Zero-offset migration

Offset is a geometrical nuisance when reflectors have dip. For this reason, we develop migration methods here and in the next chapter for forming images from hypothetical zero-offset seismic experiments. Although there is usually ample data recorded near zerooffset, we never record purely zero-offset seismic data. However, when we consider offset and dip together in chapter ?? we will encounter a widely-used technique (dip-moveout) that often converts finite-offset data into a useful estimate of the equivalent zero-offset data. For this reason, zero-offset migration methods are widely used today in industrial practice. Furthermore the concepts of zero-offset migration are the simplest starting point for approaching the complications of finite-offset migration.