Velocity analysis using $AB$ semblance

Conclusions

If one interprets the conventional semblance as a correlation with a constant, the $AB$ semblance is a correlation with an amplitude trend. I have derived an explicit expression for the $AB$ semblance and analyzed it to quantify the observable loss of resolution. I have demonstrated the advantages of the $AB$ semblance attribute using synthetic and field data examples. The ratio of the $AB$ and conventional semblances serves as a useful AVO indicator attribute. The sensitivity of this attribute to non-linear variations in the amplitude trend can be a subject of further research. Further applications may also include velocity analysis of converted waves and seismic diffractions.