Home on jam anti-ship missiles and air launched anti-radiation missiles for anti-ship

[STURM]

Greetings everyone,

I know this a hard one, but with a number of surface launched anti-ship missiles now fitted with a home on jam capability, why are many navies still opting for jammers on their surface vessels? Or do these missiles only work on jammers emitting on certain frequncies?

Also, is it part of RAF and USN doctrine to use ALARM and HARM anti-radiation missiles launched from Tornados and Hornets in the anti-shipping role? Apart from Bundesmarine Tornado's which trained in the past to use a combination of Komoran and HARM missiles for the anti-shipping role in the Baltic, I have never read of other NATO countries doing the same.

Thank you - Aplogies for the double post.

 

[rossfrb_1]

Greetings everyone,

I know this a hard one, but with a number of surface launched anti-ship missiles now fitted with a home on jam capability, why are many navies still opting for jammers on their surface vessels? Or do these missiles only work on jammers emitting on certain frequncies?
snip

Thank you - Apologies for the double post.

I would have to believe that those navies see value in having jammers onboard (& not just for defeating inbound ASM). And as always, with the development of a new threat (eg home on jam) someone somewhere then develops a countermeasure. As an example, defensive suites like Nulka reportedly have the ability to defeat home on jam threats.

rb

 

[Pre-Dreadnought]

Countering the counter-measures

Please forgive my ignorance of these matters but if a missile can be diverted from its target by counter-measures and the manufacturers come up with electronics to counter the counter-measures then the balance will shift from the attacker to the defender and vice versa until some real shooting happens. Eventually won't there come a situation when the weapons directed towards ships will be simpler? For instance the 15 shell or the basic torpedo can't be diverted.

We live in an age of electronic warfare and there is no going back but I fear that electronics aren't everything and modern ships are still vulnerable to basic weapons. Just a thought!

 

[Todjaeger]

Please forgive my ignorance of these matters but if a missile can be diverted from its target by counter-measures and the manufacturers come up with electronics to counter the counter-measures then the balance will shift from the attacker to the defender and vice versa until some real shooting happens. Eventually won't there come a situation when the weapons directed towards ships will be simpler? For instance the 15 shell or the basic torpedo can't be diverted.

We live in an age of electronic warfare and there is no going back but I fear that electronics aren't everything and modern ships are still vulnerable to basic weapons. Just a thought!

Yes and no...

While a 15" shell or shells would present a considerable danger to pretty much any vessel currently in service, there is the not insignificant issue of being able to get close enough to employ a weapon capable of firing such shells. I could be mistaken, but I believe a WWI or WWII 15" naval gun would have had an approximate range of 24 miles, long enough to fire just over the horizon. In other words, if the gun can see a target, it can it hit.

On the other hand with the sensors and weapon systems available currently, vessels can be detected and engaged at range, anywhere from dozens to potentially hundreds of miles away. Even if a hostile ship were not to successfully engage a vessel mounting a 15" gun, it would need to allow the vessel to close to within the range of the gun.

Also, there is something which seems to have been overlooked or ignored with the mention of home-on-jam AShM and ARMs, and that is the fact that ECM/ESM are not the primary defences of a vessel or battlegroup at sea. Given the radars available, it is distinctly possible that the vessel under attack could have a sensor footprint of hundreds of miles. The could allow the inbound missile(s) to be intercepted well away from the ship under attack. This interception could be done by aircraft and/or long-range SAMs. As the attacking missiles come closer, more weapon systems become available to engage them, short-range SAMs, rapid fire naval guns, CIWS, etc.

These are all things which the AShM/ARMs need to get through, before systems which can effect their guidance begin to matter.

As a side note, ARMs are not designed for an anti-shipping role. Their ranges are comparatively short, the warhead small, and the seeker would direct the missile towards an emitter array. They might achieve a mission-kill at best, though there would be a distinct possibility that the launching aircraft could be shot down making the attempt.

-Cheers

 

[STURM]

Also, there is something which seems to have been overlooked or ignored with the mention of home-on-jam AShM and ARMs, and that is the fact that ECM/ESM are not the primary defences of a vessel or battlegroup at sea. Given the radars available, it is distinctly possible that the vessel under attack could have a sensor footprint of hundreds of miles. The could allow the inbound missile(s) to be intercepted well away from the ship under attack. This interception could be done by aircraft and/or long-range SAMs.

As a side note, ARMs are not designed for an anti-shipping role. Their ranges are comparatively short, the warhead small, and the seeker would direct the missile towards an emitter array. They might achieve a mission-kill at best, though there would be a distinct possibility that the launching aircraft could be shot down making the attempt.

