Study of Low Frequency Sound Propagation in Shallow Water Ducts

摘要

This paper presents results from a recent investigation of shallow waterpropagation loss for low frequencies (500-4000 Hz). Shallow water is defined in this context as a location where acoustic energy has numerous boundary interactions. This definition leads to both physically shallow and not-so-shallow sites. The objectives of this investigation are, first, to gain a quantitative understanding of propagation loss as a function of source/receiver placement and frequency for numerous shallow water environments, in this case, for 10 geographic areas across all four seasons; second, to gain quantitative information of surface duct versus downward refracting propagation by using a statistical approach, and third, to address questions concerning frequencies which are supported in ducting propagation, effects of duct transmission loss in shallow water, and the impact of source/receiver placement in shallow water.