Browsing Reprints by Issue Date

Now showing items 81-100 of 548

    • Deterministic methods of sound field computation 

      Spofford, C. W.; Garon, H. M. (NATO. SACLANTCEN, 1975/10)
      Models for acoustic propagation in the ocean environment have matured to a level where they are used routinely to estimate deterministic phenomena and, most recently, have been applied to the investigation of stochastic ...

    • Acoustic scattering from rough surfaces 

      Hurdle, B.; Flowers, K. D.; DeSanto, John Anthony (NATO. SACLANTCEN, 1975/10)
      A review of scattering from the ocean bottom and ocean ice cover is given. Areas of deficiency are cited.

    • Inverse wave propagation in an inhomogeneous waveguide 

      DeSanto, John Anthony (NATO. SACLANTCEN, 1975/10)
      A solution is given for the problem of inverse propagation in an inhomogeneous rectangular two-dimensional waveguide. The sound speed is assumed to vary in depth and inverse propagation means the calculation of the field ...

    • A technique of comparative analysis of underwater sound transmission loss curves 

      Adams, B. B.; Giellis, G. R. (NATO. SACLANTCEN, 1975/10)
      A procedure has been developed for the analysis of transmission loss curves in which received power is known or expressible as a linear function of range. The procedure separates each curve into a sum of three components ...

    • Relative contribution of surface roughness and bottom attenuation to propagation loss in shallow water 

      Kuperman, William A.; Ingenito, Frank (NATO. SACLANTCEN, 1975/10)
      A simulation study has been performed to investigate the relative importance of the contributions of surface roughness and bottom attenuation to propagation loss under differing environmental conditionso The NRL normal ...

    • Assessment techniques for computer models of sound propagation 

      Wood, David H. (NATO. SACLANTCEN, 1975/10)
      Computer models of sound propagation have exactly three drawbacks: the model only approximates reality,the computer program only approximates the model, and the cost approximates infinity. The only way to assess these ...

    • Ocean-basin reverberation from large underwater explosions: part 1: source-level and propagation-loss modelling 

      Blatstein, Ira M. (NATO. SACLANTCEN, 1975/10)
      Predicting the reverberant returns from ocean basin reflectors requires describing acoustic source levels for large, conventional underwater explosions, defining the two way propagation loss and signal spreading from the ...

    • Some acoustic effects of internal macrostructure 

      Mellen, Robert H.; Browning, David G. (NATO. SACLANTCEN, 1975/10)
      Some recent experimental developments relating to internal oceanographic- acoustic interactions are reviewed. Besides amplitude and phase fluctuations, a major concern is scattering into shadow regions. Associated oceanographic ...

    • Effect of ship motion on sonar detection performance 

      Schothorst, Jaap G. (NATO. SACLANTCEN, 1975/10)
      For an unstabilized transducer, the effect of ship motion on sonar echoes is twofold: 1. Attenuation caused by the rotational movement of the transducer in the vertical plane. The results show that the different loss figures ...

    • Noise sources in the ocean - part 2 

      Daintith, Maurice J. (NATO. SACLANTCEN, 1975/10)
      Following a brief historical survey of the development of our knowledge of the origins and characteristics of ambient noise in the ocean, the principal known sources of noise are described. These are: environmental origin, ...

    • Acoustic scintillations of acoustic waves 

      Munk, B. (NATO. SACLANTCEN, 1975/10)

    • Noise sources in the ocean - part 1 

      Wille, Peter C. (NATO. SACLANTCEN, 1975/10)
      Following a brief historical survey of the development of our knowledge of the origins and characteristics of ambient noise in the ocean, the principal known sources of noise are described. These are: environmental origin, ...

    • Scattering from a random interface 

      DeSanto, John Anthony (NATO. SACLANTCEN, 1975/10)
      The problem of scattering from a random interface separating two fluids with different densities and sound speeds is considered. The method is to write coupled integral equations in coordinate space connecting the surface ...

    • Computer models for underwater sound propagation 

      DiNapoli, Frederick R. (NATO. SACLANTCEN, 1975/10)
      The state of affairs of computer models for underwater sound propagation loss estimation is discussed from the viewpoints of two segments of the sonar community; i.e., (1) those who develop the models and are primarily ...

    • Intensity and phase fluctuations in low-frequency acoustic transmission through internal waves 

      Flatte, S. (NATO. SACLANTCEN, 1975/10)

    • A review of oceanic fronts 

      Johannessen, Ola M. (NATO. SACLANTCEN, 1975/10)
      This paper will start with a brief account of oceanic frontal research. The definition of oceanic and acoustic fronts and the distinction between them will be discussed. Examples of frontal structure dynamics, correlation ...

    • A spectral ocean wave model 

      Ward, C. R. (NATO. SACLANTCEN, 1975/10)
      An operational wave spectral model has been developed through the cooperative efforts of FLENUMWEACEN, NAVOCEANO and W.J. Pierson. The model contains two subdivisions: 1) wave energy growth based on a modified version of ...

    • Acoustic properties of the sea floor: a review 

      Hamilton, Edwin L. (NATO. SACLANTCEN, 1975/10)

    • Effects of sea-ice ridges on sound propagation in the Arctic Ocean 

      Diachok, Orest I. (NATO. SACLANTCEN, 1975/10)
      An environmental/acoustic model of sound propagation in the Arctic Ocean, which accounts for reflection losses from ridged sea ice, has been developed. In this model sea-ice ridges are represented as infinitely long, ...

    • Acoustic noise models 

      Cox, Henry (NATO. SACLANTCEN, 1975/10)
      The question of modeling the vertical directionality of ambient noise in the ocean is considered. The problem of converting from a description in terms of directional density function to a description in terms of the ...