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Satellite-based probabilistic assessment of soil moisture using C-band quad-polarized RISAT1 data / Manali Pal in IEEE Transactions on geoscience and remote sensing, vol 55 n° 3 (March 2017)
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Titre : Satellite-based probabilistic assessment of soil moisture using C-band quad-polarized RISAT1 data Type de document : Article/Communication Auteurs : Manali Pal, Auteur ; Rajib Maity, Auteur ; Mayank Suman, Auteur ; et al., Auteur Année de publication : 2017 Article en page(s) : pp 1351 - 1362 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications
[Termes IGN] analyse en composantes principales
[Termes IGN] angle d'incidence
[Termes IGN] bande C
[Termes IGN] coefficient de rétrodiffusion
[Termes IGN] humidité du sol
[Termes IGN] image radar moirée
[Termes IGN] image Risat-1
[Termes IGN] modèle d'incertitude
[Termes IGN] polarimétrie radar
[Termes IGN] polarisation
[Termes IGN] teneur en eau liquideRésumé : (Auteur) This paper attempts to probabilistically estimate the surface soil moisture content (SMC) by using the synthetic aperture radar data provided by radar imaging satellite1. The novelty of this paper lies in: 1) developing a combined index to understand the role of all the backscattering coefficients with different polarization and soil texture information in influencing the SMC; 2) using normalized incidence angles, which enables the model to be applicable for different incidence angles; and 3) determination of uncertainty range of the estimated SMC. The dimensionality problem, which is frequently observed in the multivariate analysis, is reduced in the development of the combined index by the use of supervised principal component analysis (SPCA). The SPCA also ensures the maximum attainable association between the developed combined index and surface SMC above wilting point (WP). The association between the combined index and the surface SMC above WP is modeled through joint probability distribution by using the Frank copula. The model is developed and validated with the field soil moisture values over 334 monitoring points within the study area. The outcomes obtained by applying the proposed model indicate an encouraging potential of the model to be applied for bareland and vegetated land ( Numéro de notice : A2017-153 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2016.2623378 En ligne : http://dx.doi.org/10.1109/TGRS.2016.2623378 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=84686
in IEEE Transactions on geoscience and remote sensing > vol 55 n° 3 (March 2017) . - pp 1351 - 1362[article]X-ray microdensitometry of wood: A review of existing principles and devices / Philippe Jacquin in Dendrochronologia, vol 42 (March 2017)
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Titre : X-ray microdensitometry of wood: A review of existing principles and devices Type de document : Article/Communication Auteurs : Philippe Jacquin, Auteur ; Fleur Longuetaud, Auteur ; Jean-Michel Leban , Auteur ; Frédéric Mothe, Auteur
Année de publication : 2017 Projets : ARBRE / AgroParisTech (2007 -) Article en page(s) : pp 42 - 50 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Végétation
[Termes IGN] dendrochronologie
[Termes IGN] densité du bois
[Termes IGN] rayon X
[Termes IGN] tomographieRésumé : (auteur) Wood microdensitometry is the analysis of radial variations of density at the annual or intra-annual growth ring level. Density is related to wood quality, biomass, carbon content, tree growth and climate. Wood microdensitometry is particularly used in dendrochronology and climatology studies. The present study focuses on X-ray based methods used in wood microdensitometry analyses and provides a review of the main available devices. An exhaustive review of 75 works published on this topic in 2014 and 2015 showed that film-based equipment is still commonly used. The three other most popular devices, SilviScan, Itrax and QTRS, are also based on X-ray radiography and deliver results with comparable accuracy, below 50 μm per pixel. X-ray tomography (CT) is still rarely used in wood densitometry. Medical CT scanners currently offer a lower accuracy (above 100 μm per pixel) that is insufficient in most cases for ring or intra-ring scales. Micro-CT scanners offer good performance at the cost of much longer acquisition and reconstruction times. Numéro de notice : A2017-893 Affiliation des auteurs : LIF+Ext (2012-2019) Thématique : FORET Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.dendro.2017.01.004 Date de publication en ligne : 27/01/2017 En ligne : https://doi.org/10.1016/j.dendro.2017.01.004 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91887
in Dendrochronologia > vol 42 (March 2017) . - pp 42 - 50[article]GPS - Zenith Total Delay assimilation in different resolution simulations of a heavy precipitation event over southern France / Alberto Caldas-Álvarez in Advances in Science and Research, vol 14 (2017)
