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Study on GPS–PPP precision for short observation sessions / Stefano Gandolfi in GPS solutions, vol 21 n° 3 (July 2017)
[article]
Titre : Study on GPS–PPP precision for short observation sessions Type de document : Article/Communication Auteurs : Stefano Gandolfi, Auteur ; Luca Tavasci, Auteur ; Luca Poluzzi, Auteur Année de publication : 2017 Article en page(s) : pp 887 – 896 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement
[Termes IGN] coordonnées géodésiques
[Termes IGN] Europe (géographie politique)
[Termes IGN] GIPSY-OASIS
[Termes IGN] positionnement ponctuel précis
[Termes IGN] positionnement statique
[Termes IGN] résolution d'ambiguïté
[Termes IGN] station GNSSRésumé : (auteur) Precise point positioning is increasingly being used in geodetic applications that in many cases are based on static 24-hour RINEX files. Since there are many applications where sub-centimeter position accuracy is not required and users wish to use a single receiver and not be dependent on differential correction, we will evaluate PPP performance for static positioning with 12-, 6-, 3-, 1- and ½-h observations. We have, therefore, considered a dataset for the year 2013 from 14 European GNSS stations. The data were analyzed using GIPSY-OASIS II software package and evaluated in terms of repeatability of the coordinates and of coherence with the formal error indicated for each PPP solution. Particular attention was paid to solutions showing large discrepancies in coordinates. The test shows that PPP precision for the 24-h files is below 5 mm, but decreases slightly for the 12-, 6- and 3-h observation sets. For the 1-h and the ½-h RINEX files, precision is within 5 and 10 cm, respectively. The analysis is completed with a discussion on the impact of the ambiguity resolution that shows how it significantly improves only the easting component and moreover has a higher influence on the formal error rather than on the solutions. Lastly, the study contains an investigation into the reliability of the formal error associated with the PPP solutions. We show that the formal error can be used to identify incorrect solutions, but is not suitable to represent the real accuracy. For that reason, we propose to use the formal error given for the float solutions even for the ones with fixed ambiguities. Numéro de notice : A2017-440 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1007/s10291-016-0575-4 En ligne : https://doi.org/10.1007/s10291-016-0575-4 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=86356
in GPS solutions > vol 21 n° 3 (July 2017) . - pp 887 – 896[article]Performance evaluation of GNSS-TEC estimation techniques at the grid point in middle and low latitudes during different geomagnetic conditions / O. E. Abe in Journal of geodesy, vol 91 n° 4 (April 2017)
[article]
Titre : Performance evaluation of GNSS-TEC estimation techniques at the grid point in middle and low latitudes during different geomagnetic conditions Type de document : Article/Communication Auteurs : O. E. Abe, Auteur ; X. Otero Villamide, Auteur ; C. Paparini, Auteur ; et al., Auteur Année de publication : 2017 Article en page(s) : pp 409 - 417 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] champ géomagnétique
[Termes IGN] erreur systématique
[Termes IGN] Espagne
[Termes IGN] estimation statistique
[Termes IGN] étalonnage
[Termes IGN] évaluation
[Termes IGN] Ghana
[Termes IGN] latitude
[Termes IGN] performance
[Termes IGN] signal GNSS
[Termes IGN] teneur totale en électrons
[Termes IGN] traitement du signalRésumé : (auteur) Global Navigation Satellite Systems (GNSS) have become a powerful tool use in surveying and mapping, air and maritime navigation, ionospheric/space weather research and other applications. However, in some cases, its maximum efficiency could not be attained due to some uncorrelated errors associated with the system measurements, which is caused mainly by the dispersive nature of the ionosphere. Ionosphere has been represented using the total number of electrons along the signal path at a particular height known as Total Electron Content (TEC). However, there are many methods to estimate TEC but the outputs are not uniform, which could be due to the peculiarity in characterizing the biases inside the observables (measurements), and sometimes could be associated to the influence of mapping function. The errors in TEC estimation could lead to wrong conclusion and this could be more critical in case of safety-of-life