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As a real data test, an irregular CMP gather was used as input to
the algorithm.
This gather comes from a collection of profiles published in
Ozdagan Yilmaz' book, Seismic Data Processing
1987.
The input cmp gather and
velocity spectrum
estimated with the preconditioned inversion
are displayed in Figure 5.
As can be seen from the figure, the data are severely aliased,
and it is difficult to identify many events.
The remodeled output is displayed in Figure 6.
The data are definitely less aliased. Some artifacts have appeared, mostly
above the mute zone.
A close look at the input reveals plane waves above
the first breaks, which are like hyperbolas with negative zero-offset travel
times, and which are thus probably difficult to model with the
velocity space transform.
Simply muting the input above
the first breaks likely removes most of the artifacts.
realin
Figure 5 An aliased CMP gather used
as input to the preconditioned inversion (left), and its estimated
velocity spectrum (right).
realout
Figure 6 The estimated velocity
spectrum remodeled into a more finely sampled data space.
Next: CONCLUSION
Up: Crawley: Interpolation
Previous: SYNTHETIC EXAMPLE
Stanford Exploration Project
11/12/1997