Applied Underwater Acoustics

10.3. Single-Beam Echo Sounders

Early depth measurements were performed by using a line and a lead weight. However, since about 1920 depth sounding has been performed by using acoustic waves, where a signal from a projector is reflected from the seafloor and received by a hydrophone system, which is frequently the same system as the projector. When the sound velocity in the water is known the acoustic signal's time of flight from the projector to the seafloor and back measures the distance. The standard display known as an echogram shows depth on the vertical axis and distance traveled over the seafloor on the horizontal axis. SBESs are available from several manufacturers at various price levels and with a broad variety of capabilities for use ...