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Glacier surface velocity estimation using repeat TerraSAR-X images: Wavelet- vs. correlation-based image matching / Adrian Schubert in ISPRS Journal of photogrammetry and remote sensing, vol 82 (August 2013)
[article]
Titre : Glacier surface velocity estimation using repeat TerraSAR-X images: Wavelet- vs. correlation-based image matching Type de document : Article/Communication Auteurs : Adrian Schubert, Auteur ; Annina Faes, Auteur ; Andreas Kääb, Auteur ; Erich Meier, Auteur Année de publication : 2013 Article en page(s) : pp 49 - 62 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications
[Termes IGN] analyse comparative
[Termes IGN] appariement d'images
[Termes IGN] corrélation
[Termes IGN] glacier
[Termes IGN] image radar moirée
[Termes IGN] image TerraSAR-X
[Termes IGN] ondelette
[Termes IGN] Suisse
[Termes IGN] surveillance écologique
[Termes IGN] vitesseRésumé : (Auteur) For the observation and monitoring of glacier surface velocity (GSV), remote sensing is an increasingly suitable tool thanks to the high temporal and spatial resolution of the data. Radar sensors have the specific advantage over optical sensors of being nearly weather and time-independent. Two image pairs separated by 11 days, acquired with the high-resolution spotlight (HS) and stripmap (SM) modes of the German sensor TerraSAR-X, were used to estimate GSV over Switzerland’s Aletsch Glacier. The SM mode covers larger ground swaths, making it more suitable for glacier-wide observations, while the HS images cover less area but offer the highest-possible spatial resolution, approximately 1x1 m on the ground. The images were acquired during the summer to maximise feature visibility by minimal snow cover. GSV estimation was performed using two methods, the comparison of which was a major goal of this study: traditional cross-correlation optimisation and a dense image matching algorithm based on complex wavelet decomposition. Each method was found to have unique advantages and disadvantages, but it was concluded that for GSV monitoring, cross-correlation is probably preferable to the wavelet-based approach. While it generates fewer estimates per unit area, this is not necessarily a critical requirement for all glaciological applications, and the method requires less initial “tuning” (calibration) than the wavelet algorithm, making it a slightly better tool in operational contexts. Also, the use of the highest-resolution spotlight datasets is recommended over stripmap mode images when large-area coverage is less critical. The comparative lack of visible features at the resolution of the stripmap images made reliable GSV estimation difficult, with the exception of several small areas dominated by large crevasses. Numéro de notice : A2013-411 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2013.04.010 En ligne : https://doi.org/10.1016/j.isprsjprs.2013.04.010 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32549
in ISPRS Journal of photogrammetry and remote sensing > vol 82 (August 2013) . - pp 49 - 62[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 081-2013081 RAB Revue Centre de documentation En réserve L003 Disponible Texture classification of PolSAR data based on sparse coding of wavelet polarization textons / Chu He in IEEE Transactions on geoscience and remote sensing, vol 51 n° 8 (August 2013)
[article]
Titre : Texture classification of PolSAR data based on sparse coding of wavelet polarization textons Type de document : Article/Communication Auteurs : Chu He, Auteur ; Shuang Li, Auteur ; Zixian Liao, Auteur ; et al., Auteur Année de publication : 2013 Article en page(s) : pp 4576 - 4590 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications
[Termes IGN] classification par séparateurs à vaste marge
[Termes IGN] image radar moirée
[Termes IGN] ondelette
[Termes IGN] polarimétrie radar
[Termes IGN] polarisation
[Termes IGN] texture d'imageRésumé : (Auteur) This paper presents a frame for classifying polarimetric synthetic aperture radar (PolSAR) data. The frame is based on the combination of wavelet polarization information, textons, and sparse coding. Polarimetric synthesis unites with the discrete wavelet frame to obtain wavelet polarization variance through the calculation of the wavelet variance in the space of polarization states. The K-means cluster algorithm is implemented to cluster the wavelet polarization variance vectors of the training samples for the purpose of constructing a texton dictionary. A patch, in which all the wavelet polarization variance vectors match those in the texton dictionary, is used to obtain a statistical histogram. Sparse coding is applied to describe the histogram feature and generate a new texture feature called sparse coding of a wavelet polarization texton. Finally, support vector machine is used for the classification. All experiments are carried out on five sets of PolSAR data. The experimental results confirm that the proposed method effectively classifies PolSAR data. Numéro de notice : A2013-422 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2012.2236338 En ligne : https://doi.org/10.1109/TGRS.2012.2236338 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32560
