ASA 129th Meeting - Washington, DC - 1995 May 30 .. Jun 06

1aAO11. Frequency interpolation method for increasing speed of long-range broadband parabolic equation (PE) calculation.

K. D. Heaney

W. A. Kuperman

Marine Phys. Lab., Scripps Inst. of Oceanog., La Jolla, CA 92093-0238

An interpolation method that increases the speed of broadband range-dependent calculations by an order of magnitude using the parabolic equation has been developed. By decomposing the vertical field into complex modal amplitudes, interpolation across frequency is possible. The method was designed to be used in Monte-Carlo studies of the effects of internal waves. Signal processing algorithms are being developed to extract the deterministic signal from the internal wave noise. The method has been benchmarked against the fully broadband PE for several ocean environments. The results are in good agreement with the PE for 1000-km propagation through internal waves and for 3000-km mildly varying ocean environments. The reproduction of the internal wave effects in the SLICE89 experiment reported by Colosi [Colosi et al., 452--68 (1994)] has also been possible. Frequency interpolation predictions of the ATOC Acoustic Engineering Test will be presented and compared with preliminary results from the experiment. In particular, simulation of the statistics of the internal wave effects as measured in the Acoustic Engineering Test is of main concern.