1. Introduction
Variability of ocean physical parameters can cause significant fluctuations in broadband acoustic signals propagating in shallow water. Arrival time, arrival angle, and energy of a particular acoustic wave front depend on sound speed and current variability of the ocean through which the ray passes as well as on roughness of the ocean boundaries off which the ray reflects or scatters. To study ocean variability effects on high frequency acoustic wave propagation, a highly calibrated experiment (KauaiEx) was conducted during the summer 2003 at a shallow water location near the Kauai Island, Hawaii [1]. The main goal of this experiment was to study the environmental effects on intensity and arrival-time variations of acoustic signals in frequency range 8–50 kHz. Applications of this study relate to underwater acoustic communication in which the knowledge of the channel impulse response function is needed to help improve system performance. Parameters such as the temporal and spatial variability of the propagation path need to be understood from observation before predictive modeling could be attempted.