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Titre : Quality assessment of SLR data-related products Type de document : Article/Communication Auteurs : Jean-Michel Lemoine, Auteur ; Florent Deleflie, Auteur ; Franck Reinquin, Auteur ; David Coulot , Auteur Editeur : Greenbelt (Maryland) : Goddard Space Flight Center Année de publication : 2014 Conférence : IWLR 2013, 18th international workshop on Laser Ranging 11/11/2013 15/11/2013 Fujiyoshida Japon OA Proceedings Importance : 6 p. Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] données TLS (télémétrie)
[Termes IGN] évaluation des données
[Termes IGN] qualité des donnéesRésumé : (auteur) We analyse SLR data-related products that are computed from Lageos-1 and Lageos-2 data acquired by the ILRS network. We analyze time series of post-fit residuals for both satellites, biases and space stations coordinates (SSCs), that are deduced following the recommendations provided by the Analysis Working Group. We compute the same kind of products, with a GRGS updated version of SLRF2008. Finally, we propose a change in the operational strategy to improve the accuracy of the products delivered by the ILRS. Numéro de notice : C2013-003 Affiliation des auteurs : LASTIG LAREG+Ext (2012-mi2018) Thématique : POSITIONNEMENT Nature : Communication nature-HAL : ComAvecCL&ActesPubliésIntl DOI : sans En ligne : http://cddis.gsfc.nasa.gov/lw18/docs/papers/Session3/13-02-04-Deleflie.pdf Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=78577 Documents numériques
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Quality assessment of SLR data-related productsAdobe Acrobat PDF Using spatial data support for reducing uncertainty in geospatial applications / T. Hong in Geoinformatica, vol 18 n° 1 (January 2014)
[article]
Titre : Using spatial data support for reducing uncertainty in geospatial applications Type de document : Article/Communication Auteurs : T. Hong, Auteur ; K. Hart, Auteur ; Leen-Kiat Soh, Auteur ; Ashok Samal, Auteur Année de publication : 2014 Article en page(s) : pp 63 - 92 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications SIG
[Termes IGN] exploration de données géographiques
[Termes IGN] incertitude des données
[Termes IGN] Nebraska (Etats-Unis)
[Termes IGN] série temporelleRésumé : (Auteur) Widespread use of GPS devices and ubiquity of remotely sensed geospatial images along with cheap storage devices have resulted in vast amounts of digital data. More recently, with the advent of wireless technology, a large number of sensor networks have been deployed to monitor many human, biological and natural processes. This poses a challenge in many data rich application domains now: how to best choose the datasets to solve specific problems? In particular, some of the datasets may be redundant and their inclusion in analysis may not only be time consuming, but also lead to erroneous conclusions. On the other hand, excluding some of the datasets hastily might skew the observations drawn. We propose the concept of data support as the basis for efficient, cost-effective and intelligent use of geospatial data in order to reduce uncertainty in the analysis and consequently in the results. Data support is defined as the process of determining the information utility of a data source to help decide which one to include or exclude to improve cost-effectiveness in existing data analysis. In this paper we use mutual information—a concept popular in information theory as a measure to compute information gain or loss between two datasets—as the basis of computing data support. The flexibility and effectiveness of the approach are demonstrated using an application in the hydrological analysis domain, specifically, watersheds in the state of Nebraska. Numéro de notice : A2014-028 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1007/s10707-013-0177-z Date de publication en ligne : 12/06/2013 En ligne : https://doi.org/10.1007/s10707-013-0177-z Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32933
in Geoinformatica > vol 18 n° 1 (January 2014) . - pp 63 - 92[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 057-2014011 RAB Revue Centre de documentation En réserve L003 Disponible Assessing the accuracy of Volunteered Geographic Information arising from multiple contributors to an Internet based collaborative project / Giles M. Foody in Transactions in GIS, vol 17 n° 6 (December 2013)
