NMO equation

The NMO equation defines the normal moveout function. The total reflection (or offset) time tr is given by the NMO (or zero-offset) time tn, the offset x and the velocity of the medium V:


 * $$t^2_\mathrm{r} = t^2_\mathrm{n} + \frac{x^2}{V^2}$$

where, for an apparent depth d to a zero-dipping reflector in the subsurface,


 * $$t_\mathrm{n} = \frac{2d}{V}\ $$