hehehe
beat me to the punch
:D

the question is of course what does "big" actually mean...
:hmm:

I think it's great that you're working towards full realism, and I'd really love to be able to use your numbers if we can achieve full realism in this regard. But there's a huge spectre looming over us, and that's the fact that the devs made certain sensors in SH3 literally unbeatable. Until I'm assured that that issue is behind us I'll be proceeding very cautiously on any issue that has to do with sensor effectiveness, as my goal of realistic results may require that some details be fudged to counterbalance the devs' sometimes half-assed (or was it overzealous?) implementation of certain features. I'm thinking that the thermal layer is a detail that may be very effective as a slider function to counterbalance a developer's insanely effective sensors. I really wish we'd had it in SH3 - it would have reduced the time we spent trying to overcome the sensor imbalance by weeks.

Its hard to know what the effect is, this may be of interest:

http://www.fas.org/man/dod-101/navy/...P/snr_prop.htm

look at fig. 13 in particular, although based on what I saw in SH3, the sound propagation model is very simple compared to DW.

that's a great link.
thanks bilge_rat!

indeed, there really doesn't appear to be any sound propagation model per se in sh4, but rather we're presented with probability range values.

in that regard, of particular interest from the doc you posted i'd cite a couple of things:

so i suppose the way to phrase the prime determinant in making this sort of reductionist calculation might be -- what percentage of the ray emissions nominally diverge from those that penetrate the layer?

i definitely hear you on this, but aren't the sensors values for all intents and porpoises (couldn't resist given the topic ;)) subject to modification through the the .sim and .cfg files? and wouldn't it be good to proceed with adjusting those after the environmental variables (such as thermocline effects) are straightened out?

[and o.t., but how appropriate is it that my avatar is now "soundman"? :lol: cool!]

communism? the devs are afterall from a former warsaw pact country...
:lol:

The .sim and .cfg files are available for modification, but we found after literally months of tweaking that they don't allow the range of modification that we needed in order to reduce their effectiveness in a realistic way. They either picked the sub up or they didn't, and if they had you they couldn't be adjusted so that good manoeuvring on the part of the sub allowed it to escape. So we had the choice of completely nerfing them so that any sub could escape at will even when the sub was close to the surface, or we had to leave them effective and reduce the number of ships that carried the uber-sonar (which is, I think, what we ended up doing). There didn't seem to be any middle ground. With a thermal layer that's adjustable we finally have an option (assuming that the uber-sonar will turn up again) to save ourselves weeks of work by just adjusting that one variable rather than combing through the campaign files and removing uber-sonar from 90% of the ships as we did in RUb.

That is very hard to answer, from my limited reading on the subject, all sorts of factors can affect how sound travels in the ocean, namely: temperature, salinity, depth, bottom type, type and density of aquatic life, ambient traffic, ocean currents, etc. A sub can be nearly invisible in one environment and stick out like a hooker on a street corner in another. During the cold war, there were many instances when U.S. subs did not hear other subs until they were right on top of them.

However, for dealing with the primitive technology used by all sides in WW2, an effective thermal layer is probably all we need. How effective will have to be determined by trial and error.

By the way in SH3/4, does dropping depth charges render the escorts deaf until the water settles down?

that is a problem!
:hmm:

perhaps one middle-ground solution might be to formulate a range of acceptable values for the thermocline effects (including season, location [read from the player's campaign files], and salinity) and have some 3rd party app input random entries based on that range into the sim.cfg?
(with the obvious caveat that it'd be globally valid until the user quits and reloads)

and indeed it seems that's 'all' we've been given! :D

I'm just curious - where is this thermal layer file located. Also, where is the thermal layer located (i.e. how deep do you have to get to get under it)?

the settings for the thermal layer's effects appear to be mostly in the sim.cfg.
'haven't located if there's a depth setting for it yet (though i suspect that it might be hardcoded)... if i remember correctly it seems as though it's pretty shallow (around 185 feet or so), but then i forget exactly as i turned off the voice report of "now passing thermal layer" since my s-class doesn't have a bt installed yet. ;)

(someone who hasn't turned off the notification can say for sure here)

Suggested Mod
 

It appears that on the "Range, AOB, Speed" dial, when at the periscope, it is missing two other "click me" items on the EU DVD. As I watched Neal's film he was able to "Lock on target" on this dial as well as another function I cannot quite catch. I am sorry if this is not technically explained, but wondered if youd care to have a look and comment.
I thought this might be due to the type of boat he was using. However I cannot find these items on the Porpoise or the Gar....haven't looked at the Tabor yet.
These items seemed so important too.....My very great THANKS for the work you are doing I am following very closely.....Best Regards....Dusty

If I am not mistaken, what you are missing is the manual "send to TDC" button that is available only if you play with manual targeting. There is also a button for the split image ranging function.

Something missing ?
 

Aye ther's the rub U-Bones.....I hadn't thought of the Manual Targetting aspect....Bloomin' eck!!! after all thats all we used to do. Cheers dear friend.