A curious thought on DW passive sonar detection range

To be · 02-15-08, 03:42 PM

Were you above or below the layer?

Dr.Sid · 02-15-08, 04:07 PM

Here are some measurements I made. It is NOT detection range, but it shows pretty well how sound modelling is done in DW.

http://www.subsim.com/radioroom/showthread.php?t=117814

Edit: All hail new 'Ace of the deep, 1000 posts (and back safely)'

sonar732 · 02-15-08, 05:29 PM

When you post questions like those, it helps to provide us with information.

SSP
Where you were in relation to the world. ie...deep water, shallows, etc.

Castout · 02-15-08, 06:00 PM

There was no thermal layer as I was in a relatively shallow water with the bottom at around 50-100m.

My depth ranged from periscope depth to 60 m.

sonar732 · 02-15-08, 09:46 PM

Quote:

Originally Posted by Castout

There was no thermal layer as I was in a relatively shallow water with the bottom at around 50-100m.

My depth ranged from periscope depth to 60 m.

In another words...your sonar conditions SUCKED!

Molon Labe · 02-16-08, 04:32 AM

Those detection ranges look about right for bottom limited in mud/sand, especially from PD. It's not just the Akula, all sonars are going to work like **** in ****ty acoustic conditions!

Dr.Sid · 02-16-08, 05:40 AM

From my experience:

- AFAIK, in DW, shallow water does not affect sound travel, except for terrain blocking the signal. But I guess it should block everything or nothing, it should not weaken the signal.
- Sea state on the other hand does lower sonar performance significantly. So what was your sea state ?
- Burke at 10kts, at 3nm should be nice and bright, impossible to miss (based on my DW experience alone). There IS something fishy here, that is NOT normal. What array did you use ? What speed were you going ? All arrays are easy to washout with excessive speed. In shallow water towed array is easy to get draged on the bottom. Please post screenshots from that situation, from map and from sonar station.

02-15-08, 05:29 PM	#3
sonar732 The Old Man Join Date: Jul 2003 Location: Central MO Posts: 1,562 Downloads: 6 Uploads: 0	When you post questions like those, it helps to provide us with information. SSP Where you were in relation to the world. ie...deep water, shallows, etc.

02-15-08, 06:00 PM	#4
Castout Silent Hunter Join Date: Nov 2006 Location: Jakarta Posts: 4,794 Downloads: 89 Uploads: 6	There was no thermal layer as I was in a relatively shallow water with the bottom at around 50-100m. My depth ranged from periscope depth to 60 m. __________________ My blog: http://exposingsingapore.wordpress.com/ Last edited by Castout; 02-15-08 at 06:17 PM.

02-16-08, 04:32 AM	#6
Molon Labe Silent Hunter Join Date: Jun 2004 Location: Along the Watchtower Posts: 3,810 Downloads: 27 Uploads: 5	Those detection ranges look about right for bottom limited in mud/sand, especially from PD. It's not just the Akula, all sonars are going to work like ** in **ty acoustic conditions! __________________

02-15-08, 03:42 PM	#1
To be Electrician's Mate Join Date: Feb 2007 Posts: 140 Downloads: 8 Uploads: 0	Were you above or below the layer?

02-15-08, 04:07 PM	#2
Dr.Sid The Old Man Join Date: May 2005 Location: Czech Republic Posts: 1,458 Downloads: 6 Uploads: 0	Here are some measurements I made. It is NOT detection range, but it shows pretty well how sound modelling is done in DW. http://www.subsim.com/radioroom/showthread.php?t=117814 Edit: All hail new 'Ace of the deep, 1000 posts (and back safely)'

02-16-08, 05:40 AM	#7
Dr.Sid The Old Man Join Date: May 2005 Location: Czech Republic Posts: 1,458 Downloads: 6 Uploads: 0	From my experience: - AFAIK, in DW, shallow water does not affect sound travel, except for terrain blocking the signal. But I guess it should block everything or nothing, it should not weaken the signal. - Sea state on the other hand does lower sonar performance significantly. So what was your sea state ? - Burke at 10kts, at 3nm should be nice and bright, impossible to miss (based on my DW experience alone). There IS something fishy here, that is NOT normal. What array did you use ? What speed were you going ? All arrays are easy to washout with excessive speed. In shallow water towed array is easy to get draged on the bottom. Please post screenshots from that situation, from map and from sonar station.