Original Paper - Exploration Geophysics

Journal of Petroleum Exploration and Production Technology

, Volume 1, Issue 1, pp 11-16

First online:

Open Access This content is freely available online to anyone, anywhere at any time.

Theory of 3-D angle gathers in wave-equation seismic imaging

  • Sergey FomelAffiliated withBureau of Economic Geology, John A. and Katherine G. Jackson School of Geosciences, The University of Texas at Austin Email author 


I present two methods for constructing angle gathers in 3-D seismic imaging by downward extrapolation. Angles in angle gathers refer to the scattering angle at the reflector and provide a natural access to analyzing migration velocity and amplitudes. In the first method, angle gathers are extracted at each downward-continuation step by mapping transformations in constant-depth frequency slices. In the second method, one extracts angle gathers after applying the imaging condition by transforming local offset gathers in the depth domain. The second approach generalizes previously published algorithms for angle-gather construction in 2-D and common-azimuth imaging.


Geophysics Seismic imaging Velocity analysis Amplitude analysis