Investigation of horizontal refraction on Florida Straits continental shelf using a three-dimensional Gaussian ray bundling model

Abstract

Acoustic transmission loss measurements from the calibration operations (CALOPS) experiment for the Shallow Water Array Performance (SWAP) program included horizontally refracted returns that were as much as 30° away from the true bearing between source and receiver. In many cases, the in-shore refracted path was 20 dB stronger than the true bearing path. In this study CALOPS transmission loss measurements at 415 Hz are compared to predictions from a three-dimensional Gaussian ray bundling model. The geoacoustic model that provides good model-data comparison is consistent with the geologic and sediment core data collected at the location but differs slightly from the bottom model used at lower frequencies (206 and 52.5 Hz) in a previous study.

Underwater Sound Propagation Modeling in a Complex Shallow Water Environment

“…Moreover, ray models have the advantage that they can trace rays backward if the bathymetry leads to such paths, and that may sometimes make a difference with respect to other models. Recent applications of 3D ray and beam tracing models in ocean acoustics include the study of high-frequency horizontal refraction on the continental shelf of the Florida Straits (Reilly et al, 2016), effects of complex oceanographic and bathymetric variations on sound propagation in the East China Sea (Porter, 2019), and long reverberation tails in the Norwegian coast (Jenserud and Ivansson, 2015).…”

“…Three-dimensional (3D) effects can profoundly influence underwater sound propagation and hence soundscape at different scales in the ocean (e.g., Duda et al, 2011;Ballard et al, 2015;Heaney and Campbell, 2016;Reilly et al, 2016;Oliveira and Lin, 2019;Reeder and Lin, 2019). In the particular case of coastal seas, a range of physical oceanographic and geological features can cause horizontal reflection, refraction, and diffraction of sound.…”