Brian G. Ferguson
Gary C. Speechley
Defence Sci. and Technol. Organisation, P.O. Box 44, Pyrmont, Australia 2009
David V. Wyllie
Defence Sci. and Technol. Organisation, APW2-316, Canberra, Australia 9600
The self-noise in towed arrays can be divided into two components on the basis of its spatial correlation properties. In this paper, optimal estimates of the uncorrelated and correlated self-noise components are obtained using an adaptive frequency-wave-number analysis technique. The results of applying the technique to real data from various towed-array types are presented. The spatially uncorrelated contribution to the total self-noise is often ignored in the presence of the correlated structure-borne vibrations that travel in both axial directions along the array with a phase speed that is less than the speed-of-sound propagation in the underwater medium. The increasing importance of the uncorrelated component at higher tow speeds is discussed and, under some circumstances, the uncorrelated component is shown to dominate.