SYNOPSIS

PERL PROGRAM NAME:

AUTHOR: Juan Lorenzo (Perl module only)

DATE:

DESCRIPTION:

Version:

USE

NOTES

Examples

SYNOPSIS

SEISMIC UNIX NOTES SUMIGPSTI - MIGration by Phase Shift for TI media with turning rays

sumigpsti <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=

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

tmig=0.0	times corresponding to interval velocities in vmig	

vnmig=1500.0	interval NMO velocities corresponding to times in tmig	

vmig=1500.0	interval velocities corresponding to times in tmig	

etamig=0.0	interval eta values corresponding to times in tmig	

vnfile=	binary (non-ascii) file containing NMO velocities vn(t)	

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

etafile=	binary (non-ascii) file containing eta values eta(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					



Notes:								

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



The tmig, vnmig, vmig and etamig arrays specify an interval values	

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 vnfile is specified,

then the tmig and vnmig arrays are ignored.				



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

of the trace header field delrt.					



Trace header fields accessed:  ns and dt				

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 etafile

sub etamig

sub ltaper

sub nxpad

sub tmig

sub verbose

sub vfile

sub vmig

sub vnfile

sub vnmig

sub get_max_index

max index = number of input variables -1