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Retrieving grassland canopy water content by considering the information from neighboring pixels / Binbin He in Photogrammetric Engineering & Remote Sensing, PERS, vol 83 n° 8 (August 2017)
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Titre : Retrieving grassland canopy water content by considering the information from neighboring pixels Type de document : Article/Communication Auteurs : Binbin He, Auteur ; Xingwen Quan, Auteur ; Dasong Xu, Auteur ; et al., Auteur Année de publication : 2017 Article en page(s) : pp 553 - 565 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] Chine
[Termes IGN] classification barycentrique
[Termes IGN] classification pixellaire
[Termes IGN] modèle de transfert radiatif
[Termes IGN] prairie
[Termes IGN] réponse spectrale
[Termes IGN] teneur en eau liquideRésumé : (auteur) Accurate and robust retrieval of grassland canopy water content (CWC) using a radiative transfer model (RTM) is generally affected by the ill-posed inversion problem due to the lack of enough available a priori information. To alleviate this problem when inversing the RTM, a two-step inversion method was proposed. The key point of this method was to simultaneously consider the spectral information from neighboring pixels and the spatial dependency among these pixels, with the purpose to win more information from these neighboring pixels. The proposed methodology was then applied to retrieve CWC using the PROSAIL RTM from Landsat-8 OLI data for a plateau grassland in China. The results showed that the estimated CWC using the proposed method (RMSE = 67.31 g m-2 and R2 = 0.81) was better than that from the traditional method (RMSE = 80.11 g m-2 and R2 = 0.78) which only considered the information of single pixel. Numéro de notice : A2017-436 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.14358/PERS.83.8.553 En ligne : https://doi.org/10.14358/PERS.83.8.553 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=86340
in Photogrammetric Engineering & Remote Sensing, PERS > vol 83 n° 8 (August 2017) . - pp 553 - 565[article]A viewpoint based approach to the visual exploration of trajectory / Jie Li in Journal of Visual Languages and Computing, vol 41 (August 2017)
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Titre : A viewpoint based approach to the visual exploration of trajectory Type de document : Article/Communication Auteurs : Jie Li, Auteur ; Zhao Xiao, Auteur ; Jun Kong, Auteur Année de publication : 2017 Article en page(s) : pp 41 - 53 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] analyse géovisuelle
[Termes IGN] Chine
[Termes IGN] données spatiotemporelles
[Termes IGN] Google Earth
[Termes IGN] jeu de données localisées
[Termes IGN] KML
[Termes IGN] trajectoire (véhicule non spatial)
[Termes IGN] transport collectif
[Termes IGN] transport routier
[Termes IGN] transport urbain
[Termes IGN] visualisation de données
[Vedettes matières IGN] GéovisualisationRésumé : (auteur) We present a new viewpoint-based approach to improving the exploration effects and efficiency of trajectory datasets. Our approach integrates novel trajectory visualization techniques with algorithms for selecting optimal viewpoints to explore the generated visualization. Both the visualization and the viewpoints will be represented in the form of KML, which can be directly rendered in most of off-the-shelf GIS platforms. By playing the viewpoint sequence and directly utilizing the components of GIS platforms to explore the visualization, the overview status, detailed information, and the time variation characteristics of the trajectories can be quickly captured. A case study and a usability experiment have been conducted on an actual public transportation dataset, justifying the effectiveness of our approach. Comparing with the basic exploration approach without viewpoints, we find our approach increases the speed of information retrieval when analyzing trajectory datasets, and enhances user experiences in 3D trajectory exploration. Numéro de notice : A2017-149 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1016/j.jvlc.2017.04.001 Date de publication en ligne : 10/04/2017 En ligne : http://doi.org/10.1016/j.jvlc.2017.04.001 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=84645
in Journal of Visual Languages and Computing > vol 41 (August 2017) . - pp 41 - 53[article]Performance evaluation of ionospheric time delay forecasting models using GPS observations at a low-latitude station / G. Sivavaraprasad in Advances in space research, vol 60 n° 2 (15 July 2017)
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Titre : Performance evaluation of ionospheric time delay forecasting models using GPS observations at a low-latitude station Type de document : Article/Communication Auteurs : G. Sivavaraprasad, Auteur ; D. Venkata Ratman, Auteur Année de publication : 2017 Article en page(s) : pp 475 - 490 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] données GPS
[Termes IGN] données météorologiques
[Termes IGN] Inde
[Termes IGN] International Reference Ionosphere
[Termes IGN] latitude
[Termes IGN] modèle de simulation
[Termes IGN] modèle ionosphérique
[Termes IGN] retard ionosphèrique
[Termes IGN] teneur totale en électrons
[Termes IGN] teneur verticale totale en électrons
[Termes IGN] test de performance
