Which description matches a towed array sonar?

Which description matches a towed array sonar?

• A. A short, hull-mounted active sonar.
• B. An onboard sonar package used for local, short-range detection.
• C. A lightweight, portable sonar device used by divers.
• D. A long, deployed passive sonar system that reduces self-noise and extends detection range.

Answer: (D)

A towed array is defined by being a long set of hydrophones that is physically towed behind a ship. Because it sits well away from the hull, it experiences much less vibration, wake noise, and other self-noise from the vessel, which lets it hear quieter sounds in the water. Its length also gives it better sensitivity and direction finding, especially at the low frequencies used to detect silent submarines, creating a much greater effective detection range. Importantly, it operates passively—listening rather than emitting sound—so it doesn’t reveal the ship’s position and avoids giving away the location of the hunter. This combination—long, deployed behind the vessel, and passive listening—is what defines a towed array sonar. The other descriptions describe hull-mounted, short-range, or diver-portable sonars, which do not capture the distinctive long, towed, passive characteristics.

A towed array is defined by being a long set of hydrophones that is physically towed behind a ship. Because it sits well away from the hull, it experiences much less vibration, wake noise, and other self-noise from the vessel, which lets it hear quieter sounds in the water. Its length also gives it better sensitivity and direction finding, especially at the low frequencies used to detect silent submarines, creating a much greater effective detection range. Importantly, it operates passively—listening rather than emitting sound—so it doesn’t reveal the ship’s position and avoids giving away the location of the hunter. This combination—long, deployed behind the vessel, and passive listening—is what defines a towed array sonar. The other descriptions describe hull-mounted, short-range, or diver-portable sonars, which do not capture the distinctive long, towed, passive characteristics.