Explosive Echo Ranging

[goldorak]

Does anyone know what Explosive Echo Ranging is ?
And if yes, is it still a tactic used nowadays in asw?
A person I play DW with is trying to convince me that EER is a sound tactic to hunt a submarine but I fail to see exactly why.
What can EER achieve that a field of passive/active sonobuoys + p-3 can't achieve ?

[Frame57]

Never heard of it, but that does not mean it was/is not used. There has to be some Skimmers here that know this. Come on, fess up.

[OneShot]

Old Tactic ... sort of DICASS just with two components and explosives instead of the "Ping". Basically you drop your passive buoy(s) and then drop a small explosive charge. Theory is that the soundwaves generated by the explosion will bounce of the sub and then show up on the passive buoy(s) as blip. I think the name for that was "Julie" (part of Julie/Jezebel) but I might mistake that for something else. I think this system was mentioned in either "Third Battle - Innovations in ASW in the Cold War" or "Principles of Naval Weapon Systems". This might be in use with some "older" Navies but I seriously doubt that the USN or the Brits (or whomever on that level) use this nowadays.

[goldorak]

Ok, why were small explosive charges used instead of the sonobuoys active ping.
This is the part that I can't understand.
Was there a technical limitation of some sort on the sonobuoys that made the use of small explosive devices necessary ?
Also if small explosive charges were used, am I correct in assuming that they would not have damaged in any way a submarine ?
Last but not least, active pings at least in dw can reach out to 10 nm, what was the typical range of those small explosive devices ? 5 nm ? 10 nm or much much less ?

[SeaQueen]

EER is just an active bistatic sonobuoy. They use an explosive charge instead of an electronic transducer to create their "ping." Informally they're called "bangers," by P-3 pilots and they're definitely still used. One of my gripes with DW is that they don't model bistatics at all.

The biggest obvious advantage to them over DICASS is their higher source level. That means a higher detection range and more efficient search rate. There's other more nuanced advantages to them as well, but I'm not really able to discuss them.

DICASS ultimately, aren't very good for searching a large area for a difficult to detect target. DIFARs will probably never really get much range at all against a quiet target, and are basically useless for searching a realistically sized search area in real life.



Does anyone know what Explosive Echo Ranging is ?
And if yes, is it still a tactic used nowadays in asw?
A person I play DW with is trying to convince me that EER is a sound tactic to hunt a submarine but I fail to see exactly why.
What can EER achieve that a field of passive/active sonobuoys + p-3 can't achieve ?

[SeaQueen]

Was there a technical limitation of some sort on the sonobuoys that made the use of small explosive devices necessary ?

They used explosive charges because it was hard to make a small array with a loud enough ping to detect certain types of targets.

Also if small explosive charges were used, am I correct in assuming that they would not have damaged in any way a submarine ?

I doubt it, unless the submarine was very unlucky and was right next to one when it went off.

Last but not least, active pings at least in dw can reach out to 10 nm, what was the typical range of those small explosive devices ? 5 nm ? 10 nm or much much less ?

It's more complicated than that. Since the source and receiver in EER are not co-located, (hence it's called "bistatic") the answer is "it depends" even more so than in other sonobuoys. Detection depends on the distance from both the source and receiver as well as acoustic conditions along both acoustic paths. It's much more complicated to predict their performance than it is with ordinary sonobuoys.

[goldorak]

EER is just an active bistatic sonobuoy. They use an explosive charge instead of an electronic transducer to create their "ping." Informally they're called "bangers," by P-3 pilots and they're definitely still used. One of my gripes with DW is that they don't model bistatics at all.

The biggest obvious advantage to them over DICASS is their higher source level. That means a higher detection range and more efficient search rate. There's other more nuanced advantages to them as well, but I'm not really able to discuss them.

DICASS ultimately, aren't very good for searching a large area for a difficult to detect target. DIFARs will probably never really get much range at all against a quiet target, and are basically useless for searching a realistically sized search area in real life.



Thanks a lot SeaQueen, very interesting information right here.
At least I can understand why EER is still used today.
I have 2 questions, maybe you can answer them (at least I hope so :oops: ) :
so first, can an operator set the intensity of the detonation ? and number 2 : won't the sonobuoy be destroyed by the explosion ?

[SeaQueen]

I have 2 questions, maybe you can answer them (at least I hope so :oops: ) :
so first, can an operator set the intensity of the detonation ? and number 2 : won't the sonobuoy be destroyed by the explosion ?

No, a bang is a bang. And yes, the buoy only has two charges on it, so it's only good for two bangs. Usually the way it works is that they lay a pattern of source buoys and receiver buoys and then set them to bang in some pattern according to some schedule. It's unlikely you would drop just one. This way the pattern is BOOM!!! listen... BOOM! listen... BOOM! listen...

[goldorak]

Ah ha that makes sense.
Like opening a cage, letting the prey enter the danger zone and then zac close the door and start shaking the poor beast.

[SeaQueen]

I think you're being overly dramatic. You probably would use EERs when you didn't even know if a target was present. The high source level of the explosion means you can use it as a wide-area search buoy.

Ah ha that makes sense.
Like opening a cage, letting the prey enter the danger zone and then zac close the door and start shaking the poor beast.

