|
Titel |
Application of multifractal analysis to the study of SAR features and oil spills on the ocean surface |
VerfasserIn |
A. M. Tarquis, A. Platonov, A. Matulka, J. Grau, E. Sekula, M. Diez, J. M. Redondo |
Medientyp |
Artikel
|
Sprache |
Englisch
|
ISSN |
1023-5809
|
Digitales Dokument |
URL |
Erschienen |
In: Nonlinear Processes in Geophysics ; 21, no. 2 ; Nr. 21, no. 2 (2014-03-28), S.439-450 |
Datensatznummer |
250120904
|
Publikation (Nr.) |
copernicus.org/npg-21-439-2014.pdf |
|
|
|
Zusammenfassung |
The use of synthetic aperture radar (SAR) to investigate the ocean surface
provides a wealth of useful information that is very seldom used to its full
potential. Here we will discuss the application of multifractal techniques to
detect oil spills and the dynamic state of the sea regarding turbulent
diffusion. We present different techniques in order to relate the shape of
the multifractal spectral functions and the maximum fractal dimension to the
behaviour of the ocean surface. We compare eddy and sheared dominated flows
with convective driven flows and discuss the different features and
observation methods. We also compare the scaling of different oil spills
detected by means of SAR images. Recent spills and weathered ones are
selected and compared to investigate their behaviour in different spatial and
temporal ranges. We calculate the partition function based on the grey
intensity value of each SAR pixel deriving several types of multifractal
spectra as a function of spill residence time estimated for each image. Image
manipulations are seen to reduce the speckle noise and thus distinguish much
better the texture of the oil spill images. The results are used to discuss
how eddy diffusivity may be estimated and used in a description of the ocean
surface using a simple turbulence kinematic simulation model to predict the
shape of oil spills. Differences in the multifractal spectrum among SAR
images may detect the slicks due to plankton and also provide information on
the age of the oil spills, on the Lagrangian turbulent structure and on ocean
surface diffusivity. |
|
|
Teil von |
|
|
|
|
|
|