The reflected sound wave received after striking the seabed or an object. The echo’s time delay determines distance, while its strength reveals the reflecting surface’s hardness or texture.

Category
Data & Measurement

The Most Important Sonar Terms Explained


Acoustic Image

A visual rendering created by plotting sonar echoes by their intensity and time delay. Acoustic images resemble photographs but are generated by sound, revealing underwater scenes even in zero visibility.

Acoustic Shadow

A dark or signal-void region behind an object that blocks the sonar beam. The length and shape of acoustic shadows help infer object dimensions and orientation, enhancing target interpretation.

AUV (Autonomous Underwater Vehicle)

A self-navigating underwater robot that executes pre-programmed missions to collect sonar, imaging, or environmental data. It is used in deep-sea mapping, military reconnaissance, and oceanographic research where endurance and autonomy are required.