BB vs NB detection ranges?

MarkShot · 09-18-07, 03:42 PM

I am reading a book on naval warfare. The text states that BB detections (general non-specific noise) occur before NB detections (specific harmonics associated with various ship sub-systems). It sounded fairly reasonable.

In the meantime, as an SC/DW player NB detections are always possible prior to BB detections. In particular, those very faint lines (with high gama settings) or even shadow lines at 50Hz and 60Hz frequencies being the very first indication of a contact. The text did note that low frequency sound is the least subject to attenuation over distance and thus is the most detectable; although high frequency sound is mainly used for active sonar, since the high frequency is needed to distinguish metallic object returns compared other naturally occurring reflectors.

So, which is the more sensitive passive system BB or NB? If BB, then why does it seem reversed in SC and DW?

Thanks.

Dr.Sid · 09-19-07, 07:02 AM

I guess it should be NB .. the problem with weak signals is to distinguish them from noise. BB can't do that. And even NB can use time-averaging (it does not in DW).
But that is just theoretical and probably not-complete point of view.

Edit: hm .. here is argument for BB .. not all signals are harmonic - some of them are wide-spectrum noises. Like water flow for example and cavition noise too. These can't be detected on NB, at least not as lines. So target with great machinery and great silencing, where waterflow noise is more important (ie subs) could be favorable toward BB. But amount of these factors is unknown to me.

Linton · 09-19-07, 10:58 AM

What book would that be Markshot?

MarkShot · 09-19-07, 12:36 PM

Harpoon II: The Official Strategy Guide by Dille and Basham, published by Prima 1994

400+ pages and a most excellent read on modern naval warfare. This is effectively the book (material and concepts) which is missing from the extensive manuals that come with SC and DW.

I have recently gotten started with Harpoon ANW 3.8.0 and the H3 3.6.3; also, I'll be getting a copy of HCCE which should be released soon.

I find that Harpoon complements SC/DW and the tactical situations they paint very well. It is refreshing to see a game that casts nuke subs in some realistic roles as opposed to performing close escort duty with a nuke sub in 100' of water.

MarkShot · 09-19-07, 12:37 PM

By the way, this book can be had used for less that $2 USD (with the main cost really being the shipping/handling); an incredible bargain.

Bill Nichols · 09-19-07, 01:32 PM

NB was developed exactly because it gives much better performance than BB. For a long time it was a U.S. navy secret that our subs could do NB detection.

MarkShot · 09-19-07, 01:35 PM

Bill,

I was just looking at the other used Harpoon book I received last week; an older book 1991 by Goey. I saw your name in the acknowledgements!

You certainly have been making your presence known for a long time!

Bill Nichols · 09-19-07, 02:06 PM

Quote:

Originally Posted by MarkShot

Bill,

I was just looking at the other used Harpoon book I received last week; an older book 1991 by Goey. I saw your name in the acknowledgements!

You certainly have been making your presence known for a long time!

Yes, a quarter-century of service! I programmed one of the first naval computer games, Grey Seas Grey Skies, in 1982 for the Apple ][. I've been active in the community since then.

"Nichols, W. J. Grey Seas, Grey Skies. Bridgewater, Nova Scotia: Simulations Canada, 1983, 1987 (Apple computer game). Reviewed by John Gresham and Michael Markowitz. Proceedings (July 1984): 116–117. (Seven “prebuilt” scenarios, including Japanese destroyers versus Soviet submarines in the Kurile Islands, a Soviet amphibious group versus West German forces in the Baltic, U.S. versus Soviet carrier battle groups off the North Cape, and similar clashes in the Western Pacific and the Mediterranean.)"

MarkShot · 09-19-07, 02:40 PM

Bill,

So, let me change topic (it's my thread after all).

Aside from yourself and Ron Banks, you are the only two nuke vets I know in a way.

The other day, I was thinking how odd it must be to serve on a nuke. On a surface ship, you are going to get to go up on deck sometimes. A WWII diesel, you might have had the chance to occassionally stand watch. There you are in the middle of the vast ocean traveling the globe, but you never get to look out upon the horizon which goes as far as the eye can see; smell the sea salt; hear the surf... Instead you are living in a tube.

I tried to imagine the other day how it might feel to drive across country ... drive across the wide open spaces of New Mexico where you can see to the horizon and mountains 50+ miles in the distance. However, instead the windows of the car are all papered over. There is nothing to see but what it inside the car. Your mind can tell you what is outside, but your eyes cannot see it.

So, what is making such a transit like? How to describe it to those of us who simply look at the PC station screens, but can walk out of the room anytime we wish after pressing the PAUSE button?

Thanks.

ASW Jedi · 09-24-07, 08:36 AM

Speaking from my experiences on Nuke boats. The transits can be boring as hell. Matter of fact most of the time onboard can be boring. Its those few minutes of sheer terror or utter amazement that make up for it. I am sure Bill's accomidations on 571 was far more spartan than those of the 637 and 688s but it still isn't a cruise liner.

