Descripteur
Documents disponibles dans cette catégorie (857)
Ajouter le résultat dans votre panier
Visionner les documents numériques
Affiner la recherche Interroger des sources externes
Etendre la recherche sur niveau(x) vers le bas
Testing deformation hypotheses by constraints on a time series of geodetic observations / Hiddo Velsink in Journal of applied geodesy, vol 12 n° 1 (January 2018)
[article]
Titre : Testing deformation hypotheses by constraints on a time series of geodetic observations Type de document : Article/Communication Auteurs : Hiddo Velsink, Auteur Année de publication : 2018 Article en page(s) : pp 77 - 94 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] compensation par moindres carrés
[Termes IGN] congruence
[Termes IGN] déformation géométrique
[Termes IGN] programmation par contraintes
[Termes IGN] série temporelleRésumé : (auteur) In geodetic deformation analysis observations are used to identify form and size changes of a geodetic network, representing objects on the earth’s surface. The network points are monitored, often continuously, because of suspected deformations. A deformation may affect many points during many epochs. The problem is that the best description of the deformation is, in general, unknown. To find it, different hypothesised deformation models have to be tested systematically for agreement with the observations. The tests have to be capable of stating with a certain probability the size of detectable deformations, and to be datum invariant. A statistical criterion is needed to find the best deformation model. Existing methods do not fulfil these requirements. Here we propose a method that formulates the different hypotheses as sets of constraints on the parameters of a least-squares adjustment model. The constraints can relate to subsets of epochs and to subsets of points, thus combining time series analysis and congruence model analysis. The constraints are formulated as nonstochastic observations in an adjustment model of observation equations. This gives an easy way to test the constraints and to get a quality description. The proposed method aims at providing a good discriminating method to find the best description of a deformation. The method is expected to improve the quality of geodetic deformation analysis. We demonstrate the method with an elaborate example. Numéro de notice : A2018-016 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1515/jag-2017-0028 En ligne : https://doi.org/10.1515/jag-2017-0028 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89095
in Journal of applied geodesy > vol 12 n° 1 (January 2018) . - pp 77 - 94[article]The UN-GGIM initiative on the Global Geodetic Reference Frame and the fundamental contribution of VLBI: strengths and weaknesses / Zuheir Altamimi (2018)
Titre : The UN-GGIM initiative on the Global Geodetic Reference Frame and the fundamental contribution of VLBI: strengths and weaknesses Type de document : Article/Communication Auteurs : Zuheir Altamimi , Auteur Editeur : Saint-Mandé : Institut national de l'information géographique et forestière - IGN (2012-) Année de publication : 2018 Conférence : IVS 2018, 10th general meeting of International VLBI Service for Geodesy and Astrometry 03/06/2018 09/06/2018 Longyearbyen Norvège Open Access Proceedings Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] International Terrestrial Reference FrameNuméro de notice : C2018-077 Affiliation des auteurs : LASTIG LAREG (2012-mi2018) Thématique : POSITIONNEMENT Nature : Communication nature-HAL : ComSansActesPubliés-Unpublished DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91474 Performance analysis of BDS/GPS precise point positioning with undifferenced ambiguity resolution / Min Wang in Advances in space research, vol 60 n° 12 (15 December 2017)
[article]
Titre : Performance analysis of BDS/GPS precise point positioning with undifferenced ambiguity resolution Type de document : Article/Communication Auteurs : Min Wang, Auteur ; Hongzhou Chai, Auteur ; Yu Li, Auteur Année de publication : 2017 Article en page(s) : pp 2581 - 2595 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] données BeiDou
[Termes IGN] données GPS
[Termes IGN] erreur systématique
[Termes IGN] méthode des moindres carrés
[Termes IGN] positionnement ponctuel précis
[Termes IGN] résolution d'ambiguïtéRésumé : (auteur) The undifferenced ambiguity resolution has been proved to be an effective method to shorten the initialization of precise point positioning (PPP) solution and improve the positioning accuracy. Several techniques were proposed for undifferenced ambiguity resolution with GPS observations. However, for BeiDou navigation satellite system (BDS), the satellite-induced variation in pseudorange observation changes the characteristics of Melbourne-Wűbbena (MW) combination observation, which leads to unacceptably low fixing rate of undifferenced ambiguity. Besides, the characteristics of satellite-induced variations in BDS observations vary with orbit type of satellite, which should be considered in correction effort. In this paper, the BDS fractional cycle biases (FCBs) are estimated with least-squares estimation method using the float undifferenced ambiguity collected from the network of reference stations. Based on the analysis of weekly stability of widelane FCBs and the distribution of fractional ambiguity parts, it is proven that the satellite-induced variation correction is necessary for the FCB estimation for IGSO and MEO satellites. Contaminated by relatively large orbit error, the ambiguities of GEO satellites should be skipped for ambiguity resolution attempt. Resolving BDS ambiguities in BDS/GPS combined PPP could significantly shorten the time needed for the first correct ambiguity resolution (FCAR). The experiment results of static PPP demonstrate that 90.6% of all sessions accomplish FCAR within 1350 s with only GPS observations. Meanwhile, by adding BDS ambiguities to the subset of ambiguity resolution, 91.9% of all sessions accomplish FCAR with only 870 s. Numéro de notice : A2017-752 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.asr.2017.01.045 En ligne : https://doi.org/10.1016/j.asr.2017.01.045 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89037
