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A new global grid model for the determination of atmospheric weighted mean temperature in GPS precipitable water vapor / Liangke Huang in Journal of geodesy, vol 93 n° 2 (February 2019)
[article]
Titre : A new global grid model for the determination of atmospheric weighted mean temperature in GPS precipitable water vapor Type de document : Article/Communication Auteurs : Liangke Huang, Auteur ; Weiping Jiang, Auteur ; Lilong Liu, Auteur ; Hua Chen, Auteur ; Shirong Ye, Auteur Année de publication : 2019 Article en page(s) : pp 159 - 176 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] coordonnées GPS
[Termes IGN] données météorologiques
[Termes IGN] erreur moyenne quadratique
[Termes IGN] Global Geodetic Observing System
[Termes IGN] modèle de géopotentiel
[Termes IGN] prévision météorologique
[Termes IGN] radiosondage
[Termes IGN] régression linéaire
[Termes IGN] retard troposphérique zénithal
[Termes IGN] vapeur d'eauRésumé : (auteur) In ground-based global positioning system (GPS) meteorology, atmospheric weighted mean temperature, Tm, plays a very important role in the progress of retrieving precipitable water vapor (PWV) from the zenith wet delay of the GPS. Generally, most of the existing Tm models only take either latitude or altitude into account in modeling. However, a great number of studies have shown that Tm is highly correlated with both latitude and altitude. In this study, a new global grid empirical Tm model, named as GGTm, was established by a sliding window algorithm using global gridded Tm data over an 8-year period from 2007 to 2014 provided by TU Vienna, where both latitude and altitude variations are considered in modeling. And the performance of GGTm was assessed by comparing with the Bevis formula and the GPT2w model, where the high-precision global gridded Tm data as provided by TU Vienna and the radiosonde data from 2015 are used as reference values. The results show the significant performance of the new GGTm model against other models when compared with gridded Tm data and radiosonde data, especially in the areas with great undulating terrain. Additionally, GGTm has the global mean RMSPWV and RMSPWV/PWV values of 0.26 mm and 1.28%, respectively. The GGTm model, fed only by the day of the year and the station coordinates, could provide a reliable and accurate Tm value, which shows the possible potential application in real-time GPS meteorology, especially for the application of low-latitude areas and western China. Numéro de notice : A2019-077 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-018-1148-9 Date de publication en ligne : 15/05/2018 En ligne : https://doi.org/10.1007/s00190-018-1148-9 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=92191
in Journal of geodesy > vol 93 n° 2 (February 2019) . - pp 159 - 176[article]
Titre : Accuracy of GNSS methods Type de document : Monographie Auteurs : D. Uğur Şanli, Éditeur scientifique Editeur : London [UK] : IntechOpen Année de publication : 2019 Importance : 150 p. Format : 19 x 27 cm ISBN/ISSN/EAN : 978-1-78984-926-4 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement
[Termes IGN] données GNSS
[Termes IGN] Global Navigation Satellite System
[Termes IGN] instrumentation GNSS
[Termes IGN] international GPS service for geodynamics
[Termes IGN] positionnement par GNSS
[Termes IGN] positionnement ponctuel précis
[Termes IGN] précision du positionnement
[Termes IGN] teneur totale en électronsRésumé : (éditeur) Following the GPS, new GNSS techniques are emerging today. Various surveying and processing methods are available for the analysis of GNSS data. Equipment and software are also varied. The orbit quality, controlled by the system designer, and the IGS are continuously improved. The user is mainly interested in the quality of position and of the deformation rates produced by the GNSS. Hence, research needs to guide the user in terms of selecting the best combination of the available methods and instrumentation to produce the desired accuracy. This book reviews the current available accuracy obtainable using the GNSS methods. In fact, the main aim of this book is to make an impact on young researchers so that they keep updating the accuracy of GNSS for future generations. Note de contenu : 1- Introductory Chapter: The Philosophy Behind the Accuracy Assessment of GNSS Methods
2- Evaluation Methods of Satellite Navigation System Performance
3- Robust GNSS Positioning in Urban Environment
4- GPS Scintillations and Total Electron Content Climatology in the Southern American Sector
5- Evaluation of GNSS Data with Internet Based Services: The Case of HRUH Station
6- Comparative Study of Some Online GNSS Post-Processing Services at Selected Permanent GNSS Sites in Nigeria
7- Development of Recurrent Method with Rotation for Combined Adjustment of Terrestrial Geodetic and GNSS Networks in National Spatial Reference SystemNuméro de notice : 25934 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Recueil / ouvrage collectif DOI : 10.5772/intechopen.75424 En ligne : https://doi.org/10.5772/intechopen.75424 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=96247
