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Molon Labe
Joined: 16 Jun 2004
Posts: 1052
Location: Bloomington, IN, USA
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 Posted: Thu Oct 21, 2004 1:49 am Post subject: ESM detection of missiles |
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I just finished up reading an old thread where someone suggested an 'incoming missile' alert (tied to ESM) similar to a 'torpedo in the water' alert. This got me thinking about real world events...
IIRC, in the Falklands war, all or most of the incoming Exocets were detected visually, not by ESM. Also, when the OHP USS Stark was hit by two Iraqi Exocets, it was lookouts, not ESM, that detected the missiles.
Does anyone know why ESM isn't picking up on active radar homing missles? (And depending on the answer, will DW account for this in any way...perhaps a missile alert from the lookout instead of ESM station?)
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Smuook
Joined: 13 Jan 2004
Posts: 112
Location: Florida
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| Posted: Thu Oct 21, 2004 2:01 am Post subject: |
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I'm not an expert on exocet missiles... but I'll give it a try. I think it most similar to a US Harpoon missile. If so, it actually uses it's own guidance system to come in bound to the target at a low altitude. The radar seeker comes on at the acquisition phase and it will have a realitively small search pattern ahead of the missile. When the target is acquired it goes into the terminal phase and hits the target. This all occurs close to the target and with the missile flying in at several hundred knots... there is really very little time to react... let alone interpret ESM.
I think you just have to remember that anti-ship missiles are designed to defeat the ships systems like radar and ESM to maximize the hit success. |
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Looney11
Joined: 05 Aug 2004
Posts: 307
Location: Netherlands
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| Posted: Thu Oct 21, 2004 5:24 am Post subject: |
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The missiles are very hard to detect on ESM, especially the exocet and harpoon ones which use the I-band (if i'm not mistaking ??) for their guidance. Usually, the I-band is cluttered with every single navigational radar in a 100nm radius  so you'll either see the harpoon coming in the middele of the pacific with no contacts around but most of the time you'll miss it.. Again, i could be mistaking about the band the harpoon looks in.
A better way to "detect" missiles is look for the radar signature of the launching vessel/aircraft. So, for the exocet for example, we'll be looking for the super-etendard Cyrano radar system. If you detect 1 or 2 contacts 40nm out with this type of radar showing up on your ESM (even a few sweeps will make for a ZIPPO call!) and you see the contacts conducting a turn away manouevrer you can bet your shoes and all of your clothing cabinet that they've launched their missiles even if you don't see them.
That leaves you with 40nm travelling at 540knots = 4,4 minutes to plan your defenses. (hope i calculated it right).
The biggest threat is submarines who use passive targetting info and launch from below. Hopefully it is an active seeker which you can pick up on your ESM. Otherwise... you can hope your Phalanx works properly...
So, basically, if you know what you're facing (intelligence messages) and you know which radar corrolates with which missile system, you can plan and prepare for the missiles you will be facing. |
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Scion
Joined: 31 May 2001
Posts: 1552
Location: New Zealand
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| Posted: Thu Oct 21, 2004 5:46 am Post subject: |
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How many vampires could the single Phalanx on a Fig take care of? I would imagine 1-2 Max, with its limited range...
That means a slavo of 4 missiles is a sure way of permanently converting the fig to a submarine... Or a single 53-65K |
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Looney11
Joined: 05 Aug 2004
Posts: 307
Location: Netherlands
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| Posted: Thu Oct 21, 2004 6:07 am Post subject: |
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True, however, a frigate will also use its jamming and chaff decoys capability against incoming threats, as well as making sure the super-etendards never come within 40nm range by using the force AAW ships to take 'm down, remember, the stand-off range of the Arleigh-burke class in 100nm!
On top of that, lets hope that in the future the goalkeeper CIWS system gets its rightfull place in DW. A system capable of handling 16 threats at once, even supersonic ones, is a must for every ship that needs/wants decent protection. RAM would be nice to have also.
Which reminds me, will surface units face airborne platforms capable of launching ASM's? In that case, a hairy multihreat enviroment can exist with multi-play subs and AI airborne units engaging a carrier battle group.... (/me sounds general quarters).
