Abstract:

The SCARAB (scattering reverberation and backscatter) model takes a non-plane-wave, physics-based approach to the three-dimensional problem of ocean reverberation and seabottom scatter. Using a ray propagation model, coupled with a geoacoustic description of the sediment and physics-based interface and volume sediment scattering kernels, an ocean environment's reverberative, and scattering capability is found for given source and receiver operating characteristics. Advantages of this approach over conventional direct path methods are that received levels are modeled as if they were experimentally measured functions of time. Therefore, subsequent processing for scattering level can follow the same procedures as are used for experimental data. This has proven to be of great importance when modeling low grazing angle bottom scatter contaminated with fathometer and hybrid path contributions. A description of the model is given and model-to-data comparisons are shown for data taken during the Critical Sea Test (CST) experiments. [Work supported by ONR.]