Monday, February 7, 2011

Developments in the Use of TBMs as Anti-Ship Weapons

Developments in the Use of TBMs as Anti-Ship Weapons

Earlier I explored the viability of Iran using a wide range of artillery rockets (MLRS), tactical ballistic missiles (TBM) and ballistic missiles proper (BM) as potential anti-ship weapons to supplement their usual cruise-missile type weapons and I concluded that while the use of cluster munitions might be useful against aircraft-carriers, the available generations of missiles didn't present a significant threat against most warships. (1) One feature I did feel was important in terms of long-term significance however was the similarity found between Chinese and Iranian anti-ship technology development.

Khalij Fars anti-ship missile (Fars News)
Fast-forward to February 2011 and Ali Jafari, Commander of Iran's Islamic Revolutionary Guard Corps (IRGC), announced that the force was now producing "smart ballistic missiles" (2) The announcement was accompanied by video and photographic evidence of the missile, pointedly named the"Khalij Fars" (Persian Gulf), being launched, and of it striking its target.

The missile itself is clearly based on the Fateh-110. The timing as well as the actual photographic evidence of the impact (a rarity among Iran's various missile announcements) suggests it's closely linked to the 3rd generation of the missile shown in August 2010.While it is a much smaller missile, similarities can be drawn to specific variants of the Chinese DF-21 ballistic missile which is has been touted as a "carrier-killer".

However, one curiosity is the reported specifications. It is reported as having a 300 km range which matches the previously announced range for the 3rd-generation Fatah-110. Also reported is a 650 kg warhead which represents a 31% increase in size versus the 1st generation of the Fatah-110 (450 kg). Future generations are set to have a longer range. (3) Unfortunately the warhead size/weight of the 3rd-generation model is unknown. One explanation is simple disinformation, another is a change in fuel composition and a subsequent increase in efficiency.

Known Specifications:
Length: 8.76 m
Diameter: 616 mm
Max Range: 300 km
Warhead: 650 kg

It was previously postulated that the Fateh-110 had a separating warhead which would have made the missile more accurate and harder to intercept. However, both the video and still images show the full missile impacting the target ship.
Selected screen captures showing the missile striking the floating target (Fars News)

The most significant unknown surrounds the method of terminal guidance. In fact, the only physical difference between the Fateh-110 and the Khalij Fars can be found in the nose of the missile, the latter exchanging the former's sharp point for a rounded nose. The lone high-quality image of it available from Fars News does not provide any definitive answers. While there does not appear to be an electro-optical seeker, contour blending and specific photography angles could easily obscure it. If an optical device, it would either use basic contrast measuring, such as on early TV-guided air-to-ground missiles, or the more advanced scene-matching correlators which aligns the displayed result with previously stored imaging. The Russian SS-26 Iskander-E is an example of a ballistic missile which uses an image correlator to give a remarkable CEP of 5-7 m. (4). The other alternative is some kind of radar seeker which essentially function the same as the optical correlator, but with radar instead of visual waves. The Chinese DF-11 is an example of a ballistic missile that uses an radar for terminal guidance to give it a CEP of 500-600 m (the DF-11A uses an image correlator which improves the CEP to 200 m) (5) It is worth mentioning that the target during the test was static while real world targets are much more likely to be maneuvering. This doesn't rule out the possibility of success as the terminal phase seeker could still track the target, whether it's moving or not, it just makes it harder.

The number one concern is, of course, accuracy, can it hit a warship? Video, as well as circumstantial evidence suggest the the 750 m CEP of the original Fateh-110 has been substantially improved upon as videos of the missile striking a naval target have been published. There are however several unknowns, including at what range the missile was fired at, the number of shots it took to get one that actually hit the target, and the degree to which the testing was pre-planned or actually represented battlefield conditions. One solution might be to look to comparable missiles across the globe.

While the use of submunitions has not been suggested, with the missile during the test carrying a unitary warhead, given the focus of the previous piece on this blog, it bears examining the possibility that they are carried by the Khalij Fars. 

Following the same steps as before, we can deduce that:

Submunition Warhead
Total Weight: 650 kg
Payload: 1,083 .45 kg bomblets
Threatened Area: 126, 426 sqm
Lethal Radius: 200 m

It bears repeating that this is only a thought experiment as to what would be possible if it carried submunitions.

