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Auteur Heresh Fattahi |
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A network-based enhanced spectral diversity approach for TOPS time-series analysis / Heresh Fattahi in IEEE Transactions on geoscience and remote sensing, vol 55 n° 2 (February 2017)
[article]
Titre : A network-based enhanced spectral diversity approach for TOPS time-series analysis Type de document : Article/Communication Auteurs : Heresh Fattahi, Auteur ; Piyush Agram, Auteur ; Mark Simons, Auteur Année de publication : 2017 Article en page(s) : pp 777 - 786 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s)
[Termes IGN] angle azimutal
[Termes IGN] image multibande
[Termes IGN] image radar moirée
[Termes IGN] image Sentinel-SAR
[Termes IGN] Image TOPS
[Termes IGN] série temporelle
[Termes IGN] système de coordonnéesRésumé : (Auteur) For multitemporal analysis of synthetic aperture radar (SAR) images acquired with a terrain observation by progressive scan (TOPS) mode, all acquisitions from a given satellite track must be coregistered to a reference coordinate system with accuracies better than 0.001 of a pixel (assuming full SAR resolution) in the azimuth direction. Such a high accuracy can be achieved through geometric coregistration, using precise satellite orbits and a digital elevation model, followed by a refinement step using a time-series analysis of coregistration errors. These errors represent the misregistration between all TOPS acquisitions relative to the reference coordinate system. We develop a workflow to estimate the time series of azimuth misregistration using a network-based enhanced spectral diversity (NESD) approach, in order to reduce the impact of temporal decorrelation on coregistration. Example time series of misregistration inferred for five tracks of Sentinel-1 TOPS acquisitions indicates a maximum relative azimuth misregistration of less than 0.01 of the full azimuth resolution between the TOPS acquisitions in the studied areas. Standard deviation of the estimated misregistration time series for different stacks varies from 1.1e-3 to 2e-3 of the azimuth resolution, equivalent to 1.6-2.8 cm orbital uncertainty in the azimuth direction. These values fall within the 1-sigma orbital uncertainty of the Sentinel-1 orbits and imply that orbital uncertainty is most likely the main source of the constant azimuth misregistration between different TOPS acquisitions. We propagate the uncertainty of individual misregistration estimated with ESD to the misregistration time series estimated with NESD and investigate the different challenges for operationalizing NESD. Numéro de notice : A2017-143 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2016.2614925 En ligne : https://doi.org/10.1109/TGRS.2016.2614925 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=84631
in IEEE Transactions on geoscience and remote sensing > vol 55 n° 2 (February 2017) . - pp 777 - 786[article]DEM error correction in InSAR time series / Heresh Fattahi in IEEE Transactions on geoscience and remote sensing, vol 51 n° 7 Tome 2 (July 2013)
[article]
Titre : DEM error correction in InSAR time series Type de document : Article/Communication Auteurs : Heresh Fattahi, Auteur ; Falk Amelung, Auteur Année de publication : 2013 Article en page(s) : pp 4249 - 4259 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications
[Termes IGN] Equateur (état)
[Termes IGN] image radar moirée
[Termes IGN] interféromètrie par radar à antenne synthétique
[Termes IGN] modèle numérique de surface
[Termes IGN] série temporelle
[Termes IGN] volcanRésumé : (Auteur) We present a mathematical formulation for the phase due to the errors in digital elevation models (DEMs) in synthetic aperture radar (SAR) interferometry (InSAR) time series obtained by the small baseline (SB) or the small baseline subset method. We show that the effect of the DEM error in the estimated displacement is proportional to the perpendicular baseline history of the set of SAR acquisitions. This effect at a given epoch is proportional to the perpendicular baseline between the SAR acquisition at that epoch and the reference acquisition. Therefore, the DEM error can significantly affect the time-series results even if SB interferograms are used. We propose a new method for DEM error correction of InSAR time series, which operates in the time domain after inversion of the network of interferograms for the displacement time series. This is in contrast to the method of Berardino (2002) in which the DEM error is estimated in the interferogram domain. We show the effectiveness of this method using simulated InSAR data. We apply the new method to Fernandina volcano in the Galapagos Islands and show that the proposed DEM error correction improves the estimated displacement significantly. Numéro de notice : A2013-378 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2012.2227761 En ligne : https://doi.org/10.1109/TGRS.2012.2227761 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32516
in IEEE Transactions on geoscience and remote sensing > vol 51 n° 7 Tome 2 (July 2013) . - pp 4249 - 4259[article]Réservation
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