Détail de l'auteur
Auteur et al. |
Documents disponibles écrits par cet auteur (2731)
Ajouter le résultat dans votre panier
Visionner les documents numériques
Affiner la recherche Interroger des sources externes
Mapping collaboration in open source geospatial ecosystem / Jie Shao in Transactions in GIS, vol 16 n° 4 (August 2012)
[article]
Titre : Mapping collaboration in open source geospatial ecosystem Type de document : Article/Communication Auteurs : Jie Shao, Auteur ; M. Jackson, Auteur ; Jeremy Morley, Auteur ; et al., Auteur Année de publication : 2012 Article en page(s) : pp 581 - 597 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique web
[Termes IGN] analyse diachronique
[Termes IGN] logiciel libre
[Termes IGN] programmation informatique
[Termes IGN] réseau socialRésumé : (Auteur) Over the last decade, there has been a tremendous growth and exploitation of open source geospatial software and technologies. A combination of factors is driving this momentum, including the contributions made by hundreds of developers and the leading role played by the Open Source Geospatial Foundation (OSGeo), aiming primarily to support and promote the collaborative development of open source geospatial technologies and data. This article seeks to map out the social history of collaborative activities within the OSGeo ecosystem. We used the archival logs of developers' contributions, specifically looking for boundary spanning activities where contributions crossed multiple projects. The analysis and visualization of these activities allow us to have a better understanding of the role of boundary spanning in the resourcing of each project, the incubation mechanism advocated by OSGeo, and the significance of the social interrelatedness among projects. The data consisted of the subversion (SVN) commit history made by individual developers in the programming code repository. We applied several network analytical and visualization techniques to explore the data. Our findings indicate that more than one in seven developers spanned multiple projects which potentially had the effects of shaping the projects' directions, and increased knowledge flow and innovation. In addition, the OSGeo's incubation mechanism provided an important encouragement for boundary spanning and increased knowledge sharing. By studying the social history of contributions, further tools can be developed in future to assist tracking of the social history, and make developers mindful of the significance of the interdependence among projects and hence continuously contribute to the health of the OSGeo ecosystem. Numéro de notice : A2012-368 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1111/j.1467-9671.2012.01305.x Date de publication en ligne : 02/08/2012 En ligne : https://doi.org/10.1111/j.1467-9671.2012.01305.x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31814
in Transactions in GIS > vol 16 n° 4 (August 2012) . - pp 581 - 597[article]Mapping crop types, irrigated areas, and cropping intensities in heterogeneous landscapes of southern India using multi-temporal medium-resolution imagery: implications for assessing water use in agriculture / E. Heller in Photogrammetric Engineering & Remote Sensing, PERS, vol 78 n° 8 (August 2012)
[article]
Titre : Mapping crop types, irrigated areas, and cropping intensities in heterogeneous landscapes of southern India using multi-temporal medium-resolution imagery: implications for assessing water use in agriculture Type de document : Article/Communication Auteurs : E. Heller, Auteur ; J. Rhemtulla, Auteur ; S. Lele, Auteur ; et al., Auteur Année de publication : 2012 Article en page(s) : pp 815 - 827 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] carte agricole
[Termes IGN] classification dirigée
[Termes IGN] cultures
[Termes IGN] cultures irriguées
[Termes IGN] image à moyenne résolution
[Termes IGN] image IRS-LISS
[Termes IGN] Inde
[Termes IGN] Karnataka (Inde)
[Termes IGN] ressources en eau
[Termes IGN] rizière
[Termes IGN] Saccharum officinarumRésumé : (Auteur) In regions of water scarcity, mapping individual crops, cropping intensities and irrigation can contribute significantly to understanding agricultural water use. But such mapping is challenging in landscapes dominated by small-scale traditional agricultural land holdings with high spatial and temporal heterogeneity. Here, we assessed the benefit of using multi-temporal 24 m resolution LISS-III imagery to characterize cropping systems in the Malaprabha basin of southern India. We used hierarchical stacked supervised classification to create three increasingly detailed maps showing: (a) single rainfed paddy rice versus continuously irrigated sugarcane, (b) irrigated versus rainfed areas, and (c) multiple cropping. Although increasing detail was accompanied by decreasing overall accuracies (89 percent, 74.6 percent and 60.1 percent respectively), using multi-temporal imagery out-performed single imagery alone in all cases. Results also led to higher estimates of total (69.8 percent) and irrigated (34.7 percent) cropland than previous single-imagery studies and census data, revealing the high uncertainty in crop estimates in this region. Numéro de notice : A2012-429 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.14358/PERS.78.8.815 En ligne : https://doi.org/10.14358/PERS.78.8.815 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31875
