AVO and velocity analysis

Velocity analysis using semblance estimates velocities based on a constant amplitude model for seismograms and does not take amplitude variation with offset (AVO) into account. In the presence of AVO. the constant amplitude model becomes inaccurate. particularly for events which exhibit polarity reversals. An AVO sensitive velocity analysis procedure, which is a generalization of the traditional semblance method, can be devised by giving an offset dependence to the modeled seismograms. Incorporating AVO into velocity analysis requires additional parameters to describe the reflectivity. This results in reduced velocity precision. By introducing a regularization term which provides a controlled suppression of the contributions due to AVO effects, we describe an AVO sensitive velocity analysis algorithm that properly deals with events exhibiting polarity reversals or large amplitude variation with offset.