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In this Appendix, I show that the equations for the non-diffracted multiple
from a dipping water-bottom reduce to the equations for a flat water-bottom
when
as they should. Setting
in
equations 39 through 42 we obtain
| ![\begin{displaymath}
t_{s_2}=t_{r_2}=t_{r_1}=t_{s_1}=\frac{\tilde{Z}_s}{\cos\alpha_s}\end{displaymath}](img108.gif) |
(66) |
and from equations 5 and 6 we get (as discussed at
the end of Appendix A)
and
.Therefore,
| ![\begin{eqnarray}
h_\xi&=&2h_D-V_1[t_{s_1}\sin\alpha_s+t_{r_1}\sin\alpha_r+\rho(\...
..._{s_1}\sin\alpha_s(1+\rho^2)\\ &=&2h_D-h_D(1+\rho^2)=h_D(1-\rho^2)\end{eqnarray}](img109.gif) |
(67) |
| (68) |
| (69) |
| (70) |
Similarly,
| ![\begin{eqnarray}
z_\xi&=&V_1(t_{r_1}+\rho\tilde{t}_{s_2}\sqrt{1-\rho^2\sin^2\alp...
...^2(1-\rho^2)}=Z_{wb}+\frac{\rho}{2}\sqrt{Z_{wb}^2+h_D^2(1-\rho^2)}\end{eqnarray}](img110.gif) |
(71) |
| (72) |
| (73) |
| (74) |
| (75) |
Finally,
| ![\begin{eqnarray}
m_\xi&=&m_D+\frac{V_1}{2}(t_{s_1}\sin\alpha_s-t_{r_1}\sin\alpha...
...}\sin\alpha_s)+\rho^2(t_{s_2}\sin\alpha_s-t_{s_2}\sin\alpha_s)=m_D\end{eqnarray}](img111.gif) |
(76) |
| (77) |
E
Next: Computation of takeoff angles
Up: Alvarez: Multiples in image
Previous: Traveltime computations for dipping
Stanford Exploration Project
11/1/2005