Next: Application to the isotropic
Up: Biondi: Anistropic ADCIGs
Previous: REFERENCES
In this appendix I derive the expressions for evaluating
the derivatives of image depth with respect to
the subsurface offset and
the midpoint ;these derivatives are computed along the tangent plane to the
impulse response of the generalized migration operator,
which is defined in equations 18-24.
I start by deriving the equation for the vector normal to the
impulse-response surface,
:
| |
|
| |
| |
| (47) |
where
, , and
are respectively the unit vectors
along the three dimensions
, , and .
The equation of the tangent plane at the
image point with coordinates
is given by:
| |
|
| |
| (48) |
The derivative of the depth with respect o the subsurface offset,
at constant midpoint, is given by:
| |
(49) |
and similarly the derivative of the depth with respect to the midpoint,
at constant subsurface offset, is given by:
| |
(50) |
To evaluate
equations 49-50.
we need to evaluate the following partial derivatives,
obtained by differentiating the expressions in
equations 18-20:
| |
|
| |
| |
| |
| |
| (51) |
The derivative of path length are evaluated as following:
| |
|
| (52) |
and
| |
|
| (53) |