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Introducing spatial regularization in SAR tomography reconstruction / Clément Rambour in IEEE Transactions on geoscience and remote sensing, vol 57 n° 11 (November 2019)
[article]
Titre : Introducing spatial regularization in SAR tomography reconstruction Type de document : Article/Communication Auteurs : Clément Rambour, Auteur ; Loïc Denis, Auteur ; Florence Tupin, Auteur ; Hélène Oriot, Auteur Année de publication : 2019 Article en page(s) : pp 8600 - 8617 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications
[Termes IGN] acquisition comprimée
[Termes IGN] analyse spectrale
[Termes IGN] écho radar
[Termes IGN] fractionnement
[Termes IGN] image à très haute résolution
[Termes IGN] image radar moirée
[Termes IGN] image TerraSAR-X
[Termes IGN] mécanique de Lagrange
[Termes IGN] reconstruction 3D du bâti
[Termes IGN] scène urbaine
[Termes IGN] TerraSAR-X
[Termes IGN] tomographie radarRésumé : (auteur) The resolution achieved by current synthetic aperture radar (SAR) sensors provides a detailed visualization of urban areas. Spaceborne sensors such as TerraSAR-X can be used to analyze large areas at a very high resolution. In addition, repeated passes of the satellite give access to temporal and interferometric information on the scene. Because of the complex 3-D structure of urban surfaces, scatterers located at different heights (ground, building facade, and roof) produce radar echoes that often get mixed within the same radar cells. These echoes must be numerically unmixed in order to get a fine understanding of the radar images. This unmixing is at the core of SAR tomography. SAR tomography reconstruction is generally performed in two steps: 1) reconstruction of the so-called tomogram by vertical focusing, at each radar resolution cell, to extract the complex amplitudes (a 1-D processing) and 2) transformation from radar geometry to ground geometry and extraction of significant scatterers. We propose to perform the tomographic inversion directly in ground geometry in order to enforce spatial regularity in 3-D space. This inversion requires solving a large-scale nonconvex optimization problem. We describe an iterative method based on variable splitting and the augmented Lagrangian technique. Spatial regularizations can easily be included in this generic scheme. We illustrate, on simulated data and a TerraSAR-X tomographic data set, the potential of this approach to produce 3-D reconstructions of urban surfaces. Numéro de notice : A2019-596 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2019.2921756 Date de publication en ligne : 04/07/2019 En ligne : https://doi.org/10.1109/TGRS.2019.2921756 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=94588
in IEEE Transactions on geoscience and remote sensing > vol 57 n° 11 (November 2019) . - pp 8600 - 8617[article]Divisional ambiguity resolution for long range reference stations in network RTK / J. Deng in Survey review, vol 47 n° 343 (July 2015)
[article]
Titre : Divisional ambiguity resolution for long range reference stations in network RTK Type de document : Article/Communication Auteurs : J. Deng, Auteur ; S.L. Wang, Auteur Année de publication : 2015 Article en page(s) : pp 272 - 278 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement
[Termes IGN] analyse comparative
[Termes IGN] fractionnement
[Termes IGN] ligne de base
[Termes IGN] positionnement cinématique en temps réel
[Termes IGN] résolution d'ambiguïté
[Termes IGN] station permanenteRésumé : (auteur) Increasing the distance between reference stations of network RTK can improve the flexibility of the reference stations sitting, reduce the number of reference stations and cut down construction and maintenance costs. However, it also decreases the correlation of spatial error and affects the real time performance and effectiveness of the network RTK positioning. Thus, the key techniques of long range network RTK need to be further optimised. Ambiguity resolution between reference stations is one of the most critical techniques. In this paper a divisional ambiguity resolution for long range reference stations of network RTK is proposed, so as to deal with the long fixed time and low success rate, especially for low elevation satellites. Based on conventional two-step ambiguity resolution, firstly, this new method calculates the wide-lane ambiguity by building M-W combination of pseudo-range and carrier observations. Second, the conventional ambiguity resolution as a whole is changed and satellites are divided into high elevation ones and low elevation ones, then the integer ambiguity of high elevation satellites is resolved by means of ionosphere-free combination with the relative zenith