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.