What are major sonar arrays?

• A. Linear, Circular, Geometric, Omni
• B. Passive, Active, Hybrid, Mixed
• C. Spherical, Hull, Towed, High-frequency
• D. Deep, Shallow, Medium, Ultra

Answer: (C)

Major sonar arrays refer to the main ways sensors are arranged and deployed to detect and locate underwater objects. A spherical array uses hydrophones arranged all around a sphere, providing true 360-degree coverage in three dimensions and enabling accurate direction finding in azimuth and elevation. A hull-mounted array is integrated into the vessel’s hull, offering a compact, robust sensor fixed to the platform for general-purpose detection. A towed array is carried behind the ship on a long line, which reduces self-noise and lets the system work at very low frequencies for long-range detection in deep water. High-frequency arrays operate at higher frequencies to achieve finer resolution for close-range tasks like detailed imaging or mine detection. While other terms describe operation modes or general concepts (such as whether a sonar is passive or active, or the depth range it targets), these four categories specifically capture the major deployment and geometry approaches used for sonar arrays.