SYNOPSIS

PERL PROGRAM NAME:

AUTHOR: Juan Lorenzo (Perl module only)

DATE:

DESCRIPTION:

Version:

USE

NOTES

Examples

SYNOPSIS

SEISMIC UNIX NOTES SUPWS - Phase stack or phase-weighted stack (PWS) of adjacent traces

having the same key header word
supws <stdin >stdout [optional parameters]
Required parameters:
none
Optional parameters:
key=cdp key header word to stack on
pwr=1.0 raise phase stack to power pwr
dt=(from header) time sampling intervall in seconds
sl=0.0 window length in seconds used for smoothing
of the phase stack (weights)
ps=0 0 = output is PWS, 1 = output is phase stack
verbose=0 1 = echo additional information
Note:
Phase weighted stacking is a tool for efficient incoherent noise
reduction. An amplitude-unbiased coherency measure is designed
based on the instantaneous phase, which is used to weight the
samples of an ordinary, linear stack. The result is called the
phase-weighted stack (PWS) and is cleaned from incoherent noise.
PWS thus permits detection of weak but coherent arrivals.
The phase-stack (coherency measure) has values between 0 and 1.
If the stacking is over cdp and the PWS option is set, then the
offset header field is set to zero. Otherwise, output traces get
their headers from the first trace of each data ensemble to stack,
including the offset field. Use "sushw" afterwards, if this is
not acceptable.
Author: Nils Maercklin,
GeoForschungsZentrum (GFZ) Potsdam, Germany, 2001.
E-mail: nils@gfz-potsdam.de
References:
B. L. N. Kennett, 2000: Stacking three-component seismograms.
Geophysical Journal International, vol. 141, p. 263-269.
M. Schimmel and H. Paulssen, 1997: Noise reduction and detection
of weak , coherent signals through phase-weighted stacks.
Geophysical Journal International, vol. 130, p. 497-505.
M. T. Taner, A. F. Koehler, and R. E. Sheriff, 1979: Complex
seismic trace analysis. Geophysics, vol. 44, p. 1041-1063.
Trace header fields accessed: ns
Trace header fields modified: nhs, offset

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 key

sub ps

sub pwr

sub sl

sub verbose

sub get_max_index

max index = number of input variables -1