wet delay as a parameter. Finally, the Kalman filter model is established by the observation equation of high elevation satellites with calculated ambiguity and low elevation satellites, assisting to obtain the ambiguity of low elevation satellites quickly. The example selects a 196 km long baseline for comparative analysis. Result shows that it takes 733 s to resolve the ambiguity of all satellites by conventional ambiguity resolution in whole, and 252 s by divisional ambiguity resolution proposed in this paper. The new method saves about two thirds of resolution time, and also greatly improves the efficiency of ambiguity resolution of low elevation satellites for long baseline. Numéro de notice : A2015-921 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1179/1752270614Y.0000000123 En ligne : https://doi.org/10.1179/1752270614Y.0000000123 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=79732
in Survey review > vol 47 n° 343 (July 2015) . - pp 272 - 278[article]SAR image categorization with log cumulants of the fractional Fourier transform coefficients / Jagmal Singh in IEEE Transactions on geoscience and remote sensing, vol 51 n° 12 (December 2013)
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Titre : SAR image categorization with log cumulants of the fractional Fourier transform coefficients Type de document : Article/Communication Auteurs : Jagmal Singh, Auteur ; Mihai Dactu, Auteur Année de publication : 2013 Article en page(s) : pp 5273 - 5282 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications
[Termes IGN] fractionnement
[Termes IGN] image radar moirée
[Termes IGN] image TanDEM-X
[Termes IGN] image TerraSAR-X
[Termes IGN] transformation de FourierRésumé : (Auteur) With the advent of high-resolution (HR) synthetic aperture radar (SAR) images from satellites like TerraSAR-X and TanDEM-X, interest is now on patch-oriented image categorization in contrast to the pixel-based classification in low-resolution SAR images. SAR image categorization requires the generation of a compact feature descriptor that accurately defines the content of the image patch under consideration. As phase information plays a critical role in SAR images, this paper proposes the use of a chirplet-derived transform, i.e., the fractional Fourier transform (FrFT), for generating a compact feature descriptor for single-look complex (SLC) SAR images. Representing a SAR signal in rotated joint time-frequency planes via the FrFT allows discovering the underlying backscattering phenomenon of the objects on the ground. SAR image projections on different planes of the joint time-frequency space using the FrFT provide a simple statistical response that is easier to analyze. The proposed method has been compared with a multiscale approach, i.e., Gabor filter banks, a second-order-statistics-based method (as gray-level co-occurrence matrices), and a spectral descriptor method. We demonstrate the suitability of the FrFT-based method for image categorization on the basis of backscattering behavior, whereas the Gabor-filter-bank-based method is found mainly suitable for images with a strong texture. This paper demonstrates enhancement in the separability for most of the considered categories when using logarithmic cumulants instead of linear moments for both the FrFT-based and Gabor-filter-bank-based methods. The experimental database consists of 2000 image patches (of size 200 200 pixels) extracted from SLC HR TerraSAR-X scenes. Numéro de notice : A2013-697 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2012.2230892 En ligne : https://doi.org/10.1109/TGRS.2012.2230892 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32833
in IEEE Transactions on geoscience and remote sensing > vol 51 n° 12 (December 2013) . - pp 5273 - 5282[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 065-2013121 RAB Revue Centre de documentation En réserve L003 Disponible Mapping regional land cover with MODIS data for biological conservation: examples from the greater Yellowstone ecosystem, USA and PARA state, Brazil / K.J. Wessels in Remote sensing of environment, vol 92 n° 1 (15 July 2004)
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Titre : Mapping regional land cover with MODIS data for biological conservation: examples from the greater Yellowstone ecosystem, USA and PARA state, Brazil Type de document : Article/Communication Auteurs : K.J. Wessels, Auteur ; R.S. de Fries, Auteur ; et al., Auteur Année de publication : 2004 Article en page(s) : pp 67 - 83 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] biodiversité
[Termes IGN] carte d'occupation du sol
[Termes IGN] classification dirigée
[Termes IGN] classification par arbre de décision
[Termes IGN] déboisement