application. This work investigated the performance of Ciraolo’s and Gopi’s GNSS-TEC calibration techniques, during 5 geomagnetic quiet and disturbed conditions in the month of October 2013, at the grid points located in low and middle latitudes. The data used are obtained from the GNSS ground-based receivers located at Borriana in Spain (40∘N, 0∘E; mid latitude) and Accra in Ghana (5.50∘N, −0.20∘E; low latitude). The results of the calibrated TEC are compared with the TEC obtained from European Geostationary Navigation Overlay System Processing Set (EGNOS PS) TEC algorithm, which is considered as a reference data. The TEC derived from Global Ionospheric Maps (GIM) through International GNSS service (IGS) was also examined at the same grid points. The results obtained in this work showed that Ciraolo’s calibration technique (a calibration technique based on carrier-phase measurements only) estimates TEC better at middle latitude in comparison to Gopi’s technique (a calibration technique based on code and carrier-phase measurements). At the same time, Gopi’s calibration was also found more reliable in low latitude than Ciraolo’s technique. In addition, the TEC derived from IGS GIM seems to be much reliable in middle-latitude than in low-latitude region. Numéro de notice : A2017-107 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-016-0972-z En ligne : http://dx.doi.org/10.1007/s00190-016-0972-z Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=84497
in Journal of geodesy > vol 91 n° 4 (April 2017) . - pp 409 - 417[article]Absolute orientation based on line coordinates / Qing H. Sheng in Photogrammetric record, vol 32 n° 157 (March - May 2017)
[article]
Titre : Absolute orientation based on line coordinates Type de document : Article/Communication Auteurs : Qing H. Sheng, Auteur ; Bing Zhang, Auteur Année de publication : 2017 Article en page(s) : pp 12 - 32 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Photogrammétrie numérique
[Termes IGN] contour
[Termes IGN] coordonnées géographiques
[Termes IGN] espace image
[Termes IGN] espace objet
[Termes IGN] géoréférencement direct
[Termes IGN] orientation absolue
[Termes IGN] point d'appui
[Termes IGN] segment de droite
[Termes IGN] système de coordonnéesRésumé : (auteur) Absolute orientation based on points is a common method of precise georeferencing in photogrammetry. In images of urban areas, straight-line features such as buildings are prominent. A new absolute orientation approach dependent on line coordinates is proposed in this paper. An arbitrary spatial line can be described by its orientation vector and moment vector. Using the helical scaling displacement operator, the transformation of straight lines in model space and their corresponding control straight lines in object space can be achieved. Experimental results show that with eight control straight lines, the proposed approach is comparable to the precision of absolute orientation using four control points. Furthermore, the endpoints of corresponding line segments in the two spaces are not required to be conjugate points. Numéro de notice : A2017-195 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1111/phor.12178 En ligne : http://dx.doi.org/10.1111/phor.12178 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=84869
in Photogrammetric record > vol 32 n° 157 (March - May 2017) . - pp 12 - 32[article]Attribute profiles on derived features for urban land cover classification / Bharath Bhushan Damodaran in Photogrammetric Engineering & Remote Sensing, PERS, vol 83 n° 3 (March 2017)
[article]
Titre : Attribute profiles on derived features for urban land cover classification Type de document : Article/Communication Auteurs : Bharath Bhushan Damodaran, Auteur ; Joachim Höhle, Auteur ; Sébastien Lefèvre, Auteur Année de publication : 2017 Article en page(s) : pp 183 - 193 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] attribut
[Termes IGN] classification dirigée
[Termes IGN] données auxiliaires
[Termes IGN] hauteur ellipsoïdale
[Termes IGN] image aérienne
[Termes IGN] image multibande
[Termes IGN] indice de végétation
[Termes IGN] occupation du sol
[Termes IGN] précision de la classification
