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Water stress detection over irrigated wheat crops in semi-arid areas using the diurnal differences of Sentinel-1 backscatter / Nadia Ouaadi (2020)
Titre : Water stress detection over irrigated wheat crops in semi-arid areas using the diurnal differences of Sentinel-1 backscatter Type de document : Article/Communication Auteurs : Nadia Ouaadi, Auteur ; Lionel Jarlan, Auteur ; Jamal Ezzahar, Auteur ; Saïd Khabba, Auteur ; Valérie Le Dantec, Auteur ; Zoubair Rafi, Auteur ; Mehrez Zribi, Auteur ; Pierre-Louis Frison , Auteur Editeur : New York : Institute of Electrical and Electronics Engineers IEEE Année de publication : 2020 Projets : 2-Pas d'info accessible - article non ouvert / Conférence : M2GARSS 2020, Mediterranean and Middle-East Geoscience and Remote Sensing Symposium 09/03/2020 11/03/2020 Tunis Tunisie Proceedings IEEE Importance : pp 306 - 309 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications
[Termes IGN] bande C
[Termes IGN] blé (céréale)
[Termes IGN] coefficient de rétrodiffusion
[Termes IGN] cultures irriguées
[Termes IGN] image Sentinel-SAR
[Termes IGN] Maroc
[Termes IGN] stress hydrique
[Termes IGN] surveillance agricole
[Termes IGN] teneur en eau de la végétation
[Termes IGN] variation diurne
[Termes IGN] zone semi-arideRésumé : (auteur) This work aims to investigate the sensitivity of the diurnal differences of radar backscatter to diurnal changes in the vegetation water content (VWC). Sentinel-1 backscattering coefficient differences between two orbits (morning and evening) are analyzed over an irrigated and voluntarily stressed wheat field. A physical model of backscatter prediction is evaluated for wheat and used to examine the sensitivity of radar differences to the VWC for a range of surface soil moisture and biomass conditions. Results highlight the potential of C-band diurnal differences for the monitoring the water stress over agricultural canopies. Numéro de notice : C2020-036 Affiliation des auteurs : UGE-LASTIG+Ext (2020- ) Autre URL associée : vers HAL Thématique : IMAGERIE Nature : Communication nature-HAL : ComAvecCL&ActesPubliésIntl DOI : 10.1109/M2GARSS47143.2020.9105171 Date de publication en ligne : 02/06/2020 En ligne : https://doi.org/10.1109/M2GARSS47143.2020.9105171 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99685 Consistency and representativeness of integrated water vapour from ground-based GPS observations and ERA-Interim reanalysis / Olivier Bock in Atmospheric chemistry and physics, vol 19 n° 14 (July 2019)
[article]
Titre : Consistency and representativeness of integrated water vapour from ground-based GPS observations and ERA-Interim reanalysis Type de document : Article/Communication Auteurs : Olivier Bock , Auteur ; Ana-Claudia Bernardes Parracho , Auteur Année de publication : 2019 Projets : GNSS4SWEC / Article en page(s) : 17 p. Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] analyse comparative
[Termes IGN] analyse diachronique
[Termes IGN] données GPS
[Termes IGN] erreur
[Termes IGN] humidité de l'air
[Termes IGN] interpolation spatiale
[Termes IGN] retard troposphérique zénithal
[Termes IGN] teneur intégrée en vapeur d'eau
[Termes IGN] variation diurne
[Termes IGN] variation saisonnièreRésumé : (auteur) This study examines the consistency and representativeness differences of daily integrated water vapour (IWV) data from ERA-Interim reanalysis and GPS observations at 120 global sites over a 16-year period (1995–2010). Various comparison statistics are analysed as a function of geographic, topographic, and climatic features. A small (±1 kg m−2) bias is found in the reanalysis across latitudes (moist in northern and southern midlatitudes and dry in the tropics). The standard deviation of daily IWV differences is generally below 2 kg m−2 but peaks in the northern and southern storm-track regions. In general, the larger IWV differences are explained by increased representativeness errors, when GPS observations capture some small-scale variability that is not resolved by the reanalysis. A representativeness error statistic is proposed which measures the spatiotemporal variability in the vicinity of the GPS sites, based on reanalysis data at the four surrounding grid points. It allows to predict the standard deviation of daily IWV differences with a correlation of 0.73. In general, representativeness differences can be reduced by temporal averaging and spatial interpolation from the four surrounding grid points. A small number of outlying cases (15 sites) which do not follow the general tendencies are further examined. It is found that their special topographic and climatic features strongly enhance the representativeness errors (e.g. steep topography, coastlines, and strong seasonal cycle in monsoon regions). Discarding these sites significantly improves the global ERA-Interim and GPS comparison results. The selection of sites a priori, based on the representativeness error statistic, is able to detect 11 out of the 15 sites and improve the comparison results by 20 % to 30 %. Numéro de notice : A2019-615 Affiliation des auteurs : Géodésie+Ext (mi2018-2019) Autre URL associée : vers HAL Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.5194/acp-19-9453-2019 Date de publication en ligne : 24/07/2019 En ligne : https://hal.science/hal-02277609v1 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95311
in Atmospheric chemistry and physics > vol 19 n° 14 (July 2019) . - 17 p.[article]Evaluation of the IRI-2016 and NeQuick electron content specification by COSMIC GPS radio occultation, ground-based GPS and Jason-2 joint altimeter/GPS observations / Iurii Cherniak in Advances in space research, vol 63 n° 6 (15 March 2019)
[article]
Titre : Evaluation of the IRI-2016 and NeQuick electron content specification by COSMIC GPS radio occultation, ground-based GPS and Jason-2 joint altimeter/GPS observations Type de document : Article/Communication Auteurs : Iurii Cherniak, Auteur ; Irina Zakharenkova, Auteur Année de publication : 2019 Article en page(s) : pp 1845 - 1859 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] données altimétriques
[Termes IGN] données GPS
[Termes IGN] données Jason
[Termes IGN] International Reference Ionosphere
[Termes IGN] modèle ionosphérique
[Termes IGN] plasmasphère
[Termes IGN] teneur totale en électrons
[Termes IGN] variation diurneRésumé : (Auteur) We examined performance of two empirical profile-based ionospheric models, namely IRI-2016 and NeQuick-2, in electron content (EC) and total electron content (TEC) representation for different seasons and levels of solar activity. We derived and analyzed EC estimates in several representative altitudinal intervals for the ionosphere and the plasmasphere from the COSMIC GPS radio occultation, ground-based GPS and Jason-2 joint altimeter/GPS observations. It allows us to estimate a quantitative impact of the ionospheric electron density profiles formulation in several altitudinal intervals and to examine the source of the model-data discrepancies of the EC specification from the bottom-side ionosphere towards the GPS orbit altitudes. The most pronounced model-data differences were found at the low latitude region as related to the equatorial ionization anomaly appearance. Both the IRI-2016 and NeQuick-2 models tend to overestimate the daytime ionospheric EC and TEC at low latitudes during all seasons of low solar activity. On the contrary, during high solar activity the model results underestimated the EC/TEC observations at low latitudes. We found that both models underestimated the EC for the topside ionosphere and plasmasphere regions for all levels of solar activity. For low solar activity, the underestimated EC from the topside ionosphere and plasmasphere can compensate the overestimation of the ionospheric EC and, consequently, can slightly decrease the resulted model overestimation of the ground-based TEC. For high solar activity, the underestimated EC from the topside ionosphere and plasmasphere leads to a strengthening of the model underestimation of the ground-based TEC values. We demonstrated that the major source of the model-data discrepancies in the EC/TEC domain comes from the topside ionosphere/plasmasphere system. Numéro de notice : A2019-171 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.asr.2018.10.036 Date de publication en ligne : 02/11/2018 En ligne : https://doi.org/10.1016/j.asr.2018.10.036 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=92622
in Advances in space research > vol 63 n° 6 (15 March 2019) . - pp 1845 - 1859[article]
Titre : Learning scene geometry for visual localization in challenging conditions Type de document : Article/Communication Auteurs : Nathan Piasco , Auteur ; Désiré Sidibé, Auteur ; Valérie Gouet-Brunet , Auteur ; Cédric Demonceaux, Auteur Editeur : New York : Institute of Electrical and Electronics Engineers IEEE Année de publication : 2019 Projets : PLaTINUM / Gouet-Brunet, Valérie Conférence : ICRA 2019, International Conference on Robotics and Automation 20/05/2019 24/05/2019 Montréal Québec - Canada Proceedings IEEE Importance : pp 9094 - 9100 Format : 21 x 30 cm Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] analyse d'image orientée objet
