Tomographic Determination of Interval Velocities from CDR Data-Preliminary Results
, by Chuck Sword
The method of Controlled Directional Reception (\CDR)
can be used to determine travel times and ray parameters of waves
transmitted from a given shot
and received at a given geophone (Riabinkin et al., 1962; Sword, 1984a).
These ray and travel-time
parameters (collectively known as \CDR\ parameters) are obtained
from conventional seismic data
through an automatic picking procedure,
and can be inverted tomographically to give
interval velocities of the medium.
The inversion procedure is easily illustrated for the case of
a horizontally layered medium,
and synthetic data from such a medium have successfully been inverted.
The inversion is more difficult when both horizontal and
vertical velocity variations are permitted,
but not impossible,
and most of the necessary ray-tracing formulas
have been derived.
The inversion process is easily extended to the analysis
of converted-wave data.
STANFORD