In the general case, modeling multiples becomes more expensive. Equation
() is not valid anymore (except for smoothly varying
media), and the convolution becomes nonstationary (shot
gathers are different from one location to another).
Hence, the wavefield is not only a function of offset, *h*, but also
depends on another spatial coordinate such as shot location *s*. In
3-D, the integral in equation spans the entire
acquisition plane van Dedem (2002), which makes the prediction very expensive.
Introducing the nonstationary convolution, equation () can be
written as

(149) |

(150) | ||

5/5/2005