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Titre : GPS - Zenith Total Delay assimilation in different resolution simulations of a heavy precipitation event over southern France Type de document : Article/Communication Auteurs : Alberto Caldas-Álvarez, Auteur ; Samiro Khodayar, Auteur ; Olivier Bock , Auteur
Année de publication : 2017 Projets : HyMeX / Richard, Evelyne Conférence : EMS 2016, 16th European Meteorological Society annual meeting 12/09/2016 16/09/2016 Trieste Italie Projets : IODA-Med / Richard, Evelyne, REMEMBER / Drobinski, Philippe Article en page(s) : pp 157 - 162 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] distribution spatiale
[Termes IGN] humidité de l'air
[Termes IGN] précipitation
[Termes IGN] retard troposphérique zénithal
[Termes IGN] teneur intégrée en vapeur d'eauRésumé : (auteur) The aim of this study is to investigate the different pathways of the interaction between an improved atmospheric moisture distribution by Data Assimilation (DA) of Global Positioning System Zenith Total Delays (GPS-ZTD) on the simulation of a selected Heavy Precipitation Event (HPE) across different model horizontal resolutions (7 km, 2.8 km and 500 m). The initiation and evolution of deep moist convection and heavy precipitation taking place on the 24 September 2012, which had a dedicated Intensive Observation Period (IOP6) during the Hydrological cycle in the Mediterranean eXperiment (HyMeX) Special Observation period 1, are analysed. The results show an improvement in the representation of the Integrated Water Vapour (IWV) spatial distribution and temporal evolution when the data assimilation is applied as well as through the refinement of the model grids. However, important discrepancies between the simulated and the observed vertical profiles of humidity still remain after the DA, thus affecting the representation of convection and heavy precipitation. For the presented case study, the model simulations exhibited a wet bias. The assimilation entailed a drying of the low to middle troposphere over the study region during the 6 h prior to the storm initiation for every horizontal resolution. This reduced the instability present at the moment of storm initiation, weakening in return the intensity of convection and the number of cells triggered. The improvement observed in the atmospheric moisture content and distribution was not followed by an improved precipitation representation closer to observations. This highlights the relevance of correctly distributing the assimilated IWV in the vertical direction in the models. Numéro de notice : A2017-862 Affiliation des auteurs : LASTIG LAREG+Ext (2012-mi2018) Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.5194/asr-14-157-2017 Date de publication en ligne : 13/06/2017 En ligne : https://doi.org/10.5194/asr-14-157-2017 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89849
in Advances in Science and Research > vol 14 (2017) . - pp 157 - 162[article]Documents numériques
en open access
GPS - Zenith Total Delay assimilation ... - pdf éditeurAdobe Acrobat PDFAssessment of second- and third-order ionospheric effects on regional networks : case study in China with longer CMONOC GPS coordinate time series / Liansheng Deng in Journal of geodesy, vol 91 n° 2 (February 2017)
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Titre : Assessment of second- and third-order ionospheric effects on regional networks : case study in China with longer CMONOC GPS coordinate time series Type de document : Article/Communication Auteurs : Liansheng Deng, Auteur ; Weiping Jiang, Auteur ; Zhao Li, Auteur ; et al., Auteur Année de publication : 2017 Article en page(s) : pp 207 - 227 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] analyse diachronique
[Termes IGN] Chine
[Termes IGN] coordonnées GPS
[Termes IGN] correction ionosphérique
[Termes IGN] déformation de la croute terrestre
[Termes IGN] effet atmosphérique
[Termes IGN] propagation ionosphérique
[Termes IGN] réseau géodésique local
[Termes IGN] retard ionosphèrique
[Termes IGN] série temporelle
[Termes IGN] surcharge atmosphériqueRésumé : (Auteur) Higher-order ionospheric (HOI) delays are one of the principal technique-specific error sources in precise global positioning system analysis and have been proposed to become a standard part of precise GPS data processing. In this research, we apply HOI delay corrections to the Crustal Movement Observation Network of China’s (CMONOC) data processing (from January 2000 to December 2013) and furnish quantitative results for the effects of HOI on CMONOC coordinate time series. The results for both a regional reference frame and global reference frame are analyzed and compared to clarify the HOI effects on the CMONOC network. We find that HOI corrections can effectively reduce the semi-annual signals in the northern and vertical components. For sites with lower semi-annual amplitudes, the average decrease in magnitude can reach 30 and 10 % for the northern and vertical components, respectively. The noise amplitudes with HOI corrections and those without HOI corrections are not