Fast velocity model evaluation with synthesized wavefields |

where is the set of all image points, is the amplitude at a given point, is the subsurface offset at that point, and is an optional user-specified weighting parameter. This idea is similar to the motivation behind some inversion schemes such as differential semblance optimization (Symes and Carazzone, 1991). Using this measure, a value of means that all energy is perfectly focused at zero offset; as decreases toward zero the image becomes progressively less focused. Ideally, a measure such as this one would allow a more rigorous comparison among possible models when a more qualitative comparison fails to yield an obvious result.

Fast velocity model evaluation with synthesized wavefields |

2012-05-10