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Geodesic equations and their numerical solution in Cartesian coordinates on a triaxial ellipsoid / Georgios Panou in Journal of geodetic science, vol 9 n° 1 (January 2019)
[article]
Titre : Geodesic equations and their numerical solution in Cartesian coordinates on a triaxial ellipsoid Type de document : Article/Communication Auteurs : Georgios Panou, Auteur ; Romylos Korakitis, Auteur Année de publication : 2019 Article en page(s) : pp 1 - 12 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie
[Termes IGN] constante
[Termes IGN] coordonnées cartésiennes géocentriques
[Termes IGN] coordonnées ellipsoïdales
[Termes IGN] problème des valeurs limites
[Termes IGN] transformation de coordonnéesRésumé : (auteur) In this work, the geodesic equations and their numerical solution in Cartesian coordinates on an oblate spheroid, presented by Panou and Korakitis (2017), are generalized on a triaxial ellipsoid. A new exact analytical method and a new numerical method of converting Cartesian to ellipsoidal coordinates of a point on a triaxial ellipsoid are presented. An extensive test set for the coordinate conversion is used, in order to evaluate the performance of the two methods. The direct geodesic problem on a triaxial ellipsoid is described as an initial value problem and is solved numerically in Cartesian coordinates. The solution provides the Cartesian coordinates and the angle between the line of constant λ and the geodesic, at any point along the geodesic. Also, the Liouville constant is computed at any point along the geodesic, allowing to check the precision of the method. An extensive data set of geodesics is used, in order to demonstrate the validity of the numerical method for the geodesic problem. We conclude that a complete, stable and precise solution of the problem is accomplished. Numéro de notice : A2019-407 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1515/jogs-2019-0001 En ligne : https://doi.org/10.1515/jogs-2019-0001 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=93524
in Journal of geodetic science > vol 9 n° 1 (January 2019) . - pp 1 - 12[article]Precipitable water vapour content from ESR/SKYNET sun–sky radiometers : validation against GNSS/GPS and AERONET over three different sites in Europe / Monica Campanelli in Atmospheric measurement techniques, vol 11 n° 1 (January 2018)
[article]
Titre : Precipitable water vapour content from ESR/SKYNET sun–sky radiometers : validation against GNSS/GPS and AERONET over three different sites in Europe Type de document : Article/Communication Auteurs : Monica Campanelli, Auteur ; Alessandra Mascitelli, Auteur ; Paolo Sano, Auteur ; Henri Diémoz, Auteur ; Victor Estellés, Auteur ; Stefano Federico, Auteur ; Anna Maria Iannarelli, Auteur ; Francesca Fratarcangeli, Auteur ; Augusto Mazzoni, Auteur ; Eugenio Realini, Auteur ; Mattia Crespi, Auteur ; Olivier Bock , Auteur ; Jose A. Martínez-Lozano, Auteur ; Stefano Dietrich, Auteur Année de publication : 2018 Projets : 1-Pas de projet / Article en page(s) : pp 81 - 94 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] Aoste (val d')
[Termes IGN] constante
[Termes IGN] coordonnées GPS
[Termes IGN] données météorologiques
[Termes IGN] données spatiotemporelles
[Termes IGN] étalonnage d'instrument
[Termes IGN] photomètre
[Termes IGN] précipitation
[Termes IGN] retard troposphérique zénithal
[Termes IGN] Rome
[Termes IGN] teneur en vapeur d'eau
[Termes IGN] Valence (Espagne)
[Termes IGN] water vapour radiometerRésumé : (Auteur) The estimation of the precipitable water vapour content (W) with high temporal and spatial resolution is of great interest to both meteorological and climatological studies. Several methodologies based on remote sensing techniques have been recently developed in order to obtain accurate and frequent measurements of this atmospheric parameter. Among them, the relative low cost and easy deployment of sun–sky radiometers, or sun photometers, operating in several international networks, allowed the development of automatic estimations of W from these instruments with high temporal resolution. However, the great problem of this methodology is the estimation of the sun-photometric calibration parameters. The objective of this paper is to validate a new methodology based on the hypothesis that the calibration parameters characterizing the atmospheric transmittance at 940 nm are dependent on vertical profiles of temperature, air pressure and moisture typical of each measurement site. To obtain the calibration parameters some simultaneously seasonal measurements of W, from independent sources, taken over a large range of solar zenith angle and covering a wide range of W, are needed. In this work yearly GNSS/GPS datasets were used for obtaining a table of photometric calibration constants and the methodology was applied and validated in three European