SYNOPSIS
PERL PROGRAM NAME:
AUTHOR: Juan Lorenzo (Perl module only)
DATE:
DESCRIPTION:
Version:
USE
NOTES
Examples
SYNOPSIS
SEISMIC UNIX NOTES SUPOLAR - POLarization analysis of three-component data
supolar <stdin [optional parameters]
Required parameters:
none
Optional parameters:
dt=(from header) time sampling intervall in seconds
wl=0.1 correlation window length in seconds
win=boxcar correlation window shape, choose "boxcar",
"hanning", "bartlett", or "welsh
file=polar base of output file name(s)
rl=1 1 = rectilinearity evaluating 2 eigenvalues,
2, 3 = rectilinearity evaluating 3 eigenvalues
rlq=1.0 contrast parameter for rectilinearity
dir=1 1 = 3 components of direction of polarization
(the only three-component output file)
tau=0 1 = global polarization parameter
ellip=0 1 = principal, subprincipal, and transverse
ellipticities e21, e31, and e32
pln=0 1 = planarity measure
f1=0 1 = flatness or oblateness coefficient
l1=0 1 = linearity coefficient
amp=0 1 = amplitude parameters: instantaneous,
quadratic, and eigenresultant ir, qr, and er
theta=0 1, 2, 3 = incidence angle of principal axis
phi=0 1, 2, 3 = horizontal azimuth of principal axis
angle=rad unit of angles theta and phi, choose "rad",
"deg", or "gon
all=0 1, 2, 3 = set all output flags to that value
verbose=0 1 = echo additional information
Notes:
Three adjacent traces are considered as one three-component
dataset.
Correct calculation of angles theta and phi requires the first of
these traces to be the vertical component, followed by the two
horizontal components (e.g. Z, N, E, or Z, inline, crossline).
Significant signal energy on Z is necessary to resolve the 180 deg
ambiguity of phi (options phi=2,3 only).
Each calculated polarization attribute is written into its own
SU file. These files get the same base name (set with "file=")
and the parameter flag as an extension (e.g. polar.rl).
In case of a tapered correlation window, the window length wl may
have to be increased compared to the boxcar case, because of their
smaller effective widths (Bartlett, Hanning: 1/2, Welsh: 1/3).
Range of values:
parameter option interval
rl 1, 2 0.0 ... 1.0 (1.0: linear polarization)
rl 3 -1.0 ... 1.0
tau, l1 1 0.0 ... 1.0 (1.0: linear polarization)
pln, f1 1 0.0 ... 1.0 (1.0: planar polarization)
e21, e31, e32 1 0.0 ... 1.0 (0.0: linear polarization)
theta 1 -pi/2... pi/2 rad
theta 2, 3 0.0 ... pi/2 rad
phi 1 -pi/2... pi/2 rad
phi 2 -pi ... pi rad (see notes above)
phi 3 0.0 ... 2 pi rad (see notes above)
Author: Nils Maercklin,
GeoForschungsZentrum (GFZ) Potsdam, Germany, 1998-2001.
E-mail: nils@gfz-potsdam.de
References:
Jurkevics, A., 1988: Polarization analysis of three-component
array data. Bulletin of the Seismological Society of America,
vol. 78, no. 5.
Kanasewich, E. R., 1981: Time Sequence Analysis in Geophysics.
The University of Alberta Press.
Kanasewich, E. R., 1990: Seismic Noise Attenuation.
Handbook of Geophysical Exploration, Pergamon Press, Oxford.
Meyer, J. H. 1988: First Comparative Results of Integral and
Instantaneous Polarization Attributes for Multicomponent Seismic
Data. Institut Francais du Petrole.
Press, W. H., Teukolsky, S. A., Vetterling, W. T., and Flannery, B. P.
1996: Numerical Recipes in C - The Art of Scientific Computing.
Cambridge University Press, Cambridge.
Samson, J. C., 1973: Description of the Polarisation States of Vector
Processes: Application to ULF Electromagnetic Fields.
Geophysical Journal vol. 34, p. 403-419.
Sheriff, R. E., 1991: Encyclopedic Dictionary of Exploration
Geophysics. 3rd ed., Society of Exploration Geophysicists, Tulsa.
Trace header fields accessed: ns, dt
Trace header fields modified: noneUser'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 all
sub angle_units
sub azimuth_principal_axes
sub base_file_name_out
sub components_polarization
sub correlation_window_type
sub correlation_window_length_s
sub amp
sub angle
sub dir
sub dt
sub ellip
sub f1
sub flatness
sub file
sub l1
sub phi
sub pln
sub rl
sub rlq
sub tau
sub theta
sub verbose
sub win
sub wl
sub get_max_index
max index = number of input variables -1