The unveiling of the Khalij Fars is a significant development for naval-warfare analysts studying Iran because it concretely indicates that Iran is pursuing an anti-ship ballistic missile at least superficially similar to the DF-21. While before, Safavi's obtuse comment about the Shahab-3 as well as the use of the Fajr-3/5 rockets alongside AShMs indicated this might be the case, this development confirms it. While the Iranian missile isn't in the class of the DF-21, that's only because it's an early model (longer range models are said to be in development) and more adequately fits the needs of Iran, namely a smaller, cheaper, quick-reaction missile that threatens close to the entirety of the Persian Gulf.


References:
(1) "Artillery Rockets and Ballistic Missiles as Anti-Ship Weapons". The Arkenstone. 01/16/11 http://thearkenstone.blogspot.com/2011/01/artillery-rockets-and-ballistic.html
(2) "Commander: IRGC Mass-Producing Anti-Ship Ballistic Missiles". Fars News. 02/07/11 http://english.farsnews.com/newstext.php?nn=8911181179
(3) "خليج فارس " جديدترين موشك بالستيك و مافوق صوت سپاه عليه اهداف دريايي". Fars News. 02/07/11 http://www.farsnews.com/newstext.php?nn=8911181067
(4) ROSOBORONEXPORT Export Catalogue. http://www.roe.ru/cataloque/land_for/land_for_40-43.pdf
(5) "DongFeng 11 (CSS-7) Short-Range Ballistic Missile" Sino Defence. http://www.sinodefence.com/strategic/missile/df11.asp

4 comments:

  1. I agree that with the world's sole superpower refusing to take the military option against Iran off the table any time soon, it wouldn't make much sense wasting resources on "keeping the IRIAF flying" -while the US can take out most of Iran's airfields within an hour from thousands of miles away with a "Prompt Global Strike"- and keeping a bunch of flyboys happy playing "Top Gun".

    I like the modular concept behind the Karrar and am sure some (if not most of them) will have radar, esp. the "terrain following" versions. Besides, it wouldn't make much sense fitting them out with Kowsars (or are that Fajr-e-Daryas?) without an acquisition radar (at more than 500km roundtrip range probably on the Karrar). I thought the Kowsar doesn't have active radar itself so it'll target anything returning an echo (likely a ship, although you have to somehow avoid hitting civilian targets ;). Either that or it has an IR "CCTV" like the Fajr, but in that case the image data has to be relayed through the Karrar back to the remote operator... hmmm, how would you manage that at 500km distance? Any thoughts?

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  2. Well, the Karrar itself wouldn't necessarily needed to be fitted with a radar because the Kowsars aren't actually guided to their target by the launch platform in the same manner as AIM-7 where the launch platform illuminates the target with it's own radar - the Kowsars (and other Iranian AShMs) are fire and forget, completely autonomous.

    This means that the Karrar can be used to extend the range of the Kowsar if the target is detected by other means such as a land-based radar platform, or an airborne maritime surveillance aircraft like the P-3 or a UAV.

    In this model, the Karrar would fly toward a waypoint, release the Kowsar which would then fly to a waypoint of its own where it would then activate its own radar-seeker and search for the target completely independent of the Karrar which would then be doing its own thing such as returning to base.

    Other versions of the Kowsar have TV, but those weren't the models displayed on the Karrar mockup and are considerably less common then the radar-guided variants. These are also fire-and-forget where the missile automatically scans for targets. Other versions have the capability for the operator to actively select targets, but of course if the missile is out of range because it's being carried by the Karrar, obviously this option is out of the window.

    Hope that's clear, it's sort of a convoluted explanation.

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  3. GW, thank you for your comment.

    I was surprised to hear the Kowsar was FF, so had to have an active radar. With 0.2m diam. what kind of range are we talking about? Probably not very accurate, which would explain why an Egyptian freighter was also hit during the "Hanit" incident.

    The "Shahin" is definitely guided but I'm really not sure of any other surface/ship/sub-launched missile, are you?
    Besides, apart from this "3000km radar" they began talking about last year, I can't think of any data link system to guide an over-the horizon (beyond-visible-range) missile. Maybe the P3 mentioned and (future) UAV's, Iran-140's, satellites?

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  4. To the best of my knowledge, Iran doesn't have any non-airborne OTH data-linking capability.

    Range of the Kowsar is up to 25 km.

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