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Improved ambiguity resolution for URTK with dynamic atmosphere constraints / Weiming Tang in Journal of geodesy, vol 90 n° 12 (December 2016)
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Titre : Improved ambiguity resolution for URTK with dynamic atmosphere constraints Type de document : Article/Communication Auteurs : Weiming Tang, Auteur ; Wenjian Liu, Auteur ; Xuan Zou, Auteur ; et al., Auteur Année de publication : 2016 Article en page(s) : pp 1359 - 1369 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement
[Termes IGN] correction ionosphérique
[Termes IGN] effet atmosphérique
[Termes IGN] positionnement cinématique en temps réel
[Termes IGN] précision du positionnement
[Termes IGN] résidu
[Termes IGN] résolution d'ambiguïtéRésumé : (Auteur) Raw observation processing method with prior knowledge of ionospheric delay could strengthen the ambiguity resolution (AR), but it does not make full use of the relatively longer wavelength of wide-lane (WL) observation. Furthermore, the accuracy of calculated atmospheric delays from the regional augmentation information has quite different in quality, while the atmospheric constraint used in the current methods is usually set to an empirical value. A proper constraint, which matches the accuracy of calculated atmospheric delays, can most effectively compensate the residual systematic biases caused by large inter-station distances. Therefore, the standard deviation of the residual atmospheric parameters should be fine-tuned. This paper presents an atmosphere-constrained AR method for undifferenced network RTK (URTK) rover, whose ambiguities are sequentially fixed according to their wavelengths. Furthermore, this research systematically analyzes the residual atmospheric error and finds that it mainly varies along the positional relationship between the rover and the chosen reference stations. More importantly, its ionospheric part of certain location will also be cyclically influenced every day. Therefore, the standard deviation of residual ionospheric error can be modeled by a daily repeated cosine or other functions with the help of data one day before, and applied by rovers as pseudo-observation. With the data collected at 29 stations from a continuously operating reference station network in Guangdong Province (GDCORS) in China, the efficiency of the proposed approach is confirmed by improving the success and error rates of AR for 10-20 % compared to that of the WL-L1-IF one, as well as making much better positioning accuracy. Numéro de notice : A2016-807 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-016-0928-3 En ligne : http://dx.doi.org/10.1007/s00190-016-0928-3 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=82595
in Journal of geodesy > vol 90 n° 12 (December 2016) . - pp 1359 - 1369[article]Mobilités et numérique sous l'oeil des chercheurs / Françoise de Blomac in DécryptaGéo le mag, n° 182 (décembre 2016)
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Titre : Mobilités et numérique sous l'oeil des chercheurs Type de document : Article/Communication Auteurs : Françoise de Blomac, Auteur Année de publication : 2016 Article en page(s) : pp 14 - 15 Langues : Français (fre) Descripteur : [Vedettes matières IGN] Géomatique web
[Termes IGN] géolocalisation
[Termes IGN] internet
[Termes IGN] mobilité humaine
[Termes IGN] sociologie
[Termes IGN] téléphone intelligentRésumé : (auteur) Le groupe "Mobilités spatiales fluidité sociale" (MEUFS) rassemble de nombreux chercheurs en sciences sociales. Son dernier colloque, Mobilités et (r)évolutions numériques, montre que les technologies numériques aident à comprendre les mobilités tout en les transformant. Numéro de notice : A2016-957 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83505
in DécryptaGéo le mag > n° 182 (décembre 2016) . - pp 14 - 15[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 286-2016101 RAB Revue Centre de documentation En réserve L003 Disponible Plot location errors of National Forest Inventory: related factors and adverse effects on continuity of plot data / Haruki Nakajima in Journal of Forest Research, vol 21 n° 6 (December 2016)
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Titre : Plot location errors of National Forest Inventory: related factors and adverse effects on continuity of plot data Type de document : Article/Communication Auteurs : Haruki Nakajima, Auteur Année de publication : 2016 Article en page(s) : pp 300 - 305 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] disponibilité des données
[Termes IGN] erreur de positionnement
