SUEIPOFI - EIgenimage (SVD) based POlarization FIlter for
three-component data
sueipofi 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