Elimination of the Spread-Length Bias in the Common-Reflection-Surface Stack

The Common-Reflection-Surface (CRS) stack yields kinematic wavefield attributes and stacked sections based on a second-order traveltime approximation.<br>As the CRS stack is performed by coherence analyses this leads to attributes and traveltimes of reflection events that show a spread-length bias, i.e., the quantities obtained are subject to the search aperture. <br>Obviously, applications based on the attributes and traveltimes will suffer from these misfits and yield incorrect results.<br>In this paper a technique for the correction of the spread-length bias is presented. Based on the assumption of a linear relationship between spread-length bias and search aperture the attributes and traveltimes are extrapolated to zero aperture and thus to their correct values. <br>The method is related to multiple coherence analyses with different apertures. The so obtained stack and attribute sections form new pseudo pre-stack data volumes which are used for the estimation of the extrapolation operators. A synthetic data example shows that these corrections are able to significantly improve the results of subsequent applications.