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Empirical modelling of site-specific errors in continuous GPS data / Michael Moore in Journal of geodesy, vol 88 n° 9 (September 2014)
[article]
Titre : Empirical modelling of site-specific errors in continuous GPS data Type de document : Article/Communication Auteurs : Michael Moore, Auteur ; Christopher S. Watson, Auteur ; Matt A. King, Auteur ; et al., Auteur Année de publication : 2014 Article en page(s) : pp 887-900 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] données GPS
[Termes IGN] erreur de positionnement
[Termes IGN] modélisation
[Termes IGN] phase GPSRésumé : (Auteur) Continuous global positioning system (GPS) stations propagate biases and spurious signals into the derived parameter time series when the measurements are subject to site-specific effects, such as multipath. This is a particular problem in the investigation of geophysical and atmospheric phenomena where signals may be small in magnitude. A methodology to remove these erroneous signals from long-term time series will significantly increase the usefulness of the derived time series. This work provides the theoretical basis for use of an empirical site model (ESM) derived from post-fit phase residuals to mitigate unmodelled site-specific errors. Additionally, we also investigate the effectiveness of applying an ESM to a regional GPS network and a short baseline solution. Under most observing scenarios, we show that the ESM approach is predicted to improve the precision and accuracy of the site coordinates. However, it is important to note that we found some scenarios where the ESM can introduce a bias. For instance, when the antenna is mounted close to the ground. In this scenario, for a short baseline, we observed the introduction of a 4-mm bias in height. Use of an ESM for the same short baseline with an uncalibrated radome substantially improves the results by removing a large bias of over 10 mm in height. Similarly, application of an ESM derived from historic data yields similar improvements. This demonstrates that the ESM can be a powerful tool when applied to appropriate site-specific configurations and could potentially be implemented in routine GPS analysis for a broad range of applications. Numéro de notice : A2014-458 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-014-0729-5 Date de publication en ligne : 03/06/2014 En ligne : https://doi.org/10.1007/s00190-014-0729-5 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=74030
in Journal of geodesy > vol 88 n° 9 (September 2014) . - pp 887-900[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 266-2014091 SL Revue Centre de documentation Revues en salle Disponible Generating pit-free canopy height models from airborne lidar / Anahita Khosravipour in Photogrammetric Engineering & Remote Sensing, PERS, vol 80 n° 9 (September 2014)
[article]
Titre : Generating pit-free canopy height models from airborne lidar Type de document : Article/Communication Auteurs : Anahita Khosravipour, Auteur ; Andrew K. Skidmore, Auteur ; Martin Isenburg, Auteur ; et al., Auteur Année de publication : 2014 Article en page(s) : pp 863 - 872 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications photogrammétriques
[Termes IGN] canopée
[Termes IGN] détection de cible
[Termes IGN] données lidar
[Termes IGN] hauteur des arbres
[Termes IGN] modélisation
[Termes IGN] semis de pointsRésumé : (Auteur)Canopy height models (CHMs) derived from lidar data have been applied to extract forest inventory parameters. However, variations in modeled height cause data pits, which form a challenging problem as they disrupt CHM smoothness, negatively affecting tree detection and subsequent biophysical measurements. These pits appear where laser beams penetrate deeply into a tree crown, hitting a lower branch or ground before producing the first return. In this study, we develop a new algorithm that generates a pit-free CHM raster, by using subsets of the lidar points to close pits. The algorithm operate robustly on high-density lidar data as well as on a thinned lidar dataset. The evaluation involves detecting the finding to those achieved by using a Gaussian smoothed CHM. The results show that our pit-free CHMs derived from high-and low-density lidar data significantly improve the accuracy of tree detection. Numéro de notice : A2014-599 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article DOI : 10.14358/PERS.80.9.863 En ligne : https://doi.org/10.14358/PERS.80.9.863 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=74889
