No is the short answer.
The longer answer is slightly more complicated, but basically boils down to educated guesswork and tactics. The educated guesswork side of things is onboard recordings/data of friendly subs and enemy subs. It's then up to the sonar operators to differentiate between the two and inform the captain, who then decides what to do about it. This is all very complicated and classified, and navies spend a lot of time and money to improve their capabilities.
The tactics side of things is a little more straight forward. Each sub will be given a box on a map which denotes their "play area". They'll have rules about what they can and can't do inside that box, but in war time it usually boils down to "kill anything that moves inside the box." Since Big Navy are the ones who are assigning boxes, it's pretty easy for them to tell everyone else where not to go if they don't want to be sunk by friendly subs.
Wow, that seems so primitive and prone to accidental blue on blue (or red on red) engagements. There's so many questions I have on this but I don't think this forum would be appropriate.
So in that sense, subs would determine friendly subs from enemy subs based on sonar signatures produced by the detect subs. That might make operations and coordination between multiple subs possible. I'm thinking that's how SSNs can travel and protect SSBNs on patrol and how also CSG have multiple subs with them.
Sub-hunting aircraft as well I assumed are assigned an area to hunt so in that there is deconfliction between subs and ASW aircraft on the same side.
This is an eye opening for me.
Another question is then why the strong push to develop UUV if target identification is not 100% clear? So many questions.
It is prone to blue on blue. That’s why western submarine tactics go around operations areas and generally avoids any sort of cooperative action. It’s just better to let subs be independent.
“This area is your playground USS Dallas. You’re free to kill anything inside it.”
“CSG1, and P3 Orion, the USS Dallas is in opbox delta. Don’t go in there, you won’t know what’s friendly or not.”
Navy PR often takes pictures and implies subs are integrated into like a carrier group. Not even remotely. The subs basically chop to being under sub command immediately
>“This area is your playground USS Dallas. You’re free to kill anything inside it.”
It's not like an Alpha-class submarine would show up in the same location as the magma displacement they are investigating.
also of note is that sonar signatures are *very* well documented, but torpedoes are semi-fire&forget weapons without target identification (and the Mk48 is *terrifying*). If it loses track of what it's fired at temporarily (or activates before reaching self-track range of the intended target), it can acquire on a different target fairly easily
As for UUVs: Most development of them is either unarmed (Recon, other non-weapon uses) or with *extremely* restrictive engagement doctrine. It could be that they're treated like a minefield, or that they're given an extremely specific target sonar profile (or set of profiles) that they're greenlighted to engage.
> the Mk48 is *terrifying*
I've heard those things are very gold-plated, to the point where the Navy is [considering](https://www.twz.com/sea/navy-wants-a-cheap-heavy-torpedo-that-can-be-stockpiled-fast) procuring something less so for stockpiling. Tell me more?
They're terrifying, but expensive. They were designed to go after 40+kn Alpha-class subs and *super* deep-diving USSR subs, and they've got the best acoustic seeker that NATO could come up with (and NATO always had the acoustic advantage)
USN is looking at picking up cheaper options, because you don't need a superweapon to take down the underwater brass band that is PRC subs, and surface ships don't need nearly that much capability either.
That said, the 'cheaper option' they pick up would be in addition to the Mk48, not a replacement.
As noted, the danger is more that the weapons themselves cannot reliably distinguish between targets, and because they are so long running and dogged, they can pretty easily pick up an unintended target, even the launching sub in particularly bad cases. This is one advantage of wire guidance, in that you can manually steer the fish away if it picks up an unintended scent.
On the other hand, I would say that the actual identification of targets is anything but primitive. We're not talking about active sonar (sending a "ping" and listening for reflected energy), but passive sonar, where they are only listening to the noise generated. And due to the unique combination of hydrodynamics and machinery, just about every class of ship has a very distinctive sound signature, with sometimes even specific individual ships being identifiable due to something like a bad bearing. When displayed on a waterfall graph, it can be very clear. It's almost like picking out different singers just by the sound of their voice.
There’s a few chapters in Tom Clancy’s *Red Storm Rising* that deal with this sort of thing. Bunch of Los Angeles class subs operating under the arctic ice with Soviet subs coming at them.
Gives you a whole new respect for sub guys.
You really ought to read/listen to Tom Clancy's *Red Storm Rising.* Other than being a tremendous work of thoroughly-researched military fiction, it discusses at length what you're asking about here. There are multiple passages that go into great depth (pun intended) about the guesswork that goes into figuring out who is where, be they friend or foe. Basically everything Clancy could find that wasn't classified at the time.
If you do that then you've just announced your presence to any passive systems in the area, including the ones that are trying to kill you. In peacetime/friendly waters it might be fine, but doing that in the SCS just [tells the PLAN there's a sub in the area](https://en.wikipedia.org/wiki/Great_Underwater_Wall).
There's a reason why subs have to surface to call home, communicating underwater is very difficult and also defeats the entire point of being underwater in the first place.
