View Full Version : Hidrophones

11-21-2005, 05:25 AM
Why is it that the Uboat cannot use its hidrophone when surfaced, and all other warships seems that can hear everything, everyware ?.-

11-21-2005, 06:11 AM
Interesting question.
I assume it's something to do with the location
of the hydrophones on the hull.
I don't know how they're set up on warships though...

Someone here is bound to know. http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

11-21-2005, 06:31 AM
hydrophones need to be under the water to hear anything.

on warships,the hydrophones and asdic were under the hull,because they cant submerge and they are for searching under water.Uboats dont need to search under water,but need to know whats above them when they are under water,so its on the deck generally.

If you get the KDB upgrade or whatever its called you can see it.Its a "t" shaped thing on the front of the boat on the deck.

The first version of SH3 before the patch let you use your hydrophones above water,which was wrong.

11-21-2005, 07:09 AM
Im not quite sure about this one, i know in reality the faster you go the less distance you would be able to hear as the water rushing past the mikes would mask other sounds. Usually on the surface you would be travelling at quite a pace so i guess you would hear very little using the fin mounted hydrophones.

If you look at the front of a U-boat you can see the microphones around the front fin. They are silvery coloured dots in an arc. Technically they would work when surfaced, but I dont know how well they would work. They would be near or in the lapping waves when surfaced so probably you would not hear very far at all, and in most cases would be able to see further (making them useless).

con20or is right that the upgrade is on the deck so this would definately only work when submerged. Also fin mounted hydrophones only had an arc of listening to either side of the boat, but this is not modelled in game as you can listen behind the uboat and infront http://forums.ubi.com/groupee_common/emoticons/icon_redface.gif but meh, saves spinning the boat around!

When the hydrophone operator is listening though it is modelled. IF you watch him moving the dial around he skips the front and rear of the boat missing contacts in those two areas (though this seems intermittant, sometimes missing, other times hearing contacts).

11-21-2005, 07:15 AM
The GHG sonar array that came standard on Uboats was mounted on either side of the bow and since the bow is only partially submerged and in the noise of the bow wake, you hear nothing. If you look at your boat when in UBoat options you will see a downward crescent on the bow. that is your array, standard was 24 on each side. These are fixed and do not move. The big sonar wheel you are turning is not turning anything outside the boat, it is turning what is called a strip line compensator, which was a rather complicated electromechanical device that allowed the operator to determine the bearing from which a sound came. The way this worked (I think) is that the hydrophone membranes (and you must remember these membranes convert mechanical movement caused by sound waves into an electrical signal. If this confuses you, just think of it as a speaker working in reverse!!) were connected to pre-amps in the bow, then fed back to the sonar shack and into the console where this stripline device was. It used the time delay (very very small, but still quite measurable) involved with the sound hitting the array. The sound that had traveled the shortest time being the one most directly opposite the array membrane (I hope this is making sense!!) would cause that particular membrane to generate the larger signal than those that might pick it up from either side. You see this in action when you listen to a target. You will hear it across a band of maybe 5-10 degrees, but only in the middle of that band do you hear it the loudest.

The KDB sonar was something external to the boat that the operater actually did turn, but it sits on top near the bow, so again you are out of luck.
Concerning ship sonar, I believe that at first they were mounted in retractable encloseures towards the front of the ship, due to the fact that it was very much a retrofit device at first. In later designs you see the bow get a bulbous shape to it, and that is your sonar. It is still subject to hull noise though and in the game if you see or hear a destroyer go below 10 knots its doing so in order to listen for you better!! By the same token the faster its going the less it can hear, I would say at anything above 15 knots its hearing is very degraded, above 20 its stone deaf and unless your crew are banging on the pipes with wrenches you wont be heard.

11-21-2005, 04:23 PM
Very good explanations, thanks