Now showing items 1-7 of 7

    • Geoacoustic inversion using multipath pulse shape 

      Prior, Mark K.; Harrison, Chris H.; Nielsen, Peter L. (NURC, 2008/09)
      Experimental data, measured in a shallow water region of the Mediterranean Sea, are used to show that the variation of received intensity with time is well described by existing expressions [Harrison and Nielsen, J. Acoust. ...
    • Glider-based seabed characterization using natural-made ambient noise 

      Nielsen, Peter L.; Siderius, Martin; Muzi, Lanfranco (CMRE, 2019/06)
      Seabed characteristics (geoacoustic properties and scattering strength) are critical parameters for sonar performance predictions. However, this bottom information is considered very difficult and expensive to achieve in ...
    • Glider-based seabed characterization using natural-made ambient noise 

      Nielsen, Peter L.; Siderius, Martin; Muzi, Lanfranco (CMRE, 2019/06)
      Seabed characteristics (geoacoustic properties and scattering strength) are critical parameters for sonar performance predictions. However, this bottom information is considered very difficult and expensive to achieve in ...
    • Multipath pulse shape in a refracting environment 

      Harrison, Chris H.; Nielsen, Peter L. (NURC, 2007/11)
      Multiple boundary interactions in shallow water propagation introduce a more or less Gaussian angle distribution at a distant receiver. When all paths are added the result is 'mode-stripping', i.e. the steep rays are ...
    • Multipath pulse shapes in shallow water: theory and simulation 

      Harrison, Chris H.; Nielsen, Peter L. (NURC, 2007/04)
      In shallow water propagation the steeper ray angles are weakened most by boundary losses. Regarding the sound intensity as a continuous function of angle it can be converted into a function of travel time to reveal the ...
    • Separability of scattering and reflection parameters in reverberation inversion 

      Harrison, Chris H.; Nielsen, Peter L. (NURC, 2007/11)
      A premise of reverberation inversion is that one can separate geoacoustic reflection properties from scattering properties since their effects on reverberation are distinguishable. Some doubt has been cast on this premise ...
    • Separability of seabed reflection and scattering properties in reverberation inversion 

      Harrison, Chris H.; Nielsen, Peter L. (NURC, 2007/02)
      Separation of scattering properties (Lambert's mu) from reflection properties (the reflection loss angle derivative alpha) presents difficulties in the geoacoustic inversion of long range reverberation in isovelocity ...