[Termes IGN] analyse visuelle
[Termes IGN] appariement d'images
[Termes IGN] carte de profondeur
[Termes IGN] descripteur
[Termes IGN] géométrie de l'image
[Termes IGN] image RVB
[Termes IGN] localisation basée vision
[Termes IGN] précision de localisation
[Termes IGN] prise de vue nocturne
[Termes IGN] robotique
[Termes IGN] scène urbaine
[Termes IGN] variation diurne
[Termes IGN] variation saisonnière
[Termes IGN] vision par ordinateurRésumé : (auteur) We propose a new approach for outdoor large scale image based localization that can deal with challenging scenarios like cross-season, cross-weather, day/night and longterm localization. The key component of our method is a new learned global image descriptor, that can effectively benefit from scene geometry information during training. At test time, our system is capable of inferring the depth map related to the query image and use it to increase localization accuracy. We are able to increase recall@1 performances by 2.15% on cross-weather and long-term localization scenario and by 4.24% points on a challenging winter/summer localization sequence versus state-of-the-art methods. Our method can also use weakly annotated data to localize night images across a reference dataset of daytime images. Numéro de notice : C2019-002 Affiliation des auteurs : LASTIG MATIS+Ext (2012-2019) Thématique : IMAGERIE Nature : Communication nature-HAL : ComAvecCL&ActesPubliésIntl DOI : 10.1109/ICRA.2019.8794221 Date de publication en ligne : 12/08/2019 En ligne : http://doi.org/10.1109/ICRA.2019.8794221 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=93774 Documents numériques
en open access
Learning scene geometry... - pdf auteurAdobe Acrobat PDF A new climatology of maximum and minimum temperature (1951–2010) in the Spanish mainland: a comparison between three different interpolation methods / D. Peña-Angulo in International journal of geographical information science IJGIS, vol 30 n° 11-12 (November - December 2016)
[article]
Titre : A new climatology of maximum and minimum temperature (1951–2010) in the Spanish mainland: a comparison between three different interpolation methods Type de document : Article/Communication Auteurs : D. Peña-Angulo, Auteur ; M. Brunetti, Auteur ; N. Cortesi, Auteur ; J.C. Gonzalez-Hidalgo, Auteur Année de publication : 2016 Article en page(s) : pp 2109 - 2132 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale
[Termes IGN] base de données thématiques
[Termes IGN] carte thématique
[Termes IGN] données météorologiques
[Termes IGN] interpolation spatiale
[Termes IGN] krigeage
[Termes IGN] modèle de régression
[Termes IGN] température au sol
[Termes IGN] traitement géométrique de données
[Termes IGN] variation diurneRésumé : (Auteur) This study presents a new climatology of monthly temperature for mainland Spain (1951–2010), performed with the highest quality and spatially dense, up-to-date monthly temperature dataset available in the study area (MOTEDAS). Three different interpolation techniques were evaluated: the Local Weighted Linear Regression (LWLR), the Regression-Kriging (RK) and the Regression-Kriging with stepwise selection (RKS), a modification of RK. The performances of the different models were evaluated by the leave-one-out validation procedure, comparing the results from the models with the original data and calculating different error measurements. The three techniques performed better for Tmax than for Tmin, and for the cold, rather than warmer months, also at lower altitude than highland areas. The best results were achieved with LWLR applied for the first time on temperatures in the Spanish mainland. This method improved the accuracy of the temperature reconstruction with respect to RK and RKS. We present a collection of Tmax and Tmin monthly charts, using the same temperature legend to prevent any visual bias in the interpretation of the results. The dataset is available upon request. Numéro de notice : A2016-750 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/13658816.2016.1155712 En ligne : http://dx.doi.org/10.1080/13658816.2016.1155712 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=82336
in International journal of geographical information science IJGIS > vol 30 n° 11-12 (November - December 2016) . - pp 2109 - 2132[article]Réservation
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