Descripteur
Termes IGN > mathématiques > statistique mathématique > série temporelle
série temporelleSynonyme(s)série chronologique série chroniqueVoir aussi |
Documents disponibles dans cette catégorie (446)
Ajouter le résultat dans votre panier
Visionner les documents numériques
Affiner la recherche Interroger des sources externes
Etendre la recherche sur niveau(x) vers le bas
The ambiguous sea level rise at Brest’s 212 yearlong record elucidated / Huseyin Baki Iz in Journal of geodetic science, vol 11 n° 1 (January 2021)
[article]
Titre : The ambiguous sea level rise at Brest’s 212 yearlong record elucidated Type de document : Article/Communication Auteurs : Huseyin Baki Iz, Auteur ; C.K. Shum, Auteur Année de publication : 2021 Article en page(s) : pp 95 - 101 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] analyse diachronique
[Termes IGN] Brest
[Termes IGN] changement climatique
[Termes IGN] données marégraphiques
[Termes IGN] marégraphe
[Termes IGN] montée du niveau de la mer
[Termes IGN] série temporelleRésumé : (auteur) The tide gauge record at Brest, France, along Eastern part of Atlantic coast is one of the longest records in Europe spanning 212 years (1807–2019). Analyzing these records has important ramifications in assessing anthropogenic impact of climate change at local and regional scales during this period. All the previous studies that analyzed Brest’s tide gauge record have used vaguely defined quadratics models and did not incorporate the effect of sea level variations at various frequencies, which confounded the presence or absence of a plausible uniform acceleration. Here, we entertained two competing kinematic models; one with a uniform acceleration representing 212 years of monthly averaged tide gauge data, the other is a two-phase trend model (Phase I is 93 years long and Phase II is 119 years long). Both models include statistically significant (α= 0.05) common periodic effects, and sub and super harmonics of luni-solar origin for representing monthly averaged sea level anomalies observed at Brest. The least squares statistics for both models’ solutions cannot distinguish one model over the other, like earlier studies. However, the assessment of Phase I segment of the records disclosed the absence of a statistically significant trend and a uniform acceleration during this period. This outcome eliminates conclusively the occurrence of a uniform acceleration during the entire 212-year data span of the tide gauge record at Brest, favoring the two-phase trend model as a sound alternative. Numéro de notice : A2021-981 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1515/jogs-2020-0124 Date de publication en ligne : 20/09/2021 En ligne : https://doi.org/10.1515/jogs-2020-0124 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=100978
in Journal of geodetic science > vol 11 n° 1 (January 2021) . - pp 95 - 101[article]Time-series analysis of massive satellite images : Application to earth observation / Alexandre Constantin (2021)
Titre : Time-series analysis of massive satellite images : Application to earth observation Titre original : Analyse de séries temporelles massives d'images satellitaires : Applications à la cartographie des écosystèmes Type de document : Thèse/HDR Auteurs : Alexandre Constantin, Auteur ; Stéphane Girard, Directeur de thèse ; Mathieu Fauvel, Directeur de thèse Editeur : Grenoble [France] : Université Grenoble Alpes Année de publication : 2021 Importance : 136 p. Format : 21 x 30 cm Note générale : bibliographie
Thèse Pour obtenir le grade de Docteur de l'Université de Grenoble Alpes, Specialité : Mathématiques AppliquéesLangues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] analyse multivariée
[Termes IGN] carte d'occupation du sol
[Termes IGN] classification dirigée
[Termes IGN] classification pixellaire
[Termes IGN] covariance
[Termes IGN] échantillonnage de données
[Termes IGN] écosystème
[Termes IGN] image Sentinel-MSI
[Termes IGN] processus gaussien
[Termes IGN] Python (langage de programmation)
[Termes IGN] régression
