ASA 127th Meeting M.I.T. 1994 June 6-10

1aSA15. Wavepacket synthesis of far-field echoes from a ribbed cylindrical shell with hemispherical endcaps.

David H. Hughes

Charles F. Gaumond

Brian H. Houston

Naval Res. Lab., Washington DC 20375-5350

Recent investigations concerning acoustical signal decomposition of Wigner distributions [N. C. Yen, ``Wavepacket decomposition,'' accepted for publication in J. Acoust. Soc. Am.] have motivated further investigations of echoes from more complex submerged targets. The signal decomposition method of Boudreaux-Bartels [G. F. Boudreaux-Bartel and T. W. Parks, ``Wigner distribution synthesis techniques,'' IEEE Trans. Acoust. Speech Signal Process. ASSP-34, 442--451 (1986)] is applied to monostatic echoes from a finite, ribbed cylinder with hemispherical endcaps at frequencies below ka=42. The cylinder has a length of 1 m long, a radius of 7.0 cm, and an internal rib spacing of 1 cm. Distinct wavepackets associated with Bloch waves and Bragg waves on the target are synthesized over the suitable range of monostatic target angle.