ESR-SKYNET network sites, characterized by different atmospheric and climatic conditions: Rome, Valencia and Aosta. Results were validated against the GNSS/GPS and AErosol RObotic NET-work (AERONET) W estimations. In both the validations the agreement was very high, with a percentage RMSD of about 6, 13 and 8 % in the case of GPS intercomparison at Rome, Aosta and Valencia, respectively, and of 8 % in the case of AERONET comparison in Valencia. Analysing the results by W classes, the present methodology was found to clearly improve W estimation at low W content when compared against AERONET in terms of % bias, bringing the agreement with the GPS (considered the reference one) from a % bias of 5.76 to 0.52. Numéro de notice : A2018-053 Affiliation des auteurs : LASTIG LAREG+Ext (2012-mi2018) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.5194/amt-11-81-2018 Date de publication en ligne : 09/01/2018 En ligne : http://dx.doi.org/10.5194/amt-11-81-2018 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89371
in Atmospheric measurement techniques > vol 11 n° 1 (January 2018) . - pp 81 - 94[article]New adjustment of the Croatian first order gravity network / Marija Repanic in Geodetski vestnik, vol 61 n° 4 (December 2017 - February 2018)
[article]
Titre : New adjustment of the Croatian first order gravity network Type de document : Article/Communication Auteurs : Marija Repanic, Auteur Année de publication : 2017 Article en page(s) : pp 630 - 648 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] compensation
[Termes IGN] constante
[Termes IGN] Croatie
[Termes IGN] erreur instrumentale
[Termes IGN] étalonnage d'instrument
[Termes IGN] réseau de premier ordre
[Termes IGN] réseau gravimétrique localRésumé : (Auteur) The paper presents the new joint adjustment of the Croatian First Order Gravity Network, for the first time adjusted as a whole. The adjustment involves absolute and relative gravity measurements, latter performed in the course of four survey stages. Firstly, the measurements are concisely described. Revision of the absolute and pre-processing of the relative measurements are briefly presented. The applied adjustment model is described. Accordingly, the gravity values of all stations (absolute and relative), corrections of linear calibration coefficient and linear drift coefficients are included in the functional model as unknown parameters. The absolute measurements are included in the adjustment as observations. The new adjustment resulted in significantly different gravity values as compared to previous adjustments (of individual stages of the network). The differences in gravity values are an order of magnitude greater than the expected accuracy. It is shown that the differences are mainly due to the errors in the gravimeters’ calibration constants, which were neglected in the previous adjustments. Because of the significant differences, the new linear transformation function from the Potsdam to the Croatian Gravity System is determined. Numéro de notice : A2017-778 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.15292/geodetski-vestnik.2017.04.630-648 En ligne : http://www.geodetski-vestnik.com/61/4/gv61-4_repanic.pdf Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=88984
in Geodetski vestnik > vol 61 n° 4 (December 2017 - February 2018) . - pp 630 - 648[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 139-2017041 RAB Revue Centre de documentation En réserve L003 Disponible Assessment of the accuracy of global geodetic satellite laser ranging observations and estimated impact on ITRF scale: estimation of systematic errors in LAGEOS observations 1993–2014 / Graham Appleby in Journal of geodesy, vol 90 n° 12 (December 2016)
[article]
Titre : Assessment of the accuracy of global geodetic satellite laser ranging observations and estimated impact on ITRF scale: estimation of systematic errors in LAGEOS observations 1993–2014 Type de document : Article/Communication Auteurs : Graham Appleby, Auteur ; José Rodríguez, Auteur ; Zuheir Altamimi , Auteur Année de publication : 2016 Article en page(s) : pp 1371 - 1388 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] analyse diachronique
[Termes IGN] champ de gravitation
[Termes IGN] constante
[Termes IGN] données Lageos
[Termes IGN] données TLS (télémétrie)
[Termes IGN] erreur systématique
[Termes IGN] géocentre
