[WIP] SH4 effects for SH3

[TheDarkWraith]

PM box has at least 10 empty slots since last night. Don't see how it can be full. Just checked it and it has 14 empty slots. One bug has been reported, self lighting debris. Looking into it.

[TheDarkWraith]

Another part of this mod is fixing missing sounds and adding new sounds for the hydrophone. Hawk-U375 is working his magic on turning the sounds into underwater effect sounds. Your hydrophone station will be much more 'alive' after this. I have a small problem that I'm hoping the members here can help with.
All these are in regards to sitting and listening with the hydrophone. Given the following sounds at what distance from the surface would the sound start to diminish in strength and what distance from the surface would you not be able to hear the sound for: (all distances are in meters I'm assuming)

(here are some examples from the files for underwater)

deck gun shell explosion min 500 max 5000
depth charge explosion min 600 max 6000
torpedo impact explosion min 800 max 8000
shell water explosion min 60 max 600
dud torpedo min 50 max 500

now I'm looking for values for these:

light rain
heavy rain
burning oil fire (large)
burning oil fire (small)
cannon firing (like a turret)
Collision with anti submarine net
object collision (objects bumping into ship from explosion)
ship collision with another ship
a big fire
a small fire
deck gun firing ( <= 88mm)
big deck gun firing (>88mm)
machine gun firing
Thunder
Water splashes (from objects and bodies impacting the water)

[Jhereg]

Hey Racerboy as a Sonarman I can tell you that depending on the size of the explosion it can range up to hundreds of miles. Explosive Echo Ranging and Seismic Profiling sure do degrade sonar for a goodly distance(passive sonar).

Fire itself does not transmit hardly any energy directly to the water column so ranges should be nil to extremely short.

Thunder can be heard for a ways from the strike...say 5-9K yards ish.

Splashing objects such as debris etc(smallish) up to around 6K depending on the energy of the object and size.

Light rain pretty much only when it is literally above you, but heavy rain/storm systems can be heard for miles.

Deck guns firing, depend on the caliber of the weapon and how much of the firing forces are transmitted to the hull and also the surface area of the hull that is submerged, quite a ways tho even for smaller guns. The shell splashes of a 20mm can be heard out to at least 6000 yards in good weather.

Hope this helps you out.

[iambecomelife]

Originally Posted by Racerboy

PM box has at least 10 empty slots since last night. Don't see how it can be full. Just checked it and it has 14 empty slots. One bug has been reported, self lighting debris. Looking into it.

OK - good. You have a long PM from me.

[Jhereg]

Racerboy, the depth really does not change the propagation of the sound(range) as usually our sub is being modeled as in the surface duct above the thermal layer.

The sound arrives either direct path or thru a combination of ducting and reflection, however if you go below the layer there is attenuation to deal with and areas that are no longer in the path of sounds generated on the surface.

I do not know if it is possible to realistically model the layer and belows effects on the sounds propagation. Heck below the surface duct you can have a deep sound channel in which the sound can carry for thousands of miles...... .

[Hawk U-375]

Originally Posted by Jhereg

Hey Racerboy as a Sonarman I can tell you that depending on the size of the explosion it can range up to hundreds of miles. Explosive Echo Ranging and Seismic Profiling sure do degrade sonar for a goodly distance(passive sonar).

Fire itself does not transmit hardly any energy directly to the water column so ranges should be nil to extremely short.

Thunder can be heard for a ways from the strike...say 5-9K yards ish.

Splashing objects such as debris etc(smallish) up to around 6K depending on the energy of the object and size.

Light rain pretty much only when it is literally above you, but heavy rain/storm systems can be heard for miles.

Deck guns firing, depend on the caliber of the weapon and how much of the firing forces are transmitted to the hull and also the surface area of the hull that is submerged, quite a ways tho even for smaller guns. The shell splashes of a 20mm can be heard out to at least 6000 yards in good weather.

Hope this helps you out.

You kidding that helps out a TON! . This gives me some sort of meter to go by. Thankyou Sir! Trying to figure out what Rain/Thunder would sound like at a Sonar station is difficult.....specially when I never personally was a Sonarman. Look for me calling on you for examples.....

