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

4aUW13. Remote identification of moving acoustic objects.

Roger F. Dwyer

Naval Undersea Warfare Ctr., New London, CT 06320

Often in applications it is desired to remotely identify an object from its acoustic signature. In active sonar the object is insonified by a transmitted waveform and the received pressure is processed to localize and identify the object. Here, the received pressure time series from spherical acoustic objects in motion that have been insonified by linear frequency modulated (LFM) waveforms are used to identify the objects. The unknown object's unknown constant velocity using a unique property of the fourth-order cumulant spectrum [J. Acoust. Soc. Am. 93, 1460--1465 (1993)] is extracted and then its transfer function is extracted. The results for five spherical acoustic objects in motion are discussed. Three methods, deconvolution, matched filtering, and fourth-order cumulant spectrum deconvolution to extract the object's transfer function are compared.