On the Capability of the Degree of Polarization for Oil Spill Observation
Attilio Gambardella(1), Ferdinando Nunziata(1) and Maurizio Migliaccio(1)
(1) Università degli Studi di Napoli Parthenope, Centro Direzionale, Isola C4., 80100 Napoli, Italy
The degree of polarization (Dp) is an important invariant parameter to characterize the purity of an electromagnetic field. It deals with the amount of intensity associated to the polarized part of an electromagnet field with respect to the total field and, as was proven by Wolf, is closely related to the degree of correlation between the orthogonal components of the electric field. Most of the practical applications of Dp are related to the electronic and photonic fields, while, most of the current research studies are aimed at extending the Dp formalism, which is well established for two-dimensional planar electromagnetic fields, to cover arbitrary three-dimensional fields which may have non-planar wave fronts.
Only in seminal studies the Dp have been considered as an useful feature for polarimetric remote sensing applications and no studies at all have been accomplished about the Dp capability to assist polarimetric based oil spill detection procedures. In this study the Dp sensitivity with respect to the different scattering mechanisms which characterize the sea surface with and without oil slicks is firstly investigated. A novel and very effective filtering technique, based on the Dp have been developed and tested over Multi Look Complex (MLC) fully polarimetric SIR-C/X- Synthetic Aperture Radar (SAR) data. First experiments showed the capability of the Dp to emphasize the presence of oil slicks over the sea background in SAR images under low to moderate sea state conditions.
Keywords: ESA European
Space Agency - Agence spatiale europeenne,
observation de la terre, earth observation,
satellite remote sensing,
teledetection, geophysique, altimetrie, radar,
chimique atmospherique, geophysics, altimetry, radar,