SYNOPSIS

PERL PROGRAM NAME:

AUTHOR: Juan Lorenzo (Perl module only)

DATE:

DESCRIPTION:

Version:

USE

NOTES

Examples

SYNOPSIS

SEISMIC UNIX NOTES SUEIPOFI - EIgenimage (SVD) based POlarization FIlter for

           three-component data                                       



sueipofi <stdin >stdout [optional parameters]                         



Required parameters:                                                  

   none                                                               



Optional parameters:                                                  

   dt=(from header)  time sampling intervall in seconds               

   wl=0.1            SVD time window length in seconds                

   pwr=1.0           exponent of filter weights                       

   interp=cubic      interpolation between initially calculated       

                     weights, choose "cubic" or "linear

   verbose=0         1 = echo additional information                  



   file=polar        base name for additional output file(s) of       

                     filter weights (see flags below)                 

   rl1=0             1 = rectilinearity along first principal axis    

   rl2=0             1 = rectilinearity along second principal axis   

   pln=0             1 = planarity                                    





Notes:                                                                

   Three adjacent traces are considered as one three-component        

   dataset.                                                           



   The filter is the sum of the first two eigenimages of the singular 

   value decomposition (SVD) of the signal matrix (time window).      

   Weighting functions depending on linearity and planarity of the    

   signal are applied, additionally. To avoid edge effects, these are 

   interpolated linearily or via cubic splines between initially      

   calculated values of non-overlapping time windows.                 

   The algorithm is based on the assumption that the particle motion  

   trajectory is essentially 2D (elliptical polarization).            



Caveat:                                                               

   Cubic spline interpolation may result in filter weights exceeding  

   the set of values of initial weights. Weights outside the valid    

   interval [0.0, 1.0] are clipped.                                   







Author: Nils Maercklin, 

        GeoForschungsZentrum (GFZ) Potsdam, Germany, 2001.

        E-mail: nils@gfz-potsdam.de





References:

   Franco, R. de, and Musacchio, G., 2000: Polarization Filter with

      Singular Value Decomposition, submitted to Geophysics and

      published electronically in Geophysics online (www.geo-online.org).

   Jurkevics, A., 1988: Polarization analysis of three-comomponent

      array data, Bulletin of the Seismological Society of America, 

      vol. 78, no. 5.

   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.



Trace header fields accessed: ns, dt

Trace header fields modified: none

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 file

sub interp

sub pln

sub pwr

sub rl1

sub rl2

sub verbose

sub wl

sub get_max_index

max index = number of input variables -1

cpanm App::SeismicUnixGui

perl -MCPAN -e shell
install App::SeismicUnixGui