Volume 57, Issue 3
  • E-ISSN: 1365-2478



I derive and analyse an explicit formula for a generalized semblance attribute, which is suitable for the velocity analysis of prestack seismic gathers with distinct amplitude trends. While the conventional semblance can be interpreted as a squared correlation with a constant, the semblance is defined as a correlation with a trend. This measure is particularly attractive for analysing class II AVO anomalies and converted waves. Analytical derivations and numerical experiments show that the resolution of the semblance is approximately twice as low as that of the conventional semblance. However, this does not prevent it from being an effective attribute. I use synthetic and field data examples to demonstrate the improvements in velocity analysis from semblance.


Article metrics loading...

Loading full text...

Full text loading...


  1. AdlerF. and BrandwoodS.1999. Robust estimation of dense 3‐D stacking velocities from automated picking. 69th SEG meeting, Houston, Texas , USA , Expanded Abstracts, 1162–1165.
  2. ArnaudJ., RappinD., DunandJ.‐P. and CurinierV.2004. High density picking for accurate velocity and anisotropy determination. 74th SEG meeting, Denver, Colorado , USA , 1627–1629.
  3. DeschampsT. and CohenL.D.2001. Fast extraction of minimal paths in 3D images and applications to virtual endoscopy. Medical Image Analysis5, 281–299.
    [Google Scholar]
  4. FomelS.2007. Shaping regularization in geophysical‐estimation problems. Geophysics72, R29–R36.
    [Google Scholar]
  5. HarlanW.S.2001. Constrained automatic moveout picking from semblances. http://billharlan.com/pub/papers/autopick.pdf.
  6. LanczosC.1966. The Variational Principles of Mechanics . University of Toronto Press.
    [Google Scholar]
  7. RatcliffeA. and AdlerF.2000. Accurate velocity analysis for Class Ii AvO events. 70th SEG meeting, Calgary , Canada , Expanded Abstracts, 232–235.
  8. RutherfordS.R. and WilliamsR.H.1989. Amplitude‐versus‐offset variations in gas sands. Geophysics54, 680–688.
    [Google Scholar]
  9. SarkarD., BaumelR.T. and LarnerK.L.2002. Velocity analysis in the presence of amplitude variation. Geophysics67, 1664–1672.
    [Google Scholar]
  10. SarkarD., CastagnaJ.P. and LambW.2001. AVo and velocity analysis. Geophysics66, 1284–1293.
    [Google Scholar]
  11. ShueyR.T.1985. A simplification of the Zoeppritz‐equations. Geophysics50, 609–614. (Erratum in GEO‐50‐9‐1522).
    [Google Scholar]
  12. SiliqiR., MeurD.L., GamarF., SmithL., ToureJ. and HerrmannP.2003. High‐density moveout parameter fields V and Eta, Part 1: Simultaneous automatic picking. 73rd SEG meeting, Dallas, Texas , USA , Expanded Abstracts, 2088–2091.
  13. TanerM.T. and KoehlerF.1969. Velocity spectra – Digital computer derivation and applications of velocity functions. Geophysics34, 859–881.
    [Google Scholar]
  14. YilmazO.2000. Seismic Data Analysis . SEG.
    [Google Scholar]

Data & Media loading...

  • Article Type: Research Article
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