in IEEE Transactions on geoscience and remote sensing > vol 51 n° 8 (August 2013) . - pp 4576 - 4590[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 065-2013081 RAB Revue Centre de documentation En réserve L003 Disponible Sketch-Finder: efficient and effective sketch-based retrieval for large image collections / Carlos Alberto Pimentel Filho (August 2013)
Titre : Sketch-Finder: efficient and effective sketch-based retrieval for large image collections Type de document : Article/Communication Auteurs : Carlos Alberto Pimentel Filho, Auteur ; Arnaldo de Albuquerque Araújo, Auteur ; Michel Crucianu, Auteur ; Valérie Gouet-Brunet , Auteur Editeur : Arequipa [Pérou] : Universidad Católica San Pablo UCSP Année de publication : August 2013 Conférence : SIBGRAPI 2013, 26th Brazilian Conference on Graphics, Patterns, and Images 05/08/2013 08/08/2013 Arequipa Pérou OA Proceedings Importance : pp 234 - 241 Format : 21 x 30 cm Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image
[Termes IGN] détection de contours
[Termes IGN] indexation
[Termes IGN] ondelette
[Termes IGN] similitude
[Termes IGN] variabilitéMots-clés libres : sketch-based image retrieval multimedia indexing scalability Résumé : (auteur) Among various image retrieval approaches, the use of sketches lets one express a precise visual query with simple and widespread means. The challenge consists in finding a content representation that allows you to effectively compare sketches and images, while supporting efficient retrieval in order to make the system scalable. We put forward a sketch-based image retrieval solution where sketches and natural image contours are represented and compared in the wavelet domain. The relevant information regarding query sketches and image content has, thus, a compact representation that can be readily employed by an efficient index for retrieval by similarity. Furthermore, with this solution, the balance between effectiveness and efficiency can be easily modified in order to adapt to the available resources. A comparative evaluation with a state-of-the-art method on the Paris dataset and a subset with 535K images of the ImageNet dataset shows that our solution can preserve effectiveness while being more than one order of magnitude faster. Numéro de notice : C2013-044 Affiliation des auteurs : LASTIG MATIS+Ext (2012-2019) Thématique : IMAGERIE Nature : Communication nature-HAL : ComAvecCL&ActesPubliésIntl DOI : sans En ligne : http://www.ucsp.edu.pe/sibgrapi2013/eproceedings/technical/114547_2.pdf Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=80233 New constraints on the origin of the Hawaiian swell from wavelet analysis of the geoid-to-topography ratio / Cécilia Cadio in Earth and planetary science letters, vol 359–360 (15 December 2012)
[article]
Titre : New constraints on the origin of the Hawaiian swell from wavelet analysis of the geoid-to-topography ratio Type de document : Article/Communication Auteurs : Cécilia Cadio, Auteur ; Maxim D. Ballmer, Auteur ; Isabelle Panet , Auteur ; Michel Diament , Auteur ; Neil Ribe, Auteur Année de publication : 2012 Article en page(s) : pp 40 - 54 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] anomalie de pesanteur
[Termes IGN] convection
[Termes IGN] géoïde local
[Termes IGN] Hawaii (Etats-Unis)
[Termes IGN] houle
[Termes IGN] lithosphère
[Termes IGN] ondelette
[Termes IGN] transformation en ondelettes
[Termes IGN] volcanRésumé : (Auteur) Analyzing the formation mechanism of hotspot swells enhances our understanding of intraplate volcanism and the underlying geodynamical processes. The two main hypotheses for the origin of the archetypal Hawaiian swell are thermal lithospheric thinning, and dynamic support by an ascending plume. Any successful model would have to be able to simultaneously explain the swell topography and the corresponding geoid anomaly. In simple models of isostatic compensation, the geoid-to-topography ratio (GTR) is linearly related to the depth of the compensating mass; therefore it is often considered a fundamental parameter to assess swell support mechanisms. Previous estimates for the geoid-to-topography ratio (GTR) of the Hawaiian swell however are biased towards low values by incomplete removal of the effects of volcanic loading and lithospheric flexure. In order to resolve these issues, we here apply a continuous wavelet transform, which allows resolution of lateral variations of the GTR at various spatial scales. In a series of synthetic tests, the robustness of this approach and its power to identify the origin of hotspot swells are established. With 8 m/km on the youngest part of the chain, the recovered GTR agrees well with the predictions for dynamic support, therefore ruling out thermal rejuvenation as an important mechanism. We also find that the depth of the compensating mass decays by 20 km over a distance of 500 km from Hawaii to Kauai, and identify sublithospheric erosion by small-scale convection in the ponded plume material as a viable mechanism to support this decay. Numéro de notice : A2012-740 Affiliation des auteurs : LAREG+Ext (1991-2011) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.epsl.2012.10.006 Date de publication en ligne : 05/11/2012 En ligne : https://doi.org/10.1016/j.epsl.2012.10.006 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91475