Titre : Geospatial analyses of Earth observation (EO) data Type de document : Monographie Auteurs : Antonio Pepe, Éditeur scientifique ; Qing Zhao, Éditeur scientifique Editeur : London [UK] : IntechOpen Année de publication : 2019 Importance : 136 p. Format : 16 x 24 cm ISBN/ISSN/EAN : 978-1-78984-584-6 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] aérosol
[Termes IGN] analyse spatiale
[Termes IGN] bassin hydrographique
[Termes IGN] bruit (théorie du signal)
[Termes IGN] cartographie géologique
[Termes IGN] changement climatique
[Termes IGN] couleur (variable spectrale)
[Termes IGN] détection de changement
[Termes IGN] données environnementales
[Termes IGN] image hyperspectrale
[Termes IGN] image optique
[Termes IGN] image Sentinel-MSI
[Termes IGN] Italie
[Termes IGN] lac
[Termes IGN] Malawi
[Termes IGN] minéral
[Termes IGN] observation de la Terre
[Termes IGN] risque naturel
[Termes IGN] télédétection spatiale
[Termes IGN] transformation de coordonnées
[Termes IGN] utilisation du solRésumé : (Editeur) Earth Observation and Geospatial Analysis presents current research related to the observation of Earth with sensors operating at various wavelengths. The book describes the use of remote sensing technologies for detecting and monitoring Earth's environmental changes (including surface and atmosphere) and its modifications over time. Chapters cover different research aspects in the framework of remote sensing with a particular emphasis on the use of hyperspectral and optical imageries. The presented experiments concern the study of soil properties, the analysis of land use/land changes, the analysis of bio-aerosols as well as the color of water, the investigation of the scar and samples of a cosmic meteoritic impact, and the theoretical treatment of the operation of spatial coordinate transformation in noisy environments. Overall, this book provides an overview of the adopted methodologies for the accomplishment of geospatial analyses to identify environmental changes due to climate change and natural phenomena. Note de contenu : 1. Application of Topographic Analyses for Mapping Spatial Patterns of Soil Properties
2. Clay Minerals Mapping from Imaging Spectroscopy
3. The Impact of Land Use and Land Cover Changes on the Nkula Dam in the Middle Shire River Catchment, Malawi
4. Advanced Methods for Spatial Analysis of Bioaerosol Long-Range Transport Processes
5. The Color of Water from Space: A Case Study for Italian Lakes from Sentinel-2
6. Bacubirito: An Outstanding Cosmic Sample on Earth
7. Spatial Coordinate Transformations with Noisy DataNuméro de notice : 26673 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/IMAGERIE Nature : Recueil / ouvrage collectif DOI : 10.5772/intechopen.74888 Date de publication en ligne : 27/11/2019 En ligne : https://www.intechopen.com/books/7304 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=98967 Impact of GPS antenna phase center models on zenith wet delay and tropospheric gradients / Yohannes Getachew Ejigu in GPS solutions, vol 23 n° 1 (January 2019)
[article]
Titre : Impact of GPS antenna phase center models on zenith wet delay and tropospheric gradients Type de document : Article/Communication Auteurs : Yohannes Getachew Ejigu, Auteur ; Addisu Hunegnaw, Auteur ; Kibrom Ebuy Abraha, Auteur ; et al., Auteur Année de publication : 2019 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] antenne GPS
[Termes IGN] centre de phase
[Termes IGN] données GPS
[Termes IGN] gradient de troposphère
[Termes IGN] retard troposphérique zénithal
[Termes IGN] teneur intégrée en vapeur d'eau
[Vedettes matières IGN] Traitement de données GNSSRésumé : (Auteur) Today Global Navigation Satellite Systems (GNSS) tropospheric products, such as zenith total delays (ZTD) and zenith wet delays (ZWD), are widely used as complementary data sets in numerical weather prediction models. In particular, the wet delays are treated as unknown parameters in GNSS processing and are estimated with other parameters such as station coordinates. In this study, we investigate the effects of Phase Center Correction (PCC) models on ZWD, integrated water vapor (IWV) and horizontal gradients derived from Global Positioning System (GPS) observations. Two solutions were generated using the GAMIT software over the European Reference Frame (EUREF) Permanent GNSS Network (EPN). The first (reference) solution was derived by applying the International GNSS Service (IGS) type-mean PCC models, while for the second solution PCC models from individual calibrations were used. The solutions were generated identically, except for the PCC model differences. The tropospheric products from the two solutions were then compared, with the assumption that common signals would be differenced out. The comparison of the two solutions clearly shows a bias in all tropospheric products, which can be attributed to PCC model deficiencies. Overall, mean biases of 1.8, 0.3, 0.14 and 0.19 mm are evident in ZWD, IWV, North–South and East–West