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.

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.