[Termes IGN] série temporelleIndex. décimale : THESE Thèses et HDR Résumé : (auteur) This thesis takes place in the context of the processing of the data from Sentinel-2 mission. This mission, initiated by the European Space Agency and launched in 2017, produces an unprecedented amount of Satellite Image Time-Series (SITS). Among the key analyses of these images, this thesis focuses on the classification task, i.e. land use or land cover maps that can be produced using spectro-temporal aspect of the Sentinel-2 SITS.Two main difficulties are identified in this thesis for the process of Sentinel-2 SITS. First, the unprecedented amount of data requires both scalable classifiers and code optimization techniques (such as parallel processing). Second, the acquisition noise (clouds, shadows) combined with the temporal aspect results in irregular and unevenly sampled time-series. Conventional approaches re-sample time-series to a set of time stamps, then they use machine learning techniques to classify vectors at a large-scale (national scale). The main disadvantage of this two-step processing approach is that it increases the number of operations applied to the SITS, implying a more difficult transition to massive amount of data. To a lower extent, the re-sampling step may slightly alter the temporal characteristics of the data.This thesis contributions are the following. We introduce a novel model-based approach with the ability to classify irregularly sampled time-series based on a mixture of multivariate Gaussian processes. A two-step approach has been used, by defining on one hand a model of uni-variate time-series, independent from the spectral wavelength point of view, then by considering on the second hand both spectral and temporal information from SITS. These models allow jointly a reconstruction of unobserved or noisy data. Estimation of both models has been implemented using a parallelized python code to be scalable to large-scale data-sets. The two models are evaluated numerically on Sentinel-2 SITS in terms of classification and reconstruction accuracy and are compared with conventional approaches. Analyses of the results illustrate the relevance of the two models and the benefit of using interpretable parametric models. Note de contenu : General Introduction
1- Satellite image time-series analysis and classification
2- Statistical modelling for time-series classification
3- Model-based classification for irregularly sampled time-series
4- Joint supervised classification and reconstruction of irregularly sampled satellite image times series
5- Mixture of multivariate gaussian processes for classification of irregularly sampled SITS
Conclusion and perspectivesNuméro de notice : 15280 Affiliation des auteurs : non IGN Thématique : IMAGERIE/MATHEMATIQUE Nature : Thèse française Note de thèse : Thèse de Doctorat : Mathématiques Appliquées : Grenoble : 2021 Organisme de stage : Laboratoire Jean Kuntzmann DOI : sans En ligne : https://hal.science/tel-03682025 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=101161 Topographic, edaphic and climate influences on aspen (Populus tremuloides) drought stress on an intermountain bunchgrass prairie / Andrew Neary in Forest ecology and management, vol 479 ([01/01/2021])
[article]
Titre : Topographic, edaphic and climate influences on aspen (Populus tremuloides) drought stress on an intermountain bunchgrass prairie Type de document : Article/Communication Auteurs : Andrew Neary, Auteur ; Ricardo Mata-González, Auteur ; Heidi Schmalz, Auteur Année de publication : 2021 Article en page(s) : 12 p. Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] analyse de sensibilité
[Termes IGN] climat
[Termes IGN] écophysiologie
[Termes IGN] état du sol
[Termes IGN] facteur édaphique
[Termes IGN] hauteur des arbres
[Termes IGN] humidité du sol
[Termes IGN] manteau neigeux
[Termes IGN] Oregon (Etats-Unis)
[Termes IGN] Poaceae
[Termes IGN] Populus tremuloides
[Termes IGN] prairie
[Termes IGN] série temporelle
[Termes IGN] stress hydrique
[Vedettes matières IGN] Végétation et changement climatiqueRésumé : (auteur) Quaking aspen, Populus tremuloides, has experienced severe declines in recent years in part due to the effects of changing climate and extreme drought. This study set out to investigate these effects by assessing associations of climatic, edaphic and topographic variables with physiological drought stress in aspen. The study took place on the Zumwalt Prairie in northeastern Oregon, a semi-arid bunchgrass prairie where aspen occur in isolated stands associated with riparian areas and late-season persistence of snow drifts. Using a 33-year time series of Landsat imagery to detect associations of aspen stands late-season snow cover and