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| Titel |
Assessment of the Performance of Semblance Weighted Diffraction Stack |
| VerfasserIn |
D. Marti, I. Palomeras, E. Andara, R. Carbonell, H. Zeyen |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250023770
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| Zusammenfassung |
| A variety of seismic reflection data sets has been use to estimate the
assessment of a recently developed true amplitude limited-aperture
migration based on a modification of the weighting function in the
Kirchoff migration operator. Prestack Kirchoff depth migration has
become a conventional processing step in seismic reflection imaging.
It provides new insights of the reflecting boundaries in crustal
studies and it's also an important method for reliable velocity models
building. In this migration scheme the weight function on the
amplitude part of the diffraction stack algorithm is derived from the
semblance of the slant stack of the data. Thus this weight function is
exclusively a function of the energy and the direction from which this
reflected energy reaches the receiver. The semblance of the slant
stack for a particular offset (the receiver offset) represents the
total amount of energy that reaches a particular receiver with
specific ray parameter (i.e. direction of propagation of the seismic
energy). The weight function reduces the diffraction stack to a
weighted stack of the amplitudes at a given travel time to every point
along a corresponding isochron. This migration scheme is applied to
synthetic and real normal incidence seismic reflection data providing
a depth images with a better resolution of the sub-vertical
structures. For example it provided a depth image of the north dipping
Central Unit of the complex suture zone between the Ossa Morena Zone
and the Central Iberian Zone of the IBERSEIS Vibroseis seismic
profile. Furthermore, this scheme is also successful when migrating
wide-angle deep seismic reflection data. In this case a low fold image
of the lower crust, Moho and upper mantle across SW-Iberia was
obtained by using 6 wide-angle shot gathers. Finally, depth imaging by
using VSP's is also a possibility using this migration scheme. |
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