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A hybrid approach for recovering high-resolution temporal gravity fields from satellite laser ranging / Anno Löcher in Journal of geodesy, vol 95 n° 1 (January 2021)
[article]
Titre : A hybrid approach for recovering high-resolution temporal gravity fields from satellite laser ranging Type de document : Article/Communication Auteurs : Anno Löcher, Auteur ; Jürgen Kusche, Auteur Année de publication : 2021 Article en page(s) : n° 6 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] champ de pesanteur terrestre
[Termes IGN] changement temporel
[Termes IGN] données GRACE
[Termes IGN] données TLS (télémétrie)
[Termes IGN] facteur d'échelle
[Termes IGN] fonction orthogonale
[Termes IGN] harmonique sphérique
[Termes IGN] modélisation
[Termes IGN] série temporelleRésumé : (auteur) A new approach to recover time-variable gravity fields from satellite laser ranging (SLR) is presented. It takes up the concept of lumped coefficients by representing the temporal changes of the Earth’s gravity field by spatial patterns via combinations of spherical harmonics. These patterns are derived from the GRACE mission by decomposing the series of monthly gravity field solutions into empirical orthogonal functions (EOFs). The basic idea of the approach is then to use the leading EOFs as base functions in the gravity field modelling and to adjust the respective scaling factors straightforward within the dynamic orbit computation; only for the lowest degrees, the spherical harmonic coefficients are estimated separately. As a result, the estimated gravity fields have formally the same spatial resolution as GRACE. It is shown that, within the GRACE time frame, both the secular and the seasonal signals in the GRACE time series are reproduced with high accuracy. In the period prior to GRACE, the SLR solutions are in good agreement with other techniques and models and confirm, for instance, that the Greenland ice sheet was stable until the late 1990s. Further validation is done with the first monthly fields from GRACE Follow-On, showing a similar agreement as with GRACE itself. Significant differences to the reference data only emerge occasionally when zooming into smaller river basins with strong interannual mass variations. In such cases, the approach reaches its limits which are set by the low spectral sensitivity of the SLR satellites and the strong constraints exerted by the EOFs. The benefit achieved by the enhanced spatial resolution has to be seen, therefore, primarily in the proper capturing of the mass signal in medium or large areas rather than in the opportunity to focus on isolated spatial details. Numéro de notice : A2021-026 Affiliation des auteurs : non IGN Thématique : MATHEMATIQUE/POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-020-01460-x Date de publication en ligne : 23/12/2020 En ligne : https://doi.org/10.1007/s00190-020-01460-x Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=96710
in Journal of geodesy > vol 95 n° 1 (January 2021) . - n° 6[article]Les représentations planes cylindriques de la terre / Françoise Duquenne in XYZ, n° 157 (décembre 2018 - février 2019)
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Titre : Les représentations planes cylindriques de la terre Type de document : Article/Communication Auteurs : Françoise Duquenne , Auteur Année de publication : 2018 Article en page(s) : pp 45 - 50 Note générale : bibliographie Langues : Français (fre) Descripteur : [Vedettes matières IGN] Projections
[Termes IGN] convergence des méridiens
[Termes IGN] facteur d'échelle
[Termes IGN] latitude
[Termes IGN] ligne géodésique
[Termes IGN] module linéaire
[Termes IGN] projection cylindrique
[Termes IGN] projection Universal Transverse MercatorRésumé : (auteur) The purpose of this paper is to recall th fundamental concept of the plane cylindrical representations of the earth, especially those which are conformal. Amongst these, the most known and used projection throughout the world is the Universal Transverse Mercator (UTM). The algorithm of calculation presented here, developed by French IGN, has the advantage of using exact formulas and not limited developments like many others, and thus of beeing easily computerized. Numéro de notice : A2018-534 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91579
in XYZ > n° 157 (décembre 2018 - février 2019) . - pp 45 - 50[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 112-2018041 RAB Revue Centre de documentation En réserve L003 Disponible The development and analysis of quasi-linear map projections / Jonathan Charles Lliffe in Cartography and Geographic Information Science, Vol 45 n° 3 (May 2018)
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Titre : The development and analysis of quasi-linear map projections Type de document : Article/Communication Auteurs : Jonathan Charles Lliffe, Auteur Année de publication : 2018 Article en page(s) : pp 270 - 283 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Projections
[Termes IGN] algorithme snake
[Termes IGN] facteur d'échelle
[Termes IGN] projection conforme
