Estimating sediment interval velocity using a monostatic sonar from a seabed with tilted layers

Abstract

Recently, it has been shown that sediment layer interval velocity can be obtained from a multibeam monostatic sonar. In that work, plane-parallel sediment layering was assumed. Since tilted sediment layers are common in the marine environment, the method is expanded to treat them explicitly. The in- and out-of-plane tilted layers affect the travel times in each layer, which complicates interval velocity estimation. This effect is mitigated by applying a dip moveout correction for each sediment layer. Testing is performed using simulated scattering data from rough, tilted, layered seabeds for dip angles up to a few degrees. The interval velocity estimation method is also applied to at-sea data (acquired by the 2–9 kHz SBP29 multibeam sub-bottom profiler) in areas with tilted layers. [Research supported by ONR Coastal Geosciences]