High-Frequency Scattering from Water Saturated Sandy Sediments: Laboratory Study

Reported measurements of seabed scattering are largely confined to relatively low frequencies, up to 300 kHz, see, e.g., [Jackson and Richardson] and references therein. Still higher frequencies, up to a few megahertz, are used in seafloor imagery (e.g., in pencil-beam sonars), particularly to observe dynamic processes at the seafloor in shallow water. From the physics of sound-sediment interaction standpoint, however, interesting effects can be anticipated at these high frequencies, as the wavelength can become comparable with the sediment typical grain sizes. Unfortunately, existing observations in this case are usually non-calibrated and therefore do not allow measurements of system independent scattering characteristics of the seabed such as the bottom scattering strength.