Sigseg: a tool for the detection of position and velocity discontinuities in geodetic time-series
-- by Alfonso Vitti
The technical paper which describes this code is published in
GPS Solutions, Volume 16, Number 3, July 2012, pages 405-410, DOI: 10.1007/s10291-012-0257-9,
"Sigseg: a tool for the detection of position and velocity discontinuities in geodetic time-series"
by Alfonso Vitti
University of Trento, Trento - Italy
alfonso.vitti@ing.unitn.it
Abstract
The detection of discontinuities in geodetic data is an ever more important topic
due to both the influence of discontinuities on the results of models and analyses,
and to the very meaning of discontinuities in physical phenomena. In this work,
a mathematical model originally formulated for the approximation of images by
smooth functions is considered and described in 1D. The model was designed
to smooth the data while preserving and detecting its discontinuities following
a variational approach. A second and more complex model for the approximation of
images by functions with smooth first derivatives is also available. This second
model was designed to smooth the data while preserving and detecting the
discontinuities of the data, but also those of the first derivative. Such
interesting features suggest the chance to apply this second model to 1D geodetic
data, in particular for the detection of discontinuities and velocity changes in
position time-series rather than for signal smoothing. The sigseg (signal segmentation)
program implements the two variational models in one dimension and it is presented
herein with applications to some geodetic data. Only essential mathematical elements
are sketched in the paper and some details on the numerical implementation are given.
The C code (and sample data files) are available within the following *.tgz file:
Gzipped Tar file with Source Code (sigseg_0.9.tgz)
Please check http://www.ing.unitn.it/~vittia/sw
for updates.
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