in Earth and planetary science letters > vol 359–360 (15 December 2012) . - pp 40 - 54[article]Optimal regularization for geopotential model GOCO02S by Monte Carlo methods and multi-scale representation of density anomalies / Karl Rudolf Koch in Journal of geodesy, vol 86 n° 8 (August 2012)
[article]
Titre : Optimal regularization for geopotential model GOCO02S by Monte Carlo methods and multi-scale representation of density anomalies Type de document : Article/Communication Auteurs : Karl Rudolf Koch, Auteur ; J. Brockmann, Auteur ; W.D. Schuh, Auteur Année de publication : 2012 Article en page(s) : pp 647 - 660 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] analyse de variance
[Termes IGN] B-Spline
[Termes IGN] données GOCE
[Termes IGN] méthode de Monte-Carlo
[Termes IGN] modèle de géopotentiel
[Termes IGN] ondeletteRésumé : (Auteur) GOCO02S is a combined satellite-only geopotential model, regularized from degrees 180 to 250 of the expansion into spherical harmonics. To investigate the start of the regularization, the normal equations of GOCO02S have been used to compute additional geopotential models by regularizations beginning at degrees 160, 200, 220 and with no regularization. Three different methods are applied to determine where to start the regularization. The simplest one considers the decrease of the degree variances of the not regularized solution. The second one tests for the same solution the hypothesis that the square root of the degree variance is equal to the value computed by the estimated harmonic coefficients. If the hypothesis has to be rejected for a certain degree, the error degree variance is so large that the estimated harmonic coefficients cannot be trusted anymore so that the regularization has to start at that degree. The third method uses the density anomalies by which the disturbing potential is caused resulting from the geopotential model. The density anomalies are well suited to visualize the effects of the higher degree harmonics. In contrast to the base functions of the harmonic coefficients with global support, the density anomalies are expressed by a B-spline surface with local support. Multi-scale representations were applied and the hypotheses tested that the wavelet coefficients are equal to zero. Accepting the hypotheses means that nonsignificant wavelet coefficients were determined which lead to nonsignificant density anomalies. By comparing these anomalies for different regularizations, the degree where to start the regularization is determined. It turns out that beginning the regularization at degree 180, as was done for GOCO02S, is a correct choice. Numéro de notice : A2012-377 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-012-0546-7 Date de publication en ligne : 24/02/2012 En ligne : https://doi.org/10.1007/s00190-012-0546-7 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31823
in Journal of geodesy > vol 86 n° 8 (August 2012) . - pp 647 - 660[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 266-2012081 RAB Revue Centre de documentation En réserve L003 Disponible Estimating tropical forest biomass with a combination of SAR image texture and Landsat TM data: An assessment of predictions between regions / M. Cutler in ISPRS Journal of photogrammetry and remote sensing, vol 70 (June 2012)PermalinkWavelet‐based directional analysis of the gravity field : evidence for large‐scale undulations / M. Hayn in Geophysical journal international, vol 189 n° 3 (June 2012)PermalinkFlexible dataset combination and modelling by domain decomposition approaches / Isabelle Panet (2012)PermalinkTLS data denoising by range image processing / Eddy Smigiel in Photogrammetric record, vol 26 n° 134 (June - August 2011)PermalinkReprésentations en ondelettes du champ de pesanteur / Isabelle Panet in Bulletin d'information scientifique et technique de l'IGN, n° 77 (avril 2011)PermalinkPermalinkPermalinkWavelet modeling of the gravity field over Japan / Isabelle Panet in Bulletin of the Geographical survey institute, vol 57 (December 2009)PermalinkComparison and improvement of wavelet-based image fusion / G. Hong in International Journal of Remote Sensing IJRS, vol 29 n°3-4 (February 2008)PermalinkCoseismic and post-seismic signatures of the Sumatra 2004 December and 2005 March earthquakes in GRACE satellite gravity / Isabelle Panet in Geophysical journal international, vol 171 n° 1 (Octobre 2007)Permalink