Quote:
Originally Posted by jerseytom
If you're underwater in 3d space - target depth and bearing/distance I would think are fundamentally no different to measure - particularly with a spherical sensor array.
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On US submarines, ALL bearings are 3D.
Quote:
Originally Posted by PL_Harpoon
I think it all depends whether your sonar can get a 3d bearing or not.
If yes, then you don't even need to calculate it separately. Just do a simple trigonometry once you know your target's position.
If no, then things get a little bit more complicated.
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Incorrect. You forget that sound in water does not travel in a straight line from the source. It bends based on the Sound Velocity Profile (SVP - Temp vs. Depth). It always follows the path of least resistance. This is how Convergence Zones (CZ) are created, for example.
Quote:
Originally Posted by MBot
Considering how sound propagates in water and that sound waves that are received from the lower hemisphere might still originate from a source above you, shouldn't it be extremely hard to determine target depth?
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Your terminology is incorrect. Not hemisphere, but depth. See above.
Quote:
Originally Posted by Destex
The most sonar can do is provide an estimation whether the target is above or below the layer. Analyzing accurate depth is not possible.
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In all actuality, the only way to determine if the noise source is above or below the layer (if there is one) is to see if the noise source has a higher Signal to Noise Ratio (SNR) when you are above the layer then below it. Own ship has to do a depth excursion.... You cannot determine the actual depth. Its really only 'is the contact above or below the layer'. If there is no layer, then you cannot determine what target depth is.