[Answered] Towed array

[JOURDAN83]

In submarine tutorial 2.1, i don't understand how my submarine can detect with the towed array another sub who is 100 NM in front of me ; and if i run full speed with my towed array, it seems that il will be very damaged ?

[Rory Noonan]

Convergence zones allow you to make detections from very long distances if you have powerful enough sensors. The crew take care of the towed array for you, you don't need to worry about regulating speed.

[DWReese]

Apache,

I've recently read quite a bit on towed array sensors operated by subs. All of the data indicates that the faster that the sub travels, the larger the degradation of the results from the system. While the towed array is constantly being improved upon, none of the data that I have read has ever indicated that it could ever work while traveling at full speed as the OP mentioned.

So that I am clear, when you are saying "The crew take care of the towed array for you, you don't need to worry about regulating speed", do you mean that the crew will have the sub slow down to periodically check the sensor for maximum performance, or are you saying that the sub will alter its speed (say from 30 kts to 27 kts) to improve its detection capabilities while continuing to maintain something close to top speed?

Also, there was talk of the original towed array cable breaking off if the sub travels too fast with some of the earlier models. Is that factored into the older scenarios? In other words, is there a "speed limit" that was ever imposed? <lol>

Again, the towed array is currently evolving daily, and the capabilities have vastly improved since the beginning when they were first used.

Any thoughts that you might be able to share would sincerely be appreciated. I know that sub warfare is "your thing", so it's always great to pick your brain for tid bits of information.

Doug

[Rain08]

ORIGINAL: DWReese

"The crew take care of the towed array for you, you don't need to worry about regulating speed"

Report | Post #: 2

My understanding of this is that the crew would automatically retract the towed array if the sub will be going fast.

ORIGINAL: DWReese

All of the data indicates that the faster that the sub travels, the larger the degradation of the results from the system. While the towed array is constantly being improved upon, none of the data that I have read has ever indicated that it could ever work while traveling at full speed as the OP mentioned.

In my experience so far, I've never seen a submarine detect something while it's going fast. Also I don't think the OP is saying they're detecting submarines while going at flank speed. I'm not exactly sure what was meant by 'damaged', but I'm guessing I most likely think it's detection degradation rather than actual damage to the towed array.

[DWReese]

i don't understand how my submarine can detect with the towed array another sub who is 100 NM in front of me ; and if i run full speed with my towed array,

Maybe I read the OP's post differently than you, but it seems as though [to me] that he is wondering WHY his sub (traveling at full speed) can detect another sub 100 miles away.

I agree that that probably isn't likely the case. That is why I am asking Apache if he means that in the game "the crew" would slow down to slow speed to perform a check and then resume full speed; or if they would slow down slightly to get some kind of a reading; or is it programmed to just work regardless of what speed that the original sub is traveling at?

As I said in my first post, the use of the original towed array did have a speed maximum that could result in the cable potentially breaking off if the sub went too fast. I seem to remember a Larry Bond book (which often deals with sub warfare) having to deal with a 2-3 minute period being necessary to retract the towed array in an effort to get away from trouble. The sub was forced to deal with the option of not retracting it and immediately fleeing, thereby losing it, or waiting and retracting it properly, while allowing the enemy to close the distance between the two subs. So, what I gather from that is that speed can damage/destroy a towed array system, or at it least it could back in the day.

Doug

[Dimitris]

ORIGINAL: JOURDAN83
In submarine tutorial 2.1, i don't understand how my submarine can detect with the towed array another sub who is 100 NM in front of me ;

See here for a short primer on sound propagation and especially convergence zones (Figure 15): https://fas.org/man/dod-101/navy/docs/e ... r_prop.htm

and if i run full speed with my towed array, it seems that il will be very damaged ?

The effectiveness of any sonar sensor, and especially the towed array, is severely degraded as your ship/sub's speed increases.

