Screw sounds: closing/moving away

[Maui]

Originally Posted by kenijaru

how am i suposed to hear that?

I'm pretty sure that was a joke.

Oberon, that was classic! Thanks!

[DMarkwick]

Originally Posted by Maui

I'm pretty sure that was a joke.

Yes it was, sorry for the lack of smiley

I guess the only way to determine it, given that no-one really knows yet, is to set up a situation in the mission editor where 2 identical vessels are fairly close by, one going and one coming, then listen to them both and try to determine a difference.

It'll be difficult, later on in a "real" patrol though, trying to determine if one particular signal is going or coming without the reference of an opposite to compare it to. But then that's why you pay the hydrophone operator so much right?

[kenijaru]

you can always use the active sonar (given that you have it installed)

[greyrider]

when the sonarman exclaims, "moving away", or "closing",i think he's using the fringe bearings of the sound contact, not the bearing that the contacts is on at the moment.

in other words , he is using the width of the sound cone to determine range, called out as long, medium, or short range, and also closing and moving away.

i have been working with the hydrophones now for almost a year since the sh3 release, and so i feel like a veteran sonarman.

i am pretty close to announcing to the community that i am able to
determine course, speed, and range of a target just by listening to the hydrophones.

one way was the sonar tutorial that i put out, that was one way,

but i have been working with the ambient sound of the hydrophones vs the amplitude of the sound contact.
the ambient sound from the hydrophones is a constant level of sound, it never changes, but the sound of a targets propellers gets louder as it closes on the u-boat,
at some range, the screw sounds overcome the sound level of the ambient sound of the hydrophones, and completely drowns out the sound of the phones.

determining when this happens, will give us the range the target is from the u-boat. this is one reason why its so important to know the max listening range of the phones, because if you know the time when the contact first entered the listening range, once it gets to the point where the ambient noise of the phones are completely drowned out, you be able to calculated for speed also.

the sound cone also can be used for range estimation. the width of the sound cone gets wider as the contact closes

just a few more days work, and ill be able to post more about this.

by the way, for me anyway, the sound of the contacts propellers
drowns out the sound of the phones about 15 km.

i have to listen a few more times, because i want to get it precise

this method is going to be a user method, everyone might get different results, because someones hearing might be better than others, and so may vary from person to person, but not by much.

[Maui]

awesome, thanks greyrider