in Photogrammetric Engineering & Remote Sensing, PERS > vol 78 n° 8 (August 2012) . - pp 815 - 827[article]Monitoring GOCE gradiometer calibration parameters using accelerometer and star sensor data: methodology and first results / C. Siemes in Journal of geodesy, vol 86 n° 8 (August 2012)
[article]
Titre : Monitoring GOCE gradiometer calibration parameters using accelerometer and star sensor data: methodology and first results Type de document : Article/Communication Auteurs : C. Siemes, Auteur ; Roger Haagmans, Auteur ; M. Kern, Auteur ; et al., Auteur Année de publication : 2012 Article en page(s) : pp 629 - 645 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] champ de pesanteur terrestre
[Termes IGN] données GOCE
[Termes IGN] étalonnage d'instrument
[Termes IGN] GOCE
[Termes IGN] gradient de gravitation
[Termes IGN] gradiomètre
[Termes IGN] série temporelleRésumé : (Auteur) The Gravity field and steady-state Ocean Circulation Explorer (GOCE) satellite, launched on 17 March 2009, is designed to measure the Earth’s mean gravity field with unprecedented accuracy at spatial resolutions down to 100 km. The accurate calibration of the gravity gradiometer on-board GOCE is of utmost importance for achieving the mission goals. ESA’s baseline method for the calibration uses star sensor and accelerometer data of a dedicated calibration procedure, which is executed every 2 months. In this paper, we describe a method for monitoring the evolution of calibration parameter during that time. The method works with star sensor and accelerometer data and does not require gravity field models, which distinguishes it from other existing methods. We present time series of calibration parameters estimated from GOCE data from 1 November 2009 to 17 May 2010. The time series confirm drifts in the calibration parameters that are present in the results of other methods, including ESA’s baseline method. Although these drifts are very small, they degrade the gravity gradients, leading to the conclusion that the calibration parameters of the ESA’s baseline method need to be linearly interpolated. Further, we find a correction of -36 * 10-6 for one calibration parameter (in-line differential scale factor of the cross-track gradiometer arm), which improves the gravity gradient performance. The results are validated by investigating the trace of the calibrated gravity gradients and comparing calibrated gravity gradients with reference gradients computed along the GOCE orbit using the ITG-Grace-2010s gravity field model. Numéro de notice : A2012-376 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-012-0545-8 Date de publication en ligne : 22/02/2012 En ligne : https://doi.org/10.1007/s00190-012-0545-8 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31822
in Journal of geodesy > vol 86 n° 8 (August 2012) . - pp 629 - 645[article]Réservation
Réserver ce documentExemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 266-2012081 RAB Revue Centre de documentation En réserve L003 Disponible Near real-time flood detection in urban and rural areas using high-resolution synthetic aperture radar images / D.C. Mason in IEEE Transactions on geoscience and remote sensing, vol 50 n° 8 (August 2012)
[article]
Titre : Near real-time flood detection in urban and rural areas using high-resolution synthetic aperture radar images Type de document : Article/Communication Auteurs : D.C. Mason, Auteur ; Ian J. Davenport, Auteur ; J.C. Neal, Auteur ; et al., Auteur Année de publication : 2012 Article en page(s) : pp 3041 - 3052 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications
[Termes IGN] Angleterre
[Termes IGN] détection
[Termes IGN] image TerraSAR-X
[Termes IGN] inondation
[Termes IGN] temps réel
[Termes IGN] zone rurale
[Termes IGN] zone urbaineRésumé : (Auteur) A near real-time flood detection algorithm giving a synoptic overview of the extent of flooding in both urban and rural areas, and capable of working during night-time and day-time even if cloud was present, could be a useful tool for operational flood relief management. The paper describes an automatic algorithm using high-resolution synthetic aperture radar (SAR) satellite data that builds on existing approaches, including the use of image segmentation techniques prior to object classification to cope with the very large number of pixels in these scenes. Flood detection in urban areas is guided by the flood extent derived in adjacent rural areas. The algorithm assumes that high-resolution topographic height data are available for at least the urban areas of the scene, in order that a SAR simulator may be used to estimate areas of radar shadow and layover. The algorithm proved capable of detecting flooding in rural areas using TerraSAR-X with good accuracy, classifying 89% of flooded pixels correctly, with an associated false positive rate of 6%. Of the urban water pixels visible to TerraSAR-X, 75% were correctly detected, with a false positive rate of 24%. If all urban water pixels were considered, including those in shadow and layover regions, these figures fell to 57% and 18%, respectively. Numéro de notice : A2012-380 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2011.2178030 Date de publication en ligne : 21/02/2012 En ligne : https://doi.org/10.1109/TGRS.2011.2178030 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31826
