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Full-Text Articles in Mechanical Engineering
Passive Bottom Reflection-Loss Estimation Using Ship Noise And A Vertical Line Array, Lanfranco Muzi, Martin Siderius, Christopher M. Verlinden
Passive Bottom Reflection-Loss Estimation Using Ship Noise And A Vertical Line Array, Lanfranco Muzi, Martin Siderius, Christopher M. Verlinden
Electrical and Computer Engineering Faculty Publications and Presentations
An existing technique for passive bottom-loss estimation from natural marine surface noise (generated by waves and wind) is adapted to use noise generated by ships. The original approach—based on beamforming of the noise field recorded by a vertical line array of hydrophones—is retained; however, additional processing is needed in order for the field generated by a passing ship to show features that are similar to those of the natural surface-noise field. A necessary requisite is that the ship position, relative to the array, varies over as wide a range of steering angles as possible, ideally passing directly over the array …
Frequency Based Noise Coherence-Function Extension And Application To Passive Bottom-Loss Estimation, Lanfranco Muzi, Martin Siderius, Peter L. Nielsen
Frequency Based Noise Coherence-Function Extension And Application To Passive Bottom-Loss Estimation, Lanfranco Muzi, Martin Siderius, Peter L. Nielsen
Electrical and Computer Engineering Faculty Publications and Presentations
Accurate modeling of acoustic propagation in the ocean waveguide is important to SONAR-performance prediction. Particularly in shallow waters, a crucial contribution to the total transmission loss is the bottom refection loss, which can be estimated passively by beamforming the natural surface-noise acoustic field recorded by a vertical line array of hydrophones. However, the performance in this task of arrays below 2 m of length is problematic for frequencies below 10 kHz" role="presentation" style="display: inline; line-height: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px 2px 0px …
Automated Extraction And Classification Of Time-Frequency Contours In Humpback Vocalizations, Hui Ou, Whitlow W.L. Au, Lisa M. Zurk, Marc O. Lammers
Automated Extraction And Classification Of Time-Frequency Contours In Humpback Vocalizations, Hui Ou, Whitlow W.L. Au, Lisa M. Zurk, Marc O. Lammers
Electrical and Computer Engineering Faculty Publications and Presentations
A time-frequency contour extraction and classification algorithm was created to analyze humpback whale vocalizations. The algorithm automatically extracted contours of whale vocalization units by searching for gray-level discontinuities in the spectrogram images. The unit-to-unit similarity was quantified by cross-correlating the contour lines. A library of distinctive humpback units was then generated by applying an unsupervised, cluster-based learning algorithm. The purpose of this study was to provide a fast and automated feature selection tool to describe the vocal signatures of animal groups. This approach could benefit a variety of applications such as species description, identification, and evolution of song structures. The …