This report describes reverberation measurements made during the NATO MILOC Rapid Environmental Assessment exercise Rapid Response 97 August-September 1997. SUS charges were used as sources and data were received on two arrays towed by RJV Alliance: the 256-hydrophone Prakla array and the 32-hydrophone mid-frequency array. The arrays were towed on five-leg tracks at three locations: a deep water site in the lonian Sea and two sites in Kyparissiakos Gulf a ...
An algorithm for the calculation of acoustic normal modes in the ocean is described. The algorithm is valid for an arbitrary sound speed and density profile in the water column and bottom. Losses due to volume absorption in the water and bottom, surface and bottom roughness. and shear waves in the bottommost layer can be calculated as perturbations. The essential feature of the algorithm is a two-ended shooting method in ...
To a good first approximation acoustic propagation in an underwater sound channel is dominated by a finite number of trapped modes. However, exact solutions are known for only a few special cases making it necessary in general to use numerical methods to solve the normal mode equation. But often one is interested only in the gross features, such as the number of modes or cutoff frequencies, and one does not ...
The interactive computer program, NORM2L, calculates the discrete normal modes and acoustic propagation loss for the Pekeris model of the ocean. The Pekeris model is a simple two-layer model in which the two layers represent the seawater and seabed. For many shallow-water environments, the model is a reasonable approximation to the actual physical situation and can be used to investigate acoustic propagation at low frequencies. For ease of future expansion ...
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