Abstract
The Stacking Velocity Analysis of seismic reflection data is based on the approximation of the traveltime curves in Common-Depth-Point (CDP) gathers with hyperbolic trajectories. The analysis is customarily performed in the "physical" offset-time framework and produces a timevelocity histogram, the Velocity Spectrum. The accuracy of the velocity estimates depends on the adequacy of the CDP model to the earth’s structure, the quality of the data, and the resolving power of the estimation method chosen. In this last regard a very important role is played by the optimality criterion, i.e., the functional to be maximized. This paper introduces a new class of complex-valued coherency functionals operating on complex-valued traces, designed to emphasize phase correlation and to reduce the estimate uncertainty. The algorithms are evaluated on test cases using synthetic and field data. In particular, it is shown that higher resolutions can be obtained postprocessing the complex coherency spectra with a suitable phase-enhancement technique. © 1996-2018 Society of Exploration Geophysicists. All Rights Reserved.
