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Re: How effective are CIWS?

Unread postPosted: 01 May 2019, 13:51
by quicksilver
“Phalanx trying to shoot down parts of previously dispatched target.”

Yep. Have seen it w my own eyes.

Re: How effective are CIWS?

Unread postPosted: 01 May 2019, 17:47
by marauder2048
hornetfinn wrote:
sferrin wrote:
count_to_10 wrote:I heard a story about two phalanx firing at the same target and then following each other’s stream of bullets back toward each other.


I've heard several odd stories as well. Phalanx trying to shoot down parts of previously dispatched target. Phalanx trying to lock onto rotor-blade tips. Part of the learning process I gather.


These things happen with automated air defence gun systems. Rotor-blade tips are very attractive for fire-control radar as they give very nice doppler returns for it. Those doppler returns can be easily filtered out, but in most systems those returns are wanted. Helos are difficult to track otherwise as they are very slow moving or stationary targets at low altitude which means they themselves don't give good doppler returns. This makes them difficult to separate from ground or sea clutter. I'm sure helos are also one potential (although not always very likely) target even for Phalanx.



Blade modulation is about the only thing you have for a stationary helicopter trying to hide in sea-clutter.

"Coherent Data Collection Efforts in Support of Phalanx"

https://www.jhuapl.edu/techdigest/TD/td1803/rzerou.pdf

Re: How effective are CIWS?

Unread postPosted: 03 May 2019, 01:59
by count_to_10
So, if you want to know what the military would like to have instead of phalanx, look up mad fires.
https://www.darpa.mil/program/multi-azi ... ent-system

Re: How effective are CIWS?

Unread postPosted: 03 May 2019, 12:07
by hornetfinn
count_to_10 wrote:So, if you want to know what the military would like to have instead of phalanx, look up mad fires.
https://www.darpa.mil/program/multi-azi ... ent-system


Sounds a bit like Oto Melara 76 mm with DART ammunition.

Re: How effective are CIWS?

Unread postPosted: 03 May 2019, 12:33
by madrat
Battlespace management technology back in the 90's was promised to make AI integration much simpler.

I cannot imagine they were wrong about that. Surely CIWS in 2019 is infinitely more aware of targets, no longer just using smudge lights based on radar technology to illuminate the inbound. Surely the EODAS technology is applied to ships only on steroids compared to aircraft. You can afford EODAS spherical coverage with much longer reaching lenses.

Re: How effective are CIWS?

Unread postPosted: 03 May 2019, 22:29
by marauder2048
madrat wrote:Battlespace management technology back in the 90's was promised to make AI integration much simpler.

I cannot imagine they were wrong about that. Surely CIWS in 2019 is infinitely more aware of targets, no longer just using smudge lights based on radar technology to illuminate the inbound. Surely the EODAS technology is applied to ships only on steroids compared to aircraft. You can afford EODAS spherical coverage with much longer reaching lenses.



The destroyers do incorporate the CIWS (Phalanx or SeaRAM) radar tracks into the CEC composite tracks;
Ku-band has some really nice properties in certain propagation conditions. The optical horizon being shorter
than the RF horizon probably means that a major use of infrared would be in kill-assessment since its
better angular resolution gives it an advantage in discriminating debris from say a trailer in a stream raid.

Re: How effective are CIWS?

Unread postPosted: 07 May 2019, 10:22
by zero-one
meaning to ask this for a while now, but I'm wondering if it deserves its own thread.
What are the candidates for the most effective ASuW missile.

To me, its the AGM-158C. Its main strengths include VLO technology, very long range and low sea skimming capabilities and most importantly it is the only missile I know that has its own ESM and RWR. This means that it is the 1st missile of its kind that actually knows if it is being tracked and targeted by CIWS or other defenses.

Sure, other ASuW weapons are much faster, but they are flying blind against anti missile defenses and once they start executing their end game maneuvers which are pre-programmed and not designed to adjust to enemy defenses, they will throw all that speed out the window. Can the Brahmos and Klub missiles maneuver at supersonic speeds?

So with a premise like this, it makes sense that the USN chose Stealth and AI over raw speed when they chose the LRASM over faster counterparts. However this also suggest that modern CIWS and missile defenses are so effective that speed just won't cut it. In that case the old Harpoon and other similar weapons will not have very good Pk numbers against modern ships.

Re: How effective are CIWS?

Unread postPosted: 07 May 2019, 11:14
by knowan
zero-one wrote:Can the Brahmos and Klub missiles maneuver at supersonic speeds?


Probably, but their g-limit is unlikely to be high enough to allow for any significant manoeuvring at supersonic speeds.


hornetfinn wrote:
count_to_10 wrote:So, if you want to know what the military would like to have instead of phalanx, look up mad fires.
https://www.darpa.mil/program/multi-azi ... ent-system


Sounds a bit like Oto Melara 76 mm with DART ammunition.


57mm according to this article: https://www.navalnews.com/event-news/sa ... d-testing/

I wonder if this played a part in selection of a 57mm gun for the FFG(X)?

Re: How effective are CIWS?

Unread postPosted: 07 May 2019, 13:03
by sferrin
knowan wrote:I wonder if this played a part in selection of a 57mm gun for the FFG(X)?


Doubt it. The gun is already on the LCS and elsewhere.

Re: How effective are CIWS?

