a 0.64 kill probability ratio. Rather low for that angle of attack and what is likely an optimistic estimate, although given the era it's decent (the AIM-4 also lacked a proximately fuze and had to directly hit the target to detonate).

Standard practice was to fire an IR Falcon before firing a semi-active radar guided Falcon. I think salvoing was automated on the Aerospace Defense Command interceptors.

This is really more historical and missiles in general than ARM AAMs though. It just shows that for a period in the 1950s, USAF missile tactics were similar to those that the Soviets would later use. I think Soviet interceptors pioneered the practice in the Soviet Union as well, but the mixed missile salvo remains part of Russian tactics while it has been abandoned by the United States.

 

[Matt Wiser]

Ever hear of this weapon? The Hughes Brazo? This was an air-to-air antiradar missile based on the AIM-7E. Though successful in testing, the program was terminated.

http://en.wikipedia.org/wiki/Brazo

Its intended target: Soviet AWACS and the MiG-25.

 

[Crowbar Six]

Most western airforces don't use their radars on an air-air missions, they are largely reliant on AWACS and ground based radars. They can cue AMRAAM using external input and might only use their radar to provide mid course updates to their missiles or to burn through jamming. Even using SARH missiles it was common for Phantoms, F15, F14 to use two aircraft, one would illumimate and the second would launch, then when the opposition counter launched they would swap roles with the first aircraft evading.

IR systems have issues in wet/cloudy/poor weather and work best in clear air. Locking up an IR missile in poor weather at longer ranges can be difficult without using mid course updates, they are fine for terminal homing purposes though which is why they are the preferred choice for close range air to air missiles like AIM 9, AIM 132 or AA 8 Archer.

However what would make a Air to Air ARM somewhat pointless today is the introduction of Low Probability of Intercept radars in the 80's and 90's, LPI radars use various techniques to make it much harder for illuminated targets to realise they are being targetted or scanned. Basically they use pulse to pulse frequency agility, use the minimum power to track a target, even alter the wave forms of each pulse. The aim of this is to make it much harder to detect the radar of a modern fighter. Even so most of the time in combat radars are left in standby unless needed. Hard to kill a target if it doesn't kill look like a target.

Brazos was probably killed as it was apparent that LPI would make it much to hard to reliably hit projected future fighters.

 

[CalBear]

This type of barrage has never been tried in real life combat before. I know the Soviet Mig-23 had a two-system barrage (one heat-seeking and one radar-guided), which would force enemy pilots to simultaneously pull of two different countermeasures (and thus increase the chance of a kill). Why didn't NATO develop such systems?

Partly because radar missiies are designed to be used at long range. They are larger and less maneuverable than shorter range IR guided missiles. The double salvo negates the BVR advantage that a radar guided missile provides.

The other, perhaps less obvious factor is that NATO forces have always anticipated being outnumbered since the West embraced quality/survivablity over raw numbers. while the USSR/PRC went for lots of lower cost, less capable platforms. If you expect to be swarmed, using 2-4 missiles per target is a really bad idea.

 

[Delta Force]

Ever hear of this weapon? The Hughes Brazo? This was an air-to-air antiradar missile based on the AIM-7E. Though successful in testing, the program was terminated.

http://en.wikipedia.org/wiki/Brazo

Its intended target: Soviet AWACS and the MiG-25.

I haven't heard of that, but I've heard of the AGM-122 Sidearm . Of course it's an AGM, not an AAM.

Is the difference between AGM and AAM anti-radiation missiles essentially warhead type and programming?

Most western airforces don't use their radars on an air-air missions, they are largely reliant on AWACS and ground based radars. They can cue AMRAAM using external input and might only use their radar to provide mid course updates to their missiles or to burn through jamming. Even using SARH missiles it was common for Phantoms, F15, F14 to use two aircraft, one would illumimate and the second would launch, then when the opposition counter launched they would swap roles with the first aircraft evading.

IR systems have issues in wet/cloudy/poor weather and work best in clear air. Locking up an IR missile in poor weather at longer ranges can be difficult without using mid course updates, they are fine for terminal homing purposes though which is why they are the preferred choice for close range air to air missiles like AIM 9, AIM 132 or AA 8 Archer.

