On the Use of Reflection Coefficient Phase at Hydroacoustic Measurements of Sea Ice Cover Thickness

Bogorodskiy A. V., Malyarov K. V.

With application to the task of remote measurement of the Arctic Sea ice cover thickness from under water, the effect of vertical heterogeneity of acoustic properties of sea ice of various type and age categories caused by their layered structure on phase of reflection coefficient of acoustic low-frequency harmonic plane wave at its normal incidence on sea water-ice interface is investigated by a method of model experiment. Two acoustic models of the real sea ice cover are considered: one with constants, another with continuously changing with cover thickness acoustic parameters — elastic medium density, velocity and attenuation coefficient of longitudinal acoustic waves in the medium. Graphic curves of thickness of the sounded ice cover as function of reflection coefficient phase calculated for each of two considered acoustic models of arctic sea ice are presented. It is shown that in order to increase reliability of ice thickness data it is reasonable to use typified acoustic models of sea ice cover which parameters are adequate to its certain type, age category and period of annual cycle within limits of which the measurements are conducted.

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