f Interpolation beyond aliasing by (t,x)-domain PEFs

A great many processes are limited by the simple statement of the spatial Nyquist requirement-that no wavelength be shorter than twice the sampling interval on the data wavefield. This condition forces costly expenditures in 3-D reflection data acquisition. The sirnple statement of the Nyquist requirement oversimplifies reallife. At the 1989 SEG meeting, S. Spitz showed astonishing 2-D interpolations that seem to violate the Nyquist requirement and so they give us a deeper understanding of it. The real Nyquist limitation is on the spectral bandwidth, not on the maximum frequency, and Spitz' results can be explained by saying that the bandwidth need not be contiguous. We often characterize data as "good" or "noisy" when we really mean it contains "few" or "many" plane wave events. For noisy data there is no escaping the simple form of the Nyquist limitation but with good data it seems we can.