The Multibeam Echo Sounder (MBES) is a system that allows to perform surveys of the sea bottom, obtaining a high quality and precision digital model of the bathimetry. The MBES system can be described as a sonar that emits acoustic waves perpendicular to the direction of movement of the boat, in a simultaneous range of impulses that propagate as sound waves with a maximum coverage angle of about 150º and with a frequency between 100 and 455 kHz. The instrument emits acoustic waves through a large number of rays (from 120 to 240) or beams, acquiring for each energization a large number of data transversal to the route followed by the ship. A transducer composed of a series of receivers, detect the return times of the sound emitted by the transmitter after the reflection from the bottom; the travel times are converted into distances, knowing the speed of sound propagation in water, thus allowing the assignment of the correct spatial coordinates at each point on the sea bottom hit by the beam.
