A chief problem in seismic data processing is the filtering of unwanted events like ground roll and multiples. Methods to deal with this problem often exploit moveout or curvature differences between offending events and the events one would like to preserve (primaries). In particular, removal of multiples based on moveout discrimination can be attained via parabolic and hyperbolic Radon transf...

The lack of human interaction in automatic reflection tomography leads to a larger percentage of “bad” data points. The number of data points associated with events with spurious moveouts (such as multiples and converted waves) can be minimized by intelligently controlling the semblance scanning range. The effect of the bad data points can be limited by replacing the standard L2 norm solution w...

Dip moveout (DMO) and azimuth moveout (AMO) are considered in a general framework that allows for lateral variations in the velocity model, including those which generate caustics in the wavefield. DMO and AMO are constructed through the composition of operators, using the scattering angle and azimuth parameterization. In this parameterization, impulse responses are computed in a gaussian gas l...

The approximation of normal moveout is essential for estimating the anisotropy parameters of the transversally isotropic media with vertical symmetry axis (VTI). We have approximated the long-offset moveout using the Padé approximation based on the higher order Taylor series coefficients for VTI media. For a given anellipticity parameter, we have the best accuracy when the numerator is one orde...

In areas with structurally complex geology, tomographic velocity analysis is required to estimate velocities. This paper describes a tomographic velocity analysis algorithm which uses planewave synthesis imaging as a prestack migration. In reflection tomography, prestack migration is required for both event picking and traveltime error computation. Traveltime errors are often measured in the fo...

We introduce anisotropy continuation as a process which relates changes in seismic images to perturbations in the anisotropic medium parameters. This process is constrained by two kinematic equations, one for perturbations in the normal-moveout (NMO) velocity and the other for perturbations in the dimensionless anisotropy parameter η. We consider separately the case of post-stack migration and ...

A general linear theory is presented which describes the extension of the convolutional method to nonstationary processes. This theory can apply any linear, nonstationary filter, with arbitrary time and frequency variation, in the time, Fourier, or mixed (time-frequency) domains. The filter application equations and the expressions to move the filter between domains are all ordinary Fourier tra...