S U M M A R Y Converted phase (CP) elastic seismic signals are comparable in amplitude to the primary signals recorded at large offsets and have the potential to be used in seismic imaging and velocity analysis. We present an approach for CP elastic wave equation velocity analysis that does not use source information and is applicable to surface-seismic, microseismic, teleseismic and vertical s...

In this work, we present an efficient parallel implementation of a depth migration RTM (Reverse Time Migration) method to obtain a seismic image. This migration technique is based on the parallel solution of the acoustic wave propagation in 2D using a finite difference scheme. We have implemented a domain decomposition on the geological section and exploit an efficient asynchronous communicatio...

Finite difference is a simple, fast and effective numerical method for seismic wave modeling, and has been widely used in forward waveform inversion and reverse time migration. However, intensive calculation of three-dimensional seismic forward modeling has been restricting the industrial application of 3D pre-stack reverse time migration and inversion. Aiming at this problem, in this paper, a ...

I show that, by estimating local event slopes in prestack seismic reflection data, it is possible to accomplish all common time-domain imaging tasks, from normal moveout to prestack time migration, without the need to estimate seismic velocities or any other attributes. Local slopes contain complete information about the reflection geometry. Once they are estimated, seismic velocities and all o...

The Minimum Weighted Norm Interpolation (MWNI) algorithm (Liu and Sacchi, 2004, Trad et al. 2005) has been proposed as a method to reconstruct band-limited seismic data that depends on 1, 2, 3 and 4 spatial dimensions. In addition, Sacchi and Liu (2005) and Hunt et. al (2008) have demonstrated the ability of the method to reconstruct the data prior to true amplitude migration. Recently, Trad (2...

An angle-dependent reflection coefficient is recovered by seismic migration in the angle domain. We have developed a postmigration technique for computing scattering and dip angle common-image gathers (CIGs) from seismic images, extended by the subsurface offset, based on wave-equation migration methods. Our methodology suggests a system of Radon transform operators by introducing local transfo...

We tackle the problem of characterizing the subsurface, more specifically detecting shallow buried objects, using seismic techniques. This problem is commonly encountered in civil engineering when cavities or pipes have to be identified from the surface in urban areas. Our strategy consists of processing not only first arrivals, but also later ones, and using them both in tomography and migrati...

In this paper, first the limitations of the ray-based method and the one-way wave-field extrapolation migration (WEM) in imaging steeply dipping structures are discussed by some examples. Then a new method of the reverse time migration (RTM), used in imaging such complex structures is presented. The proposed method uses a new wave-field extrapolator called the Leapfrog-Rapid Expansion Method (L...

We investigate a pseudo-seismic approach based on the so-called inverse Q-transform as an alternative way of processing transient electromagnetic (TEM) data. This technique transforms the diffusive TEM response into that of propagating waves obeying the standard wave-equation. These transformed data can be input into standard seismic migration schemes with the potential of giving higher resolut...