Velocity analysis using semblance |

**Sergey Fomel**

Bureau of Economic Geology,

John A. and Katherine G. Jackson School of Geosciences

The University of Texas at Austin

University Station, Box X

Austin, TX 78713-8972

I derive and analyze an explicit formula for a generalized semblance
attribute, which is suitable for velocity analysis of prestack
seismic gathers with distinct amplitude trends. While the
conventional semblance can be interpreted as squared correlation
with a constant, the
semblance is defined as a correlation with a
trend. This measure is particularly attractive for analyzing class
II AVO anomalies and converted waves. Analytical derivations and
numerical experiments show that the resolution of the
semblance
is approximately twice lower than 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.

- Introduction
- Theory

- Examples

- Conclusions
- Acknowledgments
- Apendix A: Statistical analysis of semblance measures
- Appendix B: Automatic velocity picking from semblance scans
- Bibliography
- About this document ...

Velocity analysis using semblance |

2013-07-26