Analysis of 3-D Propagation Effects Due to Environmental Variability

The goals of this work were multi-faceted, consistent with the various efforts supported by this work. Particular focus was placed on predictions and analysis of the three-dimensional (3-D) propagation in the presence of 3-D environmental variations, especially shelf break canyons. Work was also performed in support of 2-D propagation in shallow water to study the impact of bottom roughness and water column variability on arrival structure coherence. Additional modeling efforts were undertaken to examine the accuracy of the treatment of the bottom density discontinuity. By continuing to expand and improve the capabilities of the numerical modeling methods, the long-term goal of this effort is to provide a useful tool for understanding the physical phenomena leading to variability in shallow water acoustic propagation.