Abstract:

The question of whether ray-based acoustic wave-field expansions break down under chaotic conditions at a range proportional to the logarithm of the acoustic frequency is investigated numerically. In the assumed idealized environment, the ray equations define an Anosov system; all ray trajectories are chaotic. To address the log breakdown question, full wave simulations are compared to simulations based on the semiclassical Maslov integral representation of the wave-field. Because the Maslov integral remains valid at caustics, one might expect that it remains valid at ranges beyond those at which uncorrected ray theory starts to fail. [Work supported by ONR.]