Applications of MultiBeam Echo Sounders Backscatter signal in the marine environment: Some Examples

MultiBeam Echo Sounder (MBES) systems are capable of collecting bathymetry and seafloor backscatter data simultaneously. The backscatter is based on the acoustic signal detected by the Multibeam's receivers, and it works as the receivers of standard sidescan sonar by recording the acoustic response of the seabed, in relation to the morphology, composition and fine scale roughness of the beds. This allows cost-effective mapping of the seafloor including discrimination and classification of different seafloor types. While various methods for processing MBS bathymetry data are well established and implemented in the software provided by the sonar manufacturers, there is no universal, standard approach to processing and interpreting MBES backscatter data (Parnum and Gavrilov, 2011). Aim of this paper is to show some examples of processing and applications of the backscatter data, both for the bottom that for the water column, with the results derived from it. The study areas are two: oThe continental shelf of the Basilicata Tyrrhenian coast, where it was used the backscatter recorded with Reson Seabat 8125 to characterize the seafloor according to the acoustic facies; othe continental shelf Strait of Sicily, where it was employed the backscatter signal of the whole water column recorded with both Simrad EM3002D and Reson Seabat 8125H in order to develop a system to study fish schools characteristics.