I can only hope the DW engine allows for a good defence against incoming ASM's. Maybe the suseptibility to chaff is fair or something of that order...
I feel the FFG can and will be a fun and versatile platform to play in DW. |
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Scion
Joined: 31 May 2001
Posts: 1552
Location: New Zealand
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| Posted: Thu Oct 21, 2004 6:17 am Post subject: |
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| I was refering to sub launched ASMs coming in from <10 nmi. |
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Looney11
Joined: 05 Aug 2004
Posts: 307
Location: Netherlands
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| Posted: Thu Oct 21, 2004 6:32 am Post subject: |
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A bit about goalkeeper:
| Quote: | In automatic mode the radar limits itself to targets within a 2-7km range bracket with target speeds of 150m/sec or more. The Dutch version of the search radar detects up to 30 degrees in elevation for maximum detection power against sea skimmers. Programmed range is 8nm but the radar can detect targets out to 16nm. Goalkeeper can track 30 targets, assign 4 for engagement in order of importance. Burst length can be shortened to deal with more. Burst last about 0.2 seconds and two pairs of sea skimmers can be dealt with about 5 seconds apart.
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On top of this, the goalkeeper will do come math on the available shells it has. If you fire 2 harpoons as it and it has 500 shells it will fire knowing that it will spend 250 shells on each target and will open fire only when it is certain it will kill 100% certainty with 250 shells. Fire 10 harpoons at it and it will open fire only if it can kill with 50 shells, so, the range decreases.
Usual filling if topped up is 1200 rounds.
Reaction time against a Mach 2 sea-skimming missile from automatic detection to IFF interrogation, 90 degree tracker slew, tracker elevation, X-band lock-on and computer run-in is claimed to be about 5.5 seconds with the engagement starting at 1,500m and ending with a kill by 300m
So it should be able to tackle close ranged sub-launched ASM's
Shame it isn't modelled (yet) in DW |
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Scion
Joined: 31 May 2001
Posts: 1552
Location: New Zealand
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| Posted: Thu Oct 21, 2004 12:47 pm Post subject: |
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| OK, here is a nice scenario. In DW, Would a Fig be able to take care of a slavo of 4 Klub Missiles launched at a range of 5 (game) Nautical Miles? Because we dont know, assume that the game speed of the Klub is 550 Knots (Similar to harpoon). That gives the Fig about 35-40 seconds of time from launch to impact. Consider that the Fig can only launch 1 standard at a time from the Mk. 13 Launcher, and fire at incoming ASMs with the Phalanx and 12.7 mm MG. (The only weapons that could possibly stop a Vampire). What are its chances? |
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TLAM Strike
Joined: 30 Apr 2002
Posts: 4866
Location: Rochester, New York
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| Posted: Thu Oct 21, 2004 3:57 pm Post subject: |
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| Looney11 wrote: | | Which reminds me, will surface units face airborne platforms capable of launching ASM's? In that case, a hairy multihreat enviroment can exist with multi-play subs and AI airborne units engaging a carrier battle group.... (/me sounds general quarters). |
Most/all the units from SC will be there so yes there will be Backfire bombers and F/A-18s to lob ASMs at you.
Also the P-3 will have Mavricks and the MH-60 Penguins and Hellfires so all the playable platforms have a Anti-Ship capablity. |
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XabbaRus
Joined: 21 Sep 2001
Posts: 6949
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| Posted: Thu Oct 21, 2004 5:07 pm Post subject: |
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As far as I know in the Falklands 2 of the 3 Type 42s called Handbrake on Excocet launch. I'm not sure if that was a result of 909 radar conact or ESM.
Now Sheffield at that time was on the SATCOM link which in effect blocked the 909 radar from working therefore she didn't pick up the Etendards.
