This rule really exists in the real world and is same for acoustics or optics. If you had perfect sound channel where the sound would be trapped, no sound from out of the channel would enter the channel. If you imagine ray tracing method it's very clear that rays would follow same trajectories independent of orientation. It does matter if you trace from sound source to listener or from listener to sound source. You will alway get same results.

Anyway I did some test right now .. and there is something fishy with the FFG. Luftwolf added 3 sensors to model towed array .. PS1, PSD1 and PSD2 .. each has different depth and different washout speed. Good idea. BUT .. I used triggers on all them and then I let them detect my sub, while changing depth (with CZ SSP). No matter what I did only the PS1 always reported contact, the other two never did, and the FFG was doing 5 kts, bellow washout speed of all sensors.

Dear Luftwolf .. how did you test those ? And if you have some mission which shows that working, could you send it to me please ? It would help me in my model measurements.

PS: btw. I was also not able to get detected by active sonar. I've heard the pings clearly, and they stopped as I got under the layer. But the sensor on AI never reported detection. Or maybe I'm doing something wrong with the triggers ?

OK, your explanation seems reasonable regarding the sound paths.

I'm stumped on the TA issue.

When I think of SSP, what comes to mind is the velocity of anything ‘heard' with respect to operating depth. So at depths right below the layer in a negative gradient (SD for example), sound will travel faster, and at deeper depths sound travels slower. Well, in a CZ SSP the curve does include a portion of it where it is a negative gradient, and technically the negative gradient is from layer depth to crush depth of submarines. After the negative gradient, CZ SSP goes into a crest(if you will) where SSP becomes linear over depth at bare minimum velocity, which occurs at depths below crush, and currently not accessible to submarines. Then as you come out of the crest, the deeper you go beyond where SSP is linear over depth(bare minimum) the SSP increases slightly again. And with the current crush depth in deep waters you can’t operate where the CZ SSP is at its’ best, so you miss out on the best this SSP can offer, I’d say.

I’ve never experienced CZ SSP, and come to think of it, if you have played the same DM map packs created and released to the public by virtual fleets and distributed by representatives of fleets, I can’t recall a map included in those map packs that included CZ; it’s always been SD or BL. I’ve played a great deal of MP mission objective maps with SSP identical to DM map packs and it seems no one has regard for CZ, until now.

I never had a reason to understand beyond the common thought of CZ until recently where it was concluded that previous SSP of SD for my mission was unacceptable and was subject to change. So we tried CZ and monitored the results. Before another round of testing took place, I conducted some tests on CZ and I’ve concluded that the curve holds true.

The MP session includes two platforms below the layer, where the detector is listening from a perpendicular and the detect-ee is approaching the 1st CZ at 30nm @ flank, and at the moment where contact is made at the 1st CZ, the detect-ee changes depth while inside the 1st CZ. It was observed that at the time = 0 (time of detection) the signal amplitude(NB contact) was at a maximum. Then after a depth order change on the detect-ee platform, there was gradual loss of amplitude of the signal where the NB contact went from a strong, highly noticeable signal amplitude to a weaker, more faint signal. By the time the detect-ee reached crush depth, the signal was faint then disappeared as the detect-ee breached the 1st CZ.

I’d like to know is there actual proof that SSP isn’t modeled in DW. And I figure another good test is to take the same platform, same test case(approach 1st CZ), maintaining same speed(this time ideal cruise) but spawned at different depths over (X) number of maps in a CZ and monitor the results. If the platform is detected at the same time regardless the depth, then I think that is evidence that the SSP isn’t modeled. But if detection occurs at different times, then that is proof it does work and the curve holds true.

I measured CZ distance in different depths using FFG's towed array and surface target. It showed first CZ is at same distance and same intensity with all different depths (between 0 and 1000 ft). But the CZ is very very narrow, it takes tens of seconds to cross it at 5 kts.
Also no CZ cen be detected just 0.1 mile from the CZ at any depth I could reach with TA.

The SCHQ missions Denmark Strait and Sea of Okhotsk, and their DW NCHQ equivalents, are 2p sub duels found in fleet map packs that use CV SSPs. Also, although not part of a fleet's map pack, OKO's Doggy Deep has been a popular dueling map and it too uses a CV SSP.

