Why is there a sonar blind spot at 0d relative?

MarkShot · 02-15-08, 09:26 PM

It is understandable for your AI SO that there is a blind spot in your baffles. However, I have observed that the AI hears best to the left or right.

First, is there a real world reason this should be so. Is the forward hull blocking the sound heads or is the forward hull creating substantial flow noise?

Second, if there is no real world reason for this, then why does the game behave like this?

Thanks.

---

By the way, I have noticed some other interesting behaviors:

(1) You can put the SO on a contact that he would otherwise not be able detect by going to the hydrophones yourself and working the station.

(2) You can spot a night contact that the WO does not first see by going to PD and then surfacing again, the WO seems to then be able to pick it up. Almost like your AI crew now has predisposition (or is alerted) to pick up the contact.

GoldenRivet · 02-15-08, 09:33 PM

you can also see targets visually yourself long before your AI crew will see it if you are manning the bridge.

Kpt. Lehmann · 02-15-08, 10:48 PM

Quote:

Originally Posted by MarkShot

It is understandable for your AI SO that there is a blind spot in your baffles. However, I have observed that the AI hears best to the left or right.

First, is there a real world reason this should be so. Is the forward hull blocking the sound heads or is the forward hull creating substantial flow noise?

Second, if there is no real world reason for this, then why does the game behave like this?

Thanks.

---

By the way, I have noticed some other interesting behaviors:

(1) You can put the SO on a contact that he would otherwise not be able detect by going to the hydrophones yourself and working the station.

(2) You can spot a night contact that the WO does not first see by going to PD and then surfacing again, the WO seems to then be able to pick it up. Almost like your AI crew now has predisposition (or is alerted) to pick up the contact.

Yes, there is a real-world hydrophone blind spot ahead of the U-boat when using GHG hydrophones and it is modelled in GWX. IIRC, the KDB set also has a forward blind spot, but it is much smaller... and its proper arcs are also modelled into GWX.

(1) Yes in effect you are drawing the crewman's attention to a new sound contact and as a result he is now following it. This has always been so in SH3... at least per my observation. The same is true for visual contacts when you momentarily lock them while on the surface... (this is especially true when using the UZO, attack scope, and obs scope.) which basically answers your final question as well.

Pisces · 02-16-08, 08:31 AM

This link should explain the theory behind how the GHG work. But I must warn you it's is quite technical/scientific:

http://www.xs4all.nl/~aobauer/sonar-ghg.htm

Basically a number of microphones (24) were built into each side of the hull, with certain distances between them. If the sound came directly from the side of the uboot the sound would reach all microphones (on one side) at the same time. But if the sound came from a bearing forward or aft of the beam then each microphone would hear the sound a little bit sooner or later than the others. This difference in time, or rather 'phase' for each frequency as electrical technicians would call it, can be reconstructed electronically to provide a bearing. But because of the orientation of the microphones they hardly can hear sounds on bearings near the bow and stern, because that is 'not in their face' for them. It doesn't make them vibrate as much, or at least relative to the unwanted noise. Also bearing uncertainty was becoming a problem in those directions.

Kpt. Lehmann · 02-16-08, 10:22 AM

Ammendment to my statement concerning the KDB:

In GWX, the KDB hydrophone unlike the GHG... does not have a 'blind spot to the front of the U-boat.

Both hydros do have 'deadzones' to the stern however, to represent engine, hull, and propellor 'noise.'

Redbear · 02-16-08, 11:22 AM

I agree with GoldenRivet about being able to spot targets long before your watch crew, at least early in a career. However, in my experience, if you keep the same crew for a long career, and continue to hand out medals and promotions as they are available (at least I think that's the secret), the watch crew will get better and better at spotting ships. It can get to the point where they are calling out ships long before I can see them.

DrMilton · 02-17-08, 07:27 AM

Quote:

Originally Posted by Kpt. Lehmann

In GWX, the KDB hydrophone unlike the GHG... does not have a 'blind spot to the front of the U-boat.

Thats the way it should be. Its location on the boat and its rotation arc wouldn't explain anything impeding it except the boat's stern.

02-15-08, 09:26 PM	#1
MarkShot Ace of the Deep Join Date: Jul 2002 Posts: 1,134 Downloads: 93 Uploads: 0	Why is there a sonar blind spot at 0d relative? It is understandable for your AI SO that there is a blind spot in your baffles. However, I have observed that the AI hears best to the left or right. First, is there a real world reason this should be so. Is the forward hull blocking the sound heads or is the forward hull creating substantial flow noise? Second, if there is no real world reason for this, then why does the game behave like this? Thanks. --- By the way, I have noticed some other interesting behaviors: (1) You can put the SO on a contact that he would otherwise not be able detect by going to the hydrophones yourself and working the station. (2) You can spot a night contact that the WO does not first see by going to PD and then surfacing again, the WO seems to then be able to pick it up. Almost like your AI crew now has predisposition (or is alerted) to pick up the contact. __________________ War games, not wars! --- Only a small few profit from war (that should not stand)!

02-15-08, 09:33 PM	#2
GoldenRivet Subsim Aviator Join Date: Mar 2007 Location: Texas Posts: 8,726 Downloads: 146 Uploads: 0	you can also see targets visually yourself long before your AI crew will see it if you are manning the bridge. __________________

02-16-08, 10:22 AM	#5
Kpt. Lehmann GWX Project Director Join Date: Jul 2005 Location: The Republic of Texas Posts: 6,993 Downloads: 124 Uploads: 0	Ammendment to my statement concerning the KDB: In GWX, the KDB hydrophone unlike the GHG... does not have a 'blind spot to the front of the U-boat. Both hydros do have 'deadzones' to the stern however, to represent engine, hull, and propellor 'noise.' __________________ www.thegreywolves.com All you need is good men. - Heinrich Lehmann-Willenbrock

02-16-08, 08:31 AM	#4
Pisces Silent Hunter Join Date: Dec 2004 Location: AN9771 Posts: 4,904 Downloads: 304 Uploads: 0	This link should explain the theory behind how the GHG work. But I must warn you it's is quite technical/scientific: http://www.xs4all.nl/~aobauer/sonar-ghg.htm Basically a number of microphones (24) were built into each side of the hull, with certain distances between them. If the sound came directly from the side of the uboot the sound would reach all microphones (on one side) at the same time. But if the sound came from a bearing forward or aft of the beam then each microphone would hear the sound a little bit sooner or later than the others. This difference in time, or rather 'phase' for each frequency as electrical technicians would call it, can be reconstructed electronically to provide a bearing. But because of the orientation of the microphones they hardly can hear sounds on bearings near the bow and stern, because that is 'not in their face' for them. It doesn't make them vibrate as much, or at least relative to the unwanted noise. Also bearing uncertainty was becoming a problem in those directions.

02-16-08, 11:22 AM	#6
Redbear Engineer Join Date: Mar 2005 Location: Pennsylvania, USA Posts: 208 Downloads: 33 Uploads: 0	I agree with GoldenRivet about being able to spot targets long before your watch crew, at least early in a career. However, in my experience, if you keep the same crew for a long career, and continue to hand out medals and promotions as they are available (at least I think that's the secret), the watch crew will get better and better at spotting ships. It can get to the point where they are calling out ships long before I can see them.