A great many processes are limited by the
requirement to avoid **spatial alias**ing--that no wavelength
should be shorter
than twice the sampling interval on the data wave field.
This condition forces costly expenditures in 3-D reflection
data acquisition and yields a mathematical dichotomy
between data processing in exploration seismology and
data processing in earthquake seismology.

The simple statement of the spatial Nyquist requirement
oversimplifies real life.
Recently, S. **Spitz** (1991) showed astonishing results
that seem to violate the Nyquist requirement.
In fact they force us to a deeper understanding of it.
In this chapter we will discuss many new opportunities
that promise much lower data-acquisition costs
and should also reduce the conceptual gap
between exploration and earthquake seismology.

- INTRODUCTION TO ALIASING
- MISSING DATA IN ONE DIMENSION
- MISSING DATA AND UNKNOWN FILTER
- 2-D INTERPOLATION BEYOND ALIASING
- A FULLY TWO-DIMENSIONAL PE FILTER
- TOMOGRAPHY AND OTHER APPLICATIONS
- References

10/21/1998