[Termes IGN] inventaire forestier étranger (données)
[Termes IGN] Japon
[Termes IGN] placette d'échantillonnage
[Termes IGN] positionnement par GPS
[Vedettes matières IGN] Inventaire forestierRésumé : (auteur) Plot location errors (distance between recorded and true coordinates) of National Forest Inventory (NFI) cause a mismatch between plot data and remotely sensed data and might prevent re-measurement because plots with large location errors are hard to find. However, few studies have examined the detailed distribution of errors and related factors, and no studies have verified whether the large errors prevent re-measurement. This study analyzed data related to 101 plots in central Japan that had been established by the First NFI (1999–2003) on a 4-km grid. Plot location errors of these plots were measured by revisiting. Selective Availability (SA) of the Global Positioning System, which degraded location accuracy until May 2000, was the most important factor in increasing plot location errors. The mean errors were 58.6 and 15.0 m, with and without SA, respectively. In 12 plots with large plot location errors (the mean error was 84.6 m), re-measurement in the Second NFI (2004–2008) was not conducted because plot locations could not be found. In these situations, alternative new plots were established; however, their species compositions were significantly different from the initial NFI plots. Plot location errors of NFI adversely affect the continuity of plot data as well as the analysis with remotely sensed data. Numéro de notice : A2016--074 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1007/s10310-016-0538-1 Date de publication en ligne : 18/08/2016 En ligne : https://doi.org/10.1007/s10310-016-0538-1 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=84444
in Journal of Forest Research > vol 21 n° 6 (December 2016) . - pp 300 - 305[article]Precise point positioning model using triple GNSS constellations: GPS, Galileo and BeiDou / Akram Afifi in Journal of applied geodesy, vol 10 n° 4 (December 2016)
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Titre : Precise point positioning model using triple GNSS constellations: GPS, Galileo and BeiDou Type de document : Article/Communication Auteurs : Akram Afifi, Auteur ; Ahmed El-Rabbany, Auteur Année de publication : 2016 Article en page(s) : pp 223 – 232 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] erreur de positionnement
[Termes IGN] erreur systématique
[Termes IGN] milieu urbain
[Termes IGN] modèle mathématique
[Termes IGN] positionnement par BeiDou
[Termes IGN] positionnement par Galileo
[Termes IGN] positionnement par GNSS
[Termes IGN] positionnement par GPS
[Termes IGN] positionnement ponctuel précis
[Termes IGN] récepteur bifréquence
[Termes IGN] temps réelRésumé : (auteur) This paper introduces a comparison between dual-frequency precise point positioning (PPP) post-processing model, which combines the observations of three different GNSS constellations, namely GPS, Galileo, and BeiDou and real-time PPP model. A drawback of a single GNSS system such as GPS, however, is the availability of sufficient number of visible satellites in urban areas. Combining GNSS observations offers more visible satellites to users, which in turn is expected to enhance the satellite geometry and the overall positioning solution. However, combining several GNSS observables introduces additional biases, which require rigorous modelling, including the GNSS time offsets and hardware delays. In this paper, a GNSS post-processing PPPP model is developed using ionosphere-free linear combination. The additional biases of the GPS, Galileo, and BeiDou combination are accounted for through the introduction of a new unknown parameter, which is identified as the inter-system bias, in the PPP mathematical model. Natural Resources Canada’s GPSPace PPP software is modified to enable a combined GPS / Galileo / BeiDou PPP solution and to handle the newly inter-system bias. A total of four data sets at four IGS stations are processed to verify the developed PPP model. Precise satellite orbit and clock products from the IGS-MGEX network are used to correct of the GPS, Galileo and BeiDou measurements. For the real-time PPP model the corrections of the satellites orbit and clock are obtained through the international GNSS service (IGS) real-time service (RTS). GPS and Galileo Observations are used for the GNSS RTS-IGS PPP model as the RTS-IGS satellite products are not available for BeiDou satellites. This paper provides the GNSS RTS-IGS PPP model using different satellite clock corrections namely: IGS01, IGC01, IGS01, and IGS03. All PPP models results of convergence time and positioning precision are compared to the traditional GPS-only PPP model. It is shown that combining GPS, Galileo, and BeiDou observations in a PPP model reduces the convergence time by 25 % compared with the GPS-only PPP model. Numéro de notice : A2016-974 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1515/jag-2016-0010 En ligne : https://doi.org/10.1515/jag-2016-0010 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83681
