## CABRILLO: Acoustic, elastic and poroelastic
finite difference modelling

### Pressure time-snapshots for acoustic sloping bottom

Cabrillo is a staggered Pseudo-spectral finite difference code for
acoustic
elastic and poroelastic media. The advantage of a FD approach is that a
geometric complicated media can be modeled. Staggered grids are
advantageous as
it provides more accuracy and can handle larger velocity and density
contrasts
than using a classic grid. In a Pseudo-spectral method the spatial
derivatives
are evaluated by a wavenumber multiplication in the wavenumber domain.
The
advantage of this approach is stability and reduction in memory and the
number
of computations required to obtain a given accuracy. Usually FD codes
cannot
handle attenuation. But, using Biot theory it is also possible to
incorporate
attenuation into the media by increasing the viscosity. Much care has
gone into
obtaining a fast and reliable code. The kernel of the code is based on
a code
from University
of Dallas. The
Temperton
Fourier transform is used as the FFT (obtained from the University of Hamburg).
This allows the number of grid points to be any combination of prime
factors up
to 11.

### Download CABRILLO

P.
Gerstoft, "CABRILLO
1.0: Acoustic, elastic and poroelastic finite difference modelling,"

Peter Gerstoft