Estimating an accurate velocity model is crucial for seismic imaging to obtain a good understanding of the subsurface structure. The objective of this thesis is to investigate methods of velocity analysis by optimizing seismic images. A conventional seismic image is obtained by zero-lag crosscorrelation of wavefields extrapolated from a source wavelet and recorded data on the surface using a ve...

Wave-equation migration with the velocity of the primaries maps non-diffracted waterbottom multiples to an hyperbola in subsurface-offset-domain-common-image-gathers. Furthermore, for positive surface offsets, the multiples are mapped to non-positive subsurface offsets if sediment velocity is faster than water. The larger the offset in the data space, the larger the subsurface offset and the sh...

In seismic data analysis, recorded data often are transformed to various domains to discriminate against coherent and incoherent noise. For instance, by mapping a shot record from time-space domain to frequency-wavenumber domain, coherent linear noise can be attenuated. Similarly, by mapping a common-midpoint gather from time-space to timevelocity domain (velocity stacks) multiples are separate...

the application of nmo (normal moveout) has been recognized as an effective method of generating quasi-zero-offset traces in traditional common-midpoint processing. artifacts of the nmo method relate to the nmo-stretch effects. conventional application of normal-moveout correction to a common-midpoint (cmp) reflection generates a stretch that increases with offset and decreases with zero-offset...

in this paper we consider several generalizations of the skew t-normal distribution, and some of their properties. also, we represent several theorems for constructing each generalized skew t-normal distribution. next, we illustrate the application of the proposed distribution studying the ratio of two heavy metals, nickel and vanadium, associated with crude oil in shadgan wetland in the south-...

Full waveform inversion (FWI) in transversely isotropic media usually requires abundant a priori information, like well data and smoothness assumptions, to make the FWI converge to a plausible solution. The proper model parameterization in transversely isotropic (TI) media with a vertical symmetry axis (VTI) can alleviate some of these limitations. Considering the limitations of our field data ...

The application of the seismic reflection method is often limited in complex terrain areas. The problem is the incorrect correction of time-shifts caused by topography. To apply normal moveout (NMO) correction to reflection data correctly, static corrections are necessary to be applied in advance for the compensation of the time distortions of topography and the time-delays from near-surface we...

We apply seismic interferometry to traffic noise to retrieve both body waves and surface waves. Our preferred algorithm in the presence of highly variable and strong additive random noise uses cross-coherence, which uses normalization by the spectral amplitude of each of the traces, rather than cross-correlation or deconvolution. This normalization suppresses the influence of additive noise and...