[Vedettes matières IGN] Traitement de données GNSSRésumé : (auteur) Ionospheric delay is one of the major atmospheric effects on the performance of satellite-based radio navigation systems. It limits the accuracy and availability of Global Positioning System (GPS) measurements, related to critical societal and safety applications. The temporal and spatial gradients of ionospheric total electron content (TEC) are driven by several unknown priori geophysical conditions and solar-terrestrial phenomena. Thereby, the prediction of ionospheric delay is challenging especially over Indian sub-continent. Therefore, an appropriate short/long-term ionospheric delay forecasting model is necessary. Hence, the intent of this paper is to forecast ionospheric delays by considering day to day, monthly and seasonal ionospheric TEC variations. GPS-TEC data (January 2013–December 2013) is extracted from a multi frequency GPS receiver established at K L University, Vaddeswaram, Guntur station (geographic: 16.37°N, 80.37°E; geomagnetic: 7.44°N, 153.75°E), India. An evaluation, in terms of forecasting capabilities, of three ionospheric time delay models – an Auto Regressive Moving Average (ARMA) model, Auto Regressive Integrated Moving Average (ARIMA) model, and a Holt-Winter's model is presented. The performances of these models are evaluated through error measurement analysis during both geomagnetic quiet and disturbed days. It is found that, ARMA model is effectively forecasting the ionospheric delay with an accuracy of 82–94%, which is 10% more superior to ARIMA and Holt-Winter’s models. Moreover, the modeled VTEC derived from International Reference Ionosphere, IRI (IRI-2012) model and new global TEC model, Neustrelitz TEC Model (NTCM-GL) have compared with forecasted VTEC values of ARMA, ARIMA and Holt-Winter’s models during geomagnetic quiet days. The forecast results are indicating that ARMA model would be useful to set up an early warning system for ionospheric disturbances at low latitude regions. Numéro de notice : A2017-252 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.asr.2017.01.031 Date de publication en ligne : 30/01/2017 En ligne : https://doi.org/10.1016/j.asr.2017.01.031 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=85254
in Advances in space research > vol 60 n° 2 (15 July 2017) . - pp 475 - 490[article]Adaptive and plastic responses of Quercus petraea populations to climate across Europe / Cuauhtémoc Saenz-Romero in Global change biology, vol 23 n° 7 (July 2017)
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Titre : Adaptive and plastic responses of Quercus petraea populations to climate across Europe Type de document : Article/Communication Auteurs : Cuauhtémoc Saenz-Romero, Auteur ; Jean-Baptiste Lamy, Auteur ; Alexis Ducousso, Auteur ; Brigitte Musch, Auteur ; et al., Auteur Année de publication : 2017 Article en page(s) : pp 2831 - 2847 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] analyse comparative
[Termes IGN] changement climatique
[Termes IGN] Danemark
[Termes IGN] forêt tempérée
[Termes IGN] France (administrative)
[Termes IGN] Hongrie
[Termes IGN] modèle de simulation
[Termes IGN] Norvège
[Termes IGN] Quercus sessiliflora
[Termes IGN] Turquie
[Vedettes matières IGN] Végétation et changement climatiqueRésumé : (auteur) How temperate forests will respond to climate change is uncertain; projections range from severe decline to increased growth. We conducted field tests of sessile oak (Quercus petraea), a widespread keystone European forest tree species, including more than 150 000 trees sourced from 116 geographically diverse populations. The tests were planted on 23 field sites in six European countries, in order to expose them to a wide range of climates, including sites reflecting future warmer and drier climates. By assessing tree height and survival, our objectives were twofold: (i) to identify the source of differential population responses to climate (genetic differentiation due to past divergent climatic selection vs. plastic responses to ongoing climate change) and (ii) to explore which climatic variables (temperature or precipitation) trigger the population responses. Tree growth and survival were modeled for contemporary climate and then projected using data from four regional climate models for years 2071–2100, using two greenhouse gas concentration trajectory scenarios each. Overall, results indicated a moderate response of tree height and survival to climate variation, with changes in dryness (either annual or during the growing season) explaining the major part of the response. While, on average, populations exhibited local adaptation, there was significant clinal population differentiation for height growth with winter temperature at the site of origin. The most moderate climate model (HIRHAM5-EC; rcp4.5) predicted minor decreases in height and survival, while the most extreme model (CCLM4-GEM2-ES; rcp8.5) predicted large decreases in survival and growth for southern and southeastern edge populations (Hungary and Turkey). Other nonmarginal populations with continental climates were predicted to be severely and negatively affected (Bercé, France), while populations at the contemporary northern limit (colder and humid maritime regions; Denmark and Norway) will probably not show large changes in growth and survival in response to climate change. Numéro de notice : A2017-676 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1111/gcb.13576 En ligne : http://doi.org/10.1111/gcb.13576 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=87202
in Global change biology > vol 23 n° 7 (July 2017) . - pp 2831 - 2847[article]Classification of European beech forests: a Gordian Knot? / Wolfgang Willner in Applied Vegetation Science, vol 20 n° 3 (July 2017)
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Titre : Classification of European beech forests: a Gordian Knot? Type de document : Article/Communication Auteurs : Wolfgang Willner, Auteur ; Borja Jimenez-Alfaro, Auteur ; Emiliano Agrillo, Auteur ; et al., Auteur Année de publication : 2017 Article en page(s) : pp 494 - 512 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] Europe (géographie politique)
[Termes IGN] Fagus orientalis
[Termes IGN] Fagus sylvatica
[Termes IGN] phytosociologie
[Termes IGN] Turquie
[Termes IGN] TWINSPAN
[Termes IGN] unité phytosociologique
[Vedettes matières IGN] Ecologie forestièreRésumé : (auteur) Questions : What are the main floristic patterns in European beech forests? Which classification at the alliance and suballiance level is the most convincing?
