Using the definitions introduced in the preceding section,
we can make the standard notations for source and
receiver coordinates:
and
.
The traveltime from a source to a receiver is a function
of all spatial coordinates of the seismic experiment
.
Differentiating with respect to all
components of the vectors and ,
and using the standard notations
,
where
, we can write:
vec3
Figure 1. Geometric relations between ray vectors at a reflection point.
By analyzing the geometric relations of various
vectors at an image point (Figure 1),
we can write the following trigonometric expressions:
(15)
(16)
Equations (15)-(16) relate wavefield quantities,
and
, to a geometric quantity, reflection angle .
Analysis of these expressions provide sufficient information for
complete decompositions of migrated images in components for
different reflection angles.