3aUW10. A numerical investigation of semiclassical predictability in the presence of chaotic ray motion.

Session: Wednesday Morning, June 18

Author: Michael G. Brown
Location: RSMAS-AMP, Univ. of Miami, 4600 Rickenbacker Cswy., Miami, FL 33149
Author: Michael A. Wolfson
Location: Penn State Univ., University Park, PA 16802
Author: Frederick D. Tappert
Location: Univ. of Miami, Miami, FL 33149


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.]

ASA 133rd meeting - Penn State, June 1997