Parametres ==================
seisfile      =DATA/viri2
modelfile     =DATA/snaps
nt            =750
dt            => will be calculated from stability criterion
dx            =10.
nop           =2
izfree        =5                           ! izfree >= nop/2+1
Model -----------------------
model_type    =1
vs0           =2828.427
vp0           =4242.641
rho0          =2000.
Source ----------------------
isx           =325
isz           =325
source_type   =2
aa            =50.
it0           =100
alpha         =20.
Receivers------------------------------
xa            =350
xe            =350
irec          =1
izrec         =350
isamp         =1
ssamp         =100
JUNK------------------------------
icheck        =100
isnap         =100
iout          =4
nabs          =0
