Future work

Berryhill (1984) generalized his earlier work for zero-offset data to constant-offset (prestack) data by downward continuing the geophones and the sources to a datum in a two pass algorithm. The same idea can be used for extrapolating data using different phase-shift algorithms for downward (or upward) continuing common-source and common-receiver sections to a datum. Moreover, due to the inherent simplicity of the algorithm the 3-D implementation is straightforward.

Another research direction was given by Yilmaz and Lucas (1986) and Berryhill (1986) who both describe a velocity replacement technique using a Kirchhoff based datuming algorithm twice. The layer replacement method consists of downward extrapolating the data to a datum using a known velocity and then upward extrapolating the data back to the surface with a different velocity in order to reduce the effect of the velocity contrast at the datum. Using the phase-shift datuming algorithm described in this paper we can apply the same technique to zero-offset data and to prestack data to obtain the same results.