However what would make a Air to Air ARM somewhat pointless today is the introduction of Low Probability of Intercept radars in the 80's and 90's, LPI radars use various techniques to make it much harder for illuminated targets to realise they are being targetted or scanned. Basically they use pulse to pulse frequency agility, use the minimum power to track a target, even alter the wave forms of each pulse. The aim of this is to make it much harder to detect the radar of a modern fighter. Even so most of the time in combat radars are left in standby unless needed. Hard to kill a target if it doesn't kill look like a target.

Brazos was probably killed as it was apparent that LPI would make it much to hard to reliably hit projected future fighters.

I wonder if the radar sharing could have allowed energy manuverability theory to have been more strictly followed. A highly manuverable transsonic fighter with cannons/guns, gunnery radar, and a datalink for BVR combat would have been interesting. I've read that the Tomcat can act as a miniature AWACS, so perhaps mixed squadrons could have been created to better coordinate light fighters and heavy fighters.

Partly because radar missiies are designed to be used at long range. They are larger and less maneuverable than shorter range IR guided missiles. The double salvo negates the BVR advantage that a radar guided missile provides.

The other, perhaps less obvious factor is that NATO forces have always anticipated being outnumbered since the West embraced quality/survivablity over raw numbers. while the USSR/PRC went for lots of lower cost, less capable platforms. If you expect to be swarmed, using 2-4 missiles per target is a really bad idea.

The Soviets were more advanced than NATO in some areas though. Ironically, they had aircraft more suited for visual range combat even though Soviet doctrine was more missile based. Supermanuverability, thrust vectoring, canards, and helmet linked missiles were primarily Soviet developed. NATO aircraft weren't as manuverable, but had better avionics.

Imagine if some of the Soviet manuverability improvements had been incorporated on NATO designs.

 

[CalBear]

I haven't heard of that, but I've heard of the AGM-122 Sidearm . Of course it's an AGM, not an AAM.

Is the difference between AGM and AAM anti-radiation missiles essentially warhead type and programming?



I wonder if the radar sharing could have allowed energy manuverability theory to have been more strictly followed. A highly manuverable transsonic fighter with cannons/guns, gunnery radar, and a datalink for BVR combat would have been interesting. I've read that the Tomcat can act as a miniature AWACS, so perhaps mixed squadrons could have been created to better coordinate light fighters and heavy fighters.



The Soviets were more advanced than NATO in some areas though. Ironically, they had aircraft more suited for visual range combat even though Soviet doctrine was more missile based. Supermanuverability, thrust vectoring, canards, and helmet linked missiles were primarily Soviet developed. NATO aircraft weren't as manuverable, but had better avionics.

Imagine if some of the Soviet manuverability improvements had been incorporated on NATO designs.

NATO aircraft were always built around killing at range. Doesn't always work, hence the IR missiles and the almost reluctant use of a gun system on fighters/interceptors.

Makes sense. That close range stuff is dangerous. Gets blood everywhere.

 

[Delta Force]

NATO aircraft were always built around killing at range. Doesn't always work, hence the IR missiles and the almost reluctant use of a gun system on fighters/interceptors.

Makes sense. That close range stuff is dangerous. Gets blood everywhere.

Modern avionics and missiles are significantly improved over their older counterparts, but I still wonder how effective they would be in a conflict between two evenly matched forces. There wasn't really any dogfighting in Iraq, and only anecdotal information on the Iran-Iraq War. Ordnance rarely performs to pre-war estimates under real world combat conditions.

 

[cracou]

There are other systems which appear to be really attractive: the French MICA seem to be really nasty/


- fire and forget with active radar
- mid air update from the plane or another one

- IR version with mid air update. This one seems nasty: you are being targeted by a surveillance radar, you're far from any other plane (so you don't expect an IR attack) and you don't get any warning(as the IR head does not emit).



Do you know if anybody else did this one:

"A Mica launched from a Rafale has successfully on June 11, 2007 for the very first time in the aviation history destroyed a target behind the launcher, the target was designated by another aircraft and coordinates were transmitted by Link 16"http://en.wikipedia.org/wiki/MICA_(missile)#cite_note-9

http://en.wikipedia.org/wiki/MICA_(missile)#cite_note-9

 

[Delta Force]

The British SRAAM was an interesting system for its intended role. It was a very short ranged missile with a range of 250 meters to 2 kilometers. Two missiles could be carried on a rail because they were carried in tubes. The missile was guided primarily by thrust vectoring, and in one incident almost shot down the Hawker Hunter that had fired it.