in Advances in space research > vol 60 n° 12 (15 December 2017) . - pp 2581 - 2595[article]Congruence analysis of geodetic networks, hypothesis tests versus model selection by information criteria / Rüdiger Lehmann in Journal of applied geodesy, vol 11 n° 4 (December 2017)
[article]
Titre : Congruence analysis of geodetic networks, hypothesis tests versus model selection by information criteria Type de document : Article/Communication Auteurs : Rüdiger Lehmann, Auteur ; Michael Lösler, Auteur Année de publication : 2017 Article en page(s) : pp 271 - 283 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] analyse de données
[Termes IGN] congruence
[Termes IGN] déformation géométrique
[Termes IGN] réseau géodésiqueRésumé : (Auteur) Geodetic deformation analysis can be interpreted as a model selection problem. The null model indicates that no deformation has occurred. It is opposed to a number of alternative models, which stipulate different deformation patterns. A common way to select the right model is the usage of a statistical hypothesis test. However, since we have to test a series of deformation patterns, this must be a multiple test. As an alternative solution for the test problem, we propose the p-value approach. Another approach arises from information theory. Here, the Akaike information criterion (AIC) or some alternative is used to select an appropriate model for a given set of observations. Both approaches are discussed and applied to two test scenarios: A synthetic levelling network and the Delft test data set. It is demonstrated that they work but behave differently, sometimes even producing different results. Hypothesis tests are well-established in geodesy, but may suffer from an unfavourable choice of the decision error rates. The multiple test also suffers from statistical dependencies between the test statistics, which are neglected. Both problems are overcome by applying information criterions like AIC. Numéro de notice : A2017-792 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1515/jag-2016-0049 En ligne : https://doi.org/10.1515/jag-2016-0049 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89064
in Journal of applied geodesy > vol 11 n° 4 (December 2017) . - pp 271 - 283[article]EGNOS monitoring prepared in Space Research Centre P.A.S. for SPMS project / Anna Swiatek in Artificial satellites, vol 52 n° 4 (December 2017)
[article]
Titre : EGNOS monitoring prepared in Space Research Centre P.A.S. for SPMS project Type de document : Article/Communication Auteurs : Anna Swiatek, Auteur ; Leszek Jaworski, Auteur ; Lukasz Tomasik, Auteur Année de publication : 2017 Article en page(s) : pp 109 - 120 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] European Geostationary Navigation Overlay Service
[Termes IGN] Pologne
[Termes IGN] réseau de contrôleRésumé : (auteur) The European Geostationary Overlay Service (EGNOS) augments Global Positioning System (GPS) by providing correction data and integrity information for improving positioning over Europe. EGNOS Service Performance Monitoring Support (SPMS) project has assumed establishment, maintenance and implementation of an EGNOS performance monitoring network.
The paper presents preliminary results of analyses prepared in Space Research Centre, Polish Academy of Sciences (Warsaw), as one of partners in SPMS project.Numéro de notice : A2017-857 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1515/arsa-2017-0010 Date de publication en ligne : 27/12/2017 En ligne : https://doi.org/10.1515/arsa-2017-0010 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89816
in Artificial satellites > vol 52 n° 4 (December 2017) . - pp 109 - 120[article]L'ITRF2014 et la modélisation des mouvements non linéaires des stations / Zuheir Altamimi in XYZ, n° 153 (décembre 2017 - février 2018)PermalinkAppraisal of the Hellenic Geodetic Reference System 1987 based on backward-transformed ITRF coordinates using a national velocity model / M. Chatzinikos in Survey review, vol 49 n° 356 (November 2017)PermalinkIGS polar motion measurement accuracy / Jim Ray in Geodesy and Geodynamics, vol 8 n° 6 (November 2017)PermalinkWeighted coordinate transformation formulated by standard least-squares theory / D. Mihajlovic in Survey review, vol 49 n° 356 (November 2017)PermalinkOn the determination of transformation parameters between different ITRS realizations using procrustes approach in Turkey / Mevlut Yetkin in Journal of applied geodesy, vol 11 n° 3 (September 2017)PermalinkDeformation monitoring of the submillimetric UPV calibration baseline / Luis García-Asenjo in Journal of applied geodesy, vol 11 n° 2 (June 2017)PermalinkGPS coordinate time series measurements in Ontario and Quebec, Canada / Hadis Samadi Alinia in Journal of geodesy, vol 91 n° 6 (June 2017)PermalinkUncertainty assessment in geodetic network adjustment by combining GUM and Monte-Carlo-simulations / Wolfgang Niemeier in Journal of applied geodesy, vol 11 n° 2 (June 2017)PermalinkEstimating benefits to Canada and the world : the canadian spatial reference system precise point positioning service / Calvin Klatt in Geomatica, vol 71 n° 1 (March 2017)PermalinkA survey of surveys : the canadian spatial reference system precise point positioning service / Calvin Klatt in Geomatica, vol 71 n° 1 (March 2017)Permalink