Small-slope simulation of acoustic backscatter from a physical model of an elastic ocean bottom
Abstract
An underwater acoustic experiment with a two-dimensional rough interface, milled from a slab of PVC, was performed at a tank facility. The purpose was to verify the predictions of numerical models of acoustic rough surface scattering, using a manufactured physical model of an ocean bottom that featured shear effects, nonhomogeneous roughness statistics, and root-mean-square roughness amplitude on the order of the acoustic wavelength. Predictions of the received time series and interface scattering strength in the 100–300kHz band were obtained from the Bottom Reverberation from Inhomogeneities and Surfaces–Small-Slope Approximation (BORIS-SSA) numerical scattering model. The predictions were made using direct measurements of scattering model inputs—specifically, the geoacoustic properties from laboratory analysis of material samples and the grid of surface heights from a touch-trigger probe. BORIS-SSA predictions for the amplitude of the received time series were shown to be accurate with a root-mean-square residual error of about 1dB, while errors for the scattering strength prediction were higher (2–3.5dB). The work is part of an ongoing effort to use physical models to examine a variety of acoustic scattering and propagation phenomena involving the ocean bottom.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Nov 01, 2007
- Source ID
- 10.1121/1.2783116
Entities
People
- Gaetano Canepa
- Harry J. Simpson
- Jason E. Summers
- Raymond J. Soukup
- Robert F. Gragg
Organizations
- Centre for Maritime Research and Experimentation
- United States Naval Research Laboratory