Thinking About Evading Searchers

[SeaQueen]

This morning I had a revelation, perhaps the best way to hide is not necessarily to be as slow and therefore quiet as possible. There's two competing processes involved in hiding. On the one hand, as you move more quickly, you are more easily detected at longer ranges. On the other hand, though, the effect of your motion is, in general, to frustrate the search plans of your opponent. That leads me to wonder, is there a best compromise between motion and silencing?

[PeriscopeDepth]

I think the main things that affect this are how far away you are from the searcher and how good his sensors are. Of course, it's also a function of how quiet you are. Surely when you think he won't hear you if you do 15 knots, it would be better to evade doing 15 rather than 5.

PD

[Kapitan]

I would hit 35 knots in viper if i was being chased by the FFG other than that like heck will i pass 15 knots unless evading a torp

[DS]

Searching for a submarine is like searching for a needle in a haystack. The faster the sub moves, the larger her noise signature, and therefore the larger a needle she is, making her that much easier to find. If we assume that a submarine stopped dead in the water has to be passed right over head to be heard (Needle), in a 100 square kilometers of ocean (haystack), it will take either a lot of time, or a lot of assets, before statisticaly you pass over the sub. If she is moving and creating a 2 square kilometer sound signature around her, she is statistically now much easier to find (much larger needle).

But then, I'm only a cyber-skipper. Maybe the BTDTs know somethign I don't.

[SeaQueen]

Now you're starting to think like I do. The thing is, she might be a larger needle to find, but she's also a moving needle which would be harder to find. One would expect that do one's best, there'd be a best compromise between being a moving needle and being slightly larger needle. I wonder where that compromise lies.

Originally Posted by DS

Searching for a submarine is like searching for a needle in a haystack. The faster the sub moves, the larger her noise signature, and therefore the larger a needle she is, making her that much easier to find. If we assume that a submarine stopped dead in the water has to be passed right over head to be heard (Needle), in a 100 square kilometers of ocean (haystack), it will take either a lot of time, or a lot of assets, before statisticaly you pass over the sub. If she is moving and creating a 2 square kilometer sound signature around her, she is statistically now much easier to find (much larger needle).

But then, I'm only a cyber-skipper. Maybe the BTDTs know somethign I don't.

[DS]

In thinking more about this, it might be more of an issue of moving into an area already searched rather than moving at a given speed. If you knew what areas had been searchd, and where the searchers were now, you could conceivably move into a pre-searcehd area and be safe for a while.

More realistically though, if you had no way of knowing what areas had already been searched, or what the size of the search area was to begin with, you are still faced with the same problem.

Still, there might be some mathematical probability formula that could be invoked to give one the best odds, but I have no idea how one would calculate that.

Cheers.

[LoBlo]

You know what I've always been curious about... whether the US Ohio SSBNs actually wander around in a organized patrol, or do they find a spot in the ocean and just sit and hover...

I've always thought that sitting and hovering were probably as good a strategy for not being found, but I guess the real answer really comes down to the orginal question you ask. Maybe they actually wander around the ocean in "systematic randomness" to decrease detection probabilities... there are probably only a handful of people in the world that actually know and ever will know.

[SeaQueen]

Just from the math, I think it's safe to infer that they probably move randomly in a fairly large box. I wouldn't be surprised if there was a computer program that somehow just generated pseudo random numbers and plotted a random course from that. Of course, the seed to the random number generator would be HIGHLY classified. I guess they could use the ship's clock, but then you could find them if you just picked the right algorithm and had a synchronized clock. I also wouldn't put it past them to just roll dice. It'd be simpler, that's for sure. I think in Blind Man's Bluff they said something about and baffles clearing.

Originally Posted by LoBlo

You know what I've always been curious about... whether the US Ohio SSBNs actually wander around in a organized patrol, or do they find a spot in the ocean and just sit and hover...

I've always thought that sitting and hovering were probably as good a strategy for not being found, but I guess the real answer really comes down to the orginal question you ask. Maybe they actually wander around the ocean in "systematic randomness" to decrease detection probabilities... there are probably only a handful of people in the world that actually know and ever will know.