Sonar questions

STURM

Well-Known Member
Have a number of question I'm curious about. Would greatly appreciate any assistance from other members.

1. For surface combatants that are not operating together with MCMs, what is the main means of avoiding or detecting moored or bottom laid mines? Would I be correct in assuming that 'obstacle avoiding sonars' that some surface combatants are equipped with, would be able to detect mines?

2. Would a sub's hull mounted or flank array sonars be useful in detecting mines? When discussing sub operations in littoral waters, we tend to put more emphasis on threats posed by other subs, surface ASW units and ASW aircraft and often forget that mines also pose a great danger.

3. Does anyone know of any surface combatants currently in service that are fitted with only a towed array and have no hull mounted sonar?

4. Apart from being able to go below the thermal layer, to listen aft of the baffles and other advantages; would I be correct in saying that an advantage offered by a towed array is the ability to pick up contacts at longer ranges, when compared to a hull mounted sonar?

5. Do current genertaion towed arrays generate enough noise, when being reeled in our out, that can be picked up by sonars from ships, subs and aircraft?

Thank you.
 

AegisFC

Super Moderator
Staff member
Verified Defense Pro
For #1 the SQS-53C sonar found on most USN ships got an upgrade called Kingfisher that added mine detection and avoidance in the early 2000's.
 

CB90

The Bunker Group
Verified Defense Pro
2 - Mine detection pretty much involves either active sonar or imagery (usually via UUVs). So you probably could tweak bow/flank arrays with active transmission capability to do that...it's just whether or not a sub really wants to be doing that. Given that subs can change depth, unless you're in shallow waters, the really scary mines are the ones like Captor. In which case active transmissions wouldn't help at all.

3- No idea. Mainly not sure what the architectural benefit of doing that would be...hull mounted arrays are pretty "conformal" to the hull shape.

4- Because ASW is 3 dimensional, going below the layer lets sound energy go "down and out" so to speak. In other words, going below the layer also means you also effectively get more range.

5-Any noise can be picked up...there's a reason submariners wear tennis shoes underway. It really depends on how loud the motor is, how much noise mitigation the hull provides, environmentals, range, receiving sensor quality, etc. I realize that's a roundabout answer, but as you can see, it's also a complicated question to answer. Not sure if the sonar equation is available via web search, but you can take an educated guess at the answer if you have it.
 

EXSSBN2005

New Member
I wasn't a sonor man but I'll try to provide some answers to what I can in a totally you can quote me on this as I'm not bound by classification issues on sonor (nuke stuff i think the NDA on that is up in like 11-12 years or so, got out in 2005).

5) The spool motor was fairly quiet, as to flow noise generated by reeling it in relative to normal sub speed, i cant say for sure but one may assume it was pretty stealthy.

4) You can also triangulate position of the other guy if you have two points that your able to make a bearing on him, localizing is much more accurate (i sucked on the plotting table underway but it was interesting to be ERS up in the control room) cudos to the tracking party who can actually find and keep a bearing on the other guy.

3) Not sure what the benifit would be but we did play with some trawlers that were pulling a rather huge array that I was not briefed in on the specifics just they were trying to find my boat (SSBN Henry M Jackson) but I would guess that the trawler would have also had some sort of hull mounted sonor but thats just a guess and it wasn't a typical warship as it was unarmed and the counterpart ship to it I would not have concidered it armed.

2) Not sure, they couldn't effectively mine the open ocean, [EDITED after typing due to specifics about own ship vunerability]

1) Stay out to sea away from restricted transit routes if possiable, not sure exactly.
 

CB90

The Bunker Group
Verified Defense Pro
3) Not sure what the benifit would be but we did play with some trawlers that were pulling a rather huge array that I was not briefed in on the specifics just they were trying to find my boat (SSBN Henry M Jackson) but I would guess that the trawler would have also had some sort of hull mounted sonor but thats just a guess and it wasn't a typical warship as it was unarmed and the counterpart ship to it I would not have concidered it armed.
Do you mean T-AGOS/SURTASS ships?

Yeah, that jogged my memory, pretty sure those guys dont have hull mounted sonars. But they have ridiculous towed arrays. For...um, "oceanographic research." Not combatants though.

[ame="http://en.wikipedia.org/wiki/Surveillance_Towed_Array_Sensor_System"]Surveillance Towed Array Sensor System - Wikipedia, the free encyclopedia[/ame]
 

gf0012-aust

Grumpy Old Man
Staff member
Verified Defense Pro

barney41

Member
An update on the ongoing tests of the MCM package intended to equip LCS . Results appear to be quite positive. Also some info on how ASW will be conducted.



Navy
 
Top