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Areal seabed classification using backscatter angular response at 95kHz
(NATO. SACLANTCEN, 1997)
A sediment classification scheme is developed based on the angular response (AR) of the seabed backscatter strength. The AR is characterised based on its mean level and slope over predefined angular sectors, and the presence ...
Seabed characterization by inversion of parametric sonar data: selection of the cost function
(NATO. SACLANTCEN, 1997)
A class of possible cost functions to be used in model-based estimation of bottom parameters from highfrequency backscatter signals is introduced. The cost is based on the properttes of the signal in the wavelettransformed ...
High-resolution characterization of seafloor sediments for modeling acoustic backscatter
(NATO. SACLANTCEN, 1997)
Quantitative information on fine-scale sediment inhomogeneity is extremely scarce and sorely needed for developing realistic volume scattering models. To address this deficiency, we present a novel approach for sediment ...
Bottom bistatic scattering: experimental results and model comparison for a carbonate sediment
(NATO. SACLANTCEN, 1997)
Bistatic scattering measurements were carried out under the Coastal Benthic Boundary Layer (CBBL) program. The results presented here are for a carbonate sand-silt-clay, and the data were collected in Februar) 1995 near ...
Temporal fluctuation of backscattered field due to bioturbatioon in marine sediments
(NATO. SACLANTCEN, 1997)
Biological activity in marine sediments creates a time-varying, randomly fluctuating medium. A bio-diffusive model is proposed for predicting the temporal and spatial spectrum of sediment density fluctuations. Perturbation ...
Vertical porosity and velocity fluctuations in shallow-water surficial sediments and their use in modeling volume scattering
(NATO. SACLANTCEN, 1997)
Variability in sediment porosity and velocity creates volume scattering which is a parameter used in high-frequency scattering models. High-resolution vertical profiles of sediment porosity and compresstonal wave velocity ...
Time-frequency representation of model based high frequency broad band scattering from a rough interface
(NATO. SACLANTCEN, 1997)
A formulism for scattering a broad band high frequency pulse from a randomly rough surface of n penetrable oceanic sediment is developed and used to investiyate the ability of local cosine transform (LCT) rime-frequency ...
Acoustical characteristics of the sea floor: experimental techniques and some examples from the Mediterranean Sea
(NATO. SACLANTCEN, 1974/11)
The acoustical properties of the sea floor are primarily determined by the physical properties of the sediments, layering in the sediments, and the roughness of the bottom and sub-bottom. Over the last decade many cores ...
An experimental investigation of the contribution of sediment volume scattering to acoustic backscatter measured in the shallow waters of the Florida Strait
(NATO. SACLANTCEN, 1997)
Experiments were conducted in the Florida Strait region of the United States in July 1995 for the purpose of investigating the contribution of sediment volume scattering to measured backscatter levels at frequencies between ...
Small scale volumetric inhomogeneities of shallow water sediments: measurements and discussion
(NATO. SACLANTCEN, 1997)
There is a consensus that high-frequency acoustic scattering by the ocean bottom is partly due to sediment volumetric inhomogeneities, r e., random fluctuations in sediment sound speed and density. Understanding the spatial ...