in IEEE Transactions on geoscience and remote sensing > vol 50 n° 8 (August 2012) . - pp 3041 - 3052[article]Réservation
Réserver ce documentExemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 065-2012081 RAB Revue Centre de documentation En réserve L003 Disponible The TropiSAR airborne campaign in French Guiana : objectives, description, and observed temporal behavior of the backscatter signal / P. Dubois-Fernandez in IEEE Transactions on geoscience and remote sensing, vol 50 n° 8 (August 2012)
[article]
Titre : The TropiSAR airborne campaign in French Guiana : objectives, description, and observed temporal behavior of the backscatter signal Type de document : Article/Communication Auteurs : P. Dubois-Fernandez, Auteur ; Thuy Le Toan, Auteur ; S. Daniel, Auteur ; et al., Auteur Année de publication : 2012 Article en page(s) : pp 3228 - 3241 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications
[Termes IGN] bande P
[Termes IGN] biomasse
[Termes IGN] forêt tropicale
[Termes IGN] Guyane (département français)
[Termes IGN] image aérienne
[Termes IGN] image radar moirée
[Termes IGN] image SETHI
[Termes IGN] polarisation croisée
[Termes IGN] qualité radiométrique (image)Résumé : (Auteur) The TropiSAR campaign has been conducted in August 2009 in French Guiana with the ONERA airborne radar system SETHI. The main objective of this campaign was to collect data to support the Phase A of the 7th Earth Explorer candidate mission, BIOMASS. Several specific questions needed to be addressed to consolidate the mission concept following the Phase 0 studies, and the data collection strategy was constructed accordingly. More specifically, a tropical forest data set was required in order to provide test data for the evaluation of the foreseen inversion algorithms and data products. The paper provides a description of the resulting data set which is now available through the European Space Agency website under the airborne campaign link. First results from the TropiSAR database analysis are presented with two in-depth analyses about both the temporal radiometric variation and temporal coherence at P-band. The temporal variations of the backscatter values are less than 0.5 dB throughout the campaign, and the coherence values are observed to stay high even after 22 days. These results are essential for the BIOMASS mission. The observed temporal stability of the backscatter is a good indicator of the expected robustness of the biomass estimation in tropical forests, from cross-polarized backscatter values as regarding environmental changes such as soil moisture. The high temporal coherence observed after a 22-day period is a prerequisite for SAR Polarimetric Interferometry and Tomographic applications in a single satellite configuration. The conclusion then summarizes the paper and identifies the next steps in the analysis. Numéro de notice : A2012-388 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2011.2178246 Date de publication en ligne : 18/01/2012 En ligne : https://doi.org/10.1109/TGRS.2011.2178246 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31834
in IEEE Transactions on geoscience and remote sensing > vol 50 n° 8 (August 2012) . - pp 3228 - 3241[article]Réservation
Réserver ce documentExemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 065-2012081 RAB Revue Centre de documentation En réserve L003 Disponible TOPS interferometry with TerraSAR-X / Pau Prats-Iraola in IEEE Transactions on geoscience and remote sensing, vol 50 n° 8 (August 2012)PermalinkApplication of time series Landsat images to examining land-use / land-cover dynamic change / Dong Lu in Photogrammetric Engineering & Remote Sensing, PERS, vol 78 n° 7 (July 2012)PermalinkDetection of large-scale forest canopy change in pan-tropical humid forests 2000–2009 with the seawinds Ku-band scatterometer / S. Frolking in IEEE Transactions on geoscience and remote sensing, vol 50 n° 7 Tome 1 (July 2012)PermalinkMonitoring water stress and fruit quality in an orange orchard under regulated deficit irrigation using narrow-band structural and physiological remote sensing indices / S. Stagakis in ISPRS Journal of photogrammetry and remote sensing, vol 71 (July 2012)PermalinkPNN query processing on compressed trajectories / S. Shang in Geoinformatica, vol 16 n° 3 (July 2012)PermalinkProcessing aggregated data: the location of clusters in health data / Kevin Buchin in Geoinformatica, vol 16 n° 3 (July 2012)PermalinkRepresentative multiple Kernel learning for classification in hyperspectral imagery / Y. Gu in IEEE Transactions on geoscience and remote sensing, vol 50 n° 7 Tome 2 (July 2012)PermalinkThe potential of spectral mixture analysis to improve the estimation accuracy of tropical forest biomass / T.M. Basuki in Geocarto international, vol 27 n° 4 (July 2012)PermalinkApport des données TerraSar-X pour le suivi de l'activité du Piton de la Fournaise / J.L. Froger in Revue Française de Photogrammétrie et de Télédétection, n° 197 (Juin 2012)PermalinkAssessment of the GOCE-based global gravity models in Canada / Elmas Sinem Ince in Geomatica, vol 66 n° 2 (June 2012)Permalink