Torpedos Should NOT Detect and Home on Sunkin Vessels.

shipkiller1 · 06-27-17, 02:18 PM

Well, I was under the impression that, 'in the game' the torpedo's use their active or passive seeker head to find the target. Sunkin targets do not have a 'sonar signature'. Its just noise, and since most of the air has been removed from the sunken hull, there is no active acoustic return for the weapon to hear.

Ramius · 06-27-17, 02:36 PM

Quote:

Originally Posted by shipkiller1

Well, I was under the impression that, 'in the game' the torpedo's use their active or passive seeker head to find the target. Sunkin targets do not have a 'sonar signature'. Its just noise, and since most of the air has been removed from the sunken hull, there is no active acoustic return for the weapon to hear.

My reply was to the other post. Don't worry I agree with you this is one thing that needs changed

Navigator857 · 06-28-17, 10:45 AM

Quote:

Originally Posted by shipkiller1

Well, I was under the impression that, 'in the game' the torpedo's use their active or passive seeker head to find the target. Sunkin targets do not have a 'sonar signature'. Its just noise, and since most of the air has been removed from the sunken hull, there is no active acoustic return for the weapon to hear.

As of now (in game) sunken vessels still put out a very strong signature, as if they are a full speed ahead while sitting on the bottom after being sunk.

Jack

Navigator857 · 06-28-17, 10:48 AM

Quote:

Originally Posted by shipkiller1

Well, I was under the impression that, 'in the game' the torpedo's use their active or passive seeker head to find the target. Sunkin targets do not have a 'sonar signature'. Its just noise, and since most of the air has been removed from the sunken hull, there is no active acoustic return for the weapon to hear.

Jack

Shadow · 06-28-17, 03:45 PM

Sunken vessels should have a unique sound signature, distinct from their usual, "alive" one. Because they don't just go dead silent once the machinery stops working. Rushing water, hull cracking and popping due to high pressure isn't quiet, and it can go on for a long while. Even years, if I recall correctly.

Now, whether that kind of sonar activity should attract a torpedo or mask a clever sub, that's another story.

shipkiller1 · 06-28-17, 07:01 PM

This is understood. But it is not a signature per se. It is just broadband noise and the MK48 does not home in on broadband noise if set to passive.

The issue is that an active torpedo should not be detecting a sunken vessel.
That is not how active sound wave return propagation works.

The energy in an active transmission is not reflected from the metal of the hull. It is reflected (actually turned) by the air/water interface.
Sound travels an ave. of 4900ft/sec in seawater, not taking into account pressure, temperature and salinity. The speed of sound in steel is anywhere from 4800-5100ft/sec. Approx. the same a sea water. The sound energy just passes through the metal hull.
Now the speed of sound through air is at a blistering 1150ft/sec. Very much slower.

The sound energy is lazy and does not like to slow when it comes into contact with a much slower medium so it is turned or reflected back when it hits the air.

There is a lot more to it than that but that is the basics.

The air volume on an non-sunken craft is much larger than a sunken one. Your weapon has let most of the air out, which lowered its buoyancy. That is why it sank in the first place.

06-28-17, 03:45 PM	#5
Shadow Torpedoman Join Date: Oct 2005 Location: Buenos Aires Posts: 112 Downloads: 10 Uploads: 2	Sunken vessels should have a unique sound signature, distinct from their usual, "alive" one. Because they don't just go dead silent once the machinery stops working. Rushing water, hull cracking and popping due to high pressure isn't quiet, and it can go on for a long while. Even years, if I recall correctly. Now, whether that kind of sonar activity should attract a torpedo or mask a clever sub, that's another story. __________________ Shadow's Cold Waters mods (JSGME-friendly) = Longer Campaigns: Marathon Edition = 500-yard MAD range

06-28-17, 07:01 PM	#6
shipkiller1 Electrician's Mate Join Date: Jun 2017 Posts: 136 Downloads: 5 Uploads: 0	This is understood. But it is not a signature per se. It is just broadband noise and the MK48 does not home in on broadband noise if set to passive. The issue is that an active torpedo should not be detecting a sunken vessel. That is not how active sound wave return propagation works. The energy in an active transmission is not reflected from the metal of the hull. It is reflected (actually turned) by the air/water interface. Sound travels an ave. of 4900ft/sec in seawater, not taking into account pressure, temperature and salinity. The speed of sound in steel is anywhere from 4800-5100ft/sec. Approx. the same a sea water. The sound energy just passes through the metal hull. Now the speed of sound through air is at a blistering 1150ft/sec. Very much slower. The sound energy is lazy and does not like to slow when it comes into contact with a much slower medium so it is turned or reflected back when it hits the air. There is a lot more to it than that but that is the basics. The air volume on an non-sunken craft is much larger than a sunken one. Your weapon has let most of the air out, which lowered its buoyancy. That is why it sank in the first place. Last edited by shipkiller1; 06-29-17 at 11:36 AM.

06-27-17, 02:18 PM	#1
shipkiller1 Electrician's Mate Join Date: Jun 2017 Posts: 136 Downloads: 5 Uploads: 0	Well, I was under the impression that, 'in the game' the torpedo's use their active or passive seeker head to find the target. Sunkin targets do not have a 'sonar signature'. Its just noise, and since most of the air has been removed from the sunken hull, there is no active acoustic return for the weapon to hear.