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IGS polar motion measurement accuracy / Jim Ray in Geodesy and Geodynamics, vol 8 n° 6 (November 2017)
[article]
Titre : IGS polar motion measurement accuracy Type de document : Article/Communication Auteurs : Jim Ray, Auteur ; Paul Rebischung , Auteur ; Jake Griffiths, Auteur Année de publication : 2017 Projets : 1-Pas de projet / Article en page(s) : pp 413 - 420 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] données GPS
[Termes IGN] erreur systématique
[Termes IGN] International GNSS Service
[Termes IGN] mouvement du pôle
[Termes IGN] orientation de la Terre
[Termes IGN] paramètres d'orientation de la Terre
[Termes IGN] précision du positionnementRésumé : (auteur) We elaborate an error budget for the long-term accuracy of IGS (International Global Navigation Satellite System Service) polar motion estimates, concluding that it is probably about 25–30 μas (1-sigma) overall, although it is not possible to quantify possible contributions (mainly annual) that might transfer directly from aliases of subdaily rotational tide errors. The leading sources are biases arising from the need to align daily, observed terrestrial frames, within which the pole coordinates are expressed and which are continuously deforming, to the secular, linear international reference frame. Such biases are largest over spans longer than about a year. Thanks to the very large number of IGS tracking stations, the formal covariance errors are much smaller, around 5 to 10 μas. Large networks also permit the systematic frame-related errors to be more effectively minimized but not eliminated. A number of periodic errors probably also influence polar motion results, mainly at annual, GPS (Global Positioning System) draconitic, and fortnightly periods, but their impact on the overall error budget is unlikely to be significant except possibly for annual tidal aliases. Nevertheless, caution should be exercised in interpreting geophysical excitations near any of the suspect periods. Numéro de notice : A2017-253 Affiliation des auteurs : LASTIG LAREG+Ext (2012-mi2018) Thématique : MATHEMATIQUE/POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.geog.2017.01.008 Date de publication en ligne : 02/03/2017 En ligne : https://doi.org/10.1016/j.geog.2017.01.008 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=85261
in Geodesy and Geodynamics > vol 8 n° 6 (November 2017) . - pp 413 - 420[article]Documents numériques
en open access
IGS polar motion measurement accuracy - pdf éditeurAdobe Acrobat PDF On the equivalence of spherical splines with least-squares collocation and Stokes’s formula for regional geoid computation / Vegard Ophaug in Journal of geodesy, vol 91 n° 11 (November 2017)
[article]
Titre : On the equivalence of spherical splines with least-squares collocation and Stokes’s formula for regional geoid computation Type de document : Article/Communication Auteurs : Vegard Ophaug, Auteur ; Christian Gerlach, Auteur Année de publication : 2017 Article en page(s) : pp 1367 - 1382 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] analyse comparative
[Termes IGN] collocation par moindres carrés
[Termes IGN] fonction de base radiale
[Termes IGN] fonction spline
[Termes IGN] formule de Stokes
[Termes IGN] géoïde local
[Termes IGN] précision millimétriqueRésumé : (Auteur) This work is an investigation of three methods for regional geoid computation: Stokes’s formula, least-squares collocation (LSC), and spherical radial base functions (RBFs) using the spline kernel (SK). It is a first attempt to compare the three methods theoretically and numerically in a unified framework. While Stokes integration and LSC may be regarded as classic methods for regional geoid computation, RBFs may still be regarded as a modern approach. All methods are theoretically equal when applied globally, and we therefore expect them to give comparable results in regional applications. However, it has been shown by de Min (Bull Géod 69:223–232, 1995. doi:10.1007/BF00806734) that the equivalence of Stokes’s formula and LSC does not hold in regional applications without modifying the cross-covariance function. In order to make all methods comparable in regional applications, the corresponding modification has been introduced also in the SK. Ultimately, we present numerical examples comparing Stokes’s formula, LSC, and SKs in a closed-loop environment using synthetic noise-free data, to verify their equivalence. All agree on the millimeter level. Numéro de notice : A2017-707 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-017-1030-1 En ligne : https://doi.org/10.1007/s00190-017-1030-1 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=88088
in Journal of geodesy > vol 91 n° 11 (November 2017) . - pp 1367 - 1382[article]Precise orbit determination of the Fengyun-3C satellite using onboard GPS and BDS observations / Min Li in Journal of geodesy, vol 91 n° 11 (November 2017)
[article]
Titre : Precise orbit determination of the Fengyun-3C satellite using onboard GPS and BDS observations Type de document : Article/Communication Auteurs : Min Li, Auteur ; Wenwen Li, Auteur ; Chuang Shi, Auteur ; et al., Auteur Année de publication : 2017 Article en page(s) : pp 1313 - 1327 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Techniques orbitales
