Iso2d - Isotropic modeling
Iso2d par=Par < Hsourcefn > Hverticalgeophone
velocity model file(c11,c44,and rho)(next 4 from file)
#of z grid points(becomes nz in the program)max=400
#of x grid points(becomes nx in the program)max=400
1 z grid point spacing (becomes dz in the program)
x grid point spacing (becomes dx in the program) The constants are 3 panels in order c11,c44,rho and are stored nz(fast) by nx
Recall Vp=sqrt(c11/rho) and Vs=sqrt(c44/rho)
Source function file (next two pars from file)
length of source
time sample interval (this will be used for calculations)so it should be within stability limits
number of time steps to run, max=4000
# of shots to make (default=1)
Position of first source (in grid points)
vertical force =1; horizontal =2; shear source =3 explosive force=4
shot increment (in x grid points) default=1
Position of first receiver for first shot default=1
Number of receivers default=nx
Shot depth (grid points)
depth of geophones (in grid points)
free surface (default) =1; absorbing =0
number of time steps between snapshots
receiver spread rollalong with the shots? 1=yes=default; 0=no
maximum velocity in model (optional stability check) for stability vpmax*dt/dx <.5 since isotropic sqrt(max(c11)/rho)*dt/dx <.5 for no dispersion (vmin/fmax)/dx >2.8
Verbose (1) or not (0,default)
Program to do isotropic heterogenous elastic modelling in 2d, explicit finite-difference 2nd order in time 16th order in x and z
output file for the vertical component seismogram
seis/model