|
charlee22009 -> Passive sonar and conversion zone detection (2/22/2018 2:48:06 AM)
|
Question. Can you guys/girls help me understand or guess the Sound Velocity Profile (SVP) in the screenshot?
How does, in this specific case, the surface temperature, season, and sea state effect the sound propagation?
Why is the convergence zone relatively stronger in this case?
My understanding is that the SVP is negative when the surface water temperature is hotter (it's 20degrees C) - not to mention it's August.
Doesn't this create a 'negative' SVP near the surface and in the 'seasonal' layer as well? (Negative in the seasonal due to the relatively warm surface temperatures, and colder temperatures as you get deeper?)
If the water 'layers' in this example were
------Surface Slightly negative
------Seasonal Moderately/strongly negative
------Main (permanent) thermocline (even more??) negative...
Then the 'layer' according to CMANO is the slope or change in sound velocity... between the 'surface/seasonal' and the main thermocline?
And if they are all negative, why does that make the layer 'stronger?' .62 isn't *that* strong but it's stronger than I've seen it elsewhere (say GIUK gap)?
Is that '.62' the strength of the convergence zone(s)??? Because if most or all of the rays bend downwards, pretty much above and below the 'layer'... and it's really deep is this making the convergence zones 'stronger' or more focused???
Here is the pic
Also the ORIGINAL detection by the Knox Class Frigate was with the hull passive sonar!!!!! Although she was at around 5 knots (in relatively calm sea state 3), isn't it pretty hard to detect subs with passive hull mounted?? Since it *was* hull mounted - does this actually suggest that the general SVP was negative? - Because if it were positive ABOVE the layer - wound't most of the sound get trapped in the surface duct???
[image]local://upfiles/52028/A656FA0387BB43C99D2F60A9CC188329.jpg[/image]
|
|
|
|
