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Qiang Li, David M. Farmer, Timothy F. Duda, and Steve Ramp

measurements a. Effects of barotropic tides Barotropic tides elevate or depress the sea surface, increasing or decreasing the total depth of the water column, which results in an increase or decrease in acoustic travel time, respectivly. If the sound speed is 1500 m s −1 , then a 1-m surface tide will cause a change in round-trip travel time of 1.3 × 10 −3 s. For our observation in the South China Sea, a millisecond travel time change is equivalent to a 24-m isopycnal displacement at the eigenfunction

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H. Czerski

acoustical extinction and includes both resonant and geometric effects. Geometric scattering is that due to the purely cross-sectional area of the bubble, separate from any resonant effects, and it increases as . In theory, if the attenuation with frequency is known, Eqs. (1) and (2) could be inverted to calculate n ( a ) da . Consequently, a single broadband measurement could be used to infer the bubble population over a wide radius range. Figure 1 shows two aspects of the extinction cross

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Anthony Finn and Kevin Rogers

using real-time kinematic carrier phase differential GPS and microelectromechanical systems (MEMS) inertial navigation systems (INS). The natural acoustic signature of a manned or unmanned aircraft is monitored synchronously on board the platform and by the sensor sets on and under the water. The signal is assumed to travel only along the direct path ( Fig. 1 ), which is a transitory phenomenon that typically lasts only while the source is almost overhead. Still, as the attenuating effects of water

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Anthony Finn, Kevin Rogers, Feng Rice, Joshua Meade, Greg Holland, and Peter May

masts), sodar, lidar, radio acoustic sounding system (RASS), radar, satellite-based techniques, and radiosondes. Each has benefits and drawbacks. Point-source observations from anemometers provide high wind velocity resolution and precision (0.01 and 0.05 m s −1 , respectively), but erection and maintenance costs for mast-based instruments become high as altitudes increase; and the presence of masts can obstruct or distort local wind flow ( Hasager et al. 2008 ). Measurements by remote sensing

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Francesco Raffa, Giovanni Ludeno, Giuseppa Buscaino, Gianmaria Sannino, Adriana Carillo, Rosario Grammauta, Domenico Spoto, Francesco Soldovieri, Salvatore Mazzola, and Francesco Serafino

. Therefore, in the development of a noise-monitoring plan in marine shallow waters, a comparative study coupling wave data and underwater acoustic measurements contributes to distinguishing the main natural abiotic underwater noise from anthropogenic noise ( Buscaino et al. 2016 ). X-band marine radars are useful active microwave remote sensing systems for sea-state monitoring either offshore or close to the coastline. Sea surface analyses by marine radar are based on the acquisition of consecutive radar

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W. Steven Holbrook, Ilker Fer, Raymond W. Schmitt, Daniel Lizarralde, Jody M. Klymak, L. Cody Helfrich, and Robert Kubichek

seismic reflection images. Our study includes full-wavefield synthetic tests of the sensitivity of seismic data in the k x domain, an analysis of the effects of random and shot-generated noise, and the first corroboration of seismically derived turbulence estimates against measurements from collocated, in situ oceanographic data. Using new approaches to estimate horizontal wavenumber content directly from the seismic data and via tracked reflections, we show that seismically derived horizontal slope

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Julien Marty, Stéphane Denis, Thomas Gabrielson, Milton Garcés, and David Brown

propagation effects within the pipe array structure. To validate the results provided by the two models in agreement, a field experiment was conducted. The measurements recorded by the system under test and the reference system were compared through a series of processing steps developed specifically for the purpose of this experiment. The modeled and measured acoustic responses appeared to fit extremely well for the six pipe array configurations. This showed that the models developed by Alcoverro and Le

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Hua Wang, Shipeng Su, Haichuan Tang, Lin Jiao, and Yunbo Li

, IEEE, 329–333, https://doi.org/10.1049/cp:19970393 . 10.1049/cp:19970393 Hocking , W. K. , 1985 : Measurement of turbulent energy dissipation rates in the middle atmosphere by radar techniques: A review . Radio Sci. , 20 , 1403 – 1422 , https://doi.org/10.1029/RS020i006p01403 . 10.1029/RS020i006p01403 Matuura , N. , Y. Masuda , H. Inuki , S. Kato , S. Fukao , T. Sato , and T. Tsuda , 1986 : Radio acoustic measurement of temperature profile in the troposphere and

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Clare E. Reimers, H. Tuba Özkan-Haller, Andrea T. Albright, and Peter Berg

called a benthic oxygen exchange rate (BOXER) lander ( Reimers et al. 2012 ) instrumented with an acoustic Doppler velocimeter (ADV) and oxygen microelectrodes as the principal collocated EC sensors. BOXER was specifically designed to provide a stable platform for autonomous EC measurements in continental shelf environments with high bottom shear stresses and has yielded oxygen fluxes comparable to benthic chambers during studies of the Oregon shelf ( Reimers et al. 2012 ; Fuchsman et al. 2015

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Joseph Park, Robert Heitsenrether, and William Sweet

the National Water Level Observation Network (NWLON), a network of more than 200 long-term, continuously operating water level stations around the United States, including island possessions, territories, and the Great Lakes ( http://tidesandcurrents.noaa.gov/ ). Since the early 1990s, the primary water level measurement system at most NWLON stations has been an acoustic time-of-flight range sensor encased in a protective well ( Edwing 1991 ). From a logistical perspective, installation and

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