Can't hear ship on hydrophone

patio87 · 08-31-08, 02:50 AM

There is a ship like .3 mile away from me, I can even hear his engines when I am inside my ship in the map section, but when I go to the hydrophone I can't hear him. Why can I hear him like he's right next to me, but not with my hydrophone pick him up.

And are there any good references on how to use it, like how can I figure out what way a ship is heading, all it does is tell me where the ship is relative to me.

The stickied videos up at the top of the forum are broken, the links just link to fileplanet games section, the downloads for those tdc videos aren't there.

Thanks.

mcf1 · 08-31-08, 04:50 AM

Welcome aboard Skipper.
Does a sound contact appear on your map? If not then the ship Is probably stationary
Is your sub diven or decks awash?
Is your hydrophone intact?

patio87 · 08-31-08, 05:02 AM

Yes I was at like 55 feet. Are you saying I should have heard him on the hydrophone?

vickers03 · 08-31-08, 05:07 AM

i had the same issue with some small fisherboats,
maybe they are not set up as sonar targets,
i checked their files but they seemed ok..

mcf1 · 08-31-08, 05:18 AM

Quote:

Originally Posted by patio87

Yes I was at like 55 feet. Are you saying I should have heard him on the hydrophone?

Yes, unless you have a broken hydrophone or the ship is not moving

Falkirion · 08-31-08, 06:37 AM

Are you using home and end to swivel the hydrophones? Most of the time when I go to the station I have to manually set the bearing the contact is on to pick it up.

Seminole · 08-31-08, 08:05 AM

I posted a similar thread some time ago. Never got any satisfactory cures but did receive a couple of confirming replies.

Funny thing though...after I mentioned it..it has never recurred...go figure...:hmm:

So I wouldn't sweat it .It probably won't turn out to be a big deal for you either.

SteamWake · 08-31-08, 09:06 AM

Given that you have followed the above suggestions (submerge a bit below Periscope depth, Rotate the hydrophone) and still dont hear the contact then...

Yes it is a rare but confirmed bug. Sometimes the sound stream for a 'contact' doesent get cued.

By the way with RFB install you can even hear the stationary boats.

Oh yea and welcome to Sub Sim Patio

patio87 · 08-31-08, 08:23 PM

Quote:

Originally Posted by SteamWake

Given that you have followed the above suggestions (submerge a bit below Periscope depth, Rotate the hydrophone) and still dont hear the contact then...

Yes it is a rare but confirmed bug. Sometimes the sound stream for a 'contact' doesent get cued.

By the way with RFB install you can even hear the stationary boats.

Oh yea and welcome to Sub Sim Patio

Hmm, well I figured it was a bug, thanks for the confirmation. BTW, what is the RFB install? And on the topic of hearing things, can other ships hear other things on my sub, other than the engines running? Like when I'm pinging the bottom to see the depth, or I ping a contact to see how far it is, are the ships somehow listening to those pings, and can they figure out where I am by my pings?

This game is crazy, it's so deep, I have so many questions, I'm loving it.

SteamWake · 08-31-08, 09:56 PM

Quote:

Originally Posted by patio87

can other ships hear other things on my sub, other than the engines running? Like when I'm pinging the bottom to see the depth, or I ping a contact to see how far it is, are the ships somehow listening to those pings, and can they figure out where I am by my pings?.

It all depends on what kind of ship / group of ships...

If it is a convoy with escorts..of course they are listening, in fact pinging the range to a DD when he is close (3k yards more or less) is like rasing a flag saying "You hoo this way... here I am."

They can also hear and react to depth pings. Range I dont know ask someone else.

But basically keep the range to target in mind when using active devices.

patio87 · 08-31-08, 10:27 PM

Ok thanks, I figured as much but wasn't positive. What about the thermal layer, what is it, and can they hear me down there?

Arclight · 09-01-08, 03:42 AM

Can't find a source right now so I'm going by memory;

It's a region / layer were the temperature of the water changes rapidly compared to the water above (and below?) it. Say the water from the surface to 80ft depth drops 5deg in temperature, and then it changes another 5deg in the next 10ft (80 to 90ft depth), then that 10ft of water would form a "thermal layer".

What it does is reflect or refract sound (and possibly other forms of energy?). This happens because the speed of sound traveling trough water is (among other things) dependent on the temperature. As the sound reaches the layer, it's speed changes, and as a result it's direction changes. It's a lot like light bending as it enters water; if you look at an object from above the surface, it appears to be in a different location then it actually is.

I think if the sound hits the layer at a very shallow angle, it is actually reflected. I think I read sometime that if the surface if perfectly smooth (0 wind), sound gets reflected back and forth between the surface and the layer, allowing anyone listening to pick up on a contact from very long ranges.

So, a sonarman listening for a passive contact or using active sonar for location, would place the contact in the wrong location (due to refraction) or would not be able to acquire a contact at all (due to reflection).

I doubt it is this accurately modeled in the game. Probably all it does is make you a bit harder to detect, by reducing the range you can be detected at under the current conditions.

Anyone please feel free to correct me, it's been a few years since I read about this stuff.

* found something on refraction, also talks a bit on sound refraction (the acoustics bit): http://en.wikipedia.org/wiki/Refraction

SteamWake · 09-01-08, 09:09 AM

Arclight pretty much covered it.

Game mechanic wise it decreases the odds of an active or passive sonar being able to locate you.

Its not a magic blanket though, if your thrashing around down there at speed and banging on stuff with hammers there still going to hear you.

iksoks · 09-01-08, 01:35 PM

never had this happen (or better didnt notice) before i started running TMO...
Now i happens quite often..
Or even worse my sonar guy cant hear a DD going full steam 21 kn from ca 3 miles away.. When i got into the seat it kinda scared the shi* out of me he was so loud...

