Now showing items 625-644 of 917

    • Performance analysis of adaptive equalization for coherent acoustic communications in the time-varying ocean environment 

      Preisig, James C. (Acoustical Society of America, 2005-07)
      Equations are derived for analyzing the performance of channel estimate based equalizers. The performance is characterized in terms of the mean squared soft decision error of each equalizer. This error is decomposed into ...
    • Performance bounds on matched-field methods for source localization and estimation of ocean environmental parameters 

      Xu, Wen (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2001-06)
      Matched-field methods concern estimation of source location and/or ocean environmental parameters by exploiting full wave modeling of acoustic waveguide propagation. Typical estimation performance demonstrates two ...
    • Performance of a new generation of acoustic current meters 

      Hogg, Nelson G.; Frye, Daniel E. (American Meteorological Society, 2007-02)
      As part of a program aimed at developing a long-duration, subsurface mooring, known as Ultramoor, several modern acoustic current meters were tested. The instruments with which the authors have the most experience are the ...
    • Performance of the parametric receiving array : effects of misalignment 

      Foote, Kenneth G.; Tjøtta, Jacqueline Naze; Tjøtta, Sigve (Acoustical Society of America, 1987-11)
      The difference frequency sound field from two concentric but misaligned, axisymmetric, planar transducers in a nondissipative and nondispersive medium is developed as a special case of the general theory [Garrett et al., ...
    • A performance update of the InterOcean S4 electromagnetic current meter 

      Clay, Peter R.; Longworth, Steven P. (Woods Hole Oceanographic Institution, 1986-10)
      This report reviews the working principles of the InterOcean S4 electromagnetic current meter and outlines the practical difficulties and engineering solutions to convert these basic principles into a working ...
    • A phase-compensated distorted wave Born approximation representation of the bistatic scattering by weakly scattering objects : application to zooplankton 

      Chu, Dezhang; Ye, Zhen (Acoustical Society of America, 1999-10)
      The distorted wave Born approximation (DWBA) method has been successfully used in modeling the acoustic backscattering by weakly scattering zooplankton [Stanton et al., J. Acoust. Soc. Am. 94, 3463–3472 (1993), Wiebe et ...
    • Physical controls on hypoxia in Chesapeake Bay : a numerical modeling study 

      Scully, Malcolm E. (John Wiley & Sons, 2013-03-14)
      A three-dimensional circulation model with a relatively simple dissolved oxygen model is used to examine the role that physical forcing has on controlling hypoxia and anoxia in Chesapeake Bay. The model assumes that the ...
    • Physically constrained maximum likelihood (PCML) mode filtering and its application as a pre-processing method for underwater acoustic communication 

      Papp, Joseph C. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2009-09)
      Mode filtering is most commonly implemented using the sampled mode shape or pseudoinverse algorithms. Buck et al placed these techniques in the context of a broader maximum a posteriori (MAP) framework. However, the MAP ...
    • Physically constrained maximum likelihood mode filtering 

      Papp, Joseph C.; Preisig, James C.; Morozov, Andrey K. (Acoustical Society of America, 2010-04)
      Mode filtering is most commonly implemented using the sampled mode shapes or pseudoinverse algorithms. Buck et al. [J. Acoust. Soc. Am. 103, 1813–1824 (1998)] placed these techniques in the context of a broader maximum a ...
    • Piecewise coherent mode processing of acoustic data recorded on two horizontally separated vertical line arrays 

      Udovydchenkov, Ilya A.; Brown, Michael G.; Duda, Timothy F. (Acoustical Society of America, 2012-05-25)
      Motivated by measurements made in the 2004 Long-Range Ocean Acoustic Propagation Experiment (LOAPEX), the problem of mode processing transient acoustic signals collected on two nearby vertical line arrays is considered. ...
    • Plankton reach new heights in effort to avoid predators 

      Gemmell, Brad J.; Jiang, Houshuo; Strickler, J. Rudi; Buskey, Edward J. (2012-01)
      The marine environment associated with the air-water interface (neuston) provides an important food source to pelagic organisms where subsurface prey is limited. However, studies on predator-prey interactions within this ...
    • A pop-up float recovery system for coastal oceanographic tripods 

