[REQ] Realistic "Ping" (not movie ping)

[vickers03]

what about this one:
http://www.liverpoolmuseums.org.uk/m...boa/asdic.aspx

btw, i read in a book from a german ww2 sonar man that
they picked up the asdic sounds first in the hydrophone,
then after some time it was heard in the whole boat.
he also described the sound as a high-pitched trilling
(in the hydrophone).

[Myxale]

We need to keep in mid that the frequencies traveling tru the plancton, salt and thermal layers and there is of cause the pressure-hull this always makes the ping sound a bit off.

I'd say lets stick to the "pepples on a hull" and movie version. The real ping frequencis will damage you ears! :hmm:

[Letum]

Well, I suppose the second best solution is just to remove the ping altogether.

I can't listen to it now that i know its fake.

[vickers03]

maybe it sounds more like this:
http://www.uboataces.com/ref-sonar-sounds.shtml

don't know if it's meant to be inside the sub,
but it sounds close to the descriptions i read
about.

[Hitman]

OK, let's make some things clear: The human can't listen to sounds behind his frequency limits, that's correct BUT:

1.- If the source which produces that sound also creates a colateral sound in the frequency heard by the human, then you BET you will hear something. An example? Quite easy: Dolphins and bats. You CAN hear a very high pitch and short scream when they emmit their ultrasonic waves, yet you don't of course hear the waves themselves. You just listen to the secondary sounds produced by the air expelled through their organs who makes them vibrate and emmit the impuses So the ping we hear in naval sims is correct in that it represents the audible part of the electromagnetic impulse made in the sonar dome (Which is made of metal itself), more or less the same as when hitting a bell.

2.- The "gravel rattle". This has been told in many accounts of submariners, I can right now indicate if memory serves me well, Richard O'Kane f.e.

That gravel rattle along the ship is the result of the ultrasonic impulses hitting a metallic empty tube (The submarine) and as such causing a vibration (As well as being reflected to their origin, thus allowing the ASDIC to show the echo or return). The frequency with which the metal vibrates IS audible by the humans, and hence the comment about the gravel rattle.

Hope that makes it all much clearer

[Letum]

Thats also my understanding Hitman, but that clear, well defines 1khz ping that is
found in all the mods I have tried is certainly not correct.

[wdq4587]

Originally Posted by vickers03

btw, i read in a book from a german ww2 sonar man that
they picked up the asdic sounds first in the hydrophone,

This discussion let me know why ping is not a 3D sound in SH3. (But no sound volume change based on distance is really sucks). And I guess in stock SH3 game you can not hear ping from hydrophone. (What you heared ping is just as in Command Room)

[geosub1978]

Originally Posted by ridgewayranger

Hi All,
The 'Ping' beloved by movie makers is the sound which the operator hears and also comes out of the speakers. Because most normal hearing cannot detect those frequencies the incoming sound is mixed with another frequency 1k/c lower or higher than that transmitted, this results in a 1 k/c note still bearing all the characteristics of the original, pitch, doppler etc. The process is known as heterodyning. The sound heard in the submarine when the beam struck the hull was sort of a click/squeak. The reducing interval between these indicated they were in contact and of course the decreasing range, giving a good skipper some idea when to take avoiding action. Because of this Hunter/Killer groups devised a creeping attack whereby one ship held contact but used constant transmission interval while the others formed a line and virtually carpet bombed the target, hence their high rate of success.
RR

Exactly. What someone hears in the submarine is not the carrier frequency (it is the information-HF) but the transient frequency (which brings the wave to the target and back-LF). The compilation is called modulation. Also the doppler (if the submarine shows movement along the bearing) increases or decreases the LF.
Modern sonars, when they are operated like WW2 era, sound like a hammer hit agaist a steel block BUT NOT as a hit against the pressure hall. If the rest water mass is quiet and the contact approaches, then it sounds very clear and is less absorped and vice versa. Some times, it seems to me like a huge bubble colapsing in sound!

The alternation of the interval is an indication but not a certain one.

[Task Force]

So is it possiable to even get the real pinging noises. we dont even have a recording.

[wdq4587]

Just found I missed ridgewayranger's post.

So it's clear. The sound we heared in Command Room in game should be heared from hydrophone earphone and what we can hear in Command Room should be a click/squeak not the sound we heared now. And the sound should be heared in hydrophone we can not hear it based on hydrophone bearing and distance in game. Why we can hear it at sonar station is because SH3 play it same way as in Command Room.

Can we hear sonar ping just like hearing ship propeller?

[Reece]

I've never actually tried but when you are being pinged is it audable from the exterior of the boat?

[Sag75]

no.. you only hear your officer voice telling you "enemy is pinging us!"

[Sailor Steve]

Originally Posted by wdq4587

So it's clear. The sound we heared in Command Room in game should be heared from hydrophone earphone...

I don't think so. The hydrophones are good at picking up sounds, but the ping is still ultrasonic, so even with the hydrophones I don't know if you'd hear it. The ones the sonarman on the sending ship hears is through a device that sends and recieves those signals.

[wdq4587]

Originally Posted by Sailor Steve

The hydrophones are good at picking up sounds, but the ping is still ultrasonic, so even with the hydrophones I don't know if you'd hear it. The ones the sonarman on the sending ship hears is through a device that sends and recieves those signals.

Yes, you are right. I misunderstand the ridgewayranger's post. What he said is the movie ping sound is from DD's sonar station speaker. We don't know does the u-boat's hydrophone using heterodyning to receive the ping ultrasonic or not. And since the u-boat sonarman does not know the exactly DD's ping ultrasonic frequency before he detect it. May be there are no heterodyning method to detect the ping ultrasonic in u-boat.

And if there are no heterodyning on hydrophone. Since the hydrophone have a sound amplifier. The sonarman of u-boat still can hear the ping early than other crews. But the sound may be some different since the passive vibration by ultrasonic pulse if not from entire hull but from hydrophone mechanism structure. And the sound may be change while hydrophone change direction, but the sound volume may be not change as much as hearing other sound.

And if the game implement the sound level meter of hydrophone. I guess it should response to ultrasonic pulse.

[geosub1978]

Originally Posted by Letum

It seams that almost all ADSIC was between 16khz and 24khz. Almost never lower
than 4Khz.

For the given frequency range what practically happens is this:

When the emittion takes place at great distancies (...) you can hear a very weak "click" comming from sonar operator's headphones. From the headphones themselves the sound is clear that it is an emition like I discribed in my previous post. Meanwhile hardly you can hear anything from the CIC. When the contact approaches (...), the sound gets even more clear, also by naked ears inside the CIC and you don't need headsets for that.

Generally speaking if just the sonarman is able to listen the emittions it is unlikely that the sub has been detected except if the sound reaches a "convergence" zone in the water, or a "surface duct" (for bow sonars). But both phenomenas, require medium or low frequency sonars to maintain enough energy along the path and back and certainly it is very difficult for sonars 16-24kHz. So, I believe in SH3 if we make pinging heard only from sonar man this should mean that the submarine is not detected. If someone can hear the pinging from the CIC, then the sub could have been detected or not.

The detection distance of a 16-24kHz sonar has to be very limited because of absorption. It is more likely that ASDIC operated at lower frequencies (10-14kHz,less seems more logical), but I don't have any input from google!