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Titre : Assessing the accuracy of Volunteered Geographic Information arising from multiple contributors to an Internet based collaborative project Type de document : Article/Communication Auteurs : Giles M. Foody, Auteur ; Steffen Fritz, Auteur ; Linda M. See, Auteur ; et al., Auteur Année de publication : 2013 Article en page(s) : pp 847 - 860 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique web
[Termes IGN] acquisition de données
[Termes IGN] cartographie collaborative
[Termes IGN] données localisées des bénévoles
[Termes IGN] information géographique numérique
[Termes IGN] participation du public
[Termes IGN] précision des données
[Termes IGN] qualité des donnéesRésumé : (Auteur) The recent rise of neogeography and citizen sensing has increased the opportunities for the use of crowdsourcing as a means to acquire data to support geographical research. The value of the resulting volunteered geographic information is, however, often limited by concerns associated with its quality and the degree to which the contributing data sources may be trusted. Here, information on the quality of sources of volunteered geographic information was derived using a latent class analysis. The volunteered information was on land cover interpreted visually from satellite sensor images and the main focus was on the labeling of 299 sites by seven of the 65 volunteers who contributed to an Internet-based collaborative project. Using the information on land cover acquired by the multiple volunteers it was shown that the relative, but not absolute, quality of the data from different volunteers could be characterized accurately. Additionally, class-specific variations in the quality of the information provided by a single volunteer could be characterized by the analysis. The latent class analysis, therefore, was able to provide information on the quality of information provided on an inter- and intra-volunteer basis. Numéro de notice : A2013-672 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/SOCIETE NUMERIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1111/tgis.12033 Date de publication en ligne : 22/05/2013 En ligne : https://doi.org/10.1111/tgis.12033 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32808
in Transactions in GIS > vol 17 n° 6 (December 2013) . - pp 847 - 860[article]Digital elevation quality derived from medium-format digital cameras / Peter T. Y. Shih in Photogrammetric record, vol 28 n° 144 (December 2013 - February 2014)
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Titre : Digital elevation quality derived from medium-format digital cameras Type de document : Article/Communication Auteurs : Peter T. Y. Shih, Auteur ; J.Y. Wu, Auteur ; et al., Auteur Année de publication : 2013 Article en page(s) : pp 416 - 435 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications photogrammétriques
[Termes IGN] analyse comparative
[Termes IGN] appariement automatique
[Termes IGN] chambre à moyen format
[Termes IGN] données lidar
[Termes IGN] modèle numérique de surface
[Termes IGN] qualité des données
[Termes IGN] semis de pointsRésumé : (Auteur) Medium-format digital cameras are a useful tool in airborne lidar missions to produce digital ortho-images. This study investigates the quality of digital elevation models (DEMs) and digital surface models (DSMs) derived from such cameras. An image-matching strategy is used to produce height information from highly overlapping images and the quality of the derived height information is analysed using synchronous lidar point clouds as the reference data. The evaluation focused on various types of land cover and DEM generation methods. The RMSE between lidar and image-derived height information for two datasets was 0·054% and 0·027% of the flying height in flat, bare-earth areas, but studies with manually edited vegetated areas using stereo photogrammetry revealed high uncertainties, especially in steep terrain. Numéro de notice : A2013-631 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1111/phor.12039 Date de publication en ligne : 09/12/2013 En ligne : https://doi.org/10.1111/phor.12039 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32767
in Photogrammetric record > vol 28 n° 144 (December 2013 - February 2014) . - pp 416 - 435[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 106-2013041 RAB Revue Centre de documentation En réserve L003 Disponible Gaussian processes uncertainty estimates in experimental Sentinel-2 LAI and leaf chlorophyll content retrieval / Jochem Verrlest in ISPRS Journal of photogrammetry and remote sensing, vol 86 (December 2013)