in Journal of applied geodesy > vol 10 n° 4 (December 2016) . - pp 223 – 232[article]Redistribution population data across a regular spatial grid according to buildings characteristics / Beata Calka in Geodesy and cartography, vol 65 n° 2 (December 2016)
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Titre : Redistribution population data across a regular spatial grid according to buildings characteristics Type de document : Article/Communication Auteurs : Beata Calka, Auteur ; Elzbieta Bielecka, Auteur ; Katarzyna Zdunkiewicz, Auteur Année de publication : 2016 Article en page(s) : pp 149 - 162 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications SIG
[Termes IGN] base de données topographiques
[Termes IGN] bati
[Termes IGN] données démographiques
[Termes IGN] géolocalisation
[Termes IGN] habitat (urbanisme)
[Termes IGN] maille carrée
[Termes IGN] Pologne
[Termes IGN] répartition géographiqueRésumé : (auteur) Population data are generally provided by state census organisations at the predefined census enumeration units. However, these datasets very are often required at userdefined spatial units that differ from the census output levels. A number of population estimation techniques have been developed to address these problems. This article is one of those attempts aimed at improving county level population estimates by using spatial disaggregation models with support of buildings characteristic, derived from national topographic database, and average area of a flat. The experimental gridded population surface was created for Opatów county, sparsely populated rural region located in Central Poland. The method relies on geolocation of population counts in buildings, taking into account the building volume and structural building type and then aggregation the people total in 1 km quadrilateral grid. The overall quality of population distribution surface expressed by the mean of RMSE equals 9 persons, and the MAE equals 0.01. We also discovered that nearly 20% of total county area is unpopulated and 80% of people lived on 33% of the county territory. Numéro de notice : A2016-978 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1515/geocart-2016-0011 En ligne : https://doi.org/10.1515/geocart-2016-0011 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83695
in Geodesy and cartography > vol 65 n° 2 (December 2016) . - pp 149 - 162[article]An approach for estimating time-variable rates from geodetic time series / Olga Didova in Journal of geodesy, vol 90 n° 11 (November 2016)
PermalinkBounding the integer bootstrapped GNSS baseline’s tail probability in the presence of stochastic uncertainty / Steven E. Langel in Journal of geodesy, vol 90 n° 11 (November 2016)
PermalinkInterference localization from space: theoretical background / Luca Canzian in Inside GNSS, vol 11 n° 6 (November - December 2016)
PermalinkLocalization of a mobile laser scanner via dimensional reduction / Ville V. Lehtola, in ISPRS Journal of photogrammetry and remote sensing, vol 121 (November 2016)
PermalinkModeling and assessment of triple-frequency BDS precise point positioning / Fei Guo in Journal of geodesy, vol 90 n° 11 (November 2016)
PermalinkA phase-altimetric simulator : studying the sensitivity of Earth-reflected GNSS signals to ocean topography / Aaron Maximilian Semmling in IEEE Transactions on geoscience and remote sensing, vol 54 n° 11 (November 2016)
PermalinkPrecision GNSS for everyone: Precise positioning using raw GPS measurements from android smartphones / Simon Banville in GPS world, Vol 27 n° 11 (November 2016)
PermalinkRelevé topographique des environnements urbains [article originellement paru dans le numéro mai/juin 2016 de la revue italienne GEOMedia] / Luigi Colombo in Géomatique expert, n° 113 (novembre - décembre 2016)
PermalinkSingle-frequency, dual-GNSS versus dual-frequency, single-GNSS: a low-cost and high-grade receivers GPS-BDS RTK analysis / Robert Odolinski in Journal of geodesy, vol 90 n° 11 (November 2016)
PermalinkThe future is already here / Sampo Savolainen in GEO: Geoconnexion international, vol 15 n° 10 (November - December 2016)
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