Observed correlations between the sediment grain size and the high-frequency backscattering strength

In March 2019, Teledyne RESON and the Applied Physics Laboratory at the University of Washington conducted surveys with a calibrated multibeam echosounder at ten sites in Sequim Bay, a shallow sheltered bay in Washington State, USA. For each site, the mean grain size was obtained from a diver core sample, and estimates of the backscattering strength at frequencies ranging between 200 and 350 kHz were calculated. The correlation between the backscattering strength and the normalized grain size have been investigated for the grazing angles 45° and 75°. For 45°, a correlation consistent with previous results has been found. It demonstrates the potential for simple seabed classification.