SYNOPSIS

PERL PROGRAM NAME:

AUTHOR: Juan Lorenzo (Perl module only)

DATE:

DESCRIPTION:

Version:

USE

NOTES

Examples

SYNOPSIS

SEISMIC UNIX NOTES SUSYNLVFTI - SYNthetic seismograms for Linear Velocity function in a

             Factorized 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)				

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=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.

User's notes (Juan Lorenzo) untested

CHANGES and their DATES

Import packages

instantiation of packages

Encapsulated hash of private variables

sub Step

collects switches and assembles bash instructions by adding the program name

sub note

collects switches and assembles bash instructions by adding the program name

sub clear

sub a

sub angxs

sub delta

sub dt

sub dvdx

sub dvdz

sub dxm

sub dxo

sub dxs

sub epsilon

sub epst

sub epsx

sub er

sub f

sub fpeak

sub ft

sub fxm

sub fxo

sub fxs

sub kilounits

sub l

sub ls

sub ndpfz

sub nitmax

sub nt

sub ntries

sub nxm

sub nxo

sub nxs

sub ob

sub ref

sub smooth

sub tmin

sub v00

sub verbose

sub x0

sub xo

sub z0

sub get_max_index

max index = number of input variables -1