The effect of turbulence and acoustic waves on underwater acoustic propagation

The primary objective of this study was to develop a predictive methodology for received signal variation as a function of ocean perturbations using a ray‐based analysis of the effects of internal waves and ocean turbulence on underwater acoustic propagation. In the present formulation the eikonal equations are considered in the form of a second‐order, nonlinear ordinary differential equation with harmonic excitation due to an internal wave. The harmonic excitation is taken imperfect, i.e., with a random phase modulation due to Gaussian white noise, accounting for both chaotic and stochastic behavior. Small scale and geostrophic turbulence are represented using the potential theory two‐wave‐number model for a vortex array. The focus is to numerically study the influence of these fluid velocity and sound speed fluctuations and the role of initial ray angle on underwater acoustic propagation to provide a realistic characterization of acoustic arrivals. Predicted arrival behavior is analyzed using ray trace,...