SYNOPSIS

PERL PROGRAM NAME:

AUTHOR: Juan Lorenzo (Perl module only)

DATE:

DESCRIPTION:

Version:

USE

NOTES

Examples

SYNOPSIS

SEISMIC UNIX NOTES SUMIGPS - MIGration by Phase Shift with turning rays

 sumigps <stdin >stdout [optional parms]				



 Required Parameters:							

 	None								



 Optional Parameters:							

 dt=from header(dt) or .004	time sampling interval			

 dx=from header(d2) or 1.0	distance between sucessive cdp's

 

 ffil=0

 

 0,0,0.5/dt,0.5/dt  trapezoidal window of frequencies to migrate	

 tmig=0.0		times corresponding to interval velocities in vmig

 vmig=1500.0		interval velocities corresponding to times in tmig

 vfile=		binary (non-ascii) file containing velocities v(t)

 nxpad=0		number of cdps to pad with zeros before FFT	

 ltaper=0		length of linear taper for left and right edges", 

 verbose=0		=1 for diagnostic print				





 tmpdir= 	 if non-empty, use the value as a directory path	

		 prefix for storing temporary files; else if the	

	         the CWP_TMPDIR environment variable is set use		

	         its value for the path; else use tmpfile()		



 Notes:								

 Input traces must be sorted by either increasing or decreasing cdp.	



 The tmig and vmig arrays specify an interval velocity function of time.

 Linear interpolation and constant extrapolation is used to determine	

 interval velocities at times not specified.  Values specified in tmig	

 must increase monotonically.						



 Alternatively, interval velocities may be stored in a binary file	

 containing one velocity for every time sample.  If vfile is specified,

 then the tmig and vmig arrays are ignored.				



 The time of first sample is assumed to be zero, regardless of the value

 of the trace header field delrt.					



 Credits:

	CWP: Dave Hale (originally called supsmig.c)



  Trace header fields accessed:  ns, dt, d2

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 dt

sub dx

sub ffil

sub ltaper

sub nxpad

sub tmig

sub tmpdir

sub verbose

sub vfile

sub vmig

sub get_max_index

max index = number of input variables -1