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statistique mathématique
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biométrie,
échantillonnage (statistique), probabilité, statistique. >>Terme(s) spécifique(s) : analyse de régression, analyse de variance, analyse des données, analyse multivariée, analyse séquentielle, calcul d'erreur, carré latin, corrélation (statistique), efficacité asymptotique (statistique), fonction pseudo-aléatoire, loi des grands nombres, modèle linéaire (statistique), modèle non linéaire (statistique), moindre carré, physique statistique, plan d'expérience, rang et sélection (statistique), rupture (statistique), SAS (logiciel), série chronologique, statistique non paramétrique, statistique robuste, tableau de contingence, test d'hypothèses (statistique), statistique stellaire. Equiv. LCSH : Mathematical statistics. Domaine(s) : 510. |
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Establishing a high-precision real-time ZTD model of China with GPS and ERA5 historical data and its application in PPP / Pengfei Xia in GPS solutions, vol 27 n° 1 (January 2023)
[article]
Titre : Establishing a high-precision real-time ZTD model of China with GPS and ERA5 historical data and its application in PPP Type de document : Article/Communication Auteurs : Pengfei Xia, Auteur ; Mengxiang Tong, Auteur ; Shirong Ye, Auteur ; et al., Auteur Année de publication : 2023 Article en page(s) : n° 2 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] Chine
[Termes IGN] correction troposphérique
[Termes IGN] données météorologiques
[Termes IGN] grille
[Termes IGN] positionnement ponctuel précis
[Termes IGN] retard troposphérique zénithal
[Termes IGN] série de Fourier
[Termes IGN] série temporelle
[Termes IGN] station GNSS
[Termes IGN] temps de convergence
[Termes IGN] temps réel
[Termes IGN] variation diurneRésumé : (auteur) A high-precision real-time troposphere model is constructed by combining ground-based GNSS observation data and the latest European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis (ERA5). First, the zenith tropospheric delay (ZTD) is extracted in real time with high accuracy by combining the data of more than 500 GNSS stations in the Crustal Movement Observation Network of China (CMONOC) and national reference station network (NRSN); second, a grid model of the elevation normalization model (ENM) in China using ERA5 data is constructed, which takes into account the annual, semiannual and daily cycles. The ZTD estimated by GNSS stations at different heights based on precise point positioning (PPP) is normalized to a uniform height based on ENM; in addition, the optimal smoothing factors of the Gauss distance weighting function in different seasons are determined based on ERA5, which contributes to improved accuracy of ZTD interpolated from GNSS-derived ZTD to ZTD at grid points; finally, a real-time 1° × 1°ZTD grid model of China is created; the broadcast interval is extended to 6 min from few seconds. The new ZTD model has been evaluated using the data of 15 GNSS stations in China in 2020. The test results show that the new ZTD model deviates from the reference value with a mean value better than − 0.09 cm and RMSE, better than 1.44 cm compared with the ZTD estimated by post-processing GNSS, while the mean value of the deviation is -0.13 cm, and the RMSE is approximately 3.11 cm compared with radiosonde-derived ZTD. The new ZTD grid model can be used to enhance GNSS/PPP. Two weeks of GNSS observations, one week in winter and another in summer, were randomly collected for PPP processing. The statistical results show the convergence time in the vertical directions is shortened by 37.4% and 38.6% at the 95% and 68% confidence levels after ZTD constraints are applied to the float PPP solution, respectively. Numéro de notice : A2023-004 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s10291-022-01338-9 Date de publication en ligne : 07/10/2022 En ligne : https://doi.org/10.1007/s10291-022-01338-9 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=101874
in GPS solutions > vol 27 n° 1 (January 2023) . - n° 2[article]Field optical clocks and sensitivity to mass anomalies for geoscience applications / Guillaume Lion (2023)
Titre : Field optical clocks and sensitivity to mass anomalies for geoscience applications Type de document : Article/Communication Auteurs : Guillaume Lion , Auteur ; Gwendoline Pajot-Métivier , Auteur ; Kristel Chanard , Auteur ; Michel Diament , Auteur Editeur : Munich [Allemagne] : European Geosciences Union EGU Année de publication : 2023 Projets : ROYMAGE / Letargat, Rodolphe Conférence : EGU 2023, General Assembly 23/04/2023 28/04/2023 Vienne Autriche OA Abstracts only Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] analyse de sensibilité
[Termes IGN] anomalie de pesanteur
[Termes IGN] chronométrie
[Termes IGN] horloge optiqueIndex. décimale : 30.60 Géodésie spatiale Résumé : (auteur) 350 years ago, the pendulum clock for astronomical observations was diverted to become an instrument for measuring gravity. The measurement of the parallax of Mars by Richer and Cassini from Cayenne and Paris showed that the period of a periodic oscillator depends on the gravity field. A link was thus established between the improvement of time measurement and the knowledge of the phenomena that govern it. Since then, the performance and nature of clocks have evolved considerably. Today, atomic clocks are used in various fields that are essential to modern society, such as the realisation of international atomic time (TAI), satellite navigation (GNSS), geodesy, the traceability of trading events, etc. In the framework of the french ANR ROYMAGE, we are interested in