Location : Europe and Asia Minor.
Methods : We applied a TWINSPAN classification to a data set of 24 605 relevés covering the whole range of Fagus sylvatica forests and the western part of Fagus orientalis forests. We identified 24 ‘operational phytosociological units’ (OPUs), which were used for further analysis. The position of each OPU along the soil pH and temperature gradient was evaluated using Ellenberg Indicator Values. Fidelity of species to OPUs was calculated using the phi coefficient and constancy ratio. We compared alternative alliance concepts, corresponding to groups of OPUs, in terms of number and frequency of diagnostic species. We also established formal definitions for the various alliance concepts based on comparison of the total cover of the diagnostic species groups, and evaluated alternative geographical subdivisions of beech forests.
Results : The first and second division levels of TWINSPAN followed the temperature and soil pH gradients, while lower divisions were mainly geographical. We grouped the 22 OPUs of Fagus sylvatica forests into acidophytic, meso-basiphytic and thermo-basiphytic beech forests, and separated two OPUs of F. orientalis forests. However, a solution with only two ecologically defined alliances of F. sylvatica forests (acidophytic vs basiphytic) was clearly superior with regard to number and frequency of diagnostic species. In contrast, when comparing groupings with three to six geographical alliances of basiphytic beech forests, respectively, we did not find a strongly superior solution.
Conclusions : We propose to classify F. sylvatica forests into 15 suballiances – three acidophytic and 12 basiphytic ones. Separating these two groups at alliance or order level was clearly supported by our results. Concerning the grouping of the 12 basiphytic suballiances into ecological or geographical alliances, as advocated by many authors, we failed to find an optimal solution. Therefore, we propose a multi-dimensional classification of basiphytic beech forests, including both ecological and geographical groups as equally valid concepts which may be used alternatively depending on the purpose and context of the classification.Numéro de notice : A2017-661 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1111/avsc.12299 En ligne : http://doi.org/10.1111/avsc.12299 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=87085
in Applied Vegetation Science > vol 20 n° 3 (July 2017) . - pp 494 - 512[article]Fusion of RADARSAT-2 and multispectral optical remote sensing data for LULC extraction in a tropical agricultural area / Mohamed Barakat A. Gibril in Geocarto international, vol 32 n° 7 (July 2017)
PermalinkAssessment of urban energy performance through integration of BIM and GIS for smart city planning / Shinji Yamamura in Procedia Engineering, vol 180 ([01/06/2017])
PermalinkPermalinkChange detection of linear features in temporally spaced remotely sensed images using edge-based grid analysis / Arati Paul in Geocarto international, vol 32 n° 6 (June 2017)
PermalinkMonitoring mangrove biomass change in Vietnam using SPOT images and an object-based approach combined with machine learning algorithms / Lien T.H. Pham in ISPRS Journal of photogrammetry and remote sensing, vol 128 (June 2017)
PermalinkPerformance evaluation of land change simulation models using landscape metrics / Sadeq Dezhkam in Geocarto international, vol 32 n° 6 (June 2017)
PermalinkTM-Based SOC models augmented by auxiliary data for carbon crediting programs in semi-arid environments / Salahuddin M. Jaber in Photogrammetric Engineering & Remote Sensing, PERS, vol 83 n° 6 (June 2017)
PermalinkDesign and evaluation of a geovisual analytics system for uncovering patterns in spatio-temporal event data / Anthony C. Robinson in Cartography and Geographic Information Science, Vol 44 n° 3 (May 2017)
PermalinkIndividual tree basal area increment models for broadleaved forests in Bhutan / Jigme Tenzin in Forestry, an international journal of forest research, vol 90 n° 3 (May 2017)
PermalinkMapping fine-scale population distributions at the building level by integrating multisource geospatial big data / Yao Yao in International journal of geographical information science IJGIS, vol 31 n° 5-6 (May-June 2017)
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