Page 318 - Acquisition and Processing of Marine Seismic Data

5.9 f-k DIP FILTERS 309

FIG. 5.73 An example shot gather (bottom) and its f-k spectra (top) to illustrate the importance of amplitudes in the neg-
ative panel of an f-k spectrum for deep reflection events. (A) Deep reflections appear almost horizontal instead of hyperbolic
events in near offset traces of the shot gathers and small parts of their amplitudes may arise in the negative panel. (B) Rejecting
all amplitudes in the negative panel of the f-k spectrum causes amplitude reduction in the late arrivals of deep reflections in the
near-channel traces. (C) Accepting the amplitudes close to the frequency axis in the negative panel restores these amplitudes
(red arrows).
distinct on the late arrivals of the traces from very amplitudes may extend into the negative panel,
near channels in deep water seismic data. These and rejecting the entire negative panel of the f-k
are the tips of the reflection hyperbolas, and since spectrum removes these signal amplitudes,
they are almost horizontal in time domain data, which ultimately results in amplitude reduction
their amplitudes accumulate around the vertical in the late arrivals of deep reflections in the
frequency axis of the f-k spectrum close to the near-channel traces (Fig. 5.73B). In this case,
zero wavenumber value. Some parts of these accepting the negative panel amplitudes close