-Cheers

ECM/ESM and CIWS's are supposed to be the last lime of defence for naval ships, the first line of defence, as you pointed out being aircraft and long range SAMs. For US or NATO vessels, this is possible as they would be operating as part of a combined task force, operating under a strong air umbrella, supported by an AEW aircraft. But for navies of other countries, ECM/ESM, CIWS's and short range missiles systems may be all that they have to prevent a missile hitting its target. They may have the ability to spot an threat many miles away through radar and ESM, but probably may not be able to deal with it. For these navies, small calibre, high rate of fire guns like 57mm or 76mm make more sense than 127mm guns.

What I find very interesting is that the USN [carriers and supply vessels], Bundesmarine and ROKN despite being able to afford long range SAM's and high end ESM/ECM, still rely on RAM for last ditch defence, unlike say the UK and Italy, who's last line of defence on its Type 45s and Andrea Doria's are a soft kill option with chaff or ECM.

At the moment, I tnink the longest range anti-radiation missile is the KH-58, which a 120km range. Anti-radiation missiles are indeed not designed for the anti-ship role, but if used in combination wiith an anti-ship missile, as the Bundesmarine did with its Tornados, a targeted ship is not going to have many options. Back in the days when Sea Eagle was still used, was it ever carried with the ALARM on RAF Tornados?

 

[Onkel]

What I find very interesting is that the USN [carriers and supply vessels], Bundesmarine and ROKN despite being able to afford long range SAM's and high end ESM/ECM, still rely on RAM for last ditch defence, unlike say the UK and Italy, who's last line of defence on its Type 45s and Andrea Doria's are a soft kill option with chaff or ECM.

Allow me to correct you, mate. Bundesmarine built in a softkill system in the F 123 Frigates,, the K 130 and some minehunters. The system´s name ist MASS. It is a Rheinmetall product.

source (in german): Softkill ? gleiche Wirkung bei weniger Zerstörung? | Hardthöhenkurier das Magazin für Soldaten und Wehrtechnik

 

[Todjaeger]

ECM/ESM and CIWS's are supposed to be the last lime of defence for naval ships, the first line of defence, as you pointed out being aircraft and long range SAMs. For US or NATO vessels, this is possible as they would be operating as part of a combined task force, operating under a strong air umbrella, supported by an AEW aircraft. But for navies of other countries, ECM/ESM, CIWS's and short range missiles systems may be all that they have to prevent a missile hitting its target. They may have the ability to spot an threat many miles away through radar and ESM, but probably may not be able to deal with it. For these navies, small calibre, high rate of fire guns like 57mm or 76mm make more sense than 127mm guns.

What I find very interesting is that the USN [carriers and supply vessels], Bundesmarine and ROKN despite being able to afford long range SAM's and high end ESM/ECM, still rely on RAM for last ditch defence, unlike say the UK and Italy, who's last line of defence on its Type 45s and Andrea Doria's are a soft kill option with chaff or ECM.

At the moment, I tnink the longest range anti-radiation missile is the KH-58, which a 120km range. Anti-radiation missiles are indeed not designed for the anti-ship role, but if used in combination wiith an anti-ship missile, as the Bundesmarine did with its Tornados, a targeted ship is not going to have many options. Back in the days when Sea Eagle was still used, was it ever carried with the ALARM on RAF Tornados?

What you describe in terms of ECM/ESM and CIWS can be true for some vessels, of some navies. As a general rule though, the vessels which lack some form of mid- or long-range air defence capability are either lower value combatants (older frigates, corvettes or patrol boats), or specialized, high-value ships (i.e. carriers and LHDs) which are escorted by vessels able to provide an air defence umbrella.

In terms of the sensor footprint, a single vessel operating alone will usually be able to detect an incoming aircraft while it is still quite a distance away, an AEW/AWACS-type aircraft is not needed. For example, a vessel with the main air search radar mounted on a mast 45 ft above sea level has a radar horizon of nearly 300 miles for targets flying at ~40,000 ft. Unless the launching aircraft (or incoming missile for that matter) was on a sea-skimming flight path, the vessel that is to come under attack will know that an aircraft or missile is inbound.

In the case of the Kh-58, even with a 120 km range, the launching aircraft could well be taken out by long-ranged SAMs before it can get close enough to launch.

For the USN, the vessels described as lacking a soft-kill option are those which would be located at the center of an area air defence umbrella, which means that a significant amount of effort is required to overcome the defences to the point that softkill systems would be useful. Additionally, I do not believe it accurate to say that such USN vessels (apart from the Sealift Command supply vessels) lack softkill options. AFAIK the USN is a user of the Nulka hovering active decoy, which has begun to replace chaff (and IIRC is fired from the same dischargers).

