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A new approach for the development of grid models calculating tropospheric key parameters over China / Ge Zhu in Remote sensing, vol 13 n° 17 (September-1 2021)  

Public [article]  inRemote sensing > vol 13 n° 17 (September-1 2021) . - n° 3546 Titre : A new approach for the development of grid models calculating tropospheric key parameters over China Type de document : Article/Communication Auteurs : Ge Zhu, Auteur ; Liangke Huang, Auteur ; Lilong Liu, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : n° 3546 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale [Termes IGN] Chine [Termes IGN] données maillées [Termes IGN] MERRA [Termes IGN] météorologie [Termes IGN] positionnement par GNSS [Termes IGN] retard troposphérique [Termes IGN] série temporelle [Termes IGN] teneur en vapeur d'eau [Termes IGN] troposphère Résumé : (auteur) Pressure, water vapor pressure, temperature, and weighted mean temperature (Tm) are tropospheric parameters that play an important role in high-precision global navigation satellite system navigation (GNSS). As accurate tropospheric parameters are obligatory in GNSS navigation and GNSS water vapor detection, high-precision modeling of tropospheric parameters has gained widespread attention in recent years. A new approach is introduced to develop an empirical tropospheric delay model named the China Tropospheric (CTrop) model, providing meteorological parameters based on the sliding window algorithm. The radiosonde data in 2017 are treated as reference values to validate the performance of the CTrop model, which is compared to the canonical Global Pressure and Temperature 3 (GPT3) model. The accuracy of the CTrop model in regards to pressure, water vapor pressure, temperature, and weighted mean temperature are 5.51 hPa, 2.60 hPa, 3.09 K, and 3.35 K, respectively, achieving an improvement of 6%, 9%, 10%, and 13%, respectively, when compared to the GPT3 model. Moreover, three different resolutions of the CTrop model based on the sliding window algorithm are also developed to reduce the amount of gridded data provided to the users, as well as to speed up the troposphere delay computation process, for which users can access model parameters of different resolutions for their requirements. With better accuracy of estimating the tropospheric parameters than that of the GPT3 model, the CTrop model is recommended to improve the performance of GNSS positioning and navigation. Numéro de notice : A2021-688 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.3390/rs13173546 date de publication en ligne : 06/09/2021 En ligne : https://doi.org/10.3390/rs13173546 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=98423 [article]

Atmospheric correction to passive microwave brightness temperature in snow cover mapping over china / Yubao Qiu in IEEE Transactions on geoscience and remote sensing, vol 59 n° 8 (August 2021)  

Public [article]  inIEEE Transactions on geoscience and remote sensing > vol 59 n° 8 (August 2021) . - pp 6482 - 6495 Titre : Atmospheric correction to passive microwave brightness temperature in snow cover mapping over china Type de document : Article/Communication Auteurs : Yubao Qiu, Auteur ; Lijuan Shi, Auteur ; Juha Lemmetyinen, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : pp 6482 - 6495 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications [Termes IGN] capteur passif [Termes IGN] Chine [Termes IGN] correction atmosphérique [Termes IGN] image NOAA [Termes IGN] image SSMIS [Termes IGN] image Terra-MODIS [Termes IGN] manteau neigeux [Termes IGN] modèle atmosphérique [Termes IGN] neige [Termes IGN] série temporelle [Termes IGN] télédétection en hyperfréquence [Termes IGN] température de luminance [Termes IGN] teneur en vapeur d'eau Résumé : (auteur) Variable atmospheric conditions are typically ignored in the retrieval of geophysical parameters of the Earth’s surface when using spaceborne passive microwave observations. However, high frequencies, for example, 91.7 GHz, are sensitive to variable atmospheric absorption, even in winter’s dry conditions. In this article, the influence of variable atmospheric absorption on snow cover extent (SCE) mapping was quantitatively investigated. A physical method was derived to enable atmospheric correction for variable atmospheric conditions. The total column precipitable water vapor (TPWV) from Moderate Resolution Imaging Spectroradiometer (MODIS) was parametrized into transmittances in this correction method. The corrected brightness temperature at 19 and 91.7 GHz from the Special Sensor Microwave Imager Sounder (SSMIS) was applied to the threshold algorithm for snow mapping over China. Compared with the Interactive Multisensor Snow and Ice Mapping System (IMS) data in winter from 2012 to 2013, for Qinghai–Tibet plateau (QTP), a significant improvement after correction was obtained from February to March over ephemeral and shallow snow, where the largest daily improvement of accuracy is up to 20%. The accuracy (incl. precision, recall, and F1 index) improved on average is from 0.77 (0.60, 0.68, and 0.63) to 0.79 (0.69, 0.7, and 0.68) over the full winter time from December to March. Over forest-rich Northeast China, where snow in winter is thicker, small improvement was observed at the onset of the snow season and over snow margin area. It was evidenced that high frequency is a promising way of snow cover mapping with the proposed atmospheric correction method. Numéro de notice : A2021-630 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2020.3031837 date de publication en ligne : 02/11/2020 En ligne : https://doi.org/10.1109/TGRS.2020.3031837 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=98279 [article]

