Remote sea bottom classification utilizing the Ulvertech bottom profiler parametric source

Computer algorithms were developed to extract certain marine sediment properties utilizing the Ulvertech bottom profiler system. A series of normal-incidence bottom reflectivity measurements was made over six test tracks. The test tracks were precise paths that varied in length from 0.1 to 0.5 m over sediments that ranged in composition from hard sand to stiff clay to soft mud. Each track was well-characterized by several core samples. The Ulvertech system uses a parametric source that has its primaries at about 200 kHz, with the difference frequency selectable, either 5, 10, 15, or 20 kHz. The algorithms developed make use of the acoustic information contained in the returns from both the primary and different frequency to extract estimates of the density, grain size, and shear strength of the top 1-2 m of sediment. Some sample data as well as a description of the algorithms are presented.<>