Sub-pixellic Methods for Sidelobes Suppression and Strong Targets Extraction in Single Look Complex SAR Images

Abstract : SAR images display very high dynamic ranges. Man-made structures (like buildings or power towers) produce echoes that are several orders of magnitude stronger than echoes from diffusing areas (vegetated areas) or from smooth surfaces (e.g., roads). The impulse response of the SAR imaging system is thus clearly visible around the strongest targets: sidelobes spread over several pixels, masking the much weaker echoes from the background. To reduce the sidelobes of the impulse response, images are generally spectrally apodized, trading resolution for a reduction of the sidelobes. This apodization procedure (global or shift-variant) introduces spatial correlations in the speckle-dominated areas which complicates the design of estimation methods. This paper describes strategies to cancel sidelobes around point-like targets while preserving the spatial resolution and the statistics of speckle-dominated areas. An irregular sampling grid is built to compensate the sub-pixel shifts and turn cardinal sines into discrete Diracs. A statistically grounded approach for point-like target extraction is also introduced, thereby providing a decomposition of a single look complex image into two components: a speckle-dominated image and the point-like targets. This decomposition can be exploited to produce images with improved quality (full resolution and suppressed sidelobes) suitable both for visual inspection and further processing (multi-temporal analysis, despeckling, interferometry).
Liste complète des métadonnées

Littérature citée [53 références]  Voir  Masquer  Télécharger

https://hal-imt.archives-ouvertes.fr/hal-01570857
Contributeur : Rémy Abergel <>
Soumis le : lundi 13 novembre 2017 - 15:05:46
Dernière modification le : jeudi 11 janvier 2018 - 06:20:36

Fichier

preprint_sardecomp_r1.pdf
Fichiers produits par l'(les) auteur(s)

Identifiants

  • HAL Id : hal-01570857, version 2

Collections

Citation

Rémy Abergel, Loïc Denis, Saïd Ladjal, Florence Tupin. Sub-pixellic Methods for Sidelobes Suppression and Strong Targets Extraction in Single Look Complex SAR Images. 2017. 〈hal-01570857v2〉

Partager

Métriques

Consultations de la notice

80

Téléchargements de fichiers

68