  Reflection of sound from ice sheets floating on water is simulated using
Thomson and Haskell's method of matrix propagation. The reflection coefficient
is computed as a function of incidence angle and frequency for selected ice
parameters of a uniform sheet and two layered ice sheets. At some incidence
angles and frequencies the reflection coefficient has very low values. It is
shown that this is related to generation of Lamb waves in the ice. The matrix
propagation method also provides a dispersion equation for a plate loaded with
fluid on one side and vacuum on the other. Finally the concept of beam
displacement is briefly discussed.
