### ASA 128th Meeting - Austin, Texas - 1994 Nov 28 .. Dec 02

## 5aSA10. Wave packet synthesis via the wavelet transform.

**David M. Drumheller
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David H. Hughes
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Brian O'Connor
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Charles F. Gaumond
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*Acoust. Div. Naval Res. Lab., Washington, DC 20375-5350
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A wavelet transform is used to synthesize distinct contributions from the
monostatic form function for a randomly ribbed, complex end-capped, finite
cylindrical shell. In order to achieve satisfactory wave packets, as measured
by their cross-correlation with the original impulse response, two wavelet
transforms are used, a temporal wavelet transform and a spectral wavelet
transform. This is in contrast to synthesizing wave packets from the Wigner
distribution where just one two-dimensional surface was necessary. However,
interference terms between components in the Wigner distribution, which is
quadratic in the underlying signal, are absent in the linear wavelet transform.
This allows for a more facile synthesis of the acoustic excitations. The
interference terms in the Wigner distribution can sometimes fall at points in
the time-frequency plane where a signal component exists, making it difficult
to synthesize that component without corruption caused by the presence of other
compounds in the form function.