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Precise orbit determination for BDS-3 GEO satellites enhanced by intersatellite links / Xiaojie Li in GPS solutions, vol 27 n° 1 (January 2023)  

Public [article]  inGPS solutions > vol 27 n° 1 (January 2023) . - n° 8 Titre : Precise orbit determination for BDS-3 GEO satellites enhanced by intersatellite links Type de document : Article/Communication Auteurs : Xiaojie Li, Auteur ; Xiaogong Hu, Auteur ; Rui Guo, Auteur ; et al., Auteur Année de publication : 2023 Article en page(s) : n° 8 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Techniques orbitales [Termes IGN] constellation BeiDou [Termes IGN] décalage d'horloge [Termes IGN] orbite géostationnaire [Termes IGN] orbite précise [Termes IGN] orbitographie [Termes IGN] qualité des données Résumé : (auteur) Geostationary orbit (GEO) satellites are an integral part of the BeiDou Navigation Satellite System (BDS). Precise orbit determination (POD) for GEO satellites is difficult due to their geostationary characteristics. The orbit determination accuracy that can be achieved based on regional tracking stations in China cannot satisfy high-precision service requirements. The third generation of BDS (BDS-3) is the first global navigation satellite system that synergistically uses regional monitoring stations and global intersatellite links (ISLs) to realize global service. In this study, the quality of ISL data is analyzed based on the residuals of the intersatellite clock offset and the observed-minus-computed residuals of the ISL data. The orbit determination accuracy is assessed based on the observation residuals, the multiday consistency of the ISL time delays, overlapping orbit comparison, the user equivalent range error (UERE), and the accuracy of the clock offset. The results show that the ISL measurement noise for the GEO satellites is 3 cm, and the multiday consistency accuracy of the ISL time delay is better than 0.07 ns. Compared to the satellite-to-ground link (SGL)-based orbit determination method, the root mean square (RMS) three-dimensional (3D) position error of the overlapping orbit differences (OODs) is improved from 1.11 to 0.22 m with the combined SGL- and ISL-based method. Simultaneously, the UERE improves from 0.57 to 0.19 m, and the accuracy of the satellite clock offset improves from 1.09 to 0.61 ns. Numéro de notice : A2023-001 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s10291-022-01330-3 Date de publication en ligne : 14/10/2022 En ligne : https://doi.org/10.1007/s10291-022-01330-3 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=101870 [article]

LinkClimate: An interoperable knowledge graph platform for climate data / Jiantao Wu in Computers & geosciences, vol 169 (December 2022)  

Public [article]  inComputers & geosciences > vol 169 (December 2022) . - n° 105215 Titre : LinkClimate: An interoperable knowledge graph platform for climate data Type de document : Article/Communication Auteurs : Jiantao Wu, Auteur ; Fabrizio Orlandi, Auteur ; Declan O'Sullivan, Auteur ; et al., Auteur Année de publication : 2022 Article en page(s) : n° 105215 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique web [Termes IGN] changement climatique [Termes IGN] données météorologiques [Termes IGN] données multisources [Termes IGN] historique des données [Termes IGN] interopérabilité sémantique [Termes IGN] National oceanic and atmospheric administration [Termes IGN] ontologie [Termes IGN] OpenStreetMap [Termes IGN] réseau sémantique [Termes IGN] site wiki [Termes IGN] SPARQL [Termes IGN] web sémantique Résumé : (auteur) Climate science has become more ambitious in recent years as global awareness about the environment has grown. To better understand climate, historical climate(e.g. archived meteorological variables such as temperature, wind, water, etc.) and climate-related data (e.g. geographical features and human activities) are widely used by today’s climate research to derive models for an explainable climate change and its effects. However, such data sources are often dispersed across a multitude of disconnected data silos on the Web. Moreover, there is a lack of advanced climate data platforms to enable multi-source heterogeneous climate data analysis, therefore, researchers must face a stern challenge in collecting and analyzing multi-source data. In this paper, we address this problem by proposing a climate knowledge graph for the integration of multiple climate data and other data sources into one service, leveraging Web technologies (e.g. HTTP) for multi-source climate data analysis. The proposed knowledge graph is primarily composed of data from the National Oceanic and Atmospheric Administration’s daily climate summaries, OpenStreetMap, and Wikidata, and it supports joint data queries on these widely used databases. This paper shows, with a use case in Ireland and the United Kingdom, how climate researchers could benefit from this platform as it allows them to easily integrate datasets from different domains and geographical locations. Numéro de notice : A2022-789 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.cageo.2022.105215 Date de publication en ligne : 30/08/2022 En ligne : https://doi.org/10.1016/j.cageo.2022.105215 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=101897 [article]

An estimation method to reduce complete and partial nonresponse bias in forest inventory / James A. Westfall in European Journal of Forest Research, vol 141 n° 5 (October 2022)  