field measurements of soil moisture in aspen stands during 2017, we found while snow dominated stands were associated with greater soil moisture during spring, levels had equilibrated to those of other upland stands by summer. Measurements of predawn and midday stem Ψ in multiple height classes of aspen ramets revealed associations of both shallow soil moisture and vapor pressure deficit with physiological drought stress in aspen. Analysis of soil texture class revealed an important association with midday stem Ψ, with finer textured soils associated with decreased stem Ψ in comparison to coarser textured soils. While neither topographical characteristics nor snow cover were found to be important drivers of drought stress, topographical curvature was found to have a strong influence on summer soil moisture in upland stands. These findings contribute to our understanding of aspen physiology, drought ecology and landscape hydrology toward the xeric margin of aspen’s range. This information can help land managers anticipate and adapt to changing climates and understand their effects on key plant species such as aspen. Numéro de notice : A2021-001 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1016/j.foreco.2020.118530 Date de publication en ligne : 08/09/2020 En ligne : https://doi.org/10.1016/j.foreco.2020.118530 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=96028
in Forest ecology and management > vol 479 [01/01/2021] . - 12 p.[article]Understanding the geodetic signature of large aquifer systems: Example of the Ozark Plateaus in Central United States / Stacy Larochelle (2021)
Titre : Understanding the geodetic signature of large aquifer systems: Example of the Ozark Plateaus in Central United States Type de document : Article/Communication Auteurs : Stacy Larochelle, Auteur ; Kristel Chanard , Auteur ; Luce Fleitout, Auteur ; Jérôme Nicolas Fortin, Auteur ; Adriano Gualandi, Auteur ; Laurent Longuevergne, Auteur ; Paul Rebischung , Auteur ; Sophie Violette, Auteur ; Jean-Philippe Avouac, Auteur Editeur : Washington DC [Etats-Unis] : Earth and Space Science Open Archive ESSOAr Année de publication : 2021 Projets : 1-Pas de projet / Importance : 29 p. Note générale : bibliographie
soumis au Journal of Geophysical Research - Solid EarthLangues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] aquifère
[Termes IGN] Arkansas (Etats-Unis)
[Termes IGN] déformation de la croute terrestre
[Termes IGN] élasticité
[Termes IGN] Kansas (Etats-Unis ; état)
[Termes IGN] masse d'eau
[Termes IGN] Missouri (Etats-Unis)
[Termes IGN] Oklahoma (Etats-Unis)
[Termes IGN] série temporelle
[Termes IGN] surcharge hydrologiqueRésumé : (auteur) The continuous redistribution of water mass involved in the hydrologic cycle leads to deformation of the solid Earth. On a global scale, this deformation is well explained by redistribution in surface loading and can be quantified to first order with space-based gravimetric and geodetic measurements. At the regional scale, however, aquifer systems also undergo poroelastic deformation in response to groundwater fluctuations. Disentangling these related but distinct 3D deformation fields from geodetic time series is essential to accurately invert for changes in continental water mass, to understand the mechanical response of aquifers to internal pressure changes as well as to correct time series for these known effects. Here, we demonstrate a methodology to accomplish this task by considering the example of the well-instrumented Ozark Plateaus Aquifer System (OPAS) in central United States. We begin by characterizing the most important sources of signal in the spatially heterogeneous groundwater level dataset using an Independent Component Analysis. Then, to estimate the associated poroelastic displacements, we project geodetic time series corrected for surface loading effects onto orthogonalized versions of the groundwater temporal functions. We interpret the extracted displacements in light of analytical solutions and a 2D model relating groundwater level variations to surface displacements. In particular, the relatively low estimates of elastic moduli inferred from the poroelastic displacements and groundwater fluctuations may be indicative of surficial layers with a high fracture density. Our findings suggest that OPAS undergoes significant poroelastic deformation, including highly heterogeneous horizontal poroelastic displacements. Numéro de notice : P2021-006 Affiliation des auteurs : UMR IPGP-Géod+Ext (2020- ) Thématique : POSITIONNEMENT Nature : Preprint nature-HAL : Préprint DOI : 10.1002/essoar.10507870.1 Date de publication en ligne : 02/09/2021 En ligne : https://doi.org/10.1002/essoar.10507870.1 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=98994 Variations of precipitable water vapor using GNSS CORS in Thailand / Chokchai Trakolkul in Survey review, vol 53 n°376 (January 2021)