[kevinkins]

Trying to learn sub warfare as well. I tend to avoid it since it’s kind of slow. Anyway, if I understand correctly, towed array sonar detection can occur at 100 nm based on the concept of convergence zones. (Thanks for the documentation BTW) But should not happen when the sub is at flank or some other high speed. Therefore, if a sub is moving at flank, it must be slowing down briefly to detect at 100 nm range even though the reported speed within the sim is shown to be at flank i.e. “The crew take care of the towed array for you, you don't need to worry about regulating speed.” In other words, towed array functions are a bit more abstracted than other aspects of the sim. Do I have this right? Seems the player does not have full control of the subs speeds under these specific circumstances. Thanks.

[LMychajluk]

I don't want to muddle the conversation or put words in the OP's mouth, but I took "...how my submarine can detect with the towed array another sub who is 100 NM in front of me..." to mean just that - it sounded like he was detecting a contact directly ahead w/ the towed array (the speed part being a different question). I was under the impression that the towed array was 'blind' at a bearing of 0, and had it's best detection angles at 90 to the heading of the sub? Does the sub maneuvering logic change course (maybe when using Sprint / Drift) align the towed array in different directions, or should you program that into your course w/ zig-zags? While I'm at it, what about clearing baffles?

[kevinkins]

Don't think interesting questions are muddling the conversation at all. But maybe this has gone beyond a regular tech support issue and might well be continued in the War Room as it's involves complicated tactics etc.. The topic name has been changed to Answered, but some of us are still trying to understand those tactics.

[thewood1]

The OP only said "in front of me". That's a pretty loose statement and not necessarily "at a bearing of 0". And even if it was at 0 deg., it might have been the main sonar that detected the other unit.

Without a save, its again just guess work to get a solid answer.

[LMychajluk]

ORIGINAL: thewood1

The OP only said "in front of me". That's a pretty loose statement and not necessarily "at a bearing of 0". And even if it was at 0 deg., it might have been the main sonar that detected the other unit.

Without a save, its again just guess work to get a solid answer.

Since you're nit-picking, I said I took 'in front of me' to mean 'directly ahead', a similarly 'loose statement', unlike the OP's 'with the towed array', which doesn't seem to leave much room for interpretation as 'with the main sonar'.

I then said the towed array is blind at a 0 degree bearing. I'm fairly certain this is a true statement about towed array sonars. It may be blind at 1,2,3, etc... degrees, but whether it's 0 degrees or (+/-) 2,5,10,15 degrees doesn't really matter (yet). The conversation has moved on from the OP's post and into the mechanics of the game, and my point was that a towed array does have a blind spot directly forward (where the end of the cable is, and the sub itself 'blocks' it's forward view), and probably a smaller cone aft (though not as much of a blind spot aft as the bow sonar has aft, since the sub itself doesn't block the 'view'). Those blind spots are cones, and they get larger the further away from the sub.

The question is does CMO model these blind spot of the towed array (and the bow sonar, for that matter)? I think it does (at least for the bow sonar...), but if the answer is 'yes' for both, then, in theory, a contact in front of the sub should not be detectable by the towed array until the sub changes heading.

The characteristics of the different sonars may also come into play as to which can detect a specific contact. For instance, one sonar may be damaged, or the towed array may be hanging through a thermal layer that the hull mounted hydrophones can't 'see' through, detecting an enemy sub below the sub's current layer. That also brings up a question of how wide that blind spot is for each sensor, and what type of maneuvering does the sub do on it's own while transiting or while on a patrol mission to look for new contacts or establish a better target solution on a contact from it's various sonar sensors.

[DWReese]

If what you are saying is true (about being blind in front), and I have no reason to doubt it, then subs should, by method of routine movement, almost always plot some kind of a zig-zag course, even when trying to head in a relatively straight direction, otherwise they would never be able to see anything directly in front of them.

If that is correct, it makes perfect sense to me. Do you know if that is actually done in the game? I don't believe that I have ever seen that. It would be cool if it was.

[Sardaukar]

One has also take into account that towed array usually trails deeper than submarine. In that sense it is not totally blind towards front, since it can "see" that way under the sub.

