### 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
**

**
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*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.