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STURM October 27th, 2012 03:38 PM

Question on missile firings from ships
 
Is there any particular reason why missile firings during exercises are normally conducted by ships that are moving at slow speed or at cruising speed - is it due to telemetry tests or simply to provide better photo opportunities for official photographers? Is there any technical reason as to why a launch wouldn't be made if a ship was moving say at 25 or 30 knots? Could FACs with speeds of 50 knots launch missiles when moving at high speeds?

Systems Adict October 27th, 2012 05:08 PM

Quote:

Originally Posted by STURM (Post 254317)
Is there any particular reason why missile firings during exercises are normally conducted by ships that are moving at slow speed or at cruising speed - is it due to telemetry tests or simply to provide better photo opportunities for official photographers? Is there any technical reason as to why a launch wouldn't be made if a ship was moving say at 25 or 30 knots? Could FACs with speeds of 50 knots launch missiles when moving at high speeds?


Logically, I would say that it had something to do with stability & accuracy.

If a ship is pootling along at minimum speed, or at dead stop / station keeping for that matter, it is a more stable platform in pitch & roll.

This stability allows the processing of data to be made easier & this makes it more accurate, as while the data may well be being fed to the command system / fire control predictor 1,000 times a second, it's not being swamped with huge variations on pitch, roll, ships heading & speed from own ship.

Additionally, the same can be said for the track extractor data being processed by the radar / tracker that is tracking the target. Less variation / solid tracking of the target leads to better accuracy.

All that said, these systems CAN operate when the ship is at speed, but there is the likelihood that unless the missile is update from own ship, mid-flight, there's a higher probability of a miss.

FAC's generally use missiles that have their own seeker heads built in, that get initial (simple) target data (range/course/speed) from own ship, then after launch lock onto target.



Well that's my 2 cents worth....

Happy to be proven incorrect ! :p:


SA

STURM October 27th, 2012 05:19 PM

Quote:

Originally Posted by Systems Adict (Post 254321)
FAC's generally use missiles that have their own seeker heads built in, that get initial (simple) target data (range/course/speed) from own ship, then after launch lock onto target.

You mean there'a a difference between say, MM-40s on an FAC and MM-40s on a destroyer in that the ones fitted on the FAC have built in seeker heads? I was under the impression that all guided surface to surface missiles have built in seeker heads and that target guidance is provided via the ships radar [and fire director?] until the missile reaches its terminal phase.

Bonza October 27th, 2012 09:10 PM

Quote:

Originally Posted by STURM (Post 254322)
You mean there'a a difference between say, MM-40s on an FAC and MM-40s on a destroyer in that the ones fitted on the FAC have built in seeker heads? I was under the impression that all guided surface to surface missiles have built in seeker heads and that target guidance is provided via the ships radar [and fire director?] until the missile reaches its terminal phase.

You can launch a missile to be guided to the target's extrapolated position via INS or something like that, whereupon it switches on its own sensors and enters the terminal phase - this is how the Exocet and many others work, if I remember correctly. Doesn't need radar illumination from the launch vessel the entire time : )

STURM October 28th, 2012 12:36 PM

Have we reached a stage where MPAs or other OTHT assets can provide mid-course guidance to ship launched anti-ship missiles in flight - the same way that some BVR missiles have a mid-course guidance update capability via a data link?

kato October 28th, 2012 02:26 PM

We reached that stage over 30 years ago (e.g. with Otomat TESEO and ERATO). The current generation of missiles introduces dual-direction datalinks.

Blackshoe October 29th, 2012 06:23 PM

2 Attachment(s)
Quote:

Originally Posted by STURM (Post 254317)
Is there any particular reason why missile firings during exercises are normally conducted by ships that are moving at slow speed or at cruising speed - is it due to telemetry tests or simply to provide better photo opportunities for official photographers? Is there any technical reason as to why a launch wouldn't be made if a ship was moving say at 25 or 30 knots? Could FACs with speeds of 50 knots launch missiles when moving at high speeds?

Generally, it gets better pictures moving at low speed, and since MISSILEXes are usually pretty rare events, there's not much reason to add speed into the process as one more thing to get wrong.

I know for a fact there's been one recent launch from an ARLEIGH BURKE-class DDG at high-speed (note that the flag is flying fully, which requires either a lot of wind or a lot of speed).

STURM November 2nd, 2012 07:05 AM

1 Attachment(s)
Judging from the way the smoke trail has moved, this ship was probably moving at medium to high speed or there was a very strong wind. The launchers on this ship are fitted amidships but the smoke trail has moved way aft which seems to give the impression that the missile was fired somewhere else.

Blackshoe November 2nd, 2012 10:27 AM

I'd argue judging by the wake that the ship must have been moving pretty slowly.

That missile has in impressive turn-over maneuver, though.

STURM November 2nd, 2012 02:22 PM

Quote:

Originally Posted by Blackshoe (Post 254597)
I'd argue judging by the wake that the ship must have been moving pretty slowly.

That missile has in impressive turn-over maneuver, though.

It's an Exocet MM-40 Block 2. You're right, from the wake the ship must have been moving probably at 7-8 knots! But there must have been a very strong wind as the smoke trail has been blown way to the aft.

dundonrl November 12th, 2012 04:36 PM

Quote:

Originally Posted by Blackshoe (Post 254406)
Generally, it gets better pictures moving at low speed, and since MISSILEXes are usually pretty rare events, there's not much reason to add speed into the process as one more thing to get wrong.

I know for a fact there's been one recent launch from an ARLEIGH BURKE-class DDG at high-speed (note that the flag is flying fully, which requires either a lot of wind or a lot of speed).

for a TLAM, you have a spot in the ocean that you shoot from, to have the most effective chance of getting all your birds on target. Depending on the range your shooting, the direction of your missiles (port or stbd flyout) depends on where the EP's (Engagement Planners) tell the LCO (Launch Control Officer) where the ship needs to be and at what time. The LCO lets the CO know where the ship needs to be, and verify's with higher authority (generally the Carrier in the region, or large deck amphib) that your "spot" is authorized.


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