Spectral Coherence and Its Application

Geologic structure produces a seismic response in certain spectral bands, which is often buried within the broadband data. For the purpose of identifying the geologic discontinuities in different scale of the same seismic data, the method named spectral coherence was put proposed. Using spectral decomposition techniques, the spectral amplitudes corresponding to the given geologic structure can be extracted, which also demonstrate higher resolution than seismic amplitudes. In order to obtain the quantitative measure of structural and stratigraphic discontinuities, eigenstructure-based coherence was employed in our work. Then, to void the phase rotation from the complex spectrum, a covariance matrix from both real and imagery components is computed, rather than just spectrum amplitude. The application of spectral coherence shows that it is valuable for identifying and quantifying different scale geologic discontinuity features, ranging from big scale faults to small scale fractures.