Fdmod2 - Finite-Difference MODeling (2nd order) for acoustic wave equation
Fdmod2 <vfile >wfile nx= nz= tmax= xs= zs= [optional parameters]
stdin - sepfile
file containing velocity[nx][nz]
stdout - sepfile
file containing waves[nx][nz] for time steps
tmax - float
maximum time
src_file - sepfile
file (2,nsrc) containg src locations (z,x)
xs - float*
x coordinates of sources
zs - float*
z coordinates of source
nt - int
[1+tmax/dt] number of time samples (dt determined for stability)
mt - int
[1] number of time steps (dt) per output time step
fmax -float
[vmin/(10.0*h)] maximum frequency in source wavelet
fpeak -float
[0.5*fmax] peak frequency in ricker wavelet
dfile- sepfile
input file containing density[nx][nz]
vsx - float
[o2] x coordinate of vertical line of seismograms
hsz - float
[o1] z coordinate of horizontal line of seismograms
vsfile -sepfile
[none] output file for vertical line of seismograms[nz][nt]
hsfile -sepfile
[none] output file for horizontal line of seismograms[nx][nt]
ssfile -sepfile
[none] output file for source point seismograms[nt]
verb -int
[0] =1 for diagnostic messages, =2 for more
abs - int[4]
[1,1,1,1] Absorbing boundary conditions on top,left,bottom,right
sides of the model. 0,1,1,1 for free surface condition on the top
pml_max - float
[1000.0] PML absorption parameter
pml_thick - int
[0] half-thickness of pml layer (0 = do not use PML)
1. This is sufdmod2 for SEPlib
2. The sources specification order is
a. src_file - seplib file containing source locations
b. xs=3,4,5 zs=4,5,6 command list of sources
c. oxs= dxs= nxs= ozs= dzs nzs - which will increase the dimensionality of the output by 1 ( ., , nxz, nzs)
Notes: | |
This program uses the traditional explicit second order differencing | |
method. |
Two different absorbing boundary condition schemes are available. The first is a traditional absorbing boundary condition scheme created by Hale, 1990. The second is based on the perfectly matched layer (PML) method of Berenger, 1995.
seis/model