SUSYNLVFTI - SYNthetic seismograms for Linear Velocity function in a factored
Transversely Isotropic medium
susynlvfti >outfile [optional parameters]
Optional Parameters:
nt=101 number of time samples
dt=0.04 time sampling interval (sec)
ft=0.0 first time (sec)
nxo=1 number of source-receiver offsets
dxo=0.05 offset sampling interval (km)
fxo=0.0 first offset (km, see notes below)
xo=fxo,fxo+dxo,... array of offsets (use only for non-uniform offsets)
nxm=101 number of midpoints (see notes below)
dxm=0.05 midpoint sampling interval (km)
fxm=0.0 first midpoint (km)
nxs=101 number of shotpoints (see notes below)
dxs=0.05 shotpoint sampling interval (km)
fxs=0.0 first shotpoint (km)
x0=0.0 distance x at which v00 is specified
z0=0.0 depth z at which v00 is specified
v00=2.0 velocity at x0,z0 (km/sec)
dvdx=0.0 derivative of velocity with distance x (dv/dx)
dvdz=0.0 derivative of velocity with depth z (dv/dz)
fpeak=0.2/dt peak frequency of symmetric Ricker wavelet (Hz)
ref=1:1,2;4,2 reflector(s): "amplitude:x1,z1;x2,z2;x3,z3;...
smooth=0 =1 for smooth (piecewise cubic spline) reflectors
er=0 =1 for exploding reflector amplitudes
ls=0 =1 for line source; default is point source
ob=0 =1 to include obliquity factors
tmin=10.0*dt minimum time of interest (sec)
ndpfz=5 number of diffractors per Fresnel zone
verbose=1 =1 to print some useful information
For transversely isotropic media:
angxs=0.0 angle of symmetry axis with the vertical (degrees)
define the media using either
a=1.0 corresponding to the ratio of elastic coef.(c1111/c3333)
f=0.4 corresponding to the ratio of elastic coef. (c1133/c3333)
l=0.3 corresponding to the ratio of elastic coef. (c1313/c3333)
Alternately use Tompson\'s parameters:
delta=0 Thomsen's 1986 defined parameter
epsilon=0 Thomsen's 1986 defined parameter
ntries=40 number of iterations in Snell's law and offset searches
epsx=.001 lateral offset tolerance
epst=.0001 reflection time tolerance
nitmax=12 max number of iterations in travel time integrations
Notes:
Offsets are signed - may be positive or negative. Receiver locations
are computed by adding the signed offset to the source location.
Specify either midpoint sampling or shotpoint sampling, but not both.
If neither is specified, the default is the midpoint sampling above.
More than one ref (reflector) may be specified. When obliquity factors
are included, then only the left side of each reflector (as the x,z
reflector coordinates are traversed) is reflecting. For example, if x
coordinates increase, then the top side of a reflector is reflecting.
Note that reflectors are encoded as quoted strings, with an optional
reflector amplitude: preceding the x,z coordinates of each reflector.
Default amplitude is 1.0 if amplitude: part of the string is omitted.
Concerning the choice of delta and epsilon. The difference between delta",
and epsilon should not exceed one. A possible break down of the program
is the result. This is caused primarly by the break down in the two point",
ray-tracing. Also keep the values of delta and epsilon between 2 and -2.