Do we need up/down decomposition for Marchenko imaging?

Marchenko redatuming, imaging, monitoring and multiple elimination methods are based on Green’s function representations, with the underlying assumption that the wave field in the subsurface can be decomposed into downgoing and upgoing waves and that evanescent waves can be neglected. In this paper we show that up/down decomposition in the...

Time-slice wavefield decomposition

We propose a novel acoustic decomposition operator for time slices, loosely based on conventional surface decomposition operators. The proposed operators hold for constant velocity models and require two 2D Fourier Transforms (one forward, one backward) per decomposed time slice per decomposition direction. We then demonstrate the capabilities...

Marchenko wavefield redatuming, imaging conditions, and the effect of model errors

Recently, a novel method to redatum the wavefield in the sub-surface from a reflection response measured at the surface has gained interest for imaging primaries in the presence of strong internal multiples. A prerequisite for the algorithm is an accurate and correct estimate of the direct-wave Green's function. However, usually we use an...

From closed-boundary to single-sided homogeneous Green's function representations

The homogeneous Green’s function (i.e., the Green’s function and its time-reversed counterpart) plays an important role in optical, acoustic and seismic holography, in inverse scattering methods, in the field of time-reversal acoustics, in reversetime migration and in seismic interferometry. Starting with the classical closed-boundary...

Imaging blended vertical seismic profiling data using full-wavefield migration in the common-receiver domain

For vertical-seismic-profiling (VSP) measurements, the use of blended acquisition, with time-overlapping shot records, can greatly reduce the downtime and, thereby, provide large cost savings. For directly imaging blended VSP measurements, we have used full-wavefield migration (FWM). FWM is an inversion-based imaging scheme that enables us to...

Autofocusing imaging: Imaging with primaries, internal multiples and free-surface multiples

Recent work on autofocusing with the Marchenko equation has shown how the Green's function for a virtual source in the subsurface can be obtained from reflection data. The response to the virtual source is the Green's function from the location of the virtual source to the surface. The Green's function is retrieved using only the reflection...

On the focusing conditions in time-reversed acoustics, seismic interferometry, and Marchenko imaging

Despite the close links between the fields of time-reversed acoustics, seismic interferometry and Marchenko imaging, a number of subtle differences exist. This paper reviews the various focusing conditions of these methods, the causality/acausality aspects of the corresponding focusing wavefields, and the requirements with respect to...