DOCUMENTATION
SYNOPSIS
PERL PROGRAM NAME: SUCCWT - Complex continuous wavelet transform of seismic traces
AUTHOR: Juan Lorenzo (Perl module only)
DATE:
DESCRIPTION:
Version: USE
NOTES
Examples
SEISMIC UNIX NOTES
SUCCWT - Complex continuous wavelet transform of seismic traces
succwt < tdata.su > tfdata.su [optional parameters]
Required Parameters:
None
Optional Parameters:
noct=5 Number of octaves (int)
nv=10 Number of voices per octave (int)
fmax=Nyq Highest frequency in transform
p=-0.5 Power of scale value normalizing CWT
=0 for amp-preserved spec. decomp.
c=1/(2*fmax) Time-domain inverse gaussian damping parameter
(bigger c means more wavelet oscillations,
default gives minimal oscillations)
k=1 Use complex Morlet as wavelet transform kernel
=2 use Fourier kernel ... Exp[i 2 pi f t]
fs=1 Use dyadic freq sampling (CWT standard, 36honors
noct, nv)
=2 use linear freq sampling (Fourier standard)
df=1 Frequency sample interval in Hz (used only for fs=2)
NOTE: not yet implimented (hardwired to df=1)
dt=(from tr.dt) Sample interval override (in secs, if time data)
verbose=0 Run silent, except echo c value. (=1 for more info)
Examples:
This generates amplitude spec of the CWT impulse response (IR).
suspike ntr=1 ix1=1 nt=125 | succwt | suamp | suximage &
Real part of Fourier IR with linear freq sampling:
suspike ntr=1 ix1=1 nt=125 | succwt k=2 fs=2 | suamp mode=real | suximage &
Real part of Fourier IR with dyadic freq sampling:
suspike ntr=1 ix1=1 nt=125 | succwt k=2 | suamp mode=real | suximage &
Inverse CWT: (within a constant scale factor)
... | succwt p=-1 | suamp mode=real | sustack key=cdp > inv.su
Notes:
1. Total number of scales: nscale = noct*nv
2. Each input trace spawns nscale complex output traces
3. Lowest frequency in the transform is fmax/( 2^(noct-1/nv) )
4. Header field (cdp) used as cwt spectrum counter
5. Header field (cdpt) used as scale counter within cwt spectrum
6. Header field (gut) holds number of cwt scales `na'
7. Header field (unscale) holds CWT scale `a'
Header fields set: tracl, cdp, cdpt, unscale, gut
Copyright (c) University of Tulsa, 2003-4.
All rights reserved.
Author: UTulsa: Chris Liner, SEP: Bob Clapp
todo:
fix fs=2 case to allow df not equal to 1
History:36
6/18/04
major overhaul by Clapp, including fourier implementation.
Speedup ~ 41 times (4100 %)
2/20/04
made p=-0.5 default
2/16/04
added p option to experiment with CWT normalization
2/12/04
replace fb (bandwidth parameter) with c (t-domain gaussian damping const.)
2/10/04 --- in sync with EAS paper in prep
changed morlet scaling (c = 1) to preserve time-domain peak amplitude
changed morlet exp sign to std CWT definition (conjugate) and
mathematica result that only gives positive freq gaussian with neg exp
1/26/04
added linear frequency sampling option36
1/23/04
figured out fb and made it a getpar
key: Look at real ccwt output and determine fb by number of
oscillations desired: Default gives -+-+-+-
1/20/04
beefed up verbose output
dimension wavelet to length 2*nt and change correlation call
... this is done to avoid conv edge effects
1/19/04
added fourier wavlet option for comparison with Fourier Transform action
1/17/04
complex morlet amp scaling now set to preserve first scale amp with IR
1/16/04
added dt getpar to handle depth input properly
preserves first tracl so tracl is ok after spice
11/11/03
initial version
Trace header fields set: tracl, cdp, cdpt, unscale, gutCHANGES 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 c
sub df
sub dt
sub fmax
sub fs
sub k
sub noct
sub nscale
sub ntr
sub nv
sub p
sub verbose
sub get_max_index
max index = number of input variables -1