[article]
Titre : Variations of precipitable water vapor using GNSS CORS in Thailand Type de document : Article/Communication Auteurs : Chokchai Trakolkul, Auteur ; Chalermchon Satirapod, Auteur Année de publication : 2021 Article en page(s) : pp 90 - 96 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] amplitude
[Termes IGN] analyse comparative
[Termes IGN] données WVR
[Termes IGN] précipitation
[Termes IGN] série temporelle
[Termes IGN] station de référence
[Termes IGN] station GNSS
[Termes IGN] Thaïlande
[Termes IGN] vapeur d'eau
[Termes IGN] variation saisonnièreRésumé : (auteur) This research aims to analyze variation in a time series of Precipitable Water Vapor (PWV time series) using data at 11 widely-distributed Continuously Operating Reference Stations (CORS) in Thailand. In this paper, the PWV time series is estimated based on data from 2007 to 2015, used to monitor trends and seasonal variations. Significant annual variations of PWV are found at all GNSS stations, with amplitude from 6 to 19 kg/m2. The variations between the annual amplitudes of PWV in the South and near the ocean coasts are generally smaller than in the inland regions. The phase shift of annual PWV variation is about −0.43 (around July, rainy season). The comparison of PWV and 24-hour cumulative rainfall data showed that the rainy season (running from around mid-May to the end of October) exhibits the slightest swing, and the highest average amount of PWV. These results are consistent with the 24-hour cumulative rainfall data. Numéro de notice : A2021-070 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/00396265.2020.1713611 Date de publication en ligne : 20/01/2020 En ligne : https://doi.org/10.1080/00396265.2020.1713611 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=96791
in Survey review > vol 53 n°376 (January 2021) . - pp 90 - 96[article]Climate sensitive single tree growth modeling using a hierarchical Bayes approach and integrated nested Laplace approximations (INLA) for a distributed lag model / Arne Nothdurft in Forest ecology and management, vol 478 ([15/12/2020])PermalinkCharacterizing the spatial and temporal variation of the land surface temperature hotspots in Wuhan from a local scale / Chen Yang in Geo-spatial Information Science, vol 23 n° 4 (December 2020)PermalinkQuality assessment of photogrammetric methods - A workflow for reproducible UAS orthomosaics / Marvin Ludwig in Remote sensing, vol 12 n° 22 (December-1 2020)PermalinkUnprecedented pluri-decennial increase in the growing stock of French forests is persistent and dominated by private broadleaved forests / Jean-Daniel Bontemps in Annals of Forest Science, vol 77 n° 4 (December 2020)PermalinkCombination of Landsat 8 OLI and Sentinel-1 SAR time-series data for mapping paddy fields in parts of West and Central Java provinces, Indonesia / Sanjiwana Arjasakusuma in ISPRS International journal of geo-information, vol 9 n° 11 (November 2020)PermalinkDisplacement monitoring of upper Atbara dam based on time series InSAR / Q.Q. Wang in Survey review, vol 52 n° 375 (November 2020)PermalinkGeostatistical analysis and mitigation of the atmospheric phase screens in Ku-band terrestrial radar interferometric observations of an alpine glacier / Simone Baffelli in IEEE Transactions on geoscience and remote sensing, vol 58 n° 11 (November 2020)PermalinkNon-stationary extreme value analysis of ground snow loads in the French Alps: a comparison with building standards / Erwann Le Roux in Natural Hazards and Earth System Sciences, vol 20 n° 11 (November 2020)PermalinkSea surface temperature and high water temperature occurrence prediction using a long short-term memory model / Minkyu Kim in Remote sensing, vol 12 n° 21 (November 2020)PermalinkMonitoring population dynamics in the Pearl River Delta from 2000 to 2010 / Sisi Yu in Geocarto international, vol 35 n° 14 ([15/10/2020])Permalink