Given a common-shot or common-midpoint (CMP) record, the objective of NMO correction is to "flatten" events, that is, align events at later offsets to that of the zero offset. NMO has long been a staple of seismic data processing, used even today for initial velocity analysis and QC purposes. In addition, it can be the domain of choice for many useful processing steps, such as angle muting.
To get started, let us create a 2D seismic dataset containing some hyperbolic events representing reflections from flat reflectors. Events are created with a true RMS velocity, which we will be using as if we picked them from, for example, a semblance panel.
NMO correction consists of applying an offset- and time-dependent shift to each sample of the trace in such a way that all events corresponding to the same reflection will be located at the same time intercept after correction.An arbitrary hyperbolic event at position (t,h) is linked to its zero-offset traveltime t0 by the following equation