SIMULATION OF BACKSCATTERING OF HIGH-FREQUENCY SOUND FROM COMPLEX OBJECTS AND SAND SEA-BOTTOM

This paper describes the simulation of backscattering of high frequenc y sound from complex objects and sand sea-bottom. Backscattering data from complex objects and sea-bottom were generated using a Universal H igh Resolution Imaging Sonar Simulation Toolkit (UHRISST) developed by the authors, Our approach here involves the approximation of objects and the sea-bottom through a series of facets that are small compared to the wavelength. The Target Strength of standard objects like the sp here, cylinder, and cone predicted by our model have been compared wit h various high frequency approximation formulations and produced a goo d fit. For the prediction of the backscattering strength from the sea- bottom, we have taken into account most of the small-scale features th at represent the sand grain properties, intermediate features that rep resent sea-bottom roughness and large features that block propagation. Sea-bottom backscattering predictions made using this model were comp ared with high frequency scattering strength values measured off Panam a City, FL, USA, and produced a moderate fit, Nonparametric statistica l analysis was carried out on the bottom backscattering signals from a hat isotropic sea-bottom. The probability distribution function and p robability of false alarm function of the bottom backscattering data w as measured and found to largely follow the normal distribution.