in Photogrammetric Engineering & Remote Sensing, PERS > vol 80 n° 9 (September 2014) . - pp 863 - 872[article]Deriving Predictive relationships of carotenoid content at the canopy level in a conifer forest using hyperspectral imagery and model simulation / Rocío Hernández-Clemente in IEEE Transactions on geoscience and remote sensing, vol 52 n° 8 Tome 2 (August 2014)
[article]
Titre : Deriving Predictive relationships of carotenoid content at the canopy level in a conifer forest using hyperspectral imagery and model simulation Type de document : Article/Communication Auteurs : Rocío Hernández-Clemente, Auteur ; R.M. Navarro Cerrillo, Auteur ; Pablo J. Zarco-Tejada, Auteur Année de publication : 2014 Article en page(s) : pp 5206 - 5217 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] canopée
[Termes IGN] chlorophylle
[Termes IGN] image hyperspectrale
[Termes IGN] indice de végétation
[Termes IGN] modélisation
[Termes IGN] photosynthèse
[Termes IGN] Pinophyta
[Termes IGN] réflectance végétale
[Termes IGN] surveillance forestièreRésumé : (Auteur) Recent studies have demonstrated that the R570/R515 index is highly sensitive to carotenoid (Cx + c) content in conifer forest canopies and is scarcely influenced by structural effects. However, validated methods for the prediction of leaf carotenoid content relationships in forest canopies are still needed to date. This paper focuses on the simultaneous retrieval of chlorophyll (Cα + b) and (Cx + c) pigments, which are critical bioindicators of plant physiological status. Radiative transfer theory and modeling assumptions were applied at both laboratory and field scales to develop methods for their concurrent estimation using high-resolution hyperspectral imagery. The proposed methodology was validated based on the biochemical pigment quantification. Canopy modeling methods based on infinite reflectance formulations and the discrete anisotropic radiative transfer (DART) model were evaluated in relation to the PROSPECT-5 leaf model for the scaling-up procedure. Simpler modeling methods yielded comparable results to more complex 3-D approximations due to the high spatial resolution images acquired, which enabled targeting pure crowns and reducing the effects of canopy architecture. The scaling-up methods based on the PROSPECT-5+DART model yielded a root-mean-square error (RMSE) and a relative RMSE of 1.48 μg/cm2 (17.45%) and 5.03 μg/cm2 (13.25%) for Cx + c and Cα + b, respectively, while the simpler approach based on the PROSPECT-5+Hapke infinite reflectance model yielded 1.37 μg/cm2 (17.46%) and 4.71 μg/cm2 (14.07%) for Cx + c and Cα+b, respectively. These predictive algorithms proved to be useful to estimate Cα + b and Cx + c from high-resolution hyperspectral imagery, providing a methodology for the monitoring of these photosynthetic pigments in conifer forest canopies. Numéro de notice : A2014-433 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2013.2287304 En ligne : https://doi.org/10.1109/TGRS.2013.2287304 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=73970
in IEEE Transactions on geoscience and remote sensing > vol 52 n° 8 Tome 2 (August 2014) . - pp 5206 - 5217[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 065-2014081B RAB Revue Centre de documentation En réserve L003 Disponible An algebra for spatiotemporal data: From observations to events / Karine Reis Ferreira in Transactions in GIS, vol 18 n° 2 (April 2014)
[article]
Titre : An algebra for spatiotemporal data: From observations to events Type de document : Article/Communication Auteurs : Karine Reis Ferreira, Auteur ; Gilberto Camara, Auteur ; Antônio Miguel V. Monteiro, Auteur Année de publication : 2014 Article en page(s) : pp 253 - 269 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale
[Termes IGN] algèbre
[Termes IGN] analyse spatio-temporelle
[Termes IGN] base de données d'objets mobiles
[Termes IGN] couverture (données géographiques)
[Termes IGN] données spatiotemporelles
[Termes IGN] modélisation
[Termes IGN] risque naturel
[Termes IGN] santé
[Termes IGN] série temporelle
[Termes IGN] service fondé sur la position
