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Old 06-29-20, 04:32 PM   #11
Pisces
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Join Date: Dec 2004
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Quote:
Originally Posted by Polak2 View Post
So it looks like a lesson for the newb (like me) to be learned that the shadow zone is really a "shadow" from the HULL or UNDERKEEL sonar but not really Towed Array which can be after all lowered below thermal layer anytime (say by other surface unit in the back or search Helo) as long as that thermal layer depth is within dipping sonar or TA (of other surface unit) effective reach parameters.

I think the other thing hard to visualize for the newcomers us the 3D aspect of those acoustical anomalies. Tutorial is showing only 2D slither of the vast 3D "shadow" volume around the surface unit. Only after reading above posts I can perhaps slowly visualise that 3D ring feature which should be around the entire vessel.

Quite fascinating that all of this is modeled into DW simulation.
The shadow zone has nothing to do with baffles or obstruction by the hull. It is the effect of curved and reflected soundwave paths around the layer (look at that sharp peak in the soundspeed curve) The shadow zone is where the sound does not reach. Like light-shadows, it is accoustically 'dark'.
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