You might not be controlling your range. The CZ is very narrow and at 30 knots closure isn't going to last very long. I think you should try this with both subs at 15 knots and on a parallel course so that you're measuring the signal strength at the same horizontal part of the CZ.

Just finished testing 3 different maps at 3 different depths.

Each map, detector & detect-ee were both under the layer, detect-ee was inbound from 36nm, 12kts, time compression on.

Regardless the depth under the layer, you can be spotted at 1st CZ, so please disregard item 1.

Thanks

For everyones consideration:

Purposed Active SLs:
688 75
688i 73
SW 72
Ohio 83
Trafalger 72
Akula 80
Victor III 77
Oscar 82
Kilo 70
Delta IV 85
Typhoon 87
Han 80
Song 74
Foxtrot 77
Rubis 77
Collins 71
206 70
209 73
Hangor 73
Hai Lung 75
Harushio 68
Xia 85
Ming 76
Santa Cruz 75
Hashmat 74
Akula Imp/II 75
Kilo Imp Klub India 68
Kilo All 877s except india 72
Kilo All 636s and India 877s 70
Midget 60

Basic Guidelines
<1K ~70
old 1K-2K 75
New 1K-2K 70
Old 3K-6K 80
New 3K-6K 75
Old >7 85
New >7 80
Bad/Big SSBNs >80
Good SSBNs >80 <85

There is some leeway in these numbers so do research and judgement.

Subs made by the west or expert countries (Japan, Sweden) get 1-2 pts dropped.
Subs with hull coatings get 1 pt dropped.

If three generations of subs built by that country since WWII drop 1 pts.

If four generations of subs built by that country since WWII drop 2-3 pts.

If the submarine has been "improved" or modified since the class ship was launched drop 1 pt.

if the sub is "Cutting Edge New" IE from the 2000s drop 1-2 pts.

Subs built by Russia after 1980 get 1 pt dropped (Walker's Spying).

Subs in disrepair gain 1 pt, think Iran, North Korea etc.

If any sub hase a characteristic that would increase or decrease how Active Sonar would detect it add or subtract (duh).

Eastern countries get 1-2 points added

Nuclear Vs. Diesel dosn't really matter size is the critical issue and bigger isn't better! Midgets and littoral subs are very hard to find while big SOBs like the Typhoon stand out like a sore thumb.

For example a Russian Kilo Project 877s is 3K tons sub from the 80s (New) so it starts at 75, the Russians built 3 (major) generations of subs since WWII so its bumped down to 74, The sub has hull coatings so its now 73, it was first launched around 1982 so its now 72. Project 636s get 1 pt dropped since its "improved" so its 71, then they get another dropped since there is now 4 gens of subs since WWII for Russia so its down to 70 pts for baseline Proj 636s India's standard Kilos are here since those subs have recive further improvments.

Another Example The Seawolf is a new sub of >7K tons so it starts at 80, Its from the US so its now 78, its cutting edge so its now 76, the US has built more than four gens of subs since WWII so its now 74, and it has a sound absorbing hull coating so its down to 73. And it probaly has stuff we don't even know about so its 72.

Some subs like the Harushio, Collins, 206 and Kilo would be harder to detect on active. While some are still about the same.

I agree with the concept you've shown (although I think you're crediting the West without enough of a justification at times) and that the current SLs need work, but I think we need to measure the effect of changing the SL first and come to a decision on what the baseline should be. Knowing thosem, you can build the rest of the SLs around them.

It would be nice to have a good dive sound file.
In one of the missions I played, there was a file that played when you reached your assigned dive point. It was something around:

Dive the boat!
Dive dive
(Siren)
Dive dive
(siren)

:up:

That can't be done with the database or doctrines. SCS would have to make that to have it work in all cases (like we had in SC), or mission designers can set up a trigger for certain missions.

Yes they need some in game testing but the formula should give a fair ballance to the game, while giving us moders sufficent leaway.

Not with the DB or Doctrines but we could change the required .wav files in the SFX.agg files in the interface folder.

Damn, if we can do that we should have done it ages ago! Heh. There is a file in there; currently its the COW just saying dive two, maybe three times. If the old SC file can be imported into DW, that would be nice emersion improvement. (Unless it overlaps onto the next audio report from the COW anyway).

if it does overlap we can just delete the overlaping one and let a long way play through both reports. I'll work on making the dive.wav file from the RSR cam for the US subs when I get the chance.