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Reflected and diffracted waves have different nature and role in the applied seismics. Diffractions itself can be classified in both real seismic and hypothetical diffractions. The real seismic diffractions are seismic waves which are scattered on small heterogeneities in the subsurface or diffracted at the edges and tips, and recorded as the diffracted part of the whole wavefield. To image objects beyond the classical Rayleigh limit, it is indispensable to use real seismic diffractions.The hypothetical diffractions are mathematical constructions resulting from Huygens principle which helps to correctly image reflected events. These Huygens diffractions build a kernel of seismic reflection imaging, particularly, Kirchhoff migration. The migrated data represent pure reflected data with a higher resolution. Considering either real or Huygens diffractions allows to adjust seismic tools for particular needs depending on the interpreter´s goal and the geological interpretation. The book is intended for all who want to have a look at non-conventional seismic methods.

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Sergius Dell, Dr. rer. nat.: Physics study at the University of Yekaterinburg. Geophysics study at the University of Hamburg. R+D Geophysicist, FUGRO SI Ltd, Swanley, United Kingdom

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