DOCUMENTATION
SYNOPSIS
PERL PROGRAM NAME: SUCCEPSTRUM - Compute the complex CEPSTRUM of a seismic trace "
AUTHOR: Juan Lorenzo (Perl module only)
DATE:
DESCRIPTION:
Version:
USE
NOTES
Examples
SEISMIC UNIX NOTES
SUCCEPSTRUM - Compute the complex CEPSTRUM of a seismic trace "
sucepstrum < stdin > stdout
Required parameters:
none
Optional parameters:
sign1=1 sign of real to complex transform
sign2=-1 sign of complex to complex (inverse) transform
...phase unwrapping .....
mode=ouphase Oppenheim's algorithm for phase unwrapping
=suphase simple unwrap phase
unwrap=1 |dphase| > pi/unwrap constitutes a phase wrapping
(operative only for mode=suphase)
trend=1 deramp the phase, =0 do not deramp the phase
zeromean=0 assume phase starts at 0, =1 phase is zero mean
Notes:
The cepstrum is defined as the fourier transform of the the decibel
spectrum, as though it were a time domain signal.
CC(t) = FT[ln[T(omega)] ] = FT[ ln|T(omega)| + i phi(omega) ]
T(omega) = |T(omega)| exp(i phi(omega))
phi(omega) = unwrapped phase of T(omega)
Phase unwrapping:
The mode=ouphase uses the phase unwrapping method of Oppenheim and
Schaffer, 1975, which operates integrating the derivative of the phase
The mode=suphase generates unwrapped phase assuming that jumps
in phase larger than dphase=pi/unwrap constitute a phase wrapping. In this case
the jump in phase is replaced with the average of the jumps in phase
on either side of the location where the suspected phase wrapping occurs.
In either mode, the user has the option of de-ramping the phase, by
removing its linear trend via trend=1 and of deciding whether the
phase starts at phase=0 or is of zero mean via zeromean=1.
Author: John Stockwell, Dec 2010
based on sucepstrum.c by:
Credits:
Balazs Nemeth of Potash Corporation of Saskatchewan Inc.
given to CWP in 2008
CHANGES and their DATES
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 mode
sub phase
sub sign1
sub sign2
sub trend
sub unwrap
sub zeromean
sub get_max_index
max index = number of input variables -1