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Ionospheric effects on SAR imaging: a numerical study / J. Liu in IEEE Transactions on geoscience and remote sensing, vol 41 n° 5 (May 2003)  

Public [article]  inIEEE Transactions on geoscience and remote sensing > vol 41 n° 5 (May 2003) . - pp 939 - 947 Titre : Ionospheric effects on SAR imaging: a numerical study Type de document : Article/Communication Auteurs : J. Liu, Auteur ; Y. Kuga, Auteur ; et al., Auteur Année de publication : 2003 Article en page(s) : pp 939 - 947 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s) [Termes IGN] correction ionosphérique [Termes IGN] dégradation d'image [Termes IGN] image radar moirée [Termes IGN] propagation ionosphérique Résumé : (Auteur) There has been an increasing interest in the use of spaceborne very high frequency ultra high frequency (VHFUHF) synthetic aperture radar (SAR) for measuring forest biomass and for detecting underground facilities. The propagation characseristics of the lowfrequency electromagnetic wave are severely affected by the ionosphere. Recently, Faraday rotation effects and SAR image degradation have been studied using an analytical model and a homogeneous ionosphere. In this paper, a numerical model is developed to investigate the SAR image degradation caused by an inhomogeneous ionosphere. Both horizontal and a vertical structures of the ionosphere are considered in this model. Three different cases are studied. The first is a vertically homogemous ionosphere, where the simulation condition is the same as in the analytical study by Ishimaru and others. The second is a vertical profile, which is introduced using the Chapman formula. The raybending effect is added for the ionosphere with a layered structure. Finally, both the vertical profile in electron density and the horizontal gradient in total electron content are considered b the simulation. Simulation results show good agreement with the theoretical analysis under the same conditions of the ionosphere. When both horizontal and vertical structures and the inhomogeneity of the ionosphere are considered in the model, the simulation result shows further image degradation and shift caused by the raybending effect. The simulation results also show the strong frequency dependence of the SAR image resolution. Numéro de notice : A2003-203 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2003.811813 En ligne : https://doi.org/10.1109/TGRS.2003.811813 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=22499 [article]

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The effect of modified Markov random fields on the local minima occurrence in microwave imaging / G. Ferraiuolo in IEEE Transactions on geoscience and remote sensing, vol 41 n° 5 (May 2003)  

Public [article]  inIEEE Transactions on geoscience and remote sensing > vol 41 n° 5 (May 2003) . - pp 1043 - 1055 Titre : The effect of modified Markov random fields on the local minima occurrence in microwave imaging Type de document : Article/Communication Auteurs : G. Ferraiuolo, Auteur ; Vito Pascazio, Auteur Année de publication : 2003 Article en page(s) : pp 1043 - 1055 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image [Termes IGN] champ aléatoire de Markov [Termes IGN] estimation bayesienne [Termes IGN] hyperfréquence [Termes IGN] image satellite [Termes IGN] tomographie Résumé : (Auteur) The application of a maximum a posteriori estimation method for microwave imaging that makes use of a Markov random field (MRF) a priori statistical model is presented in this paper. In particular, the MRF family adopted is generalized for complex profiles, characterized by a quadratic energy function and "modified" such to make it possible to statistically represent spatial interactions between real and imaginary parts. Thanks to its peculiarities, the use of this approach simultaneously favors in many cases well posedness and robustness against local minima occurrence, as well as high quality in the reconstructed images. Numerical results show the performance of the method. Numéro de notice : A2003-204 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2003.811549 En ligne : https://doi.org/10.1109/TGRS.2003.811549 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=22500 [article]

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Assessment of different topographic corrections in Landsat-TM data for mapping vegetation type (2003) / D. Riano in IEEE Transactions on geoscience and remote sensing, vol 41 n° 5 (May 2003)  

Public [article]  inIEEE Transactions on geoscience and remote sensing > vol 41 n° 5 (May 2003) . - pp 1056 - 1061 Titre : Assessment of different topographic corrections in Landsat-TM data for mapping vegetation type (2003) Type de document : Article/Communication Auteurs : D. Riano, Auteur ; E. Chuvieco, Auteur ; J. Salas, Auteur ; I. Aguado, Auteur Année de publication : 2003 Article en page(s) : pp 1056 - 1061 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique [Termes IGN] carte de la végétation [Termes IGN] correction d'image [Termes IGN] correction géométrique [Termes IGN] correction radiométrique [Termes IGN] image Landsat-TM [Termes IGN] pente Résumé : (Auteur) Different methods for topographic correction of Landsat Thematic Mapper images have been assessed in the context of mapping vegetation types. The best results were obtained with a variation of the C method, which takes into account the overcorrection of low illuminated slopes by the original C method. The performance of this method was tested using two criteria: the changes in the spectral characteristics of the image and the reduction in standard deviation of each vegetation type after the correction. Numéro de notice : A2003-205 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2003.811693 En ligne : https://doi.org/10.1109/TGRS.2003.811693 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=22501 [article]

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Comparison of interannual intrinsic modes in hemispheric sea ice covers and other geophysical parameters / P. Gloersen in IEEE Transactions on geoscience and remote sensing, vol 41 n° 5 (May 2003)  

