SUSYNLV - SYNthetic seismograms for Linear Velocity function		

 susynlv >outfile [optional parameters]				

 Optional Parameters:							
 nt=101                 number of time samples				
 dt=0.04                time sampling interval (sec)			
 ft=0.0                 first time (sec)				
 kilounits=1            input length units are km or kilo-feet		
			 =0 for m or ft					
                        Note: Output (sx,gx,offset) are always m or ft 
 nxo=1                  number of source-receiver offsets		
 dxo=0.05               offset sampling interval (kilounits)		
 fxo=0.0                first offset (kilounits, 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 (kilounits)		
 fxm=0.0                first midpoint (kilounits)			
 nxs=101                number of shotpoints (see notes below)		
 dxs=0.05               shotpoint sampling interval (kilounits)	
 fxs=0.0                first shotpoint (kilounits)			
 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 (kilounits/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=1                   =1 to include obliquity factors		
 tmin=10.0*dt           minimum time of interest (sec)			
 ndpfz=5                number of diffractors per Fresnel zone		
 verbose=0              =1 to print some useful information		

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. Do this by putting	
additional ref= entries on the commandline. 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.	


 Credits: CWP Dave Hale, 09/17/91,  Colorado School of Mines
	    UTulsa Chris Liner 5/22/03 added kilounits flag

 Trace header fields set: trid, counit, ns, dt, delrt,
				tracl. tracr, fldr, tracf,
				cdp, cdpt, d2, f2, offset, sx, gx