An integrated methodology for surface soil moisture estimating using remote sensing data approach / Rida Khellouk in Geocarto international, vol 36 n° 13 ([15/07/2021])  

Public [article]  inGeocarto international > vol 36 n° 13 [15/07/2021] . - pp 1443 - 1458 Titre : An integrated methodology for surface soil moisture estimating using remote sensing data approach Type de document : Article/Communication Auteurs : Rida Khellouk, Auteur ; Ahmed Barakat, Auteur ; Aafaf El Jazouli, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : pp 1443 - 1458 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes IGN] évapotranspiration [Termes IGN] humidité du sol [Termes IGN] image Terra-MODIS [Termes IGN] indice d'humidité [Termes IGN] Maroc [Termes IGN] modèle numérique de surface [Termes IGN] Normalized Difference Vegetation Index [Termes IGN] température au sol [Termes IGN] texture du sol Résumé : (auteur) The present study aimed to propose an operational approach for estimating surface soil moisture from Moderate Resolution Imaging Spectroradiometer (MODIS) data by considering diverse environmental variables such as Normalized Difference Vegetation Index (NDVI), land surface temperature (Ts), evapotranspiration, topographic parameters (elevation and aspect) and soil texture (clay, loam and silt). A soil moisture index (SMI) derived from NDVI-Ts space is combined to all other variables, based on stepwise multiple regression, to develop a new SSMC model. Performance of this model was assessed using field-measured data of SSM. Accuracy was performed by the k-fold cross validation method, it showed a R2 (coefficients of determination) of 0.70, RMSE of 1.58% and unRMSE of 0.5%. In addition, the results of the developed model were compared with another soil moisture model SMM proposed in the irrigated perimeter of Tadla (Morocco), and revealed that the established model provided effectiveness results in the study areas. Numéro de notice : A2021-554 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/10106049.2019.1655797 date de publication en ligne : 12/12/2019 En ligne : https://doi.org/10.1080/10106049.2019.1655797 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=98105 [article]

Temperature and humidity effects on CG-6 gravity observations / P. I. A. Weerasinghe in Journal of applied geodesy, vol 15 n° 3 (July 2021)  

Public [article]  inJournal of applied geodesy > vol 15 n° 3 (July 2021) . - pp 225 - 231 Titre : Temperature and humidity effects on CG-6 gravity observations Type de document : Article/Communication Auteurs : P. I. A. Weerasinghe, Auteur ; H. M. I. Prasanna, Auteur Année de publication : 2021 Article en page(s) : pp 225 - 231 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique [Termes IGN] corrélation linéaire [Termes IGN] force de gravitation [Termes IGN] gravimètre [Termes IGN] humidité de l'air [Termes IGN] instrument de mesure [Termes IGN] Sri Lanka [Termes IGN] température de l'air [Termes IGN] thermomètre Résumé : (Auteur) The CG6 is an automated gravity meter that has a worldwide measurement range of over 8000 mGals and a reading resolution of 0.0001 mGal. Some factors that may influence the gravity readings are corrected by the instrument’s software. In this paper, the effects of the ambient temperature and humidity changes on the CG-6’s gravity measurements were investigated with the aim of reducing the uncertainty which remains in gravity measurements in microgal level, and giving recommendations for more accurate results. A controlled heating experiment was used to determine the impact of ambient temperature on gravity and 12 hours of continuous gravity observations were used to identify the impact of humidity on gravity measurements. It was observed that the sensor temperature and the gravity reading were highly correlated with the ambient temperature. The linear correlation with R2 > 0.94 and R2 > 0.90 were found for the corrected gravity reading and the residual sensor temperature variations respectively with the ambient temperature when heating. It was demonstrated that the calculated ambient temperature correction, −0.0011 mGal/oC, is more stable than the correction given by the instrument in terms of standard deviation though the impact of humidity on gravity reading was not clear. Numéro de notice : A2021-468 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1515/jag-2020-0047 date de publication en ligne : 28/04/2021 En ligne : https://doi.org/10.1515/jag-2020-0047 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=98106 [article]

