To construct the 3-D steering filter operator I followed
the methodology described in Clapp (2000), cascading
two 2-D steering filter operators to form my 3-D steering filter operator.
I used the
five reflectors picked in the last section. To calculate
the dip field I began by calculating the slope in the *x*-*z* and *y*-*z* planes.
I mapped these two dip fields into model space.
I then interpolated the field to the entire model space.

Once I had the dips in both the *x*-*z* and *y*-*z* planes I constructed
two filter banks which encompassed the range of dips in each direction.
It was then a simple matter of creating a mapping operator that
mapped the dip at a given model point to a specific filter in the bank.
To see the effect of this new complex operator I filled the model
with random noise and then applied *A*_{3d}*A*_{3d}'
(Figure ). As you can see the 3-D steering
filter does a good job in spreading energy along reflector directions.

Figure 5

9/5/2000