09-01-08, 04:18 PM

patio87

Quote:

Yes I was at like 55 feet. Are you saying I should have heard him on the hydrophone?

Try going below 60'.

Urge

08-31-08, 02:50 AM	#1
patio87 Swabbie Join Date: Aug 2007 Posts: 9 Downloads: 0 Uploads: 0	Can't hear ship on hydrophone There is a ship like .3 mile away from me, I can even hear his engines when I am inside my ship in the map section, but when I go to the hydrophone I can't hear him. Why can I hear him like he's right next to me, but not with my hydrophone pick him up. And are there any good references on how to use it, like how can I figure out what way a ship is heading, all it does is tell me where the ship is relative to me. The stickied videos up at the top of the forum are broken, the links just link to fileplanet games section, the downloads for those tdc videos aren't there. Thanks.

08-31-08, 08:05 AM	#7
Seminole Ace of the Deep Join Date: Sep 2002 Location: Oregon Posts: 1,012 Downloads: 102 Uploads: 0	I posted a similar thread some time ago. Never got any satisfactory cures but did receive a couple of confirming replies. Funny thing though...after I mentioned it..it has never recurred...go figure...:hmm: So I wouldn't sweat it .It probably won't turn out to be a big deal for you either. __________________

09-01-08, 03:42 AM	#12
Arclight Navy Seal Join Date: Jun 2008 Location: Land of windmills, tulips, wooden shoes and cheese. Lots of cheese. Posts: 8,467 Downloads: 53 Uploads: 10	Can't find a source right now so I'm going by memory; It's a region / layer were the temperature of the water changes rapidly compared to the water above (and below?) it. Say the water from the surface to 80ft depth drops 5deg in temperature, and then it changes another 5deg in the next 10ft (80 to 90ft depth), then that 10ft of water would form a "thermal layer". What it does is reflect or refract sound (and possibly other forms of energy?). This happens because the speed of sound traveling trough water is (among other things) dependent on the temperature. As the sound reaches the layer, it's speed changes, and as a result it's direction changes. It's a lot like light bending as it enters water; if you look at an object from above the surface, it appears to be in a different location then it actually is. I think if the sound hits the layer at a very shallow angle, it is actually reflected. I think I read sometime that if the surface if perfectly smooth (0 wind), sound gets reflected back and forth between the surface and the layer, allowing anyone listening to pick up on a contact from very long ranges. So, a sonarman listening for a passive contact or using active sonar for location, would place the contact in the wrong location (due to refraction) or would not be able to acquire a contact at all (due to reflection). I doubt it is this accurately modeled in the game. Probably all it does is make you a bit harder to detect, by reducing the range you can be detected at under the current conditions. Anyone please feel free to correct me, it's been a few years since I read about this stuff. * found something on refraction, also talks a bit on sound refraction (the acoustics bit): http://en.wikipedia.org/wiki/Refraction __________________ Contritium praecedit superbia.

08-31-08, 04:50 AM	#2
mcf1 Seasoned Skipper Join Date: Oct 2007 Location: Greece, Volos Posts: 710 Downloads: 10 Uploads: 0	Welcome aboard Skipper. Does a sound contact appear on your map? If not then the ship Is probably stationary Is your sub diven or decks awash? Is your hydrophone intact?

08-31-08, 05:02 AM	#3
patio87 Swabbie Join Date: Aug 2007 Posts: 9 Downloads: 0 Uploads: 0	Yes I was at like 55 feet. Are you saying I should have heard him on the hydrophone?

08-31-08, 05:07 AM	#4
vickers03 Pooped from posting Join Date: May 2007 Location: germany Posts: 999 Downloads: 712 Uploads: 37	i had the same issue with some small fisherboats, maybe they are not set up as sonar targets, i checked their files but they seemed ok..

08-31-08, 06:37 AM	#6
Falkirion Ace of the Deep Join Date: Aug 2008 Location: Melbourne, AUS Posts: 1,043 Downloads: 34 Uploads: 0	Are you using home and end to swivel the hydrophones? Most of the time when I go to the station I have to manually set the bearing the contact is on to pick it up.

08-31-08, 09:06 AM	#8
SteamWake Rear Admiral Join Date: Mar 2005 Posts: 13,224 Downloads: 5 Uploads: 0	Given that you have followed the above suggestions (submerge a bit below Periscope depth, Rotate the hydrophone) and still dont hear the contact then... Yes it is a rare but confirmed bug. Sometimes the sound stream for a 'contact' doesent get cued. By the way with RFB install you can even hear the stationary boats. Oh yea and welcome to Sub Sim Patio

08-31-08, 10:27 PM	#11
patio87 Swabbie Join Date: Aug 2007 Posts: 9 Downloads: 0 Uploads: 0	Ok thanks, I figured as much but wasn't positive. What about the thermal layer, what is it, and can they hear me down there?

09-01-08, 09:09 AM	#13
SteamWake Rear Admiral Join Date: Mar 2005 Posts: 13,224 Downloads: 5 Uploads: 0	Arclight pretty much covered it. Game mechanic wise it decreases the odds of an active or passive sonar being able to locate you. Its not a magic blanket though, if your thrashing around down there at speed and banging on stuff with hammers there still going to hear you.

09-01-08, 01:35 PM	#14
iksoks Swabbie Join Date: Nov 2006 Posts: 11 Downloads: 0 Uploads: 0	never had this happen (or better didnt notice) before i started running TMO... Now i happens quite often.. Or even worse my sonar guy cant hear a DD going full steam 21 kn from ca 3 miles away.. When i got into the seat it kinda scared the shi* out of me he was so loud...