[Termes IGN] système de référence géodésiqueRésumé : (Auteur) Satellite laser ranging (SLR) to the geodetic satellites LAGEOS and LAGEOS-2 uniquely determines the origin of the terrestrial reference frame and, jointly with very long baseline interferometry, its scale. Given such a fundamental role in satellite geodesy, it is crucial that any systematic errors in either technique are at an absolute minimum as efforts continue to realise the reference frame at millimetre levels of accuracy to meet the present and future science requirements. Here, we examine the intrinsic accuracy of SLR measurements made by tracking stations of the International Laser Ranging Service using normal point observations of the two LAGEOS satellites in the period 1993 to 2014. The approach we investigate in this paper is to compute weekly reference frame solutions solving for satellite initial state vectors, station coordinates and daily Earth orientation parameters, estimating along with these weekly average range errors for each and every one of the observing stations. Potential issues in any of the large number of SLR stations assumed to have been free of error in previous realisations of the ITRF may have been absorbed in the reference frame, primarily in station height. Likewise, systematic range errors estimated against a fixed frame that may itself suffer from accuracy issues will absorb network-wide problems into station-specific results. Our results suggest that in the past two decades, the scale of the ITRF derived from the SLR technique has been close to 0.7 ppb too small, due to systematic errors either or both in the range measurements and their treatment. We discuss these results in the context of preparations for ITRF2014 and additionally consider the impact of this work on the currently adopted value of the geocentric gravitational constant, GM. Numéro de notice : A2016-808 Affiliation des auteurs : LASTIG LAREG+Ext (2012-mi2018) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-016-0929-2 Date de publication en ligne : 29/06/2016 En ligne : http://dx.doi.org/10.1007/s00190-016-0929-2 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=82596
in Journal of geodesy > vol 90 n° 12 (December 2016) . - pp 1371 - 1388[article]Advanced methods for the estimation of an unknown projection from a map / Tomáš Bayer in Geoinformatica, vol 20 n° 2 (April - June 2016)
[article]
Titre : Advanced methods for the estimation of an unknown projection from a map Type de document : Article/Communication Auteurs : Tomáš Bayer, Auteur Année de publication : 2016 Article en page(s) : pp 241 - 284 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Projections
[Termes IGN] constante
[Termes IGN] distribution spatiale
[Termes IGN] géoréférencement
[Termes IGN] ligne caractéristique
[Termes IGN] logiciel de calcul scientifique
[Termes IGN] système de projectionRésumé : (auteur) This article presents three new methods (M5, M6, M7) for the estimation of an unknown map projection and its parameters. Such an analysis is beneficial and interesting for historic, old, or current maps without information about the map projection; it could improve their georeference. The location similarity approach takes into account the residuals on the corresponding features; the minimum is found using the non-linear least squares. For the shape similarity approach, the minimized objective function ϕ takes into account the spatial distribution of the features, together with the shapes of the meridians, parallels and other 0D-2D elements. Due to the non-convexity and discontinuity, its global minimum is determined using the global optimization, represented by the differential evolution. The constant values of projection φ k , λ k , φ 1, λ 0, and map constants R,ΔX,ΔY, α (in relation to which the methods are invariant) are estimated. All methods are compared and the results are presented for the synthetic data as well as for 8 early maps from the Map Collection of the Charles University and the David Rumsay Map Collection. The proposed algorithms have been implemented in the new version of the detectproj software. Numéro de notice : A2016-373 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/POSITIONNEMENT Nature : Article DOI : 10.1007/s10707-015-0234-x En ligne : http://dx.doi.org/10.1007/s10707-015-0234-x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81138
in Geoinformatica > vol 20 n° 2 (April - June 2016) . - pp 241 - 284[article]Mesurer les avions de Swisstopo, un mandat plutôt inhabituel / Jim Ray in Géomatique suisse, vol 110 n° 11 (01/11/2012)PermalinkOn estimating total daily evapotranspiration from remote surface temperature measurements / T.N. Carlson in Remote sensing of environment, vol 29 n° 2 (01/08/1989)PermalinkRobust estimation for photogrammetric data using an adaptive tuning constant / W. Faig (02/04/1989)PermalinkProceedings of the International Conference on Earth rotation and the Terrestrial Reference Frame, July 31 - August 2, 1985, Colombus, Ohio, 2. Volume 2 / Ivan I. Mueller (1985)PermalinkPremiers résultats de mesures géodésiques avec le terramètre, appareil électronique de mesure de distances à deux longueurs d'ondes / Jean Gervaise in Géomètre, vol 1983 n° 10 (octobre 1983)PermalinkLa physique / Bureau des longitudes (1981)PermalinkConstantes et formules / IGN (1955)PermalinkConstants, formulae and methods used in traverse Mercator projection / Ordnance Survey (1950)Permalink