oa Velocity Estimation by Focal Transform

Obtaining a reliable velocity function is still an important problem in seismic processing. The most<br>important reason to construct a reliable velocity function is to obtain the best quality stack of a given<br>signal. In this paper, focal transform is introduced as a tool in velocity analysis. By using focal<br>transform, it is possible to have a velocity function with higher resolution compared to that of the<br>traditional method. From a physical point of view, the principal action of forward focal operator is<br>removing the spatial phase of the signal content from the input data and the inverse focal operator<br>restores what the forward operator has removed. This method is based on the fact that shape of<br>hyperbolic event in focal domain depends on the difference between operator shape and the event.<br>Measuring the difference between operator and event can be somehow used as an indicator and<br>through applying this indicator, velocity of each event can be determined. This method works properly<br>for synthetic data with different level of noise and also it can distinguish similar events with small<br>differences in velocity and time. Quality of the velocity function that is obtained through this method is<br>not affected by multiples and those are easily distinguished from primaries.