Optimum frequency of propagation in shallow water environments

Abstract

The optimum frequency of propagation in shallow-water environments is the result of competing propagation and attenuation mechanisms at high and low frequencies. It is shown that the optimum frequency is strongly dependent on water depth, that it has some dependence on the sound-speed profile, while it is only weakly dependent on the bottom type. A comparison between experimental data and normal-mode theory indicates the importance of shear waves in the bottom, both in determining the optimum frequency of propagation and in determining the actual propagation-loss levels at lower frequencies.