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Extraction of structural and dynamic properties of forests from polarimetric-interferometric SAR data affected by temporal decorrelation / Marco Lavalle in IEEE Transactions on geoscience and remote sensing, vol 53 n° 9 (September 2015)  

Public [article]  inIEEE Transactions on geoscience and remote sensing > vol 53 n° 9 (September 2015) . - pp 4752 - 4767 Titre : Extraction of structural and dynamic properties of forests from polarimetric-interferometric SAR data affected by temporal decorrelation Type de document : Article/Communication Auteurs : Marco Lavalle, Auteur ; S. Hensley, Auteur Année de publication : 2015 Article en page(s) : pp 4752 - 4767 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications [Termes IGN] bande L [Termes IGN] cohérence (physique) [Termes IGN] décorrélation [Termes IGN] hauteur des arbres [Termes IGN] Massachusetts (Etats-Unis) [Termes IGN] Pol-INSAR [Termes IGN] polarimétrie radar Résumé : (Auteur) This paper addresses the important yet unresolved problem of estimating forest properties from polarimetric-interferometric radar images affected by temporal decorrelation. We approach the problem by formulating a physical model of the polarimetric-interferometric coherence that incorporates both volumetric and temporal decorrelation effects. The model is termed random-motion-over-ground (RMoG) model, as it combines the random-volume-over-ground (RVoG) model with a Gaussian-statistic motion model of the canopy elements. Key features of the RMoG model are: 1) temporal decorrelation depends on the vertical structure of forests; 2) volumetric and temporal coherences are not separable as simple multiplicative factors; and 3) temporal decorrelation is complex-valued and changes with wave polarization. This third feature is particularly important as it allows compensating for unknown levels of temporal decorrelation using multiple polarimetric channels. To estimate model parameters such as tree height and canopy motion, we propose an algorithm that minimizes the least square distance between model predictions and complex coherence observations. The algorithm was applied to L-band NASA's Uninhabited Aerial Vehicle Synthetic Aperture Radar data acquired over the Harvard Forest (Massachussetts, USA). We found that the RMS difference at stand level between estimated RMoG-model tree height and NASA's lidar Laser Vegetation and Ice Sensor tree height was within 12% of the lidar-derived height, which improved significantly the RMS difference of 37% obtained using the RVoG model and ignoring temporal decorrelation. This result contributes to our ability of estimating forest biomass using in-orbit and forthcoming polarimetric-interferometric radar missions. Numéro de notice : A2015-524 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2015.2409066 Date de publication en ligne : 13/04/2015 En ligne : https://doi.org/10.1109/TGRS.2015.2409066 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=77535 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
065-2015091	SL	Revue	Centre de documentation	Revues en salle	Disponible

Geodetically accurate InSAR data processor / H. Zebker in IEEE Transactions on geoscience and remote sensing, vol 48 n° 12 (December 2010)  

Public [article]  inIEEE Transactions on geoscience and remote sensing > vol 48 n° 12 (December 2010) . - pp 4309 - 4321 Titre : Geodetically accurate InSAR data processor Type de document : Article/Communication Auteurs : H. Zebker, Auteur ; S. Hensley, Auteur ; P. Shanker, Auteur ; C. Wortham, Auteur Année de publication : 2010 Article en page(s) : pp 4309 - 4321 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications [Termes IGN] coin réflecteur [Termes IGN] compensation [Termes IGN] image ALOS-PALSAR [Termes IGN] image radar moirée [Termes IGN] interféromètrie par radar à antenne synthétique [Termes IGN] précision du positionnement [Termes IGN] superposition d'images Résumé : (Auteur) We present a new interferometric synthetic aperture radar (InSAR) processing approach that capitalizes on the precise orbit tracking that is available with modern radar satellites. Our method uses an accurate orbit information along with motion-compensation techniques to propagate the radar echoes to positions along a noninertial virtual orbit frame in which the location and focusing equations are particularly simple, so that images are focused without requiring autofocus techniques and are computed efficiently. Motion compensation requires two additional focus correction phase terms that are implemented in the frequency domain. If the images from an interferometric pair or stack are all computed along the same reference orbit, flat-Earth topographic correction is not needed, and image coregistration is simplified, obviating many difficulties that are often encountered in InSAR processing. We process several data sets collected by the ALOS PALSAR instrument and find that the geodetic accuracy of the radar images is 10-20 m, with up to 20 m of additional image distortion needed to align 100 km x 100 km scenes with reference digital elevation models. We validated the accuracy by using both known radar corner reflector locations and by the registration of the interferograms with digital maps. The topography-corrected interferograms are free from all geometric phase terms, and they clearly show the geophysical observables of crustal deformation, atmospheric phase, and ionospheric phase. Numéro de notice : A2010-513 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2010.2051333 Date de publication en ligne : 15/07/2010 En ligne : https://doi.org/10.1109/TGRS.2010.2051333 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30705 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
065-2010121	RAB	Revue	Centre de documentation	En réserve L003	Disponible