[Termes IGN] analyse comparative
[Termes IGN] correction du trajet multiple
[Termes IGN] Feng-Yun-3
[Termes IGN] orbite géostationnaire
[Termes IGN] orbitographie
[Termes IGN] orbitographie par GNSS
[Termes IGN] positionnement par BeiDou
[Termes IGN] positionnement par GPS
[Termes IGN] précision du positionnement
[Termes IGN] satellite météorologiqueRésumé : (Auteur) The GNSS Occultation Sounder instrument onboard the Chinese meteorological satellite Fengyun-3C (FY-3C) tracks both GPS and BDS signals for orbit determination. One month’s worth of the onboard dual-frequency GPS and BDS data during March 2015 from the FY-3C satellite is analyzed in this study. The onboard BDS and GPS measurement quality is evaluated in terms of data quantity as well as code multipath error. Severe multipath errors for BDS code ranges are observed especially for high elevations for BDS medium earth orbit satellites (MEOs). The code multipath errors are estimated as piecewise linear model in 2∘×2∘ grid and applied in precise orbit determination (POD) calculations. POD of FY-3C is firstly performed with GPS data, which shows orbit consistency of approximate 2.7 cm in 3D RMS (root mean square) by overlap comparisons; the estimated orbits are then used as reference orbits for evaluating the orbit precision of GPS and BDS combined POD as well as BDS-based POD. It is indicated that inclusion of BDS geosynchronous orbit satellites (GEOs) could degrade POD precision seriously. The precisions of orbit estimates by combined POD and BDS-based POD are 3.4 and 30.1 cm in 3D RMS when GEOs are involved, respectively. However, if BDS GEOs are excluded, the combined POD can reach similar precision with respect to GPS POD, showing orbit differences about 0.8 cm, while the orbit precision of BDS-based POD can be improved to 8.4 cm. These results indicate that the POD performance with onboard BDS data alone can reach precision better than 10 cm with only five BDS inclined geosynchronous satellite orbit satellites and three MEOs. As the GNOS receiver can only track six BDS satellites for orbit positioning at its maximum channel, it can be expected that the performance of POD with onboard BDS data can be further improved if more observations are generated without such restrictions. Numéro de notice : A2017-705 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-017-1027-9 En ligne : https://doi.org/10.1007/s00190-017-1027-9 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=88086
in Journal of geodesy > vol 91 n° 11 (November 2017) . - pp 1313 - 1327[article]Application of the undifferenced GNSS precise positioning in determining coordinates in national reference frames / Grzegorz Krzan in Artificial satellites, vol 52 n° 3 (September 2017)
[article]
Titre : Application of the undifferenced GNSS precise positioning in determining coordinates in national reference frames Type de document : Article/Communication Auteurs : Grzegorz Krzan, Auteur ; Katarzyna Stępniak, Auteur Année de publication : 2017 Article en page(s) : pp 49 - 69 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement
[Termes IGN] coordonnées géodésiques
[Termes IGN] Napeos
[Termes IGN] positionnement par GNSS
[Termes IGN] positionnement ponctuel précis
[Termes IGN] précision centimétrique
[Termes IGN] récepteur bifréquence
[Termes IGN] récepteur GPS
[Termes IGN] réseau permanent EUREF
[Termes IGN] système de référence géodésique
[Termes IGN] système de référence localRésumé : (Auteur) In high-accuracy positioning using GNSS, the most common solution is still relative positioning using double-difference observations of dual-frequency measurements. An increasingly popular alternative to relative positioning are undifferenced approaches, which are designed to make full use of modern satellite systems and signals. Positions referenced to global International Terrestrial Reference Frame (ITRF2008) obtained from Precise Point Positioning (PPP) or Undifferenced (UD) network solutions have to be transformed to national (regional) reference frame, which introduces additional bases related to the transformation process. In this paper, satellite observations from two test networks using different observation time series were processed. The first test concerns the positioning accuracy from processing one year of dual-frequency GPS observations from 14 EUREF Permanent Network (EPN) stations using NAPEOS 3.3.1 software. The results were transformed into a national reference frame (PL-ETRF2000) and compared to positions from an EPN cumulative solution, which was adopted as the true coordinates. Daily observations were processed using PPP and UD multi-station solutions to determine the final accuracy resulting from satellite positioning, the transformation to national coordinate systems and Eurasian intraplate plate velocities. The second numerical test involved similar processing strategies of post-processing carried out using different observation time series (30 min., 1 hour, 2 hours, daily) and different classes of GNSS receivers. The centimeter accuracy of results presented in the national coordinate system satisfies the requirements of many surveying and engineering applications. Numéro de notice : A2017-594 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1515/arsa-2017-0006 En ligne : https://doi.org/10.1515/arsa-2017-0006 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=86802
