ASA 124th Meeting New Orleans 1992 October

4aUW1. Detection of a submerged object insonified by surface noise in an ocean waveguide.

N. C. Makris

W. A. Kuperman

Naval Res. Lab., Washington, DC 20375

F. Ingenito

SACLANT Undersea Res. Ctr., La Spezia, Italy

Recent results indicate the possibility of imaging an object using ambient noise in the frequency region of 5 to 45 kHz [Buckingham et al., Nature 356, 327--329 (1992)]. For lower frequencies, numerical simulations have been performed to determine whether an object submerged in an ocean waveguide and insonified by surface noise can be detected. An object is placed in a surface-generated noise field of an ocean waveguide [Kuperman and Ingenito, J. Acoust. Soc. Am. 67, 1988--1996 (1980)]. The noise field is then scattered from the object using a modification of a previously developed theory for scattering from an object in a waveguide [Ingenito, J. Acoust. Soc. Am. 82, 2051--2059 (1987)]. An assortment of array processing algorithms are then used to detect the object.