Accession Number:

ADA237458

Title:

Hamiltonian 3-D Ray Tracing in the Oceanic Waveguide on the Ellipsoidal Earth

Descriptive Note:

Technical rept.,

Corporate Author:

WASHINGTON UNIV SEATTLE APPLIED PHYSICS LAB

Personal Author(s):

Report Date:

1990-12-01

Pagination or Media Count:

79.0

Abstract:

Ray equations based on an acoustic Hamiltonian, and formulated by Jones et al. 1986 for spherical coordinates in NOAAs three dimensional ray tracer HARPO, are adapted to ellipsoidal coordinates in the oceanic waveguide. The ensuing modified HARPO is used to model very long range up to antipodal acoustic paths in which the difference between geodesics and great circles is measurable. The eventual objective of this modeling is to extract the predictable part of the travel time trend and fluctuations along several long paths that will be used to monitor hypothetical global warming effects. The requirements for easy assimilation and representation of realistic environmental inputs are discussed. These requirements, when coupled with the possibility of classical chaos in the ray paths, dictate a new software architecture. We use the existing software, however, to breadboard and test features of new ray tracers in the global boundary layer, and to support the experimental design of a forthcoming pilot experiment that will use a transmitter located at Heard Island in the Indian Ocean near Antarctica.

Subject Categories:

  • Physical and Dynamic Oceanography
  • Seismic Detection and Detectors

Distribution Statement:

APPROVED FOR PUBLIC RELEASE