Public [article]  inIEEE Transactions on geoscience and remote sensing > vol 41 n° 5 (May 2003) . - pp 1062 - 1074 Titre : Comparison of interannual intrinsic modes in hemispheric sea ice covers and other geophysical parameters Type de document : Article/Communication Auteurs : P. Gloersen, Auteur ; N. Huang, Auteur Année de publication : 2003 Article en page(s) : pp 1062 - 1074 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Télédétection [Termes IGN] analyse comparative [Termes IGN] Antarctique [Termes IGN] banquise [Termes IGN] géophysique externe [Termes IGN] glace de mer [Termes IGN] mesurage de la fréquence [Termes IGN] oscillation [Termes IGN] télédétection spatiale [Termes IGN] transformation de Fourier Résumé : (Auteur) Recent papers have described 18year trends and interannual oscillations in the Arctic and Antarctic sea ice extents, areas, and enclosed open water areas based on newly formulated 18.2year ice concentration time series. They were obtained by finetuning the sea ice algorithm tie points individually for each of the four sensors used to acquire the data. In this paper, these analyses are extended to an examination of the intrinsic modes of these time series, obtained by means of empirical mode decomposition, which handles both nonstationary and nonlinear data as found in these time series, unlike filtering techniques based on Fourier analysis. Our analysis centers on periodicities greater than one year. Quasibiennial and quasiquadrennial oscillations similar to those observed earlier with a multitaperfiltered Fourier analysis technique were also observed here. The intrinsic modes described here feature frequency as well as amplitude modulation within their respective frequency bands. The slowest varying mode in the Antarctic sea ice cover has slightly less than a full period during this 18.2year time period, but the change in sign of its curvature hints at a modal period of about 19 years, with important implications for the trend analyses published earlier. Numéro de notice : A2003-206 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2003.811814 En ligne : https://doi.org/10.1109/TGRS.2003.811814 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=22502 [article]

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Quantitative assessment of a haze suppression methodology for satellite imagery: effect on land cover classification performance / Y. Zhang in IEEE Transactions on geoscience and remote sensing, vol 41 n° 5 (May 2003)  

Public [article]  inIEEE Transactions on geoscience and remote sensing > vol 41 n° 5 (May 2003) . - pp 1082 - 1089 Titre : Quantitative assessment of a haze suppression methodology for satellite imagery: effect on land cover classification performance Type de document : Article/Communication Auteurs : Y. Zhang, Auteur ; B. Guindon, Auteur Année de publication : 2003 Article en page(s) : pp 1082 - 1089 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique [Termes IGN] cartographie topographique [Termes IGN] classification [Termes IGN] estimation statistique [Termes IGN] fumée [Termes IGN] image Landsat-TM [Termes IGN] précision radiométrique [Termes IGN] recherche d'information [Termes IGN] représentation multiple [Termes IGN] test de performance Résumé : (Auteur) A number of haze removal methods for, satellite imagery have been described in the literature, but few papers have quantified their effectiveness within the context of a postprocessing applications scenario. In this, paper, the haze optimized transform (HOT) approach for visibleband correction is described, and its impact on classification performance is evaluated. Assessment is conducted at three levels: radiometric level of accuracy, improvement in interclass separability, and classification accuracy. Results obtained from hazy scenes and their dehazed, counterparts are compared with those from reference or "benchmark" clear scenes. Radiometric analyses of pseudoinvariant features (dense forest stands) indicate that effective haze reduction can be realized for differential HOT response levels of up to 20 for Landsat Thematic Mapper scenes. This level of atmospheric contamination is severe enough, to result in significant thematic class confusion, wherein visibleband radiances of vegetated areas are at levels normally associated with urban features under clear sky conditions. Numéro de notice : A2003-207 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2003.811817 En ligne : https://doi.org/10.1109/TGRS.2003.811817 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=22503 [article]

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Hyperspectral texture recognition using a multiscale opponent representation / M. Shi in IEEE Transactions on geoscience and remote sensing, vol 41 n° 5 (May 2003)  

Public [article]  inIEEE Transactions on geoscience and remote sensing > vol 41 n° 5 (May 2003) . - pp 1090 - 1095 Titre : Hyperspectral texture recognition using a multiscale opponent representation Type de document : Article/Communication Auteurs : M. Shi, Auteur ; G. Healey, Auteur Année de publication : 2003 Article en page(s) : pp 1090 - 1095 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique [Termes IGN] analyse en composantes principales [Termes IGN] analyse multiéchelle [Termes IGN] bande infrarouge [Termes IGN] bande spectrale [Termes IGN] filtre de Gabor [Termes IGN] image AVIRIS [Termes IGN] image hyperspectrale [Termes IGN] reconnaissance de formes [Termes IGN] spectromètre imageur [Termes IGN] texture d'image Résumé : (Auteur) We use Gabor filters to extract texture features at different scales and orientations from hyperspectral images. The texture features are derived from both individual bands and combinations of bands. We consider both spectral binning and principal components analysis for reducing the dimensionality of the input data. Using a database of Airborne Visible Infrared Imaging Spectrometer image regions, we evaluate the performance of this approach for recognizing hyperspectral textures. We show that opponent features that consider combinations of spectral bands often help improve performance. We also examine the dependence of recognition performance on the dimensionality reduction strategy and the number of spectral bands. Numéro de notice : A2003-208 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2003.811076 En ligne : https://doi.org/10.1109/TGRS.2003.811076 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=22504 [article]

Exemplaires(1)

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