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Titre	Optimization of the degree of polarization for enhanced ship detection using polarimetric RADARSAT-2
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Auteur	Touzi, R; Hurley, J; Vachon, P W
Source	IEEE Transactions on Geoscience and Remote Sensing (Institute of Electrical and Electronics Engineers) vol. 53, no. 10, 7118674, 2015 p. 5403-5424, https://doi.org/10.1109/TGRS.2015.2422134
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Année	2015
Séries alt.	Ressources naturelles Canada, Contribution externe 20150424
Éditeur	Institute of Electrical and Electronics Engineers (IEEE)
Document	publication en série
Lang.	anglais
DOI	https://doi.org/10.1109/TGRS.2015.2422134
Media	papier; en ligne; numérique
Formats	pdf
Sujets	télédétection; géophysique; Sciences et technologie
Programme	Science de la télédétection spatiale
Diffusé	2015 06 05
Résumé	(disponible en anglais seulement) The scattered wave is represented in terms of two independent and rotation invariant parameters: the degree of polarization (DoP) and the total scattered intensity R0. The scattered wave polarization signature is introduced as a convenient graphical representation of the variations of the two scattered wave observable parameters as a function of the transmitting antenna polarization. It is shown that the signature of the DoP and the total scattered intensity (R0) provide information on ocean and ship scattering that is complementary to that provided by the conventional received wave intensity polarization signature. While R0 polarization signature of the ocean's Bragg scattering is sensitive to wind speed and synthetic aperture radar illumination angle, the DoP polarization signature appears to depend mainly on ocean surface roughness. The large dynamic range and low pedestal height of ship DoP polarization signature, in comparison with that of the ocean, favors the use of DoP for ship detection in comparison with R0. Optimization of the scattered wave parameters appears to be a convenient tool for efficient ship detection. The scattered wave optimization technique introduced by R. Touzi et al. in the nineties, is reconsidered and applied for enhanced ship detection. It is shown that the excursion of DoP, delta-p, and the minimum DoP, pmin, permits a significant improvement in ship-sea contrast in comparison with conventional (i.e., scalar) single channel polarizations (HH, VV, and HV). The additional information provided by the maximum DoP, pmax solves for ship ambiguities with land targets. Quantification of the ship-ocean contrast is reconsidered in the context of nonstationary ship signal. The ship peak signal quantification appears to be the most suitable method for accurate measurement of ship-ocean contrast in the presence of a nonstationary ship signal. The local pmin performs better than the peak of delta-p and single polarizations (HH, VV, and HV). The added value of polarimetric RS2 information for ship detection is demonstrated using wide swath (50 km) polarimetric RADARSAT-2 data collected at 29° and 40° incidence angle over vessels (validated with Automatic Identification System data) in the Strait of Georgia, near Vancouver, Canada.
Sommaire	(Résumé en langage clair et simple, non publié) La surveillance maritime, à partir de données radar à synthèse d'ouverture (RSO)en polarisation singulière et en double polarisation, a été largement étudiée en utilisant des données RADARSAT-1 et ENVISAT. Ces études ont démontré des résulats très prometteurs pour la détection de bateaux et l'identification de fuites de pétrole. Cependant, il est admis aujourd'hui que les performances des modes en polarisation singulière (ou double)et à large couverture sont limitées en présence de petits bateaux. Il existe un besoin urgent pour des capteurs d'observation de la Terre qui permettent une meilleure détection de petits navires. Dans cette étude, une méthode avancée est introduite pour la détection de bateaux à partir des données polarimétriques de RADARSAT-2. Cette nouvelle method, qui exploite pleinement la valeur ajoutée de l'information polarimétrique, permet le rehaussement significatif de petits navires en comparaison avec les modes conventionnel en polarisation singulière (HH, HV and VV) et en double polarisation (HH-HV, VV-VH, et Compact RSO).
GEOSCAN ID	312110