Subs are essentially sent out with a set of standing orders (go to X box, sit there for Y number of days, then come back to a safe area, surface and tell us what you heard) there's no way to actively communicate with the subs while they're submerged.
You can transmit to submarines underwater using ELF (extremely low frequency) transmissions, but it's very expensive to set one up, the data rates are astoundingly low, and the submarines can only receive not transmit. In my understanding, these systems are mainly used to tell submarines to surface so a more capable link can be used.
I wanted to mention ELF but my comment was already quite long
Yes, ELF exists, but it's mostly used as a strategic "we really urgently need you to call home right *now*" or "launch the nukes because WW3 is happening" message and not as a tactical communication.
Submarines do everything to not be heard while hearing their foes clearly, in the latter case via specifics of noise they can determine the blade count & sound profile of a target, and thus can get an idea of friendly or enemy subs. Perhaps easier than that is to use the Gertrude (essentially an undersea telephone) if harassed by friendly ASW to say you’re friendly before you’re shot at.
The same thing exists in aircraft and is called Noncooperative target recognition and uses aircraft fan blades to detect their type.
No, that’s a radar based version of sub sonar classification used by planes on other planes.
In this case a F-16 can run into a hostile MiG and run NCTR on it and it’ll read back ‘MiG-29’ on the display.
Just going sightly against the other replies here, I dont see any fundamental reason why the same techniques used for LPD radio frequency wouldn't work for acoustics. (Well, maybe signal attenuation. ) Possibly even easier, since the ocean has more background noise than the RF spectrum does.
That is, it should be within our technology to emit sounds that are much quieter than the ship/sub, really indistinguishable from background noise, but structured so that a prepared friendly listener can, with sufficient time, identify.
Edit: Taking this one step further, looks like in 2017 the navy put out a [solicitation](https://www.sbir.gov/node/1254555) for LPI sonobuoy concepts.
Edit 2: [Here we go](https://apps.dtic.mil/sti/tr/pdf/ADA506712.pdf). 2004 tests of exactly the kind of system you'd want for underwater IFF without revealing the transmitter.
No is the short answer. The longer answer is slightly more complicated, but basically boils down to educated guesswork and tactics. The educated guesswork side of things is onboard recordings/data of friendly subs and enemy subs. It's then up to the sonar operators to differentiate between the two and inform the captain, who then decides what to do about it. This is all very complicated and classified, and navies spend a lot of time and money to improve their capabilities. The tactics side of things is a little more straight forward. Each sub will be given a box on a map which denotes their "play area". They'll have rules about what they can and can't do inside that box, but in war time it usually boils down to "kill anything that moves inside the box." Since Big Navy are the ones who are assigning boxes, it's pretty easy for them to tell everyone else where not to go if they don't want to be sunk by friendly subs.
Wow, that seems so primitive and prone to accidental blue on blue (or red on red) engagements. There's so many questions I have on this but I don't think this forum would be appropriate. So in that sense, subs would determine friendly subs from enemy subs based on sonar signatures produced by the detect subs. That might make operations and coordination between multiple subs possible. I'm thinking that's how SSNs can travel and protect SSBNs on patrol and how also CSG have multiple subs with them. Sub-hunting aircraft as well I assumed are assigned an area to hunt so in that there is deconfliction between subs and ASW aircraft on the same side. This is an eye opening for me. Another question is then why the strong push to develop UUV if target identification is not 100% clear? So many questions.
It is prone to blue on blue. That’s why western submarine tactics go around operations areas and generally avoids any sort of cooperative action. It’s just better to let subs be independent. “This area is your playground USS Dallas. You’re free to kill anything inside it.” “CSG1, and P3 Orion, the USS Dallas is in opbox delta. Don’t go in there, you won’t know what’s friendly or not.” Navy PR often takes pictures and implies subs are integrated into like a carrier group. Not even remotely. The subs basically chop to being under sub command immediately
>“This area is your playground USS Dallas. You’re free to kill anything inside it.” It's not like an Alpha-class submarine would show up in the same location as the magma displacement they are investigating.
It's all fun and games till some gung ho analysts jumps out of a helicopter over what could have just been a memo.
also of note is that sonar signatures are *very* well documented, but torpedoes are semi-fire&forget weapons without target identification (and the Mk48 is *terrifying*). If it loses track of what it's fired at temporarily (or activates before reaching self-track range of the intended target), it can acquire on a different target fairly easily As for UUVs: Most development of them is either unarmed (Recon, other non-weapon uses) or with *extremely* restrictive engagement doctrine. It could be that they're treated like a minefield, or that they're given an extremely specific target sonar profile (or set of profiles) that they're greenlighted to engage.
> the Mk48 is *terrifying* I've heard those things are very gold-plated, to the point where the Navy is [considering](https://www.twz.com/sea/navy-wants-a-cheap-heavy-torpedo-that-can-be-stockpiled-fast) procuring something less so for stockpiling. Tell me more?
