Which term refers to the long-range underwater sound channel used for detection at great distances?

Which term refers to the long-range underwater sound channel used for detection at great distances?

• A. Sofar Layer
• B. SOFAR Channel
• C. Sound Channel
• D. Sofar

Answer: (D)

The long-range underwater sound channel is the SOFAR channel. In the ocean, sound speed varies with temperature, salinity, and depth. There’s a depth where the speed of sound is at a minimum. Sound waves entering this layer bend toward slower speeds and become trapped within it, effectively guiding them along a vertical duct. This creates a natural waveguide that lets acoustic signals travel great distances with relatively little loss, which is why the SOFAR channel is used for detection over vast ranges. The full term is the SOFAR channel (Sound Fixing and Ranging); using Sofar alone isn’t the standard name, though you may see it informally.

The long-range underwater sound channel is the SOFAR channel. In the ocean, sound speed varies with temperature, salinity, and depth. There’s a depth where the speed of sound is at a minimum. Sound waves entering this layer bend toward slower speeds and become trapped within it, effectively guiding them along a vertical duct. This creates a natural waveguide that lets acoustic signals travel great distances with relatively little loss, which is why the SOFAR channel is used for detection over vast ranges. The full term is the SOFAR channel (Sound Fixing and Ranging); using Sofar alone isn’t the standard name, though you may see it informally.