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Titre : Gaussian processes uncertainty estimates in experimental Sentinel-2 LAI and leaf chlorophyll content retrieval Type de document : Article/Communication Auteurs : Jochem Verrlest, Auteur ; Juan Pablo Rivera, Auteur ; José Moreno, Auteur ; Gustavo Camps-Valls, Auteur Année de publication : 2013 Article en page(s) : pp 157 - 167 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] algorithme de Gauss
[Termes IGN] apprentissage automatique
[Termes IGN] chlorophylle
[Termes IGN] image Sentinel-MSI
[Termes IGN] incertitude des données
[Termes IGN] indice foliaire
[Termes IGN] Leaf Area Index
[Termes IGN] régression
[Termes IGN] surveillance de la végétation
[Termes IGN] teneur en chlorophylle des feuilles
[Termes IGN] variable biophysique (végétation)Résumé : (Auteur) ESA’s upcoming Sentinel-2 (S2) Multispectral Instrument (MSI) foresees to provide continuity to land monitoring services by relying on optical payload with visible, near infrared and shortwave infrared sensors with high spectral, spatial and temporal resolution. This unprecedented data availability leads to an urgent need for developing robust and accurate retrieval methods, which ideally should provide uncertainty intervals for the predictions. Statistical learning regression algorithms are powerful candidats for the estimation of biophysical parameters from satellite reflectance measurements because of their ability to perform adaptive, nonlinear data fitting. In this paper, we focus on a new emerging technique in the field of Bayesian nonparametric modeling. We exploit Gaussian process regression (GPR) for retrieval, which is an accurate method that also provides uncertainty intervals along with the mean estimates. This distinct feature is not shared by other machine learning approaches. In view of implementing the regressor into operational monitoring applications, here the portability of locally trained GPR models was evaluated. Experimental data came from the ESA-led field campaign SPARC (Barrax, Spain). For various simulated S2 configurations (S2-10m, S2-20m and S2-60m) two important biophysical parameters were estimated: leaf chlorophyll content (LCC) and leaf area index (LAI). Local evaluation of an extended training dataset with more variation over bare soil sites led to improved LCC and LAI mapping with reduced uncertainties. GPR reached the 10% precision required by end users, with for LCC a NRMSE of 3.5–9.2% (r2: 0.95–0.99) and for LAI a NRMSE of 6.5–7.3% (r2: 0.95–0.96). The developed GPR models were subsequently applied to simulated Sentinel images over various sites. The associated uncertainty maps proved to be a good indicator for evaluating the robustness of the retrieval performance. The generally low uncertainty intervals over vegetated surfaces suggest that the locally trained GPR models are portable to other sites and conditions. Numéro de notice : A2013-708 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2013.09.012 En ligne : https://doi.org/10.1016/j.isprsjprs.2013.09.012 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32844
in ISPRS Journal of photogrammetry and remote sensing > vol 86 (December 2013) . - pp 157 - 167[article]PermalinkScanners laser terrestres en conditions réelles : Alter 2, auscultation via scanner laser terrestre. 2ème partie / Vincent Barras in XYZ, n° 137 (décembre 2013 - février 2014)PermalinkUsing pattern-oriented modeling (POM) to cope with uncertainty in multi-scale agent-based models of land change / Nicholas R. Magliocca in Transactions in GIS, vol 17 n° 6 (December 2013)PermalinkHuman computation VGI provenance : Semantic web-based representation and publishing / Irene Celino in IEEE Transactions on geoscience and remote sensing, vol 51 n° 11 (November 2013)PermalinkIntroducing provenance capture into a legacy data system / Helen Conover in IEEE Transactions on geoscience and remote sensing, vol 51 n° 11 (November 2013)PermalinkMapping geospatial metadata to open provenance model / Chieh-Chieh Feng in IEEE Transactions on geoscience and remote sensing, vol 51 n° 11 (November 2013)PermalinkMethodological proposals to handle imperfect spatial and temporal information in the context of natural hazard studies / Mouna Snoussi in Revue internationale de géomatique, vol 23 n° 3 - 4 (septembre 2013 - février 2014)PermalinkProviding reliable user reports from the emergency scene for better situation awareness using EMdroid mobile application / Nikola Davidovic in Revue internationale de géomatique, vol 23 n° 3 - 4 (septembre 2013 - février 2014)PermalinkLes référentiels en question / Françoise de Blomac in DécryptaGéo le mag, n° 150 (01/10/2013)PermalinkA world of data / James Brayshaw in GEO: Geoconnexion international, vol 12 n° 9 (october 2013)Permalink