Seabed images create waves

Long waves over a bi-viscous seabed: transverse patterns

The coupled interaction of long standing hydrodynamic waves with a deformable non-Newtonian seabed is examined using a two-layer model for which the upper layer fluid is inviscid and the lower layer is bi-viscous. The two-dimensional response of the system to forcing by a predominantly longitudinal (cross-shore) standing wave perturbed by a small transverse (along-shore) component is determined...

Simple Programs Create 3D Images

Attenuation of long interfacial waves over a randomly rough seabed

The effects of randomly irregular bathymetry on the propagation of interfacial gravity waves are studied. Modelling sea water by a two-layer fluid of different densities, weakly nonlinear waves much longer than the sea depth but comparable to the horizontal scale of bathymetry are treated by Boussinesq approximation and multiplescale analysis. For transient wave pulses, the governing equation f...

A New Method for Acquisition of High-Resolution Seabed Topography by Matching Seabed Classification Images

The multibeam echo sounders (MBES) can acquire accurate positional but low-resolution seabed terrain and images, whereas side scan sonars (SSS) can only acquire inaccurate positional but high-resolution seabed images. In this study, a new method for superimposing corrected-positional SSS images on multibeam bathymetric terrain is proposed to obtain high-resolution and accurate-positional seabed...

Statistical Seabed Segmentation – from Images and Echoes to Objective Clustering

Acoustic segmentation is the provincing of a survey region based on acoustic characteristics. Geotechnical classification requires further non-acoustic information, in general. QTC systems are capable of segmentation starting with either uncalibrated echoes from a singlebeam sounder, or images from a multibeam system or a sidescan sonar. Unsupervised segmentation requires clustering, in which r...