the stolt (f-k) migration algorithm is a direct (i.e. non-recursive) fourier-domain technique based on a change of variables (or equivalently, a mapping) that converts the input spectrum to the output spectrum. the algorithm is simple and efficient but limited to constant velocity. a v(z)(f-k) migration method, capable of very high accuracy for vertical variations of velocity, can be formulated...

In this paper we present a new algorithm to reconstruct prestack (5D) seismic data. If one considers seismic data at a given frequency and, for instance, in the x midpoint, y midpoint, offset and azimuth domain, the data volume can be represented via a 4th order tensor. Seismic data reconstruction can be posed as a tensor completion problem where it is assumed that the fully sampled data can be...

It is well known that source deghosting can best be applied to common-receiver gathers, whereas receiver common-shot records. The source-ghost wavefield observed in the domain contains imprint of subsurface, which complicates domain, particular when subsurface complex. Unfortunately, alternative, is, often coarsely sampled, this as well. To solve latter issue, we have trained a convolutional ne...

Angle domain common image gathers offer advantages for subsurface image analysis in complex media. We compare two angle decomposition methods using extended images and wave propagation directions based on Poynting vectors of the source and receiver wavefields. We evaluate the ability of each method to produce accurate and efficient angle gathers for wave-equation migration in the presence of mu...

I present a general methodology for computing Angle-Domain Common Image Gathers (ADCIGs) in conjunction with anisotropic wavefield-continuation migration. The method is based on the transformation of the prestack image from the subsurface-offset domain to the angle domain by use of slant stacks. The processing sequence is the same as for the computation of ADCIGs for the isotropic case, though ...

We propose a robust interpolation scheme for aliased regularly sampled seismic data that uses the curvelet transform. In a first pass, the curvelet transform is used to compute the curvelet coefficients of the aliased seismic data. The aforementioned coefficients are divided into two groups of scales: alias-free and alias-contaminated scales. The alias-free curvelet coefficients are upscaled to...

STIK is a platform that gathers Speech, Texts and Images of Knowledge. It allows browsing and navigating through collections of multimedia, facilitating access to archives in the domain of Knowledge resources. STIK includes a back-end with a specific automatic metadata extraction pipeline, a frontend with innovative interfaces for navigating within a document and a specific implementation of a ...

I derive and analyze an explicit formula for a generalized semblance attribute, which is suitable for velocity analysis of prestack seismic gathers with distinct amplitude trends. While the conventional semblance can be interpreted as squared correlation with a constant, the AB semblance is defined as a correlation with a trend. This measure is particularly attractive for analyzing class II AVO...