Improved Discrimination of Small Events in Stacking by Extrapolation
, by Jeff Thorson
A method is introduced to improve stacking, not by merely differentially weighting each individual trace in the gather before stack, but by laterally extending the gather and then stacking. The central part of the extended gather is unaltered (apart from muting) and each trace contributes unit weight to the stack. By recognizing that a sharp truncation of the recorded wavefield at the edges of the gather is a prime source of stacking error, the extension method is seen to be an attractive solution to this problem. Yet there are some serious deficiencies with the extrapolation used here: mainly that the extrapolation assumes stationarity of the data along the time axis.
STANFORD