Extended images obtained from reverse-time migration (RTM) contain information about the accuracy of the velocity field and subsurface illumination at different incidence angles. Here, we evaluate the influence of errors in the anisotropy parameters on the residual moveout (RMO) in P-wave extended images obtained with RTM for VTI (transversely isotropic with a vertical symmetry axis) media. Assuming the actual spatial distribution of the zero-dip normal-moveout velocity, we analyze extended images computed with distorted fields of the parameters η and δ. Differential semblance optimization (DSO) and stackpower criteria are employed to study the sensitivity of focusing to the anisotropy parameters. The results show that the signature of η is dip-dependent, whereas errors in δ cause defocusing in extended images only if that parameter varies laterally. We also obtain and analyze the gradients of the DSO objective function with respect to the anisotropy parameters. The results of this work provide the foundation for anisotropic wavefield tomography operating with extended images.


Article metrics loading...

Loading full text...

Full text loading...


  1. Alkhalifah, T., Fomel, S. and Biondi, B.
    [2001] The space-time domain: theory and modelling for anisotropic media. Geophysical Journal International, 144, 105–113.
    [Google Scholar]
  2. Alkhalifah, T. and Tsvankin, I.
    [1995] Velocity analysis for transversely isotropic media. Geophysics, 60(5), 1550–1566.
    [Google Scholar]
  3. Chavent, G. and Jacewitz, C.A.
    [1995] Determination of background velocities by multiple migration fitting. Geophysics, 60(2), 476–490.
    [Google Scholar]
  4. Duveneck, E. and Bakker, P.M.
    [2011] Stable P-wave modeling for reverse-time migration in tilted TI media. Geophysics, 76(2), S65–S75.
    [Google Scholar]
  5. Fowler, P.J., Du, X. and Fletcher, R.P.
    [2010] Coupled equations for reverse time migration in transversely isotropic media. Geophysics, 75(1), S11–S22.
    [Google Scholar]
  6. Li, Y., Biondi, B., Clapp, R. and Nichols, D.
    [2014] Wave-equation migration velocity analysis for VTI models. Geophysics, 79(3), WA59–WA68.
    [Google Scholar]
  7. Plessix, R.E.
    [2006] A review of the adjoint-state method for computing the gradient of a functional with geophysical applications. Geophysical Journal International, 167(2), 495–503.
    [Google Scholar]
  8. Rickett, J. and Sava, P.
    [2002] Offset and angle–domain common image-point gathers for shot-profile migration. Geophysics, 67(3), 883–889.
    [Google Scholar]
  9. Sava, P. and Alkhalifah, T.
    [2012] Anisotropy signature in extended images from reverse-time migration. SEG, Technical Program Expanded Abstracts, 1–6.
    [Google Scholar]
  10. Sava, P. and Fomel, S.
    [2006] Time-shift imaging condition in seismic migration. Geophysics, 71(6), S209–S217.
    [Google Scholar]
  11. Symes, W.W. and Carazzone, J.J.
    [1991] Velocity inversion by differential semblance optimization. Geophysics, 56(5), 654–663.
    [Google Scholar]
  12. Tsvankin, I.
    [2012] Seismic Signatures and Analysis of Reflection Data in Anisotropic Media, Third Edition. Society of Exploration Geophysicists.
    [Google Scholar]
  13. Yang, T. and Sava, P.
    [2011] Wave-equation migration velocity analysis with time-shift imaging. Geophysical Prospecting, 59(4), 635–650.
    [Google Scholar]

Data & Media loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error