Mapping the Oceans

            Sonar plays the major role in surveying the ocean floor taking measurements on the depth and form of features on the seabed. Sonar is based on the principal of the echo. Sound waves are bounced to the ocean bottom and back, with distance determined by the time this process takes.
             In multi beam sonar,the sound source and receiver are built into the hull of the ship, and the sonar system scans a wide area as the ship moves along. In side scan sonar, the sound originates in a towed source.