gradients, respectively. Moreover, the differences between the two solutions show seasonal variations. For all antenna types, the ZWD and IWV differences are dominated by white plus power-law noise, with the latter characterizing the low-frequency spectrum. On the other hand, the horizontal gradients exhibit a white plus first-order autoregressive noise characteristic with less than 1% white noise. The individual PCC model provides a better fit to an external independent model in terms of gradient estimates and also provides up to 3% more carrier phase integer ambiguity resolution. Numéro de notice : A2019-056 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s10291-018-0796-9 Date de publication en ligne : 25/10/2018 En ligne : https://doi.org/10.1007/s10291-018-0796-9 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=92085
in GPS solutions > vol 23 n° 1 (January 2019)[article]Quality assessment of CNES real-time ionospheric products / Zhixi Nie in GPS solutions, vol 23 n° 1 (January 2019)
[article]
Titre : Quality assessment of CNES real-time ionospheric products Type de document : Article/Communication Auteurs : Zhixi Nie, Auteur ; Hongzhou Yang, Auteur ; Peiyuan Zhou, Auteur ; et al., Auteur Année de publication : 2019 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] positionnement ponctuel précis
[Termes IGN] qualité de service
[Termes IGN] récepteur monofréquence
[Termes IGN] temps réel
[Termes IGN] teneur verticale totale en électronsRésumé : (Auteur) Real-time single-frequency precise point positioning (RT-SF-PPP) has become a desired positioning approach because it can achieve high positioning accuracy with a low-cost global navigation satellite system (GNSS) chipset or receiver. For single-frequency precise point positioning (SF-PPP) applications, the ionospheric delay is a dominant error source, and thus the quality of applied ionospheric products is critical to the performance of SF-PPP. To meet the demands of the RT-SF-PPP users, the international GNSS service (IGS) is planning to provide open-access real-time ionospheric products. By now, the Centre National d’Études Spatiales (CNES) is the only IGS analysis center (AC) to broadcast real-time ionospheric vertical total electron content (VTEC) message through its real-time service (RTS). The quality of the CNES real-time ionospheric products is drawing increasing attention from the GNSS community. We evaluate the quality of CNES real-time VTEC message both in the ionospheric correction domain and positioning domain. First, 374 consecutive days of CNES VTEC products are collected and compared with the IGS final global ionospheric map (GIM) products. Second, slant total electron content (STEC) computed with CNES VTEC message is fully assessed with respect to STEC derived from dual-frequency GNSS measurements. Finally, RT-SF-PPP is conducted for assessing the quality of CNES real-time ionospheric products in the positioning domain. The degree and order of the spherical harmonic expansions broadcasted in the CNES VTEC messages changed from 6 to 12 in the time span of collected data, the effects of higher degree and order parameters are investigated at the same time in the experiments above. Numéro de notice : A2019-054 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s10291-018-0802-2 Date de publication en ligne : 15/11/2018 En ligne : https://doi.org/10.1007/s10291-018-0802-2 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=92083
in GPS solutions > vol 23 n° 1 (January 2019)[article]Enhanced local ionosphere model for multi-constellations single frequency precise point positioning applications: Egyptian case study / Emad El Manaily in Artificial satellites, vol 53 n° 4 (December 2018)PermalinkReal-Time Precise Point Positioning (RTPPP) with raw observations and its application in real-time regional ionospheric VTEC modeling / Teng Liu in Journal of geodesy, vol 92 n° 11 (November 2018)PermalinkMulti‐scale observations of atmospheric moisture variability in relation to heavy precipitating systems in the northwestern Mediterranean during HyMeX IOP12 / Samiro Khodayar in Quarterly Journal of the Royal Meteorological Society, vol 144 n° 717 (October 2018 Part B)PermalinkRevisit the calibration errors on experimental slant total electron content (TEC) determined with GPS / Wenfeng Nie in GPS solutions, vol 22 n° 3 (July 2018)PermalinkA two-stage tropospheric correction model combining data from GNSS and numerical weather model / Jan Douša in GPS solutions, vol 22 n° 3 (July 2018)PermalinkCarrier phase bias estimation of geometry-free linear combination of GNSS signals for ionospheric TEC modeling / Anna Krypiak-Gregorczyk in GPS solutions, vol 22 n° 2 (April 2018)PermalinkJoint estimation of vertical total electron content (VTEC) and satellite differential code biases (SDCBs) using low-cost receivers / Baocheng Zhang in Journal of geodesy, vol 92 n° 4 (April 2018)PermalinkPermalinkAn accurate Kriging-based regional ionospheric model using combined GPS/BeiDou observations / Mohamed Abdelazeem in Journal of applied geodesy, vol 12 n° 1 (January 2018)PermalinkPermalink