[thewood1]

"I said I took 'in front of me' to mean 'directly ahead"

Again, my point isn't with you making that assumption, its that without a save, we have no idea what is going on. We don't even know if the towed array is what detected the enemy. He says the towed array detected the other unit. Without some confirmation, he might just be assuming that.

As to moving on, I am trying to reset the conversation back to the OP's original question to get more that a bunch of guesses and assumptions. I'm not sure who's in charge of "moving on".

[LMychajluk]

ORIGINAL: DWReese
If what you are saying is true (about being blind in front), and I have no reason to doubt it, then subs should, by method of routine movement, almost always plot some kind of a zig-zag course, even when trying to head in a relatively straight direction, otherwise they would never be able to see anything directly in front of them.

If that is correct, it makes perfect sense to me. Do you know if that is actually done in the game? I don't believe that I have ever seen that. It would be cool if it was.

Don't forget about the bow array. That can also be used to listen ahead of the sub. But, I think the towed array, by virtue of having the hydrophones spread 'wider' along the length of the array, which I understand could be >1mi long, would be better at triangulating a more precise position of a contact, whereas the bow array may just be able to provide a general bearing. So, a sub may detect a contact w/ the bow array, but then turn to one side and use the towed array to get a more precise location(?). I don't know how much of this is modelled in CMO, since the larger 'scale' of the game abstracts some details, but I suppose it would be similar to how radar arcs work. Some of these sonar concepts are modeled in 'Cold Waters' (which is also a fun game, if not 100% realistic).

ORIGINAL: Sardaukar
One has also take into account that towed array usually trails deeper than submarine. In that sense it is not totally blind towards front, since it can "see" that way under the sub.

Good point.

I guess, technically, there's could be a cone that's a blind spot for each of the hydrophones in the array, and each might be at a slightly different angle based on the position of the array at a given point in time. Since the array would hang below the sub as you say, any 'blind spot' for the towed array as a whole may be more forward and up rather than directly ahead, but if anything is in that blind spot, it would think it would have to be pretty close to the sub already. I suppose there's also the possibility that noises from the sub itself may mask sounds ahead, even if it's not directly in the path of any contacts(?).

[Dimitris]

Waiting for a save...

[kevinkins]

The guy has one post in over a year and will likely never be back. Just move this interesting tactical discussion over to the War Room. If you don't, I will. LOL

[guanotwozero]

ORIGINAL: LMychajluk
Good point.

I guess, technically, there's could be a cone that's a blind spot for each of the hydrophones in the array, and each might be at a slightly different angle based on the position of the array at a given point in time. Since the array would hang below the sub as you say, any 'blind spot' for the towed array as a whole may be more forward and up rather than directly ahead, but if anything is in that blind spot, it would think it would have to be pretty close to the sub already. I suppose there's also the possibility that noises from the sub itself may mask sounds ahead, even if it's not directly in the path of any contacts(?).

It would make sense that the 'hanging profile' of the array would be known for any given speed, hence the dynamic orientation of the many detectors. With modern computers it should be possible to take account of the signals accordingly including fore/aft detection, noise notwithstanding. I'd still expect a much greater lateral sensitivity though, as the surface area (hence hydrophones) per angle would be much greater.

[User1984]

I have played this scenario sub tutorial 2.1 multiple times, however, I have never been able to get a solid contact on the enemy sub. Additionally, I can rarely even get a general contact except at the beginning of the tutorial.

I have followed the instructions, and am a bit frustrated with this scenario. Does this scenario have bugs, or am I probably doing something wrong?

[cmanouser1]

I have played this scenario sub tutorial 2.1 multiple times, however, I have never been able to get a solid contact on the enemy sub. Additionally, I can rarely even get a general contact except at the beginning of the tutorial.

I have followed the instructions, and am a bit frustrated with this scenario. Does this scenario have bugs, or am I probably doing something wrong?

Just completed it with no issue, following the instructions as written. An issue could be that you're too slow moving after you lose contact, and the enemy slips away. Go over the layer, flank speed. Then when on position, slow to creep so that the sonar works fine again.
You could also open it in the editor and use the omniscient to see what the enemy sub is doing.