[fatty]

I have been told that some method of EER is used (or will be used) in 'ice-pick' sonobuoys for detecting submarines travelling underneath layers of ice.

[SeaQueen]

That might have been the case, however, these days nobody particularly cares about detecting SSBNs. That might change some time in the near future if Russian continues to behave like it has been, but right now, people in charge of handing out money for R&D are like, "yawn... that's so '80s!"

I have been told that some method of EER is used (or will be used) in 'ice-pick' sonobuoys for detecting submarines travelling underneath layers of ice.

[goldorak]

That might have been the case, however, these days nobody particularly cares about detecting SSBNs. That might change some time in the near future if Russian continues to behave like it has been, but right now, people in charge of handing out money for R&D are like, "yawn... that's so '80s!"



Why is that ? :hmm:
It doesn't make any sense.

[Marcantilan]

You are talking about JULIE, a system developed at the same time as JEZEBEL (now LOFAR)

As far as I know, the system is now totally outdated.

[SeaQueen]

Why is that ? :hmm:
It doesn't make any sense.

The Soviet Union collapsed. Nobody spends a lot of time worrying about nuclear war in the same way they did in the '80s, say. Back in the day, there were people in the Pentagon sweating bullets because they fully expected to get hit within the first few minutes of a conflict. Twenty years ago, everyone pretty much expected a conflict in Europe and it was going to be nuclear almost immediately. That's not really very likely now. Now a days, conventional wars are actually looking passe. Almost all of the thinking is about unconventional warfare, in which nuclear weapons have little role if any.

It's not that it isn't something people think about every now and then, it's just that it's not a major priority for the Navy's ASW programs. Now a days they're more worried about diesel electric submarines in coastal environments. Before, the Soviets planned to use their SSBNs as a survivable deterrent and the US seeked to threaten that, so that in the event of a nuclear war, they'd have the option of undermining the Soviet's most unpredictable threat. Now a days, they're thinking about inexpensive diesel electric submarines in a small, limited, regional conflict, positioned in such a way as to "deny access" to US carriers, amphibious forces, and logistics ships. The strategy is that if they can make it such that US will have to pay such a high price to intervene in a regional conflict that the US public will decide that it's not worth the enormous cost to participate in a conflict in a part of the world many probably can't even find on a map. If a foreign country, managed to sink even one US carrier or big-deck amphib, that'd be an enormous loss. It could be bigger than September 11 in terms of deaths. If that happened, it's not clear whether political support for such a war could be sustained or not. I could see it going either way, honestly. It really depends on what the politics of the time look like. Regardless, it's almost certainly be a blow to the US attitude that we can arbitrarily brush aside foreign militaries with our overwhelming conventional forces.

Back in Soviet days, though, we fully expected to lose multiple carriers in the course of the conflict. It was going to be grim and bloody. I don't think it's really possible for people today to really understand the fundamental shift in mentalities that's occured since the end of the Cold War. Nor do I think the public really comprehends how different warfare is today. Back then, people were talking about a global nuclear conflict in which the national survival of the United States and all of her allies was at stake, and the extinction of humanity was a possibility. Now a days, people are talking about small, regional conventional conflicts as well as unconventional war such as insurgencies, peacekeeping, counterterrorism, etc. Any conventional warfare that might break out is nowhere near the kind of global conflict people used to anticipate.

Actually, what I think is interesting, is that even as the US was preparing for The Big One, most of the conflicts that actually happened look at lot more like the conflicts people plan around today. It always makes me wonder if that's what they really ought to have been planning on back then.

[glmm]

A bit late, but still……

The development of the narrow band analysis was a revolution. Problem was LOFAR buoys were omnidirectional and it was possible to get long range contacts when acoustic conditions were good with no bearing information. At the time there were active sonobuoys, but they were large, expensive, omnidirectional and had low radiated power. The use of an explosive, high intensity source, was a cheap abd efective way to solve the bearing ambiguity with early LOFAR bouoys and also provided range to the target if close enough to the explosive charge. A P-2 or P-3 could carry a large number of SUS charges, which could also be used for communications with submerged submarines. The Emerson AQA-5 sonobuoy analyzer added CODAR, which used paired groups of ommi sonobuoys to solve the bearing ambiguity problem passively , but needed a well trained crew. CODAR was superseded by DIFAR (Directional LOFAR) in the 1960s so the bearing could be solved using DIFAR buoys like the SSQ-53, still in widespread use. Directional active buoys were also deployed (DICASS) and, used in combination, DIFAR/DICASS was the mainstay of VP aircraft well into the 1990s. The development of quieter nuclear subs by the Soviets in the 1980s eroded the passive advantage enjoyed by the West as passive detection ranges would fall sharply. Also, the rise of the moder SSK menace, a very quiet foe by nature, forced a rethink. Biestatic techniques were dusted off, using both an active or explosive source, and became again in use. Surface ships also moved to bistatic long range search using towed arrays mating a powerful, LF active component and a very large passive array for listening. Using modern computer power, long range adquisition against very quiet targets has become again possible, at least on paper.

[Aktungbby]

a bit late but stillgimm! :Kaleun_Salute:...finlly surfaced after 16 year's silent running' by an errant explosive SUS charge!??:timeout::up:

[glmm]

It was a well placed SUS!:Kaleun_Wink: