Abstract:

For applications such as beamforming and matched field processing, the spatial behavior of the shallow water acoustic field is relevant. Oceanic and geoacoustic variabilities introduce random fluctuations into the field, which can be characterized by the spatial coherence. The spatial coherence of the acoustic field can be described by its correlation function. In this presentation results from an investigation of the sensitivity of the horizontal correlation function to variations in parameters of shallow water propagation will be discussed. In order to demonstrate key sensitivities, stratified environmental models with one or more sediment layers will be used. Variabilities are assumed to arise from small random fluctuations within the layers and at the layer interfaces. Formulas based on a modal perturbation approach are used. The dependence of the correlation function on such parameters as range and frequency is of particular interest, and in addition effects of mode coupling are estimated. Numerical simulations illustrating the results will be presented. [Work supported by NSF.]