Ducimas, another TMO sonar question.
 

It's always been stated the enemy can do one of two things regarding sonar, active or listen, that sonar is basically always active, but you only hear it if you fall into the sonar cone, correct?

I assume the enemy is always active when underway and not able to listen at all and can only listen when stationary, is this correct?

If the above is true, I'm trying to figure out what will often bring escorts towards you when you're not in their sonar cone. If they can't listen underway and you're not hearing pings, what brings them towards you? Sometimes I can be 5000 yards in calm water from a lead escort off the groups track and he peels off with his buddies coming in my direction. He's not pinging and I'm not in the cone, so seems he's listening, even at higher speed. I only have this issue in calmer water.

Is it possible they listen underway, but sonar only goes active if you fall into the sonar cone. Just recall the many statments that escorts are always active unless stationary. I swore I once saw a hydrophone speed factor, sense speed doesn't seem to have any effect on subs, seems it must be ships.

If they can hear you underway, does their speed effect the ability, I assume not, as it doesn't in the subs.

BTW, do you recall what Thermal Layer value you used in 1.9, seems I read you change that later and toned it down. I set my escorts to elite and would love a better value to balance it.

+ 1
 

This is an excellent question. I pose too.

I think the enemy detect you with its hydrophone.
I hope I do not say something stupid.

I always wondered about that. If you are not inside the cone, they will not pick up your signal, but wouldn'y you be able to hear the pings anyway? I mean, sound is not uni-directional, it travels in all directions. It is one thing being undetected because the active sonar scope only picks up returning signals in a certain cone or area, but if you are nearby, I think you probably could hear the pings.

Real life yes, not in the game. I think they only go active when you fall in the sonar cone, like a auto switch, like it's alway on within the cone. Course, that's the question, what are they doing otherwise, I assume listening, but that's the question, if they can hear when at speed, does their speed effect hearing? Just heard so many times in the past they can only hear stationary, just hard to believe that, the game doesn't act that way, so I assume they have good ears at high speed just like our subs.

I'm not with you.
Commencing with a certain speed, even our current submarines are deaf like pots.

Our subs have as good as ears surfaced in game as they do dived, seemingly regardless of speed. Speed does effect sonar, but hearing seems to be the same surfaced or dived. I don't think the game has a seperate hydrophone setting that switches values between dived and surfaced.

I agree with you on this last point.
But the fundamental question was this:
And I think the answer is: hydrophone, unless the speed of the escort is too high. But how much?

What is the opinion of Ducimus?

I don't know how it all works out in the game but, after reading Capt. Tameichi Hara's book, higher speeds made the sonar less effective. I don't recall the speeds referenced in his book but I do recall them being rather high when he mentioned that "there was little chance of detecting anything at that speed." 12 knots seemed to be acceptable, if not ideal, but (I think) 20 to 30+ knots was almost futile.
I'd have to go back and check the numbers to be sure.:hmmm:

I think this makes a lot of sense, specially because sonar at those days was pretty analogic (meaning, an actual GUY was there listening and sorting out what he was hearing). Background noise probably made a lot of influence, it is hard to imagine it otherwise.

As to what Escorts were doing when not in active mode, I am pretty sure there was a sonar operator there all the time - or mostly - listening. It would be interesting to ckech out what was the standard crewmen compliment in those day, and see if there were several 'funkmen'. If there were.. it is probably because they worked in shifts, hence, someone was listening to the ocean all the time.

That sounds about right, just wish I knew how it worked it game, but my guess is it does, just don't know how much speed effects sonar, water state and other factors do.

These parameters are recorded in the file Data\Cfg\sim.cfg
But I found nothing about the speed of the escort.

To have clearer ideas, I made a chart for the threshold of detection with submarine speed and with wind speed, at periscope depth. Escort at 12 knots.
The results are inspiring.

I've seen a hydrophone value linked to speed, can't remember if it was sub or escorts, maybe both, but I'll get in and look again. I would like to tone it down a tad when they're at higher speed.

There is an entry for ship speed.

From Data/cfg/sim.cfg
(this is for TMO)

[Hydrophone]
Detection time=1 ;[s]
Sensitivity=0.15 ;(0..1)
Height factor=0 ;[m]
Waves factor=0.5 ;1.0 ;[>=0]
Speed factor=15 ;[kt]
Noise factor=0.35 ;0.25 ;1.0 ;[>=0]
Thermal Layer Signal Attenuation=2.0 ;[>0], 1 means no signal reduction, 3 equals signal reduction to 33%

[Sonar]
Detection time=5 ;[s]
Sensitivity=0.05 ;(0..1)
Waves factor=1.0 ;[>=0]
Speed factor=20 ;[kt]
Enemy surface factor=200 ;[m2]
Lose time=30 ;[s]
Thermal Layer Signal Attenuation=5.0 ;[>0], 1 means no signal reduction, 5 equals signal reduction to 20%

The speed factor value.
I'm sure I remember reading in a post somewhere ages ago that the speed factor value applies to the escort (not your own sub speed).
Of course I can't find that thread now, no idea what it's even called, so we'd need confirmation on this.

A little bit of supposition here.
I would assume that escorts going above the figure in the 'Speed Factor' line have their hydrophone/sonar effieiency reduced.
By how much? Who knows?

You are right. It must be the speed of DD because the sonar only detects objects underwater. No US submarine did 20 knots, diving.