      Dunn, Christopher V. R.; Gordon, Allan G. (Woods Hole Oceanographic Institution, 1989-11)
      The recovery package described here was used as the primary retrieval system to recover tripod instrument platforms from a depth of 90 meters. The device uses dual in-line burn wires, one of which is acoustically commanded ...
    • Postprocessing system for echo sounder data 

      Foote, Kenneth G.; Knudsen, Hans Petter; Korneliussen, Rolf J.; Nordbø, Per Erik; Røang, Kjell (Acoustical Society of America, 1991-07)
      Echo sounding is a powerful and widely used technique for remote sensing of the marine environment. In order to enhance the power of the echo sounder, a postprocessing system has been designed and realized in standard ...
    • Predicted scattering of sound by diffuse hydrothermal vent plumes at mid-ocean ridges 

      Duda, Timothy F.; Trivett, D. Andrew (Acoustical Society of America, 1998-01)
      Amplitude and phase fluctuations of monochromatic acoustic signals traveling through diffuse mid-ocean ridge hydrothermal vent plumes are modeled using existing theory in an attempt to find suitable frequencies and path ...
    • Predicting seabed burial of cylinders by wave-induced scour : application to the sandy inner shelf off Florida and Massachusetts 

      Trembanis, Arthur C.; Friedrichs, Carl T.; Richardson, Michael D.; Traykovski, Peter A.; Howd, Peter A.; Elmore, Paul A.; Wever, Thomas F. (IEEE, 2007-01)
      A simple parameterized model for wave-induced burial of mine-like cylinders as a function of grain-size, time-varying, wave orbital velocity and mine diameter was implemented and assessed against results from inert ...
    • Predicting wave-induced ripple equilibrium geometry 

      Nelson, Timothy R.; Voulgaris, George; Traykovski, Peter A. (John Wiley & Sons, 2013-06-28)
      A comprehensive database of existing (since 1954) field and laboratory measurements of ripple geometry is compiled and combined with newly collected field data to examine the performance of ripple equilibrium predictors. ...
    • The prediction, verification, and significance of flank jets at mid-ocean ridges 

      Lavelle, J. William; Thurnherr, Andreas M.; Mullineaux, Lauren S.; McGillicuddy, Dennis J.; Ledwell, James R. (The Oceanography Society, 2012-03)
      One aspect of ocean flow over mid-ocean ridges that has escaped much attention is the capacity of a ridge to convert oscillatory flows into unidirectional flows. Those unidirectional flows take the form of relatively narrow ...
    • Predictions and observations of seafloor infrasonic noise generated by sea surface orbital motion 

      Lindstrom, Timothy E. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1991-09)
      A model is developed for the prediction of the seismo-acoustic noise spectrum in the microseism peak region (0.1 to 0.7 Hz). The model uses a theory developed by Cato [J. Acoust. Soc. Am., 89 , 1096-1112 (1991)] for an ...
    • Preface 

      Anderson, Donald M.; McGillicuddy, Dennis J.; DeGrasse, Stacey L.; Sellner, Kevin G.; Bricelj, V. Monica; Turner, Jefferson T.; Townsend, David W.; Kleindinst, Judith L. (2014-02)
      The Gulf of Maine (GOM) is a continental shelf sea in the northwest Atlantic, USA that supports highly-productive shellfisheries that are frequently contaminated by toxigenic Alexandrium fundyense blooms and outbreaks of ...
    • Preliminary acoustic and oceanographic observations from the ASIAEX 2001 South China Sea Experiment 

      Newhall, Arthur E.; Costello, Lawrence; Duda, Timothy F.; Dunn, James M.; Gawarkiewicz, Glen G.; Irish, James D.; Kemp, John N.; McPhee, Neil M.; Liberatore, Stephen P.; Lynch, James F.; Ostrom, William M.; Schroeder, Ted; Trask, Richard P.; von der Heydt, Keith (Woods Hole Oceanographic Institution, 2001-09)
      The Asian Seas International Experiment (ASIAEX) was a very successful scientific collaboration between the United States of America (USA), the People’s Republic of China (PRC), Taiwan (ROC), the Republic of Korea (ROK), ...