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Civil and Environmental Engineering
Electrical and Computer Engineering Faculty Publications and Presentations
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Full-Text Articles in Engineering
Terahertz Imaging Of Thin Film Layers With Matched Field Processing, Scott Schecklman, Lisa M. Zurk
Terahertz Imaging Of Thin Film Layers With Matched Field Processing, Scott Schecklman, Lisa M. Zurk
Electrical and Computer Engineering Faculty Publications and Presentations
Terahertz (THz) time of flight (TOF) tomography systems offer a new measurement modality for non-destructive evaluation (NDE) of the subsurface layers of protective coatings and/or laminated composite materials for industrial, security and biomedical applications. However, for thin film samples, the time-of-flight within a layer is less than the duration of the THz pulse and consequently there is insufficient range resolution for NDE of the sample under test. In this paper, matched field processing (MFP) techniques are applied to thickness estimation in THz TOF tomography applications, and these methods are demonstrated by using measured THz spectra to estimate the the thicknesses …
Performance Metrics For Depth-Based Signal Separation Using Deep Vertical Line Arrays, Gabriel Paul Kniffin, John Kenneth Boyle, Lisa Zurk, Martin Siderius
Performance Metrics For Depth-Based Signal Separation Using Deep Vertical Line Arrays, Gabriel Paul Kniffin, John Kenneth Boyle, Lisa Zurk, Martin Siderius
Electrical and Computer Engineering Faculty Publications and Presentations
A recent publication by McCargar and Zurk [(2013). J. Acoust. Soc. Am. 133(4), EL320–EL325] introduced a modified Fourier transform-based method for passive source depth estimation using vertical line arrays deployed below the critical depth in the deep ocean. This method utilizes the depth-dependent modulation caused by the interference between the direct and surface-reflected acoustic arrivals, the observation of which is enhanced by propagation through the reliable acoustic path. However, neither the performance of this method nor its limits of applicability have yet been thoroughly investigated. This paper addresses both of these issues; the first by identifying and analyzing the factors …
A Computational Method To Predict And Study Underwater Noise Due To Pile Driving, Scott Schecklman, Nathan Laws, Lisa M. Zurk, Martin Siderius
A Computational Method To Predict And Study Underwater Noise Due To Pile Driving, Scott Schecklman, Nathan Laws, Lisa M. Zurk, Martin Siderius
Electrical and Computer Engineering Faculty Publications and Presentations
A hybrid modeling approach that uses the parabolic equation (PE) with an empirical source model is presented to study and predict the underwater noise due to pile driving in shallow, inhomogeneous environments over long propagation ranges. The empirical source model uses a phased point source array to simulate the time-dependent pile source. The pile source is coupled with a broadband application of a PE wave propagation model that includes range dependent geoacoustic properties and bathymetry. Simulation results are shown to be in good agreement with several acoustic observations of pile driving in the Columbia River between Portland, OR and Vancouver, …