title: Flow noise of an underwater vector sensor embedded in a flexible towed array.
abstract: The objective of this work is to simulate the flow noise of a vector sensor embedded in a flexible towed array. The mathematical model developed, based on long-wavelength analysis of the inner space of a cylindrical multipole source, predicts the reduction of the flow noise of a vector sensor embedded in an underwater flexible towed array by means of intensimetric processing (cross-spectral density calculation of oscillatory velocity and sound-pressure-sensor responses). It is found experimentally that intensimetric processing results in flow noise reduction by 12-25 dB at mean levels and by 10-30 dB in fluctuations compared to a squared oscillatory velocity channel. The effect of flow noise suppression in the intensimetry channel relative to a squared sound pressure channel is observed, but only for frequencies above the threshold. These suppression values are 10-15 dB at mean noise levels and 3-6 dB in fluctuations. At towing velocities of 1.5-3 ms(-1) and an accumulation time of 98.3 s, the threshold frequency in fluctuations is between 30 and 45 Hz.
authors.affiliation: VI Il'ichev Pacific Oceanological Institute, Far Eastern Branch, Russian Academy of Sciences, 43, Baltiyskaya Str, Vladivostok 690041, Russia. v-kor@poi.dvo.ru
authors.forename: Vladimir I
authors.initials: VI
authors.lastname: Korenbaum
authors.forename: Alexander A
authors.initials: AA
authors.lastname: Tagiltsev