Public [article]  inEuropean Journal of Forest Research > vol 141 n° 5 (October 2022) . - pp 901 - 907 Titre : An estimation method to reduce complete and partial nonresponse bias in forest inventory Type de document : Article/Communication Auteurs : James A. Westfall, Auteur Année de publication : 2022 Article en page(s) : pp 901 - 907 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] enquête [Termes IGN] erreur systématique [Termes IGN] estimateur [Termes IGN] estimation statistique [Termes IGN] Etats-Unis [Termes IGN] incertitude des données [Termes IGN] inventaire forestier étranger (données) [Termes IGN] méthode de Monte-Carlo [Termes IGN] modèle de simulation [Termes IGN] placette d'échantillonnage [Termes IGN] post-stratification de données [Termes IGN] propriété foncière [Vedettes matières IGN] Inventaire forestier Résumé : (auteur) Survey practitioners commonly encounter various types of nonresponse and strive to implement methods that mitigate any resulting bias when reporting results. In national forest inventories (NFI), complete or partial nonresponse usually results from hazardous conditions or lack of plot access permission. While many factors may be related to nonresponse, the two primary factors in the NFI of the USA are public/private land ownership and office/field plot status. To ameliorate potential nonresponse bias, these factors should be accounted for in the estimation process. An estimation method is presented where response homogeneity groups (RHGs) account for differential nonresponse rates between forest/nonforest plots. In a post-stratified estimation context, ratio-to-size estimators are used in RHGs within post-strata to avoid potential bias in variance estimates arising from partial plot nonresponse. Combining RHGs within post-strata requires a complex variance estimator that includes four sources of uncertainty. Testing of the estimation method on a synthetic population showed the approach is essentially unbiased. Application to NFI data from 10 states in the USA consistently showed the RHG method produced state-level estimates of forestland area that were 0.1%–3.6% larger than the current post-stratified estimation procedure. It is suggested that these differences are indicative of the nonresponse bias present when plots having differential nonresponse rates are not accounted for. Numéro de notice : A2022-759 Affiliation des auteurs : non IGN Thématique : FORET/MATHEMATIQUE Nature : Article DOI : 10.1007/s10342-022-01480-6 Date de publication en ligne : 14/07/2022 En ligne : https://doi.org/10.1007/s10342-022-01480-6 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=101770 [article]

Comparison of methods for the automatic classification of forest habitat types in the Southern Alps : Application to ecological data from the French national forest inventory / Charlotte Labit in Biodiversity & Conservation, vol 31 n° inconnu (2022)  

Public [article]  inBiodiversity & Conservation > vol 31 n° inconnu (2022) . - n° Titre : Comparison of methods for the automatic classification of forest habitat types in the Southern Alps : Application to ecological data from the French national forest inventory Type de document : Article/Communication Auteurs : Charlotte Labit, Auteur ; Ingrid Bonhême , Auteur ; Sébastien Delhaye, Auteur Année de publication : 2022 Article en page(s) : n° Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] Alpes-de-haute-provence (04) [Termes IGN] Alpes-maritimes (06) [Termes IGN] analyse comparative [Termes IGN] classification par forêts d'arbres décisionnels [Termes IGN] Drôme (26) [Termes IGN] habitat (nature) [Termes IGN] habitat forestier [Termes IGN] incertitude des données [Termes IGN] inventaire forestier national (données France) [Termes IGN] surveillance écologique [Vedettes matières IGN] Inventaire forestier Mots-clés libres : algorithm inspired by the habitat identification key used in the field Résumé : (auteur) The monitoring of habitats at plant association level, has been developed by the French-National Forest Inventory (NFI) progressively since 2011, whereas ecological and floristic data exist since the mid-1980s. The NFI habitat monitoring is the French tool of surveillance of forest habitats decreed by Natura 2000 Directive (article 11). Determination of plant association in NFI plots concerns all the habitats, whether they are of community interest or not. The objective of this study is to compare different methods of automatic classification of floristic and ecological surveys into forest habitat groups. Indeed, enriching the old surveys, which contain only ecological, floristic and trees data, with information on habitats would increase the accuracy of the calculated statistical results on habitats. The uncertainty of the attribution of a habitat outside the field (ex-situ) by experts was quantified by comparison with the determination in the field (in situ). This result was used as a benchmark to compare to the error rates obtained by two methods of automatic classification: an algorithm inspired by the habitat identification key used in the field and Random forest, a learning classification method. The classification performance was evaluated for three levels of habitat groupings. The results showed that the lower the level of clustering, the higher the error rate. Depending on the classification method used and the level of aggregation, the error rates varied between 5 and 15%. In all cases, the error rates were below the estimated uncertainty of the expert attribution of ex-situ habitat. Numéro de notice : A2022-696 Affiliation des auteurs : IGN+Ext (2020- ) Thématique : FORET/MATHEMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s10531-022-02487-6 Date de publication en ligne : 25/10/2022 En ligne : https://doi.org/10.1007/s10531-022-02487-6 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=101980 [article]

3D LiDAR aided GNSS/INS integration fault detection, localization and integrity assessment in urban canyons / Zhipeng Wang in Remote sensing, vol 14 n° 18 (September-2 2022)  

