Scattering from inclusions in Marine Sediments: SAX04 Data/Model Comparisons
2008
Ivakin, Anatoliy N.
Submitted by author to IEEE Journal of Ocean Engineering, special issue on sediment acoustics/SAX04 data analysis. The original document contains color images.
显示更多 [+] 显示较少 [-]The role of discrete scatterers in marine sediments is evaluated based on acoustic and environmental measurements at the shallow water sediment acoustics experiment, SAX04, and shown to be significant. The sediment at SAX04 site was complicated and characterized as a mostly medium sand / mud mixture. Analysis of the sediment samples showed presence of a small volume portion of arger particles, such as coarse sand fraction and shell fragments, which were considered as inclusions, or sparsely distributed discrete scatterers, embedded in a homogeneous effective fluid with parameters corresponding to medium sand or mud sediment frame. This analysis provided also the size distributions for both types of inclusions, coarse sand particles and shells, which were used as inputs to a model of incoherent discrete scattering in the sediment. It is demonstrated that this approach in general is capable to provide a reasonable explanation of both frequency and angular dependencies of the SASX04 bottom backscattering strength, and discrete scattering from the sediment inclusions can be a significant mechanism of the SAX04 high frequency reverberation in a wide range of grazing angles (15 to 50 degrees) and frequencies (30 kHz to 500 kHz).
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