ASA 126th Meeting Denver 1993 October 4-8

5aUW15. The calculation of time domain signals in a waveguide with applications.

M. F. Werby E. White

NRL, Theoretical Acoustics, Code 7181, Stennis Space Center, MS 39529

A fast normal mode code has been developed that is based on an expansion method and a fast Fourier transform integral method. This has enabled one to perform broadband pulse calculations to high frequencies quickly. Further the pulse returns can be decomposed into their constituent modes. Studies on pulse returns were performed for realistic shallow water waveguides for signals out to 25 km and the various dispersion effects and separate model arrivals with increasing distance from the source were illustrated. Particular emphasis is placed on strong channeling. [Work supported by Naval Research Laboratory 6.1 program (element 601153N) with technical management provided by NRL-SSC.]