[Termes IGN] zone urbaineRésumé : (Auteur) This research deals with the automatic generation of 2D land cover maps of urban areas using very high resolution multispectral aerial imagery. The appropriate selection of classifier and attributes is important to achieve high thematic accuracies. In this paper, new attributes are generated to increase the discriminative power of auxiliary information provided by remote sensing images. The generated attributes are derived from the vegetation index and elevation information using morphological attribute profiles. The extended experimental evaluation and comparison of attribute profile-based mapping solutions is conducted to derive the optimal combinations of attributes required for classification and to understand the genericity of attributes on a range of classifiers, i.e., various combinations of attributes and classifiers. Experimental results with two high resolution images show that the proposed attributes derived on auxiliary information outperform the existing attribute profiles computed on original image and its principal components. Numéro de notice : A2017-087 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.14358/PERS.83.3.183 En ligne : https://doi.org/10.14358/PERS.83.3.183 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=84422
in Photogrammetric Engineering & Remote Sensing, PERS > vol 83 n° 3 (March 2017) . - pp 183 - 193[article]Geodesic equations and their numerical solutions in geodetic and cartesian coordinates on an oblate spheroid / Georgios Panou in Journal of geodetic science, vol 7 n° 1 (February 2017)
[article]
Titre : Geodesic equations and their numerical solutions in geodetic and cartesian coordinates on an oblate spheroid Type de document : Article/Communication Auteurs : Georgios Panou, Auteur ; Romylos Korakitis, Auteur Année de publication : 2017 Article en page(s) : pp 31 - 42 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] coordonnées cartésiennes
[Termes IGN] coordonnées géodésiques
[Termes IGN] géométrie différentielle
[Termes IGN] problème des valeurs limites
[Termes IGN] sphèroïde
[Termes IGN] système de coordonnéesRésumé : (Auteur) The direct geodesic problem on an oblate spheroid is described as an initial value problem and is solved numerically using both geodetic and Cartesian coordinates. The geodesic equations are formulated by means of the theory of differential geometry. The initial value problem under consideration is reduced to a system of first-order ordinary differential equations, which is solved using a numerical method. The solution provides the coordinates and the azimuths at any point along the geodesic. The Clairaut constant is not used for the solution but it is computed, allowing to check the precision of the method. An extensive data set of geodesics is used, in order to evaluate the performance of the method in each coordinate system. The results for the direct geodesic problem are validated by comparison to Karney’s method. We conclude that a complete, stable, precise, accurate and fast solution of the problem in Cartesian coordinates is accomplished. Numéro de notice : A2017-300 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1515/jogs-2017-0004 En ligne : https://doi.org/10.1515/jogs-2017-0004 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=85335
in Journal of geodetic science > vol 7 n° 1 (February 2017) . - pp 31 - 42[article]Determination of a terrestrial reference frame via Kalman filtering of very long baseline interferometry data / Benedikt Soja in Journal of geodesy, vol 90 n° 12 (December 2016)PermalinkPermalinkTechnical considerations for modernizing Nova Scotia’s Coordinate Referencing System / Jason Bond in Geomatica, vol 70 n° 2 (June 2016)PermalinkTransformation des coordonnées relevées sur la carte topographique ancienne en coordonnées géodésiques RGC11 au Cameroun / Joseph Kamguia in XYZ, n° 147 (juin - août 2016)PermalinkEffect of sensor modelling methods on computation of 3-D coordinates from Cartosat-1 stereo data / Mritunjay Kumar Singh in Geocarto international, vol 31 n° 5 - 6 (May - June 2016)PermalinkEvaluating the use of GPS heights in water conservation applications / Ahmed F. Elaksher in Survey review, vol 48 n° 348 (May 2016)PermalinkPotential of GPS common clock single-differences for deformation monitoring / Steffen Schön in Journal of applied geodesy, vol 10 n° 1 (March 2016)PermalinkAutomatic geolocation correction of satellite imagery / Ozge C. Ozcanli in International journal of computer vision, vol 116 n° 3 (February 2016)PermalinkQuality evaluation of the weekly vertical loading effects induced from continental water storage models / Z. Li (2016)PermalinkMulti-GNSS as a combination of GPS, GLONASS and Beidou measurements carried out in real time / Zbigniew Siejka in Artificial satellites, vol 50 n° 4 (December 2015)Permalink