The critical point in the attainment of an elastic wavefield
in marine environments is the process of separation of
the several modes that cohabit in the recorded data.
Particularly important is the step regarding the
deconvolution of water-bottom multiples
and peg-legs, that will share a common
range of horizontal slownesses with the converted
modes associated with deep reflectors.
The use of a constant slowness filter in the
-kx
domain proves to be ineffective for deep reflectors, for which
even the converted modes have a small ray parameter value.
The usual solution is to perform the splitting process in
the
-p domain, in which an appropriate filter
can be designed for each particular case. In this paper
an alternative method was
introduced: it makes use of Snell rays to delimit zones of
different P wave horizontal slownesses in the data, and
applies a different filter to each region.
Although a better treatment of the multiples is
still required, the method shows to be effective even
in a conventional survey.
The next step is the application of the whole
process in a more appropriate dataset (long cable,
small group interval, etc.).