Result Exocet 1 RN 0 |
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Looney11
Joined: 05 Aug 2004
Posts: 307
Location: Netherlands
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| Posted: Thu Oct 21, 2004 5:51 pm Post subject: |
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| Quote: | | here is a nice scenario. In DW, Would a Fig be able to take care of a slavo of 4 Klub Missiles launched at a range of 5 (game) Nautical Miles? Because we dont know, assume that the game speed of the Klub is 550 Knots (Similar to harpoon). That gives the Fig about 35-40 seconds of time from launch to impact. Consider that the Fig can only launch 1 standard at a time from the Mk. 13 Launcher, and fire at incoming ASMs with the Phalanx and 12.7 mm MG. (The only weapons that could possibly stop a Vampire). What are its chances |
Klub missile:
| Quote: | The Antiship 3M-54E missile is designed to be fired either from standardized vertical launch tubes of surface ships or through torpedo tubes of submarines. The 3M-54E antiship missile is made up of a launch stage, a winged low-flying subsonic cruise stage, and a low-flying supersonic kill vehicle that attacks the target in a final terminal phase.
SPEED - MACH .6 TO .8 TURBOJET CRUISE
ANTI-SHIP THIRD STAGE KILL VEHICLE HYPESONIC MACH 2.9
SEPERATES INSIDE LAST 15 N. MILES OF TARGET
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(can you launch a klub missile 5 miles from your target i wonder??)
At 5nm the launch will be visually detected (if the lookouts do their job), the CIWS will already be active (i really hope so for the FFG), I don't think the FC will have enough time to get a solid lock on the incoming club missiles, but lets day it does on 1, SM will be useless, instead, the 76mm gun will take down 1 (give the gun some credit), that still leaves 3 other missiles coming in. 1 might be fooled by chaff and the other 2 are for the phalanx which can take down 1. Leaving 1 missile to have frigate steel for breakfast.
With jamming, the FFG might use RGC on one missile fooling it to believe the target is way further down its current trajectory. Or increase the noise level to basically blind the vessel out from the seekers view, hoping it will find a juicier target.
And this is as good as it gets for the FFG. Or some lucky sailor on the MG got extremely lucky but there's another thread to that.
Basically, with 4 klub missiles you can asume your frigate DIW and most probably looking for a watery grave.
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TLAM Strike
Joined: 30 Apr 2002
Posts: 4866
Location: Rochester, New York
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| Posted: Thu Oct 21, 2004 6:16 pm Post subject: |
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A Sub could fire its missiles head on to the FFG, forcing the FFG to turn to bring its 76MM and CIWS to bear on the incoming ASMs. That might cut 15 to 30 seconds off the FFGs weapons response time.
Of course in Multi-Play a sub driver might send a Shkval set very shallow and a standard fish at the FFG to insure a kill/finish her off. |
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Scion
Joined: 31 May 2001
Posts: 1552
Location: New Zealand
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| Posted: Thu Oct 21, 2004 6:17 pm Post subject: |
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Or, in my first example, a 53-65K 
No chance of evasion |
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TLAM Strike
Joined: 30 Apr 2002
Posts: 4866
Location: Rochester, New York
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| Posted: Thu Oct 21, 2004 6:31 pm Post subject: |
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Unless it turns in the wrong direction!  |
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finiteless
Joined: 05 Aug 2004
Posts: 751
Location: Australia
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| Posted: Fri Oct 22, 2004 4:58 am Post subject: |
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| TLAM Strike wrote: | | A Sub could fire its missiles head on to the FFG, forcing the FFG to turn to bring its 76MM and CIWS to bear on the incoming ASMs. |
I observed something interesting in Sub Command today (v1.08 SCU SCXIIc), an FFG fired at a Chinese Luda Class DD, directly head-on to it, and 5 Harpoons hit the bow area of the Luda, but only yielded 56% damage (!). But soon after another Harpoon landed on the Luda from directly abeam, and that single missile used up all of the Luda’s remaining 44% of allowable damage.
What gives? It seems that the angle of incidence of the missile’s arrival had a large bearing on the degree of damage inflicted. This doesn't seem too 'realistic' because I would imagine that 4 to 5 Harpoon warheads could blow the bow right off back to the bridge, and the ship would almost certainly be permanently RS after that.
I bring this observation up here because if that were the case within DW, then an FFG driver might be able to use that head-on tactic to incoming to absorb more missile impacts than they rightly should be able, thus remaining effective in combat and afloat when they shouldn’t be.
(hopefully a beta tester will check on this situation with regard to DW) |
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