[Termes IGN] fractionnement
[Termes IGN] habitat animal
[Termes IGN] image Landsat-TM
[Termes IGN] image Terra-MODIS
[Termes IGN] limite de résolution géométrique
[Termes IGN] occupation du sol
[Termes IGN] Para (Brésil)
[Termes IGN] parc naturel nationalRésumé : (Auteur) The paper investigated the application of MODIS data for mapping regional land cover at moderate resolutions (250 and 500 m), for regional conservation purposes. Land cover maps were generated for two major conservation areas (Greater Yellowstone Ecosystem-GYE, USA and the Pard State, Brazil) using MODIS data and decision tree classifications. The MODIS land cover products were evaluated using existing Landsat TM land cover maps as reference data. The Landsat TM land cover maps were processed to their fractional composition at the MODIS resolution (250 and 500 m). In GYE, the MODIS land cover was very successful at mapping extensive cover types (e.g. coniferous forest and grasslands) and far less successful at mapping smaller habitats (e.g. wetlands, deciduous tree cover) that typically occur in patches that are smaller than the MODIS pixels, but are reported to be very important to biodiversity conservation. The MODIS classification for Pard State was successful at producing a regional forest/non-forest product which is useful for monitoring the extreme human impacts such as deforestation. The ability of MODIS data to map secondary forest remains to be tested, since regrowth typically harbors reduced levels of biodiversity. The two case studies showed the value of using multi-date 250 m data with only two spectral bands, as well as single day 500 m data with seven spectral bands, thus illustrating the versatile use of MODIS data in two contrasting environments. MODIS data provide new options for regional land cover mapping that are less labor-intensive than Landsat and have higher resolution than previous 1km AVHRR or the current 1 km global land cover product. The usefulness of the MODIS data in addressing biodiversity conservation questions will ultimately depend upon the patch sizes of important habitats and the land cover transformations that threaten them. Numéro de notice : A2004-299 Affiliation des auteurs : non IGN Thématique : BIODIVERSITE/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2004.05.002 En ligne : https://doi.org/10.1016/j.rse.2004.05.002 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26826
in Remote sensing of environment > vol 92 n° 1 (15 July 2004) . - pp 67 - 83[article]Le procédé de navigation spatiale Transmap (R) : application à l'imagerie territoriale / Franck Perdrizet in Bulletin [Société Française de Photogrammétrie et Télédétection], n° 168 (Octobre 2002)
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Titre : Le procédé de navigation spatiale Transmap (R) : application à l'imagerie territoriale Type de document : Article/Communication Auteurs : Franck Perdrizet, Auteur Année de publication : 2002 Article en page(s) : pp 3 - 11 Note générale : bibliographie Langues : Français (fre) Descripteur : [Vedettes matières IGN] Bases de données localisées
[Termes IGN] arbre quadratique
[Termes IGN] données matricielles
[Termes IGN] échantillonnage d'image
[Termes IGN] emprise de carte
[Termes IGN] fractionnement
[Termes IGN] image binaire
[Termes IGN] image numérique
[Termes IGN] quadrant
[Termes IGN] tessellation
[Termes IGN] visualisation de donnéesRésumé : (Auteur) Bien des systèmes de gestion d'images géographiques numériques reposent sur le principe des tétraarbres, dont la logique binaire, qui est aussi celle du codage informatique, commande le fractionnement récursif de l'emprise initiale en quadrants. Les avantages offerts par une approche ternaire pour l'exploitation des représentations territoriales, sont exposés ci-après, à l'aide de la comparaison entre pyramides d'images binaire et ternaire. Cette dernière structure assoit le procédé original de navigation spatiale Transmap®, à indexation topologique ternaire, qui est présenté par étapes. On indique comment la solution Transmap®, tout en guidant l'utilisateur dans son exploration du territoire, optimise l'organisation des données matricielles, et leur transmission, dans une perspective de consultation en ligne. Numéro de notice : A2002-367 Affiliation des auteurs : non IGN Thématique : IMAGERIE/POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueNat DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=22279
in Bulletin [Société Française de Photogrammétrie et Télédétection] > n° 168 (Octobre 2002) . - pp 3 - 11[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 018-02031 RAB Revue Centre de documentation En réserve L003 Disponible Tropical forest remnants / R.O. Bierregaard (1997)Permalink