Article,
Velocity imaging by tau-p transformation of refracted seismic traveltimes
Geophysical Prospecting, 51 (3): 195--203 (May 2003)
DOI: 10.1046/j.1365-2478.2003.00365.x
Abstract
We present a new method for producing a 'brute' velocity image rapidly
and automatically from traveltimes picked from densely sampled refraction
data. The procedure involves imaging by data transformation from
the time-offset domain into the tau-p (intercept-slope) domain, and
does not include conventional modelling steps. Differences in apparent
velocity and tau along reciprocal paths in the up- and downdip directions
allow the estimation of the true velocity and geometrical position
of the ray turning points. The tau-velocity-turningpoint (tau-v-x)
map distributes phases automatically on the basis of geometry and
velocity to give a two-dimensional representation of subsurface structure.
This map may be converted simply to depth and two-way-time images.
Such images have potential for direct geological interpretation,
for use as a starting model for seismic inversion, for superimposition
on to conventional reflection images, or for input into prestack
depth migration and other processing routines.