Now, if the defensive situation is to be considered for a non-US/NATO/major allied nation, the story becomes quite different. For one thing, such nations as indicated are typically not as capable for mounting an air defence for their ship(s). The other item which needs to be considered is actually a question, who is shooting at them? If a given nation lacks a significant and capable naval presence, chances are their nearby neighbors (and potential opponents) are similarly lacking, which means that while their air defence capabilities are lacking, their potential opponents ability to launch just such an attack is also likely to be lacking. Or if they have the ability to carry out such an attack, they are likely just as able (or unable rather) to withstand a similar attack in kind.

A last item to consider, AFAIK the assets primarily tasked with an anti-shipping role in the USN is actually the submarine force, not the surface fleet. In point of fact, the Harpoon AShM is more apt to be used against a strategic or land-based target than a vessel at sea. This is due to a variety of reasons, the major ones being the difficulty of ensure a target at sea is a legitimate target (as opposed to a neutral or allied vessel), or that an AShM warhead can have difficulty in actually sinking a vessel. The other is that a heavyweight torpedoe warhead like found on a Mk 48 detonating beneath the hull of a vessel is far more likely to cause a ship to sink than a missile impact above the waterline.

-Cheers

 

[STURM]

Additionally, I do not believe it accurate to say that such USN vessels (apart from the Sealift Command supply vessels) lack softkill options. AFAIK the USN is a user of the Nulka hovering active decoy, which has begun to replace chaff (and IIRC is fired from the same dischargers).

Todjaeger, thanks for your inputs, appreciate.

I never said that USN vessels lack softkill options. My sentence perhaps was not worded correctly , apologies. What I was trying to highlight was the different approaches adopted towards ship survivabiliy against anti-ship missiles. Leading navies like the UK and Italy, with the Type 45 and Andrea Doria class, have put all their faith in their long range missiles systems, leaving it to mainguns, chaff and ECM to deal with any missiles that get through. Even prior to the Type 45s, the Type 23s only had Seawolf and chaff/ECM, no CIWS as insurance. On the other hand, navies like the USN [especially for its supply/logistics fleet], the Bundesmarine and the ROKN have RAM and Phalanx, along with softkill options, to back up their long range missile systems. Off topic - but can gun based CIWS's like Goalkeeper and Phalanx deal with supersonic threats like Sunburn or Klub?

A last item to consider, AFAIK the assets primarily tasked with an anti-shipping role in the USN is actually the submarine force, not the surface fleet. -Cheers

This is probably because it is very unlikely any hostile naval vessel in time of war will be able to get within missile range of any USN ship without first being detected and dealt with by US air and submarine assets.

 

[Arc Light]

Greetings everyone,

I know this a hard one, but with a number of surface launched anti-ship missiles now fitted with a home on jam capability, why are many navies still opting for jammers on their surface vessels? Or do these missiles only work on jammers emitting on certain frequncies?

Mainly because missiles in HOJ mode ca burn though jam noise in certain distances.

Also, is it part of RAF and USN doctrine to use ALARM and HARM anti-radiation missiles launched from Tornados and Hornets in the anti-shipping role? Apart from Bundesmarine Tornado's which trained in the past to use a combination of Komoran and HARM missiles for the anti-shipping role in the Baltic, I have never read of other NATO countries doing the same.

This is perfectly possible. Those anti-radiation missiles have also shipborne radars placed in their signal databases. Simply well-balanced mixed attack strategy: ARMs can destroy warship radars first and then ASMs can hit her without problems because radar guided weapons are out of action.

 

[Pedro C]

Greetings everyone,

I know this a hard one, but with a number of surface launched anti-ship missiles now fitted with a home on jam capability, why are many navies still opting for jammers on their surface vessels? Or do these missiles only work on jammers emitting on certain frequncies?

Also, is it part of RAF and USN doctrine to use ALARM and HARM anti-radiation missiles launched from Tornados and Hornets in the anti-shipping role? Apart from Bundesmarine Tornado's which trained in the past to use a combination of Komoran and HARM missiles for the anti-shipping role in the Baltic, I have never read of other NATO countries doing the same.

Thank you - Aplogies for the double post.

1) Sometimes you do want the missile to home on you so as a more important ship can get rid of the missile.

2) When you are locked-on, you may want to make the missile processor to think about something (jam) whilst you do something different (you name it... I can't)

 

[Pedro C]

Greetings everyone,

I know this a hard one, but with a number of surface launched anti-ship missiles now fitted with a home on jam capability, why are many navies still opting for jammers on their surface vessels? Or do these missiles only work on jammers emitting on certain frequncies?