[mkubani]

Jhereg, sorry for a stupid question, but your sound ranges refer to the sound being heard on the surface or those being heard underwater only by sonar? Sorry, just being a bit confused.

[TheDarkWraith]

Originally Posted by Jhereg

Racerboy, the depth really does not change the propagation of the sound(range) as usually our sub is being modeled as in the surface duct above the thermal layer.

The sound arrives either direct path or thru a combination of ducting and reflection, however if you go below the layer there is attenuation to deal with and areas that are no longer in the path of sounds generated on the surface.

I do not know if it is possible to realistically model the layer and belows effects on the sounds propagation. Heck below the surface duct you can have a deep sound channel in which the sound can carry for thousands of miles...... .

Just from examining the SH3.sdl file they (developers) made provisions for a min radius and max radius the sound can be heard. From my testing it appears that the min range is the range at which the sound 'volume' starts to diminish in strength. Max range being the maximum range at which the sound isn't heard anymore. There is a doppler factor in there but I'm not sure what it's purpose is or what it does as I haven't found an entry that uses it (has a value other than 0h in it). They also made provisions for pitch and pitch variance and volume variance to add some randomness to the sounds.

EDIT: the only objects that use this doppler factor are airplanes and the shell noises you hear in the air

Can you hear airplanes (their engines and all) from underwater?

[3Jane]

I presume the dopler-shift for aircraft would help the watch crew to determine it's direction of travel relative to the u-boat. Perhaps at night when a visual tracking might be more problematic.
*Actually having thought about it, it might be more relevant to the u-boat radar detection of aircraft.

[Bosk]

I'm getting even more excited about the next version of this mod than I am about GWX 1.04 if that's possible.

[urfisch]

same for me! that might be reasoned by the visible progress...there are too less updates for gwx 1.04 - but racerboy really lets us take part in his work, nearly every day. very nice indeed!

but im sure gwx 1.04 will be blasting as well.

[Jhereg]

@ mkubani, I am referring to the propagation of sound in the water as heard from any sensor that is submerged.

Racerboy, just to clarify I am a Surface Sonar Tech tho I have ridden on the Pittsburgh (SSN). We do however, use sensors at variable depths, sonobouys etc...

Aircraft can pretty much only be heard when they are directly overhead or mark on top as the prop or jet noise can not easily couple with the water column as it is airborne. The doppler shift would be very fast due to limited range but still noticeable.

Just remember something must be directly vibrating in contact with the watermass in which the sensor is immersed to ensure a valid/likely propagation path. An airburst nuke of course being an exception...LOL! Just a matter of relative strengths(Db, Overpressure, and such).

Here is a good link that goes over Spherical/Cylindrical spreading of sound in the water http://solmar.saclantc.nato.int/solm...opagation.html and http://www.dosits.org/science/adv/cvss1.htm HTH.

[Jhereg]

Racerboy the doppler setting may also have been there for an unimplemented feature of measuring the doppler on an active return to determine the contacts speed in the line of sound. If you have that and a course from the plot table you could determine the contacts actual speed for fully submerged attacks. All this is of course easier if your sub is motionless as I do not know if they had a means to nullify own ships doppler in WWII on U-boats.

[Jhereg]

3Jane, the aircraft will be heard thru the air long before it is close enough to be heard over sonar. Would have been good for the submariners tho if that was reversed.

Maybe RB could mod us up a U-boat with one of those huge listening devices the Brits used vs the Zepplins in WWI.....:rotfl:

[TheDarkWraith]

Originally Posted by Jhereg

3Jane, the aircraft will be heard thru the air long before it is close enough to be heard over sonar. Would have been good for the submariners tho if that was reversed.

Maybe RB could mod us up a U-boat with one of those huge listening devices the Brits used vs the Zepplins in WWI.....:rotfl:

now the question remains on how to model the airplane noise underwater.....:hmm: ....I want to be able to hear the aircraft if it flies over my sub and I'm at periscope depth or slightly deeper.