Unread postPosted: 07 May 2019, 17:30
by marauder2048
knowan wrote:I wonder if this played a part in selection of a 57mm gun for the FFG(X)?


It was another guided round:


Re: How effective are CIWS?

Unread postPosted: 08 May 2019, 00:27
by marauder2048
knowan wrote:
zero-one wrote:Can the Brahmos and Klub missiles maneuver at supersonic speeds?


Probably, but their g-limit is unlikely to be high enough to allow for any significant manoeuvring at supersonic speeds.


And GQM-163A isn't the least bit weight optimized.

Re: How effective are CIWS?

Unread postPosted: 08 May 2019, 00:32
by sferrin
marauder2048 wrote:
knowan wrote:
zero-one wrote:Can the Brahmos and Klub missiles maneuver at supersonic speeds?


Probably, but their g-limit is unlikely to be high enough to allow for any significant manoeuvring at supersonic speeds.


And GQM-163A isn't the least bit weight optimized.


But is 12Gs at Mach 2.5 really much of a turn? Here's a Vandal getting shot down by ESSM years ago performing a 10G weave at Mach 2+

(The good stuff starts at 3:30)

Re: How effective are CIWS?

Unread postPosted: 08 May 2019, 01:11
by gc
zero-one wrote:meaning to ask this for a while now, but I'm wondering if it deserves its own thread.
What are the candidates for the most effective ASuW missile.

To me, its the AGM-158C. Its main strengths include VLO technology, very long range and low sea skimming capabilities and most importantly it is the only missile I know that has its own ESM and RWR. This means that it is the 1st missile of its kind that actually knows if it is being tracked and targeted by CIWS or other defenses.

Sure, other ASuW weapons are much faster, but they are flying blind against anti missile defenses and once they start executing their end game maneuvers which are pre-programmed and not designed to adjust to enemy defenses, they will throw all that speed out the window. Can the Brahmos and Klub missiles maneuver at supersonic speeds? .


Yep i read an analysis on Janes. Supersonic ASMs are limited to sctive radar seekers due to the heating of the nose cone at high speeds and low altitude. Active seekes will give its presence and location away the moment it comes on. The thing i like most about LRASMs and NSMs is its passive RF and iR seekers. The only way a ship can get warning is by radiating. And by forcing them to radiate continuously, they give away their location, which is the most important step in surface warfare kill chain. And radiating doesnt protect the ship at the end of the day due to the VLO designs of such missiles.

Re: How effective are CIWS?

Unread postPosted: 08 May 2019, 04:34
by marauder2048
sferrin wrote:
But is 12Gs at Mach 2.5 really much of a turn? Here's a Vandal getting shot down by ESSM years ago performing a 10G weave at Mach 2+



For a conventional (non-airbursting, unguided) single mount, gun-based CIWS, absolutely.

Even for large caliber (76mm) dual-mounts firing airburst rounds some of the analysis I've read is
pretty sobering for 10G targets.


"Limitations of Guns as a Defence against Manoeuvring Air Weapons"
(my OCR'ed version attached).

https://apps.dtic.mil/dtic/tr/fulltext/u2/a426717.pdf

Re: How effective are CIWS?

Unread postPosted: 08 May 2019, 12:10
by michaelemouse
zero-one wrote:meaning to ask this for a while now, but I'm wondering if it deserves its own thread.
What are the candidates for the most effective ASuW missile.

To me, its the AGM-158C. Its main strengths include VLO technology, very long range and low sea skimming capabilities and most importantly it is the only missile I know that has its own ESM and RWR. This means that it is the 1st missile of its kind that actually knows if it is being tracked and targeted by CIWS or other defenses.

Sure, other ASuW weapons are much faster, but they are flying blind against anti missile defenses and once they start executing their end game maneuvers which are pre-programmed and not designed to adjust to enemy defenses, they will throw all that speed out the window. Can the Brahmos and Klub missiles maneuver at supersonic speeds?

So with a premise like this, it makes sense that the USN chose Stealth and AI over raw speed when they chose the LRASM over faster counterparts. However this also suggest that modern CIWS and missile defenses are so effective that speed just won't cut it. In that case the old Harpoon and other similar weapons will not have very good Pk numbers against modern ships.



I suggest that it mainly comes down to reaction time. Can you reduce reaction time more through stealth/jamming/decoys or through speed? Bear with me through this simplified illustration; If I try to provide an exhaustive illustration using entire militaries acting against each other, I'll need to write a PhD thesis:

If the radar horizon is, say, 30km and you're going at 300m/s, that means the target has 100 seconds of reaction time from the moment it identifies the missile as a valid threat to the time it impacts the target. If you go at 600m/s, the target will have 50 seconds of reaction time. If you go at 1200m/s, the target will have 25 seconds. The problem with increasing speed is that, especially if you're flying at low altitude, drag increases exponentially as a function of velocity so you need ever larger amounts of propellant and ever more powerful engines.

The question then becomes: How much can you reduce enemy reaction time using electronic warfare elements like stealth, jamming, decoys or other means? More knowledgeable people than I may be able to give us partial answers which we can put together.

My guess is that Russia and China are betting on speed not because that's the most effective option but because the US is a head above them when it comes to information warfare so they have to make up for lack of smarts with brute force. That's how Arab militaries try to win wars and it hasn't worked out for them against the Americans, the Israelis or the Chadians.