Browsing by Author "Fawcett, John A."
Now showing items 1-13 of 13
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A classification technique combining aspect dependence and elastic properties of target scattering
Zerr, Benoit; Tesei, Alessandra; Maguer, Alain; Fox, Warren L. J.; Fawcett, John A. (NATO. SACLANTCEN, 1999/04)Discrimination between man-made and natural underwater objects and between man-made objects of different characteristics are the key objectives of target classication. The current approach is mainly based on the analysis ... -
A plane-wave decomposition method for modeling scattering from objects and bathymetry in a waveguide
Fawcett, John A. (NATO. SACLANTCEN, 1996/11)In this paper a straightforward plane-wave decomposition method which can be used for solving object andlor interface scattering problems in a waveguide is described. The method utilizes the free-space scattering matrix ... -
Coupled-mode modelling of acoustic scattering from three-dimensional, axisymmetric objects
Fawcett, John A. (NATO. SACLANTCEN, 1997/01)In this memorandum a coupled-mode method for computing the wavefield scattered by three-dimensional, axisymmetric objects is presented. The method provides a unified approach to solving three-dimensional scattering problems ... -
Finite difference modelling of scattering by objects in the seabed
Fawcett, John A.; Grimbergen, Joris L. T. (NATO. SACLANTCEN, 1996/07)In this report we describe the theory and some implementation issues of a finite difference code used at SACLANT Centre. In particular, we consider the modelling of attenuation and the excitation of a remote incident field ... -
Modelling acousto-elastic waveguide/object scattering with the Rayleigh hypothesis
Fawcett, John A. (NATO. SACLANTCEN, 1998/06)In this memorandum the plane wave scattering matrices for a range-dependent seabed and upper free surface are computed using the -
Modelling of scattering by objects on the seabed
Fawcett, John A.; Fox, Warren L. J.; Maguer, Alain (NATO. SACLANTCEN, 1997/12)This paper describes some of the theory and implementation issues of modeling the backscattered -
Modelling of scattering by partially buried elastic cylinders
Fawcett, John A. (NATO. SACLANTCEN, 1998/02)The work of a previous memorandum on the modelling of scattering by a partially buried cylinder is extended to allow the cylinder to have full elasticity (and not just be a fluid structure as in the previous work). The ... -
Modelling scattering from partially buried cylinders = Acoustic scattering from cylindrical objects embedded between two half-spaces/The computation of the scattered pressure field from a cylinder embedded between two half-spaces = The computation of the scattered pressure field from a cylinder embedded between two half-spaces with different densities
Fawcett, John A. (NATO. SACLANTCEN, 1996/12)1. A boundary integral equation method is presented for the computation of the acoustic field scattered from a cylindrical object which is totally within the water column, totally buried in sediment, or partially buried. ... -
Numerical simulation of the effects of bathymetry on underwater sound propagation using three-dimensional parabolic models
Sturm, Frédéric B.; Fawcett, John A. (NATO. SACLANTCEN, 1998/03)Two different three-dimensional parabolic equation (PE) methods are -
Resonance analysis of the acoustic response of a water-filled cylindrical shell
Tesei, Alessandra; Fawcett, John A.; Fox, Warren L. J.; Maguer, Alain (NATO. SACLANTCEN, 1998/09)The resonance analysis approach developed for characterizing free-field air-filled cylindrical shells in terms of geometrical and mechanical pararneters is extended to fluid-filled shells either in the freefield or proud ... -
Scattering by spheres buried in sediment
Tamasauskas, Henriette T.; Fawcett, John A. (NATO. SACLANTCEN, 1997/01)In this report the scattering of acoustic energy by an elastic sphere buried in sediment is examined. The geoacoustic model consists of two homogeneous fluid halfspaces separated by an intermediate layer. The source field ... -
Scattering from an elastic cylinder buried beneath a rough water/sediment interface
Fawcett, John A. (NATO. SACLANTCEN, 1997)In this paper a plane-wave decomposition method is used to compute the two-dimensional backscattering from a buried elastic cylinder as a function of frequency. The cases of a pat water/sediment interface and deteministically ... -
Transmission-loss characteristics and geoacoustic model for an outer Albanian continental shelf platform in the south-east Adriatic sea
Max, Michael D.; Hollett, Reginald D.; Fawcett, John A.; Berkson, Jonathan M. (NATO. SACLANTCEN, 1996/03)Transmission-loss experiments have been canied out on the outer Albanian Shelf. The acoustic measurements were performed together with a combined oceanographic and geological-geophysical survey which identified the different ...