LFASS

Hawk66 · 06-23-11, 01:06 PM

A question for the experts here :-) :

Is LFASS modelled somehow in Dangerous Waters? To my understanding LFASS is the successor of the classical, passive Towed Arrays to detect very quite subs, used by ships and there are currently upgrade programs ongoing (for example like for the German F123 ASW class)

Is LFASS (simplified expressed) an optimized active sonar, which also works in coastal waters or would the modelling of such sensors need a complete different modeling, thus it cannot be modeled easily in DW?

Thx.

Molon Labe · 06-23-11, 02:09 PM

LFA is really just another active sonar in the DW world, and could easily be mounted on a towed array type sensor entity. It's hard to find good information on any sonar's capabilities, though, and the newer the technology the harder it is to guess. But it certainly wouldn't be that hard for appropriate ships to be given active sensors that reach beyond the "standard" 10nmi or so.

EDIT: actually the more difficult issue would be in deciding what it does tactically. Depending on your estimate of how far it can detect a submarine and of what size, it might just reduce ASW to prosecuting a link with a helicopter without the fleet ever being in any danger whatsoever.

Hawk66 · 06-23-11, 02:32 PM

Ok, so the purpose of LFA is then mainly to protect the fleet from very quiet subs?

I mean you can hardly 'surprise' a sub, when you ping like hell the whole time (and I think LFA would then be online the whole time to fulfill its role?)

So, what I did not fully get so far: Is the time of big passive sonar arrays (ship platforms) over - and then also system like Prairie Maske (sorry did not found the correct spelling, I mean the system which influences the bubbles so that you get a noise reduction) - because what sense does it make to reduce your noise profile if your main sensor is active?

Dr.Sid · 06-23-11, 02:51 PM

Found some more info here: http://www.fas.org/irp/program/collect/lfa.htm
I'm not really sure how it can be tactically interesting ..

Molon Labe · 06-23-11, 04:33 PM

LFA does not appear to be very much in use. You can't even google it without being swarmed with environmental activist crap. As far as I know the USN only has it deployed on one T-AGOS ship and it's purely experimental at this point.

Would it make other systems obsolete? I'm guessing no. I would imagine ranging data isn't all that accurate with this system, and filtering out false returns would be a headache. You're also going to have several minutes between pings, as much as 15 minutes, so you're going to need to rely on other sensors for a 'good enough to shoot' solution. And due to environmental or EMCON concerns, you're not going to have it on all the time. My take on it is that it is an underwater AWACS to be used in wartime, and that other assets would be sent to investigate contacts at long range to see if it really is a sub or something else. Sort of like a datum-prosecution type thing... and perhaps not all that different from cold-war style convergence zone prosecutions that we've all read about, from back in the day when the threat came from noisy SSNs.

Unless it turns out you can accurately model the likely drawbacks of such a system in DW, it might be better off just using it as a mission design tool, give a platform a message that LFA platform might have detected something in X area, go investigate.

Hawk66 · 06-23-11, 04:47 PM

Yup, that makes sense...have also read in the meantime that it needs huge processing capabilities; don't know if they have to upgrade the IT infrastructure also on the F123s. The question is also how long they need to get that system really running but I've read somewhere that they did do already some tests 2006-2008.

Perhaps you model it via a dynamic trigger (dependent on the range LFASS platform <-> target), give then the player a rough solution and make it a little unpredictable via randomization...another usecase for the 'random whale'

.

So, modelling a 'moveable' SOSUS.

06-23-11, 01:06 PM	#1
Hawk66 Commodore Join Date: Sep 2006 Location: Germany Posts: 609 Downloads: 36 Uploads: 0	LFASS A question for the experts here :-) : Is LFASS modelled somehow in Dangerous Waters? To my understanding LFASS is the successor of the classical, passive Towed Arrays to detect very quite subs, used by ships and there are currently upgrade programs ongoing (for example like for the German F123 ASW class) Is LFASS (simplified expressed) an optimized active sonar, which also works in coastal waters or would the modelling of such sensors need a complete different modeling, thus it cannot be modeled easily in DW? Thx.

06-23-11, 02:09 PM	#2
Molon Labe Silent Hunter Join Date: Jun 2004 Location: Along the Watchtower Posts: 3,810 Downloads: 27 Uploads: 5	LFA is really just another active sonar in the DW world, and could easily be mounted on a towed array type sensor entity. It's hard to find good information on any sonar's capabilities, though, and the newer the technology the harder it is to guess. But it certainly wouldn't be that hard for appropriate ships to be given active sensors that reach beyond the "standard" 10nmi or so. EDIT: actually the more difficult issue would be in deciding what it does tactically. Depending on your estimate of how far it can detect a submarine and of what size, it might just reduce ASW to prosecuting a link with a helicopter without the fleet ever being in any danger whatsoever. __________________

06-23-11, 02:51 PM	#4
Dr.Sid The Old Man Join Date: May 2005 Location: Czech Republic Posts: 1,458 Downloads: 6 Uploads: 0	Found some more info here: http://www.fas.org/irp/program/collect/lfa.htm I'm not really sure how it can be tactically interesting .. __________________ ComSubSim forum at CADC

06-23-11, 04:33 PM	#5
Molon Labe Silent Hunter Join Date: Jun 2004 Location: Along the Watchtower Posts: 3,810 Downloads: 27 Uploads: 5	LFA does not appear to be very much in use. You can't even google it without being swarmed with environmental activist crap. As far as I know the USN only has it deployed on one T-AGOS ship and it's purely experimental at this point. Would it make other systems obsolete? I'm guessing no. I would imagine ranging data isn't all that accurate with this system, and filtering out false returns would be a headache. You're also going to have several minutes between pings, as much as 15 minutes, so you're going to need to rely on other sensors for a 'good enough to shoot' solution. And due to environmental or EMCON concerns, you're not going to have it on all the time. My take on it is that it is an underwater AWACS to be used in wartime, and that other assets would be sent to investigate contacts at long range to see if it really is a sub or something else. Sort of like a datum-prosecution type thing... and perhaps not all that different from cold-war style convergence zone prosecutions that we've all read about, from back in the day when the threat came from noisy SSNs. Unless it turns out you can accurately model the likely drawbacks of such a system in DW, it might be better off just using it as a mission design tool, give a platform a message that LFA platform might have detected something in X area, go investigate. __________________

06-23-11, 02:32 PM	#3
Hawk66 Commodore Join Date: Sep 2006 Location: Germany Posts: 609 Downloads: 36 Uploads: 0	Ok, so the purpose of LFA is then mainly to protect the fleet from very quiet subs? I mean you can hardly 'surprise' a sub, when you ping like hell the whole time (and I think LFA would then be online the whole time to fulfill its role?) So, what I did not fully get so far: Is the time of big passive sonar arrays (ship platforms) over - and then also system like Prairie Maske (sorry did not found the correct spelling, I mean the system which influences the bubbles so that you get a noise reduction) - because what sense does it make to reduce your noise profile if your main sensor is active?

06-23-11, 04:47 PM	#6
Hawk66 Commodore Join Date: Sep 2006 Location: Germany Posts: 609 Downloads: 36 Uploads: 0	Yup, that makes sense...have also read in the meantime that it needs huge processing capabilities; don't know if they have to upgrade the IT infrastructure also on the F123s. The question is also how long they need to get that system really running but I've read somewhere that they did do already some tests 2006-2008. Perhaps you model it via a dynamic trigger (dependent on the range LFASS platform <-> target), give then the player a rough solution and make it a little unpredictable via randomization...another usecase for the 'random whale' . So, modelling a 'moveable' SOSUS.