The presence of shade-intolerant conifers facilitates the regeneration of Quercus petraea in mixed stands / Jeremy Borderieux in Forest ecology and management, vol 491 (1st July 2021)  

Public [article]  inForest ecology and management > vol 491 (1st July 2021) . - n° 119189 Titre : The presence of shade-intolerant conifers facilitates the regeneration of Quercus petraea in mixed stands Type de document : Article/Communication Auteurs : Jeremy Borderieux, Auteur ; Yoan Paillet, Auteur ; Marine Dalmasso , Auteur ; Anders Mårell, Auteur ; Thomas Pérot, Auteur ; Patrick Vallet, Auteur Année de publication : 2021 Projets : 1-Pas de projet / Article en page(s) : n° 119189 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] Cervidae [Termes IGN] évapotranspiration [Termes IGN] inventaire forestier national (données France) [Termes IGN] peuplement mélangé [Termes IGN] Pinophyta [Termes IGN] Quercus sessiliflora [Termes IGN] régénération (sylviculture) [Termes IGN] sol forestier [Termes IGN] température de surface [Vedettes matières IGN] Foresterie Résumé : (auteur) Positive productivity-diversity relationships, pest-effect mitigation and increased resilience and stability maintain an ongoing interest for mixed stands in forestry. However, how mixing species affects forest regeneration is yet to be further explored. We used data from the French National Forest Inventory (from 2006 to 2016) to model Quercus petraea (Matt.) Liebl regeneration cover in pure and mixed Quercus petraea stands; we included the effects of abiotic and biotic factors as well as mixture. We hypothesized that the characteristics of the companion species would prevent or facilitate the regeneration of oak. Quercus petraea regeneration cover in this study responded negatively to total canopy cover and herbivory pressure. Mean July potential evapotranspiration (PET), mean December maximal temperature and soil pH are variables whose spatial variations over a given territory structure regeneration cover; all three of these variables have optimum values. Quercus petraea regeneration cover is linked to the proportion of Quercus petraea in the canopy layer in all mixed stands, except when the oak is mixed with shade-intolerant conifers: in this case, Quercus petraea regeneration is enhanced. The shade tolerance of admixed broadleaved species did not affect the Quercus petraea regeneration. This suggests that oak regeneration was facilitated with a shade-intolerant coniferous companion species due to better light transmittance through the crown or the competitive advantage of Quercus petraea over coniferous shade-intolerant species. These results are of interest for oak mixtures since Quercus petraea regeneration cover benefits from mixtures with shade-intolerant conifers and is at least equal to that of pure stands. Numéro de notice : A2021-309 Affiliation des auteurs : IGN+Ext (2020- ) Autre URL associée : vers HAL ouvert Thématique : FORET Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.foreco.2021.119189 date de publication en ligne : 08/04/2021 En ligne : https://doi.org/10.1016/j.foreco.2021.119189 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97743 [article]

A combined drought monitoring index based on multi-sensor remote sensing data and machine learning / Hongzhu Han in Geocarto international, vol 36 n° 10 ([01/06/2021])  

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Reference evapotranspiration (ETo) methods implemented as ArcMap models with remote-sensed and ground-based inputs, examined along with MODIS ET, for Peloponnese, Greece / Stavroula Dimitriadou in ISPRS International journal of geo-information, vol 10 n° 6 (June 2021)  

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Integrated water vapour observations in the Caribbean arc from a network of ground-based GNSS receivers during EUREC4A / Olivier Bock in Earth System Science Data, vol 13 n° 5 (May 2021)  

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Integrated water vapour content retrievals from ship-borne GNSS receivers during EUREC4A / Pierre Bosser in Earth System Science Data, vol 13 n° 4 (April 2021)  

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G-band radar for humidity and cloud remote sensing / Ken B. Cooper in IEEE Transactions on geoscience and remote sensing, vol 59 n° 2 (February 2021)  

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IWV retrieval from ground GNSS receivers during NAWDEX / Pierre Bosser in Advances in geosciences, vol 55 ([01/02/2021])  

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Évaluation de l'évapotranspiration des zones irriguées en piémont du Haut Atlas, Maroc / Jamal Elfarkh (2021)  

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A new segmentation method for the homogenisation of GNSS-derived IWV time-series / Annarosa Quarello in Journal of the Royal Statistical Society: Series C Applied Statistics, vol inconnu ([01/01/2021])  

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Precipitation frequency in MED and EURO-CORDEX ensembles from 0.44° to convective permitting resolution: what explains the differences? / Minh Ha-Truong (2021)  

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Sensitivity of segmentation of GNSS IWV time series and trend estimates to data properties / Khanh Ninh Nguyen (2021)  

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