in Artificial satellites > vol 52 n° 3 (September 2017) . - pp 49 - 69[article]Documentation of heritage buildings using close-range UAV images: dense matching issues, comparison and case studies / Arnadi Murtiyoso in Photogrammetric record, vol 32 n° 159 (September 2017)
[article]
Titre : Documentation of heritage buildings using close-range UAV images: dense matching issues, comparison and case studies Type de document : Article/Communication Auteurs : Arnadi Murtiyoso, Auteur ; Pierre Grussenmeyer, Auteur Année de publication : 2017 Article en page(s) : pp 206 - 229 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications photogrammétriques
[Termes IGN] analyse comparative
[Termes IGN] appariement dense
[Termes IGN] capteur aérien
[Termes IGN] drone
[Termes IGN] image aérienne
[Termes IGN] patrimoine immobilier
[Termes IGN] photogrammétrie métrologique
[Termes IGN] précision centimétrique
[Termes IGN] reconstruction 3D du bâti
[Termes IGN] structure-from-motionRésumé : (Auteur) Three-dimensional (3D) documentation of heritage buildings has long employed both image-based and range-based techniques. Unmanned aerial vehicles (UAVs) provide a particular advantage for image-based techniques in acquiring aerial views, which are difficult to attain using classical terrestrial-based methods. The technological development of optical sensors and dense matching algorithms also complement existing photogrammetric workflows for the documentation of heritage objects. In this paper, fundamental concepts in photogrammetry and 3D reconstruction based on structure from motion (SfM) will be briefly reviewed. Two case studies were performed using two types of UAVs, one being a state-of-the-art platform dedicated to obtaining close-range images. Comparisons with laser scanning data were performed and several issues regarding the aerial triangulation and dense matching results were assessed. The results show that although the dense matching of these UAV images may generate centimetre-level precision, a further increase in precision is often hampered by the quality of the onboard sensor. Numéro de notice : A2017-576 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1111/phor.12197 En ligne : http://dx.doi.org/10.1111/phor.12197 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=86712
in Photogrammetric record > vol 32 n° 159 (September 2017) . - pp 206 - 229[article]ERTK: extra-wide-lane RTK of triple-frequency GNSS signals / Bofeng Li in Journal of geodesy, vol 91 n° 9 (September 2017)PermalinkImproving BeiDou real-time precise point positioning with numerical weather models / Cuixian Lu in Journal of geodesy, vol 91 n° 9 (September 2017)PermalinkMaintaining real-time precise point positioning during outages of orbit and clock corrections / Ahmed El-Mowafy in GPS solutions, vol 21 n° 3 (July 2017)PermalinkNe plus négliger le recul des falaises méditerranéennes / Marielle Mayo in Géomètre, n° 2149 (juillet - août 2017)PermalinkReview of code and phase biases in multi-GNSS positioning / Martin Håkansson in GPS solutions, vol 21 n° 3 (July 2017)PermalinkPermalinkLes géomètres du CERN et les faisceaux de particules / Dominique Missiaen in Géomètre, n° 2148 (juin 2017)PermalinkGNSS antenna caused near-field interference effect in Precise Point Positioning results / Karol Dawidowicz in Artificial satellites, vol 52 n° 2 (June 2017)PermalinkEvaluation of the range accuracy and the radiometric calibration of multiple terrestrial laser scanning instruments for data interoperability / Kim Calders in IEEE Transactions on geoscience and remote sensing, vol 55 n° 5 (May 2017)PermalinkGalileo face à une panne d'horloge / Anonyme in Géomètre, n° 2147 (mai 2017)PermalinkControl quality of open source Digital Elevation Models (DEMs) in Tunisia / Noamen Rebaï in Revue internationale de géomatique, vol 27 n° 2 (avril - juin 2017)PermalinkPrecision on board : orbit determination of LEO satellites with real-time corrections / André Hauschild in GPS world, vol 28 n° 4 (April 2017)PermalinkLa BD Topage prend source / Marielle Mayo in Géomètre, n° 2145 (mars 2017)PermalinkBias compensation for rational function model based on total least squares / Anzhu Yu in Photogrammetric record, vol 32 n° 157 (March - May 2017)PermalinkCalcul du quasi-géoïde QGF16 et de la grille de conversion altimétrique RAF16 : état d'avancement et perspectives / François L'écu in XYZ, n° 150 (mars - mai 2017)PermalinkPermalinkPermalinkIndustrialisation des processus d'extraction d'objets à partir de données photogrammétriques par drones / Jérémie Brossard in XYZ, n° 150 (mars - mai 2017)PermalinkPerformance analysis of precise point positioning using multi-constellation GNSS : GPS, GLONASS, Galileo and BeiDou / Mahmoud Abd Rabbou in Survey review, vol 49 n° 352 (March 2017)PermalinkReference satellite selection method for GNSS high-precision relative positioning / Xiao Gao in Geodesy and Geodynamics, vol 8 n° 2 (March 2017)Permalink