Public [article]  inRemote sensing > vol 14 n° 18 (September-2 2022) . - n° 4641 Titre : 3D LiDAR aided GNSS/INS integration fault detection, localization and integrity assessment in urban canyons Type de document : Article/Communication Auteurs : Zhipeng Wang, Auteur ; Bo Li, Auteur ; Zhiqiang Dan, Auteur ; et al., Auteur Année de publication : 2022 Article en page(s) : n° 4641 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie [Termes IGN] canyon urbain [Termes IGN] couplage GNSS-INS [Termes IGN] détection de cible [Termes IGN] données lidar [Termes IGN] données localisées 3D [Termes IGN] erreur de positionnement [Termes IGN] filtre adaptatif [Termes IGN] intégration de données [Termes IGN] intégrité des données [Termes IGN] khi carré [Termes IGN] semis de points Résumé : (auteur) The performance of Global Navigation Satellite System (GNSS) and Inertial Navigation System (INS) integrated navigation can be severely degraded in urban canyons due to the non-line-of-sight (NLOS) signals and multipath effects. Therefore, to achieve a high-precision and robust integrated system, real-time fault detection and localization algorithms are needed to ensure integrity. Currently, the residual chi-square test is used for fault detection in the positioning domain, but it has poor sensitivity when faults disappear. Three-dimensional (3D) light detection and ranging (LiDAR) has good positioning performance in complex environments. First, a LiDAR aided real-time fault detection algorithm is proposed. A test statistic is constructed by the mean deviation of the matched targets, and a dynamic threshold is constructed by a sliding window. Second, to solve the problem that measurement noise is estimated by prior modeling with a certain error, a LiDAR aided real-time measurement noise estimation based on adaptive filter localization algorithm is proposed according to the position deviations of matched targets. Finally, the integrity of the integrated system is assessed. The error bound of integrated positioning is innovatively verified with real test data. We conduct two experiments with a vehicle going through a viaduct and a floor hole, which, represent mid and deep urban canyons, respectively. The experimental results show that in terms of fault detection, the fault could be detected in mid urban canyons and the response time of fault disappearance is reduced by 70.24% in deep urban canyons. Thus, the poor sensitivity of the residual chi-square test for fault disappearance is improved. In terms of localization, the proposed algorithm is compared with the optimal fading factor adaptive filter (OFFAF) and the extended Kalman filter (EKF). The proposed algorithm is the most effective, and the Root Mean Square Error (RMSE) in the east and north is reduced by 12.98% and 35.1% in deep urban canyons. Regarding integrity assessment, the error bound can overbound the positioning errors in deep urban canyons relative to the EKF and the mean value of the error bounds is reduced. Numéro de notice : A2022-769 Affiliation des auteurs : non IGN Thématique : IMAGERIE/POSITIONNEMENT Nature : Article DOI : 10.3390/rs14184641 Date de publication en ligne : 16/09/2022 En ligne : https://doi.org/10.3390/rs14184641 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=101795 [article]

A general model for creating robust choropleth maps / Wangshu Mu in Computers, Environment and Urban Systems, vol 96 (September 2022)  

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A geographical and content-based approach to prioritize relevant and reliable tweets for emergency management / A. Marcela Suarez in Cartography and Geographic Information Science, Vol 49 n° 5 (September 2022)  

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Using multi-temporal tree inventory data in eucalypt forestry to benchmark global high-resolution canopy height models. A showcase in Mato Grosso, Brazil / Adrián Pascual in Ecological Informatics, vol 70 (September 2022)  

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Assuring the quality of VGI on land use and land cover: experiences and learnings from the LandSense project / Giles M. Foody in Geo-spatial Information Science, vol 25 n° inconnu ([01/08/2022])  

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Modeling and propagating inventory-based sampling uncertainty in the large-scale forest demographic model “MARGOT” / Timothée Audinot in Natural Resource Modelling, vol 35 n° 3 (August 2022)  

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Quality assessment of volunteered geographic information for outdoor activities: an analysis of OpenStreetMap data for names of peaks in Japan / Jun Yamashita in Geo-spatial Information Science, vol 25 n° inconnu ([01/08/2022])  

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Uncertainty interval estimates for computing slope and aspect from a gridded digital elevation model / Carlos López-Vázquez in International journal of geographical information science IJGIS, vol 36 n° 8 (August 2022)  

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Evaluation of the GSRM2.1 and the NUVEL1-A values in Europe using SLR and VLBI based geodetic velocity fields / Mina Rahmani in Survey review, vol 54 n° 385 (July 2022)  

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Outliers and uncertainties in GNSS ZTD estimates from double-difference processing and precise point positioning / Katarzyna Stępniak in GPS solutions, vol 26 n° 3 (July 2022)  

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Quantifying the influence of plot-level uncertainty in above ground biomass up scaling using remote sensing data in central Indian dry deciduous forest / Thangavelu Mayamanikandan in Geocarto international, vol 37 n° 12 ([01/07/2022])  

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