calculability

[Nexus7]

I was thinking a moment about a scenario with me in a sub and an Helo hunting me. Now the helo drops sonobuoys and i detect them. Assume there is a layer, more or less strong.

Another scenario with me in a Seawolf and the opponent in an Akula. Assume he is hunting me again and there is a strong layer. I detect him first (probable) and assume i can get the range.

Given those two scenarios, the question arises... how much calculations would do a crew in order to maintain the overhand with good probability?

Would my crew be able to calculate enemy capability to detect me at different distances and depths? Can I assume that a layer with a given strength will cover me totally?

Often the fascinating thing in sub warfare (in game) is the inpossibility to know, has he detected me or not? Will he possibly have a firing solution on me at this time?

So basically the question is, is the stealth factor somehow mathematically predictable, given the values sound speed, distance, sonar capability and such? :hmm:

[SeaQueen]

Originally Posted by Nexus7

So basically the question is, is the stealth factor somehow mathematically predictable, given the values sound speed, distance, sonar capability and such? :hmm:

It is possible to model the performance of sonar. If you want to really get down into it, read Computational Ocean Acoustics. It's pretty heavy if you're not an advanced undergraduate in physics, at least, though. Penn State has a really good program for underwater acoustics and the Navy works with them a lot. They also do a lot of stuff like that at the Applied Physics Lab at Johns Hopkins University. NATO has a research facility in Italy where they do that too. The simplest sonar model is just a ray trace, using Snell's Law, like you learn in highschool physics. You could make one in Excel. The most advanced numerically solve for the normal modes of the wave equation.

The proliferation of powerful computers has made underwater acoustics modeling fairly widespread where ever people are using sonar of any kind, including fish finders, salvaging, and hunting for oil. How good the models are depends a lot on how well understood the oceanography is in a given area, though. There's always some uncertainty in their predictions, which might be quite a lot. Sometimes, I think it's almost more important to understand the uncertainty in these computer models than it is to understand their results. But... I digress...

As far as what the Navy does specifically with all of these computer models... I'm not sure I can tell you much. This is sort of one of my favorite topics, though. :-)

[Nexus7]

SQ, I could've bet 100$ that you was going to answer this :rotfl:

From your answer I understand there is no efficent procedure so far, to predict opponent's knowledge using maths.

When I was playing the game correctly, with aTMA always off (the times of ASAT with the Seawolves), the TMA work gave me quite a quantity of material to start making considerations on my opponent. I remember I was able to guess if he detected me or not, if he was about to find me or not and such.

Maybe the profis know when they've been counterdetected by watching enemy's moves?

I should force myself to study and use manual TMA again Makes the game so much more interesting

[compressioncut]

You're not going to get many answers here because it comes down to operational procedures, and thus security.

But you can predict sonar performance fairly well, for both sides. But you normally very much overpredict the performance of your opponent's sonar to give yourself a cushion.

[SeaQueen]

Originally Posted by Nexus7

From your answer I understand there is no efficent procedure so far, to predict opponent's knowledge using maths.

In principle, you could predict your opponents sonar performance if you know what values to plug into the acoustics models in order to accurately represent your opponents systems. That's the kind of thing that intelligence services try to come up with.

I remember I was able to guess if he detected me or not, if he was about to find me or not and such.

Right... that's more intuition, than anything hard, though.

I'm really not able to discuss a lot of this stuff much further.

[Nexus7]

This has probably been asked before and I don't know where to post this so I'll spam in my own topic.

Reading about countermeasures i had to think, ain't it possible to make an enemy sonar station totally blind? For example, in game, when a torpedo explodes the sonar is "blinded".
I think that the actual tech-level should allow to "fire" a lot of noise in direction of the contact blinding his sensors?

[SeaQueen]

Originally Posted by Nexus7

Reading about countermeasures i had to think, ain't it possible to make an enemy sonar station totally blind? For example, in game, when a torpedo explodes the sonar is "blinded".
I think that the actual tech-level should allow to "fire" a lot of noise in direction of the contact blinding his sensors?

That's sort of an artifact of the simulation. While typically people model ambient noise as omnidirectional, in reality ambient noise is highly directional. So you can't really "blind" a sensor that way. Unless the sensor is omnidirectional, you just turn the sensor away from the noise.

[Amizaur]

Originally Posted by SeaQueen

That's sort of an artifact of the simulation. While typically people model ambient noise as omnidirectional, in reality ambient noise is highly directional. So you can't really "blind" a sensor that way. Unless the sensor is omnidirectional, you just turn the sensor away from the noise.

But if direction of the noise is also direction of the target you track... like torpedo warhead detonating between you and your target.

[Nexus7]

Since Noise is very directional, I'd expect an explosion to blind only a little portion of my sensors, instead, it blinds the whole spectrum.

Now I assume, the noise can be directed to a bearing with the amount of error you like. If I am able to cover some degrees down my bearing this would be a success

[SeaQueen]

Originally Posted by Nexus7

Since Noise is very directional, I'd expect an explosion to blind only a little portion of my sensors, instead, it blinds the whole spectrum.

You don't need an explosion. Any broadband signal will work. You can make a sensor "blind" to you by keeping another ship along the same bearing as you. In broadband, you look like one signal. In narrowband, you get overlapping narrowband signatures, so you can't really pick the two apart. There's nothing new here. In the game we call these things "passive countermeasures."

[Nexus7]

In the game, in the narrowband station, you can assign two distinct trackers to overlapping signals, and they never overlap perfectly...

[SeaQueen]

Originally Posted by Nexus7

In the game, in the narrowband station, you can assign two distinct trackers to overlapping signals, and they never overlap perfectly...

There's nothing, in principle that says you can't. If you're smart enough to know the signature of countermeasures versus your submarine. One would HOPE that an enemy would be smarter and make their countermeasures emit a narrow band signature that was closer to it's intended target, but in all honestly, I don't know if that's the case.

Even if they don't match up perfectly, though, overlapping signatures presents a unique problem for TMA. Which target is in front? If one target is maintaining constant speed, and the other one is changing his course and speed to keep a constant bearing rate, (i.e. keep the thing he's masking himself with along the same bearing as you) it's really tough to figure out exactly where the guy is. The trackers don't matter so much, unless you have broadband in the game, and then you can figure out the speed of each target from DEMON and get a pretty good range.