Also, is it part of RAF and USN doctrine to use ALARM and HARM anti-radiation missiles launched from Tornados and Hornets in the anti-shipping role? Apart from Bundesmarine Tornado's which trained in the past to use a combination of Komoran and HARM missiles for the anti-shipping role in the Baltic, I have never read of other NATO countries doing the same.

Thank you - Aplogies for the double post.

Mainly because missiles in HOJ mode ca burn though jam noise in certain distances.



This is perfectly possible. Those anti-radiation missiles have also shipborne radars placed in their signal databases. Simply well-balanced mixed attack strategy: ARMs can destroy warship radars first and then ASMs can hit her without problems because radar guided weapons are out of action.

HARM missiles don´t try to hit the ship. They want you to switch off the radar.
Two options there: 1) you do it: ASM hits you 2) you don't do it: HARM hits you

Evil.... but true tactics

 

[STURM]

Two options there: 1) you do it: ASM hits you 2) you don't do it: HARM hits you

Evil.... but true tactics

This was a well known Budesmarine tactic during the Cold War, with Tornados armed with HARMs and Komarons. I've been unable to find out if RAF Tornados and USN Intruders trained to do the same thing.

 

[Pedro C]

This was a well known Budesmarine tactic during the Cold War, with Tornados armed with HARMs and Komarons. I've been unable to find out if RAF Tornados and USN Intruders trained to do the same thing.

Not only RAF and USAF/USN but also a number of countries practice that tactics

 

[Invicta]

Defence Contractor

Greetings everyone,

I know this a hard one, but with a number of surface launched anti-ship missiles now fitted with a home on jam capability, why are many navies still opting for jammers on their surface vessels? Or do these missiles only work on jammers emitting on certain frequncies?

Also, is it part of RAF and USN doctrine to use ALARM and HARM anti-radiation missiles launched from Tornados and Hornets in the anti-shipping role? Apart from Bundesmarine Tornado's which trained in the past to use a combination of Komoran and HARM missiles for the anti-shipping role in the Baltic, I have never read of other NATO countries doing the same.

Thank you - Aplogies for the double post.

Excellent question. Three reasons come to mind for fitting jammers to counter missiles which have a home-on-jam (HOJ) capability:

1) Even if a missile has HOJ, there are special signal processing techniques which can be Incorporated in the jamming signal to render render HOJ ineffective... even though the jammer is radiating.

The objective of HOJ is to provide guidance information to the autopilot from the seeker so the missile can hit the target. Anything that disrupts that flow of information will degrade the probability that the missile will hit (or come close enough to) its target. Remember that the missile designers are under a lot of technical pressure to make a weapon work in the real world. Some of the compromises that they are forced to make -- by the laws of physics, basically, and information theory -- can be exploited by a jammer.

2) Jammers can be used to counter other missiles which do not have a HOJ capability, and might not be used for those that do (i.e. leave it switched off).

3) A jammer could be used to cause a missile to reject a legitimate target.

Here is my thinking regarding point 3: HOJ is predicated on the idea that the ECM is a beacon -- this is how offboard decoys work; they are a beacon intended to attract the missile away from the ship ( or aircraft or whatever). There are active decoys like Nulka and Siren, and there are/were passive decoys, like Rubber Duck.

But the missile designers know about offboard decoys, and they know what ships are supposed to look like to a missile under combat conditions. Consequently, modern missiles can be expected to be equipped with target discriminant features: the seeker will turn on and do a quick scan to build up a tactical picture, to identify -- quickly -- possible targets. It can then be expected to stare at each one of the targets and apply its target discriminants, to try to separate out the decoys and the jammers from the "real thing".

Now imagine a ship is equipped with an active onboard jammer that acts as a simple point-source beacon. The missile stares at it, it sees... what looks like a decoy, so the onboard targeting computer rejects it. Imagine also that at the same time you have kicked overboard a more capable decoy (or something else) that creates radar reflections that look like a ship, in terms of scintillation (ampltidue fluctuations) and glint (angle fluctuations), and with the correct correlation between scintillation and the glint.

I'm not saying that any of these things are actually done, only that they are logical possibilities, and in my mind a reasonable explanation for why jammers would be put on ships even though there are missiles with a HOJ capability.

And just to hit it one more time: remember, not all missiles have HOJ. There is still plenty of the old wood-burning threats out there, and if you've got three of these inbound and no jammer, it doesn't matter how sophisticted the missiles are that weren't fired at you.

Hope this helps. Great question.