NAME

Aniso2d - anisotropic modeling


SYNOPSIS

Aniso2d par=Par < Hsourcefn > Hverticalgeophone


INPUT PARAMETERS

moduli - file
        velocity model file (c11,c13,c33,c14, and rho ) (next 4 pars
        from this file
n1 - integer
        # of z grid points (becomes nz in the program) max=400
n2 - integer
        # of x grid points (becomes nz in the program) max=400
d1 - real
        z grid point spacing (becomes dz in the program)
d2 - real
        x grid point spacing (becomes dx in the program)
        The constants are in order c11,c13,c33,c44,rho and
        are stored nz(fast) by nx
Hsource - file
       Source function file (next two pars from this file)
n1 - integer
       length of source
d1- real
       time sample interval (this will be used for calculations)
       so it should be within stability limits
nt - integer
       number of time steps to run, max=4000
nsrc- integer #
        of shots to make (default=1)
src_1 - integer
       Position of first source (in grid points)
src_type - integer
       vertical force =1; horizontal =2; shear source =3
       explosive force=4
src_inc - integer
       shot increment (in x grid points) default=1
group_1 - integer
       Position of first receiver for first shot default=1
ngroup - integer
       Number of receivers default=nx
src_depth- integer
       Shot depth (grid points)
geo_depth- integer
       depth of geophones (in grid points)
surf_type- integer
       free surface (default) =1; absorbing =0
snap_i - integer
       number of time steps between snapshots
rollalong- integer
       receiver spread rollalong with the
       shots? 1=yes=default; 0=no
vpmax - real
       maximum velocity in model (optional stability check)
       for stability vpmax*dt/dx <.5
       since anisotropic sqrt(max(c11,c33)/rho)*dt/dx <.5
       for no dispersion (vmin/fmax)/dx >2.8


OUTPUT PARAMETERS

Hverticalgeophone - file
      is output file for the vertical component seismogram


DESCRIPTION

   Program to do anisotropic heterogenous elastic modelling in 2d,
   explicit finite-difference 2nd order in time 16th order in x and z


SEE ALSO

the Iso2d manpage


CATEGORY

seis/model