[Termes IGN] surveillance écologiqueRésumé : (Auteur) Recent technological advances in geospatial data gathering have created massive data sets with better spatial and temporal resolution than ever before. These large spatiotemporal data sets have motivated a challenge for Geoinformatics: how to model changes and design good quality software. Many existing spatiotemporal data models represent how objects and fields evolve over time. However, to properly capture changes, it is also necessary to describe events. As a contribution to this research, this article presents an algebra for spatiotemporal data. Algebras give formal specifications at a high-level abstraction, independently of programming languages. This helps to develop reliable and expressive applications. Our algebra specifies three data types as generic abstractions built on real-world observations: time series, trajectory and coverage. Based on these abstractions, it defines object and event types. The proposed data types and functions can model and capture changes in a large range of applications, including location-based services, environmental monitoring, public health, and natural disasters. Numéro de notice : A2014-166 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1111/tgis.12030 Date de publication en ligne : 22/05/2022 En ligne : https://doi.org/10.1111/tgis.12030 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=33071
in Transactions in GIS > vol 18 n° 2 (April 2014) . - pp 253 - 269[article]Dynamic modeling of GNSS troposphere wet delay for estimation of precipitable water vapour / Ahmed El-Mowafy in Journal of applied geodesy, vol 8 n° 1 (April 2014)
[article]
Titre : Dynamic modeling of GNSS troposphere wet delay for estimation of precipitable water vapour Type de document : Article/Communication Auteurs : Ahmed El-Mowafy, Auteur ; Johnny Lo, Auteur Année de publication : 2014 Article en page(s) : pp 31 - 42 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] autocorrélation
[Termes IGN] humidité de l'air
[Termes IGN] modèle dynamique
[Termes IGN] positionnement par GNSS
[Termes IGN] précipitation
[Termes IGN] propagation troposphérique
[Termes IGN] signal GNSS
[Termes IGN] vapeur d'eauRésumé : (Auteur) Proper dynamic modelling of the troposphere wet delay using the Global Navigation Satellite Systems (GNSS) measurements is important in precise point positioning and in estimation of the Precipitable Water Vapour (PWV) for weather forecast. The random walk (RW) and the first-order Gauss-Markov (GM) autocorrelation models are commonly used for this purpose. However, it was found that these models consistently underestimate the temporal correlations that exist among the troposphere wet delay. Therefore, a new dynamic model is proposed. The performance of the proposed model in following the autocorrelation of actual data is demonstrated and its impact on the near-real time estimation of the wet delay was tested and compared to that of the GM and RW models. Results showed that the proposed model outperformed these models. When the computed wet delays were used to compute PWV, their estimated valueswere very close to actual PWV data measured by radiosonde with differences less than 1 mm. Numéro de notice : A2014-271 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1515/jag-2013-0012 2 2 total citations on Dimensions. Date de publication en ligne : 08/04/2014 En ligne : https://doi.org/10.1515/jag-2013-0012 2 2 total citations on Dimensions. Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=33174
in Journal of applied geodesy > vol 8 n° 1 (April 2014) . - pp 31 - 42[article]The co-evolution of residential segregation and the built environment at the turn of the 20th century: A Schelling model / Seth Spielman in Transactions in GIS, vol 18 n° 1 (February 2014)PermalinkCollaborative BIM learning via an academia-industry partnership / Thomas Ken in International journal of 3-D information modeling, vol 3 n° 1 (January - March 2014)PermalinkPermalinkOutils méthodologiques pour l'analyse d'images MSG : estimation du mouvement, suivi des masses nuageuses et détection de fronts / Thomas Corpetti in Revue Française de Photogrammétrie et de Télédétection, n° 205 (Janvier 2014)PermalinkLe MOS : une modélisation visionnaire et moderne / Patricia Bordin in Cahiers de l'Institut d'aménagement et d'urbanisme de la région Île-de-France, n° 168 (décembre 2013)PermalinkPaysans et pasteurs sur les marches du Levant Sud / Claudine Dauphin in Géomatique expert, n° 95 (01/11/2013)PermalinkApport des données Formosat2 à la modélisation du contenu en eau du manteau neigeux du haut atlas marocain / Abdelghani Boudhar in Revue Française de Photogrammétrie et de Télédétection, n° 204 (Octobre 2013)PermalinkNew frontiers of forest economics / Shashi Kant in Forest policy and economics, vol 35 (October 2013)PermalinkPrévisibilité du cycle du blé : Mobilisation par approche globale et assimilation de données / Sylvain Mangiarotti in Revue Française de Photogrammétrie et de Télédétection, n° 204 (Octobre 2013)PermalinkClassification automatique des images satellitaires optimisée par l'algorithme des chauves-souris / Soumia Benmostefa in Revue Française de Photogrammétrie et de Télédétection, n° 203 (Juillet 2013)Permalink