the contribution of a transportable optical field clock for geoscience applications by using the principle of chronometric geodesy. The idea is based on the gravitational redshift, a relativistic effect that predicts that the beat of a clock depends on the speed at which it is moving and the strength of the surrounding gravitational potential. In practice, this means that if we compare the beat of two clocks, then it is possible to directly measure a difference in gravitational potential (or a change in height) between these two clocks. This type of measurement is original because classical geodetic techniques only allow to determine the potential indirectly from gravimetric and classical levelling data. In this work, we model the gravitational signature (potential, acceleration and tensor) of a mass anomaly as a function of its geometry, depth, size and density contrast. These synthetic simulations allow us to identify which types of structures can be detected by clock comparison measurements with a relative frequency uncertainty fixed at 10-17-18-19 (i.e. a vertical sensitivity of less than 10 cm - 1 cm - 1 mm respectively). We are also interested in the spatial resolution required for a clock measurement to detect two mass anomalies depending on its orientation. Finally, we show that this new chronometric observable combined with gravimetry and gradiometry data could allow a better separation of the sources by adding an additional constraint thanks to the medium and long wavelength gravitational information it provides. Numéro de notice : C2023-003 Affiliation des auteurs : UMR IPGP-Géod+Ext (2020- ) Autre URL associée : vers HAL Thématique : POSITIONNEMENT Nature : Poster nature-HAL : Poster-avec-CL DOI : 10.5194/egusphere-egu23-3646 En ligne : https://doi.org/10.5194/egusphere-egu23-3646 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=103216 Forest road extraction from orthophoto images by convolutional neural networks / Erhan Çalişkan in Geocarto international, vol 38 n° inconnu ([01/01/2023])
[article]
Titre : Forest road extraction from orthophoto images by convolutional neural networks Type de document : Article/Communication Auteurs : Erhan Çalişkan, Auteur ; Yusuf Sevim, Auteur Année de publication : 2023 Article en page(s) : pp Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] chemin forestier
[Termes IGN] classification par réseau neuronal convolutif
[Termes IGN] extraction automatique
[Termes IGN] orthoimage
[Termes IGN] segmentation sémantiqueRésumé : (auteur) Continuous monitoring of the forest road infrastructure and keeping track of the changes occurred are important for forestry practices, map updating, forest fire and forest transport decision support systems. In this context, the most of up to date data can be obtained by automatic forest road extraction from satellite images via machine learning (ML). Acquiring sufficient data is one of the most important factors which affect the success of ML and deep learning (DL). DL architectures yield more consistent results for complex data sets compared with ML algorithms. In the present study, three different deep learning (Resnet-18, MobileNet-V2 and Xception) architectures with semantic segmentation architecture were compared for extracting the forest road network from high-resolution orthophoto images and the results were analyzed. The architectures were evaluated through a multiclass statistical analysis based precision, recall, F1 score, intersection over union and overall accuracy (OA). The results present significant values obtained by the Resnet-18 architecture, with 99.72% of OA and 98.87% of precision and by the MobileNet-V2 architecture, with 97.76% of OA and 98.28% of precision. Also the results show that Resnet-18, MobileNet-V2 semantic segmentation architectures can be used efficiently for forest road extraction. Numéro de notice : A2022-159 Affiliation des auteurs : non IGN Thématique : IMAGERIE/INFORMATIQUE Nature : Article DOI : 10.1080/10106049.2022.2060319 Date de publication en ligne : 06/04/2022 En ligne : https://doi.org/10.1080/10106049.2022.2060319 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=100380
in Geocarto international > vol 38 n° inconnu [01/01/2023] . - pp[article]Generation of high-resolution orthomosaics from historical aerial photographs using Structure-from-motion and Lidar data / Ji Won Suh in Photogrammetric Engineering & Remote Sensing, PERS, vol 89 n° 1 (January 2023)
[article]
Titre : Generation of high-resolution orthomosaics from historical aerial photographs using Structure-from-motion and Lidar data Type de document : Article/Communication Auteurs : Ji Won Suh, Auteur ; William Ouimet, Auteur Année de publication : 2023 Article en page(s) : pp 37 - 46 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Photogrammétrie
[Termes IGN] ArcGIS Desktop
[Termes IGN] Connecticut (Etats-Unis)
[Termes IGN] données lidar
[Termes IGN] erreur moyenne quadratique
[Termes IGN] estompage
[Termes IGN] image ancienne
[Termes IGN] MNS lidar
[Termes IGN] orthophotoplan numérique
[Termes IGN] photographie aérienne
[Termes IGN] point d'appui