 

[Crowbar Six]

That program had been bubbling along since the 60's and went through various iterations although it went onto the back burner when AIM 9L appeared in the late 70's.

Isreali experience in the Bekka valley in 82 and RN/RAF experience both pointed towards the need for a longer range IR dogfight missile with larger off bore targetting capabilities. The UK and USA agreed to a deal in the early 80's where the US would develop an active medium AAM to replace Sparrow which would be adopted by the USAF and RAF whilst the UK would develop an advanced AAM leveraging SRAAM technology for use by both countries. The deal fell apart as the UK wanted to mount the cryogenic cooler on the missile, whilst the US insisted on mounting it on the launch rail. The RAF ended up with the AIM 132 which has a neat imaging IR seeker and the US got the AIM 9X.

 

[Delta Force]

There are other systems which appear to be really attractive: the French MICA seem to be really nasty/


- fire and forget with active radar
- mid air update from the plane or another one

- IR version with mid air update. This one seems nasty: you are being targeted by a surveillance radar, you're far from any other plane (so you don't expect an IR attack) and you don't get any warning(as the IR head does not emit).

What about dual seeker missiles? I know at one point the AIM-47 was proposed with both radar and IR seekers, but it would have grown in weight. More crucially for the rotary bay designs it was planned for, diameter would have increased by two inches.

 

[Delta Force]

Going back to an earlier question, what distinguishes a ground attack ARM from an air to air ARM, seeing as several AAM designs have served as the airframe for ARM designs. Is it warhead design and/or software, or something else?

Also, what about dual seeker missiles (ARM and IR), and aircraft without BVR radars using long range ARM variants of missiles similar to the AIM-7 Sparrow and AIM-54 Phoenix, perhaps with assistance from aircraft with advanced BVR radars?

 

[Crowbar Six]

A lot of missiles from the same manufacture use the same layouts as it was simply cheaper to recycle the same same research and they had a much better understanding of the aerodynamics. A classic example is Hughes who recycled the same layout from the AIM 4 and used it on AGM 65 Maverick, AGM76, AIM 26, AIM46 and AIM 54 Phoenix. General Dynamics did the same thing with their RIM 26 Tartar and RIM 66/7 Standard missiles which look very similar and also the AGM 78 Standard ARM.

The main difference between ARMs and other missiles lies in the design of the seeker head - they have to fit an antenna which is tuned to a particular set of frequencies which are used by various threat radars. With Shrike or MARTEL ARM they had different seeker heads for different threats. More modern ARM's such as HARM, ALARM, ARMAT etc have broadband seekers which mean they can normally hit a wide variety of emitters without resorting to changing the seeker. Warheads are normally very similar to AAM/SAM warheads ie normally blast/fragmentation warheads intended to shred the targets antennae but often have different fusing arrangements.

When developing the earlier ARM's it again made sense to use an existing AAM or SAM airframe as the basis for a new ARM, by maximising the existing components they kept the costs down and shortened development time.

They were generally carried out as urgent programs to provide a desperately needed capability. For example the AGM 45 shrike missile was derived from the Sparrow missile with the addition of a new seeker head, Standard ARM was similarly modified with some neat additions including the ability to remember the target location if the radar went off air.

I once asked on a pilots forum why the RAF used Shrike instead of Standard for the anti-radar Black Buck missions in 1982. I was told partly it was easier to add Shrike to the Vulcan but mainly the RN was having fits about a Standard ARM hitting one of their ships and sinking it. Shrike has a 149lbs warhead whereas Standard wieghed in at a whopping 220lbs

 

[Matt Wiser]

Now you know why Weasel crews in SEA preferred the AGM-78 over the Shrike: that thing was a SAM site-killer.

AIM-7R was proposed with a dual radar/IR seeker. AIM-152 may have had that as well had it been proceeded with.

 

[Crowbar Six]

The Israeli's used Standard in both air launched and surface launched variants.