This section details how multiples are generated by convolution of shot gathers.
For a 1-D earth, the convolution can be done directly in the
*f*-*k* domain. For a 2-D earth, the convolution becomes nonstationary.
In addition, one convolution of the shot gathers tends to overpredict
high-order multiples.

If *p*(*g*|*s*) represents a single frequency component of the
primary reflected wavefield recorded at *g* after an impulsive shot at
*s*, then the *first-order* surface-related multiple,
*m*(*g*|*s*), can be computed with a Kirchhoff-style integral over the
reflection surface:

(10) |

Figure 12

- One-dimensional earth and impulsive source
- Two-dimensional earth
- Limitations of the multiple prediction using real data

4/29/2001