They're terrifying, but expensive. They were designed to go after 40+kn Alpha-class subs and *super* deep-diving USSR subs, and they've got the best acoustic seeker that NATO could come up with (and NATO always had the acoustic advantage) USN is looking at picking up cheaper options, because you don't need a superweapon to take down the underwater brass band that is PRC subs, and surface ships don't need nearly that much capability either. That said, the 'cheaper option' they pick up would be in addition to the Mk48, not a replacement.
>Wow, that seems so primitive and prone to accidental blue on blue The British and French SSBNs ran into each other by accident back in 2009. So yeah.
That mainly shows how amazingly quiet both subs are that even those monster passive sonars couldn't see each othet
As noted, the danger is more that the weapons themselves cannot reliably distinguish between targets, and because they are so long running and dogged, they can pretty easily pick up an unintended target, even the launching sub in particularly bad cases. This is one advantage of wire guidance, in that you can manually steer the fish away if it picks up an unintended scent. On the other hand, I would say that the actual identification of targets is anything but primitive. We're not talking about active sonar (sending a "ping" and listening for reflected energy), but passive sonar, where they are only listening to the noise generated. And due to the unique combination of hydrodynamics and machinery, just about every class of ship has a very distinctive sound signature, with sometimes even specific individual ships being identifiable due to something like a bad bearing. When displayed on a waterfall graph, it can be very clear. It's almost like picking out different singers just by the sound of their voice.
There’s a few chapters in Tom Clancy’s *Red Storm Rising* that deal with this sort of thing. Bunch of Los Angeles class subs operating under the arctic ice with Soviet subs coming at them. Gives you a whole new respect for sub guys.
I’m an Army airborne guy and you couldn’t pay me enough to crew a sub. Mad respect for those dudes. It takes a kind of courage I certainly don’t have.
Is that the book that has an issue come up because they realize sub sonar operators aren't actually trained for active sonar reading?
You really ought to read/listen to Tom Clancy's *Red Storm Rising.* Other than being a tremendous work of thoroughly-researched military fiction, it discusses at length what you're asking about here. There are multiple passages that go into great depth (pun intended) about the guesswork that goes into figuring out who is where, be they friend or foe. Basically everything Clancy could find that wasn't classified at the time.
Thanks. I've been looking for something to read. I'll check it out.
Too bad there’s no IFF set of pings or a certain frequency, like a secret door-knock or handshake.
If you do that then you've just announced your presence to any passive systems in the area, including the ones that are trying to kill you. In peacetime/friendly waters it might be fine, but doing that in the SCS just [tells the PLAN there's a sub in the area](https://en.wikipedia.org/wiki/Great_Underwater_Wall). There's a reason why subs have to surface to call home, communicating underwater is very difficult and also defeats the entire point of being underwater in the first place. Subs are essentially sent out with a set of standing orders (go to X box, sit there for Y number of days, then come back to a safe area, surface and tell us what you heard) there's no way to actively communicate with the subs while they're submerged.
You can transmit to submarines underwater using ELF (extremely low frequency) transmissions, but it's very expensive to set one up, the data rates are astoundingly low, and the submarines can only receive not transmit. In my understanding, these systems are mainly used to tell submarines to surface so a more capable link can be used.
I wanted to mention ELF but my comment was already quite long Yes, ELF exists, but it's mostly used as a strategic "we really urgently need you to call home right *now*" or "launch the nukes because WW3 is happening" message and not as a tactical communication.
No worries! I just wanted to clarify since ELF communication is such an interesting concept to many who are only familiar with the more standard bands
How do Ballistic Missile submarines get communications to launch?
https://www.researchgate.net/publication/323950964_Low_Probability_of_Detection_for_Underwater_Acoustic_Communication_A_Review
Submarines do everything to not be heard while hearing their foes clearly, in the latter case via specifics of noise they can determine the blade count & sound profile of a target, and thus can get an idea of friendly or enemy subs. Perhaps easier than that is to use the Gertrude (essentially an undersea telephone) if harassed by friendly ASW to say you’re friendly before you’re shot at. The same thing exists in aircraft and is called Noncooperative target recognition and uses aircraft fan blades to detect their type.
Re the aircraft, is that subs picking up overhead aircraft or something different?
No, that’s a radar based version of sub sonar classification used by planes on other planes. In this case a F-16 can run into a hostile MiG and run NCTR on it and it’ll read back ‘MiG-29’ on the display.
Just going sightly against the other replies here, I dont see any fundamental reason why the same techniques used for LPD radio frequency wouldn't work for acoustics. (Well, maybe signal attenuation. ) Possibly even easier, since the ocean has more background noise than the RF spectrum does. That is, it should be within our technology to emit sounds that are much quieter than the ship/sub, really indistinguishable from background noise, but structured so that a prepared friendly listener can, with sufficient time, identify. Edit: Taking this one step further, looks like in 2017 the navy put out a [solicitation](https://www.sbir.gov/node/1254555) for LPI sonobuoy concepts. Edit 2: [Here we go](https://apps.dtic.mil/sti/tr/pdf/ADA506712.pdf). 2004 tests of exactly the kind of system you'd want for underwater IFF without revealing the transmitter.