James B

USS Pogy (SSN-647)
USS Jefferson City (SSN-759)
USS Momsen (DDG-92)

09-18-07, 03:42 PM	#1
MarkShot Ace of the Deep Join Date: Jul 2002 Posts: 1,134 Downloads: 93 Uploads: 0	BB vs NB detection ranges? I am reading a book on naval warfare. The text states that BB detections (general non-specific noise) occur before NB detections (specific harmonics associated with various ship sub-systems). It sounded fairly reasonable. In the meantime, as an SC/DW player NB detections are always possible prior to BB detections. In particular, those very faint lines (with high gama settings) or even shadow lines at 50Hz and 60Hz frequencies being the very first indication of a contact. The text did note that low frequency sound is the least subject to attenuation over distance and thus is the most detectable; although high frequency sound is mainly used for active sonar, since the high frequency is needed to distinguish metallic object returns compared other naturally occurring reflectors. So, which is the more sensitive passive system BB or NB? If BB, then why does it seem reversed in SC and DW? Thanks. __________________ War games, not wars! --- Only a small few profit from war (that should not stand)!

09-19-07, 10:58 AM	#3
Linton Sea Lord Join Date: Dec 2003 Posts: 1,898 Downloads: 0 Uploads: 0	What book would that be Markshot? __________________ http://lintonsview.blogspot.com/

09-19-07, 12:36 PM	#4
MarkShot Ace of the Deep Join Date: Jul 2002 Posts: 1,134 Downloads: 93 Uploads: 0	Harpoon II: The Official Strategy Guide by Dille and Basham, published by Prima 1994 400+ pages and a most excellent read on modern naval warfare. This is effectively the book (material and concepts) which is missing from the extensive manuals that come with SC and DW. I have recently gotten started with Harpoon ANW 3.8.0 and the H3 3.6.3; also, I'll be getting a copy of HCCE which should be released soon. I find that Harpoon complements SC/DW and the tactical situations they paint very well. It is refreshing to see a game that casts nuke subs in some realistic roles as opposed to performing close escort duty with a nuke sub in 100' of water. __________________ War games, not wars! --- Only a small few profit from war (that should not stand)!

09-19-07, 12:37 PM	#5
MarkShot Ace of the Deep Join Date: Jul 2002 Posts: 1,134 Downloads: 93 Uploads: 0	By the way, this book can be had used for less that $2 USD (with the main cost really being the shipping/handling); an incredible bargain. __________________ War games, not wars! --- Only a small few profit from war (that should not stand)!

09-19-07, 01:32 PM	#6
Bill Nichols Master of Defense Join Date: Mar 2000 Posts: 1,502 Downloads: 125 Uploads: 0	NB was developed exactly because it gives much better performance than BB. For a long time it was a U.S. navy secret that our subs could do NB detection. __________________ My Dangerous Waters website:

09-19-07, 07:02 AM	#2
Dr.Sid The Old Man Join Date: May 2005 Location: Czech Republic Posts: 1,458 Downloads: 6 Uploads: 0	I guess it should be NB .. the problem with weak signals is to distinguish them from noise. BB can't do that. And even NB can use time-averaging (it does not in DW). But that is just theoretical and probably not-complete point of view. Edit: hm .. here is argument for BB .. not all signals are harmonic - some of them are wide-spectrum noises. Like water flow for example and cavition noise too. These can't be detected on NB, at least not as lines. So target with great machinery and great silencing, where waterflow noise is more important (ie subs) could be favorable toward BB. But amount of these factors is unknown to me.

09-19-07, 01:35 PM	#7
MarkShot Ace of the Deep Join Date: Jul 2002 Posts: 1,134 Downloads: 93 Uploads: 0	Bill, I was just looking at the other used Harpoon book I received last week; an older book 1991 by Goey. I saw your name in the acknowledgements! You certainly have been making your presence known for a long time! __________________ War games, not wars! --- Only a small few profit from war (that should not stand)!

09-19-07, 02:40 PM	#9
MarkShot Ace of the Deep Join Date: Jul 2002 Posts: 1,134 Downloads: 93 Uploads: 0	Bill, So, let me change topic (it's my thread after all). Aside from yourself and Ron Banks, you are the only two nuke vets I know in a way. The other day, I was thinking how odd it must be to serve on a nuke. On a surface ship, you are going to get to go up on deck sometimes. A WWII diesel, you might have had the chance to occassionally stand watch. There you are in the middle of the vast ocean traveling the globe, but you never get to look out upon the horizon which goes as far as the eye can see; smell the sea salt; hear the surf... Instead you are living in a tube. I tried to imagine the other day how it might feel to drive across country ... drive across the wide open spaces of New Mexico where you can see to the horizon and mountains 50+ miles in the distance. However, instead the windows of the car are all papered over. There is nothing to see but what it inside the car. Your mind can tell you what is outside, but your eyes cannot see it. So, what is making such a transit like? How to describe it to those of us who simply look at the PC station screens, but can walk out of the room anytime we wish after pressing the PAUSE button? Thanks. __________________ War games, not wars! --- Only a small few profit from war (that should not stand)!

09-24-07, 08:36 AM	#10
ASW Jedi Swabbie Join Date: Dec 2006 Location: Iowa Posts: 10 Downloads: 0 Uploads: 0	Speaking from my experiences on Nuke boats. The transits can be boring as hell. Matter of fact most of the time onboard can be boring. Its those few minutes of sheer terror or utter amazement that make up for it. I am sure Bill's accomidations on 571 was far more spartan than those of the 637 and 688s but it still isn't a cruise liner. James B USS Pogy (SSN-647) USS Jefferson City (SSN-759) USS Momsen (DDG-92)