| In this paper, the marine sediment is regarded as wet loose granular medium where the propagation of sound can excite a dilatation wave but not a rotating wave, and the seawater-sediment interface is assumed to be a plane. The reflection coefficient V at sediment surface is derived as
(For the equations please see the PDF file.)
where k0 is the wave number of the sea water, k1 the wave number of the sediment, ω the angular frequency, ρ0 the density of the sea water, q the porosity of the sediment, α0 the grazing angle in sea water, α1 the grazing angle in sediment,
B0 = q/[(q/B1) + (1-q)/ B2], B1 and B2 are the bulk modulus of the pore water and the sediment grains, respectively.
Thus, the connection of the derived reflection coefficient with various parameters in sediment is established. The obtained result is identical with that obtained by phenomenon theory and agrees well with practical data. |