[Termes IGN] structure-from-motionRésumé : (auteur) This study presents a method to generate historical orthomosaics using Structure-from-Motion (SfM ) photogrammetry, historical aerial photographs, and lidar data, and then analyzes the horizontal accuracy and factors that can affect the quality of historical orthoimagery products made with these approaches. Two sets of historical aerial photographs (1934 and 1951) were analyzed, focused on the town of Woodstock in Connecticut, U.S.A. Ground control points (GCPs) for georeferencing were obtained by overlaying multiple data sets, including lidar elevation data and derivative hillshades, and recent orthoimagery. Root-Mean-Square Error values of check points (CPs ) for 1934 and 1951 orthomosaics without extreme outliers are 0.83 m and 1.37 m, respectively. Results indicate that orthomosaics can be used for standard mapping and geographic information systems (GIS ) work according to the ASPRS 1990 accuracy standard. In addition, results emphasize that three main factors can affect the horizontal accuracy of orthomosaics: (1) types of CPs, (2) the number of tied photos, and (3) terrain. Numéro de notice : A2023-046 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.14358/PERS.22-00063R2 Date de publication en ligne : 01/01/2023 En ligne : https://doi.org/10.14358/PERS.22-00063R2 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102355
in Photogrammetric Engineering & Remote Sensing, PERS > vol 89 n° 1 (January 2023) . - pp 37 - 46[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 105-2023011 SL Revue Centre de documentation Revues en salle Disponible Geographic-dependent variational parameter estimation: A case study with a 2D ocean temperature model / Zhenyang Du in Journal of Marine Systems, vol 237 (January 2023)
[article]
Titre : Geographic-dependent variational parameter estimation: A case study with a 2D ocean temperature model Type de document : Article/Communication Auteurs : Zhenyang Du, Auteur ; Xuefeng Zhang, Auteur ; et al., Auteur Année de publication : 2023 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image
[Termes IGN] assimilation des données
[Termes IGN] estimation statistique
[Termes IGN] modèle océanographique
[Termes IGN] océanographie spatiale
[Termes IGN] température de surface de la mer
[Termes IGN] teneur en chaleur de l'océanRésumé : (auteur) Using observational information to tune uncertain physical parameters in an ocean model via a robust data assimilation method has great potential to reduce model bias and improve the quality of sea temperature analysis and prediction. However, how observational information should be used to optimize geographic-dependent parameters through four-dimensional variational (4DVAR) data assimilation, which is one of the most prevailing assimilation methods, has not been fully studied. In this study, a two-step 4DVAR method is proposed to enhance parameter correction when the assimilation model contains biased geographic-dependent parameters within a biased model framework. Here, the biased parameters are set to an oceanic eddy diffusion coefficient, Kv, that plays an important role in modulating synoptic, seasonal and long-term changes in ocean heat content. Within a twin assimilation experiment framework, the temperature “observations” generated from sampling a “truth” model are assimilated into a biased model to investigate to what extent Kv can be estimated using the 4DVAR method when Kv remains geographic-dependent. The results show that the geographic-dependent Kv distribution can be optimally estimated to further improve the sea temperature analysis performance compared with the state estimation only method. In addition, the model prediction performance is also discussed with optimally estimated parameters under various conditions of noisy and/or sparse ocean observations. These results provide some insights for the prediction of ocean temperature mixing and stratification in a 3D primitive ocean numerical model using 4DVAR data assimilation. Numéro de notice : A2023-080 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1016/j.jmarsys.2022.103824 En ligne : https://doi.org/10.1016/j.jmarsys.2022.103824 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102716
in Journal of Marine Systems > vol 237 (January 2023)[article]Geographically masking addresses to study COVID-19 clusters / Walid Houfaf-Khoufaf in Cartography and Geographic Information Science, vol inconnu (2023)PermalinkA geometry-aware attention network for semantic segmentation of MLS point clouds / Jie Wan in International journal of geographical information science IJGIS, vol 37 n° 1 (January 2023)PermalinkGeoMultiTaskNet: remote sensing unsupervised domain adaptation using geographical coordinates / Valerio Marsocci (2023)PermalinkGeospatial-based machine learning techniques for land use and land cover mapping using a high-resolution unmanned aerial vehicle image / Taposh Mollick in Remote Sensing Applications: Society and Environment, RSASE, vol 29 (January 2023)PermalinkA hexagon-based method for polygon generalization using morphological operators / Lu Wang in International journal of geographical information science IJGIS, vol 37 n° 1 (January 2023)PermalinkA hierarchical deformable deep neural network and an aerial image benchmark dataset for surface multiview stereo reconstruction / Jiayi Li in IEEE Transactions on geoscience and remote sensing, vol 61 n° 1 (January 2023)PermalinkHow to optimize the 2D/3D urban thermal environment: Insights derived from UAV LiDAR/multispectral data and multi-source remote sensing data / Rongfang Lyu in Sustainable Cities and Society, vol 88 (January 2023)PermalinkImprovement of 3D LiDAR point cloud classification of urban road environment based on random forest classifier / Mahmoud Mohamed in Geocarto international, vol 38 n° inconnu ([01/01/2023])PermalinkImproving generalized models of forest structure in complex forest types using area- and voxel-based approaches from lidar / Andrew W. Whelan in Remote sensing of environment, vol 284 (January 2023)PermalinkImproving methods to predict aboveground biomass of Pinus sylvestris in urban forest using UFB model, LiDAR and digital hemispherical photography / Ihor Kozak in Urban Forestry & Urban Greening, vol 79 (January 2023)Permalink