significantly different. Generally, the HOI effects on CMONOC networks in a global reference frame are less obvious than the results in the regional reference frame, probably because the HOI-induced errors are smaller in comparison to the higher noise levels seen when using a global reference frame. Furthermore, we investigate the combined contributions of environmental loading and HOI effects on the CMONOC stations. The largest loading effects on the vertical displacement are found in the mid- to high-latitude areas. The weighted root mean square differences between the corrected and original weekly GPS height time series of the loading model indicate that the mass loading adequately reduced the scatter on the CMONOC height time series, whereas the results in the global reference frame showed better agreements between the GPS coordinate time series and the environmental loading. When combining the effects of environmental loading and HOI corrections, the results with the HOI corrections reduced the scatter on the observed GPS height coordinates better than the height when estimated without HOI corrections, and the combined solutions in the regional reference frame indicate more preferred improvements. Therefore, regional reference frames are recommended to investigate the HOI effects on regional networks. Numéro de notice : A2017-064 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-016-0957-y En ligne : http://dx.doi.org/10.1007/s00190-016-0957-y Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=84278
in Journal of geodesy > vol 91 n° 2 (February 2017) . - pp 207 - 227[article]Double take : mitigating interference with a dual-polarized antenna array in a real environment / Matteo Sgammini in GPS world, vol 28 n° 2 (February 2017)
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Titre : Double take : mitigating interference with a dual-polarized antenna array in a real environment Type de document : Article/Communication Auteurs : Matteo Sgammini, Auteur ; Stefano Caizzone, Auteur ; Achim Hornbostel, Auteur ; Michael Meurer, Auteur Année de publication : 2017 Article en page(s) : pp 66 - 72 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement
[Termes IGN] antenne
[Termes IGN] anti-leurrage
[Termes IGN] interférence
[Termes IGN] méthode robuste
[Termes IGN] polarisation
[Termes IGN] récepteur GPSRésumé : (Auteur) [Introduction] The rapid growth of the wireless telecommunication sector and, consequently, the high demand of spectrum assigned to the new services make the frequency spectrum very crowded and quite saturated. With the weak received signal power of GNSS signals, spurious harmonics from other systems can cause unintentional interference and, therefore, a serious problem to the reliable estimation of user position, velocity and time (PVT). Besides unintentional interference, more virulent intentionally radiated signals, called jammers, may knock out the GNSS receiver; this is especially the case when a jammer with high time-frequency dynamics (such as a chirp-like jammer) affects the GNSS signal spectrum. Whether unintentional or intentional, interference represents a serious threat to GNSS in applications ranging from safety-of-life to critical sectors like law enforcement, transportation, communication and finance. In such critical applications, it is important that the GNSS receiver provides a minimum level of reliability and robustness, even at the cost of increased price and complexity. To meet this need, some manufacturers and research institutions have been developing GNSS receivers equipped with anti-jamming capabilities. In this article, we propose a novel approach to interference mitigation. [...] Numéro de notice : A2017-289 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=85324
in GPS world > vol 28 n° 2 (February 2017) . - pp 66 - 72[article]Pulse compression waveform and filter optimization for spaceborne cloud and precipitation radar / Robert M. Beauchamp in IEEE Transactions on geoscience and remote sensing, vol 55 n° 2 (February 2017)
PermalinkTropospheric refractivity and zenith path delays from least-squares collocation of meteorological and GNSS data / Karina Wilgan in Journal of geodesy, vol 91 n° 2 (February 2017)
PermalinkEtude de l'impact d'un projet de développement sur les propriétés avoisinantes / Sylvain Jourdan (2017)
PermalinkPermalinkHandbook on advances in remote sensing and geographic information systems / Margarita N. Favorskaya (2017)
PermalinkHierarchically exploring the width of spectral bands for urban material classification / Arnaud Le Bris (2017)
PermalinkPermalinkJoint analysis of passive and active land surface responses for Global Precipitation Measurement / Iris de Gelis (2017)
PermalinkModeling spatial and temporal variabilities in hyperspectral image unmixing / Pierre-Antoine Thouvenin (2017)
PermalinkModeling tropospheric wet delays with dense and sparse network configurations for PPP-RTK / Paulo S. de Oliveira in GPS solutions, vol 21 n° 1 (January 2017)
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