Impulse response of density contrast wedge using normal coordinates

The exact impulse response of a point source to a rigid wedge was derived by Biot and Tolstoy [I. Tolstoy, Wave Propagation (McGraw‐Hill, New York, 1973)]. The solution by the experiments has been verified. The wedge having free (pressure release) boundaries has the same form as the rigid boundary solution [W. A. Kinney et al., J. Acoust. Soc. Am. 73, 183–194 (1983)]. These solutions cannot be applied directly to many actual cases such as ocean floor, where the ratio of density of the base sediment to that of the water approaches neither infinite (rigid) nor zero (pressure release). The solution is the impulse response to an isovelocity (v₁ = v₂) and density contrast (ρ₁≠ρ) wedge. It is an extension of the solution given by Biot and Tolstoy. The reflection part of the solution is an impulse series weighted by reflection coefficient with different order. The diffraction part is the summation of the diffractions due to the individual image sources. The amplitudes are a function of the reflection coefficient and the number of multiple reflections. [This work was partly supported by the People's Republic of China and the Office of Naval Research.]