[Termes IGN] réseau ferroviaireRésumé : (Auteur) Map projections are an essential component of coordinate systems used in applications such as surveying, topographic mapping, and engineering, and care needs to be taken to select ones that minimize distortion for each case. This article explores the selection process for near-linear features on the surface of the Earth and derives limits for the extent of a project that can be projected within specified distortion tolerances. It is then demonstrated that a multifaceted set of projections of the Earth may be used to extend this concept to the mapping of features such as highways and railways that are quasi-linear but do not exactly follow a standard geometrical line (a great circle or a small circle) on the surface of the Earth. A continuous, conformal coordinate system may be derived in such situations, extending to indefinite length and applicable over a swath of several kilometers width, but it cannot be extended to cover situations with extensive variations in height. Instead, the Snake Projection is analyzed, and it is shown that this can be used to develop continuous (non-zonal) projected coordinate systems for major engineering projects extending for hundreds of kilometers and having extensive height ranges. Examples are shown of the application to railway projects. Numéro de notice : A2018-133 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/15230406.2017.1325332 Date de publication en ligne : 19/05/2017 En ligne : https://doi.org/10.1080/15230406.2017.1325332 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89664
in Cartography and Geographic Information Science > Vol 45 n° 3 (May 2018) . - pp 270 - 283[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 032-2018031 RAB Revue Centre de documentation En réserve L003 Disponible DORIS Starec ground antenna characterization and impact on positioning / Cédric Tourain in Advances in space research, vol 58 n° 12 (15 December 2016)
[article]
Titre : DORIS Starec ground antenna characterization and impact on positioning Type de document : Article/Communication Auteurs : Cédric Tourain, Auteur ; Guilhem Moreaux, Auteur ; Albert Auriol, Auteur ; Jérôme Saunier , Auteur Année de publication : 2016 Article en page(s) : pp 2707 - 2716 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] antenne DORIS
[Termes IGN] caractérisation
[Termes IGN] centre de phase
[Termes IGN] facteur d'échelle
[Termes IGN] International Terrestrial Reference FrameRésumé : (auteur) In a geodetic radio frequency observing system the phase center offsets and phase center variations of ground antennae are a fundamental component of mathematical models of the system observables. In this paper we describe work aimed at improving the DORIS Starec ground antenna phase center definition model. Seven antennas were analyzed in the Compact Antenna Test Range (CATR), a dedicated CNES facility. With respect to the manufacturer specified phase center offset, the measured antennae varied between −6 mm and +4 mm due to manufacturing variations. To solve this problem, discussions were held with the manufacturer, leading to an improvement of the manufacturing process. This work results in a reduction in the scatter to ±1 mm. The phase center position has been kept unchanged and associated phase law has been updated and provided to users of the International DORIS Service (IDS). This phase law is applicable to all Starec antennas (before and after manufacturing process consolidation) and is azimuth independent. An error budget taking into account these updated characteristics has been established for the antenna alone: ±2 mm on the horizontal plane and ±3 mm on the up component, maximum error values for antennas named type C (Saunier et al., 2016) produced with consolidated manufacturing process. Finally the impact of this updated characterization on positioning results has been analyzed and shows a scale offset only of the order of +12 mm for the Terrestrial Reference Frame. Numéro de notice : A2016--185 Affiliation des auteurs : IGN+Ext (2012-2019) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.asr.2016.05.013 Date de publication en ligne : 14/05/2016 En ligne : https://doi.org/10.1016/j.asr.2016.05.013 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91820
in Advances in space research > vol 58 n° 12 (15 December 2016) . - pp 2707 - 2716[article]Joint analysis of GOCE gravity gradients data of gravitational potential and of gravity with seismological and geodynamic observations to infer mantle properties / Marianne Greff-Lefftz in Geophysical journal international, vol 205 n° 1 (April 2016)
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Titre : Joint analysis of GOCE gravity gradients data of gravitational potential and of gravity with seismological and geodynamic observations to infer mantle properties Type de document : Article/Communication Auteurs : Marianne Greff-Lefftz, Auteur ; Laurent Métivier , Auteur ; Isabelle Panet , Auteur ; Lambert Caron, Auteur ; Gwendoline Pajot-Métivier , Auteur ; Johannes Bouman, Auteur Année de publication : 2016 Projets : TOSCA / Article en page(s) : pp 257 - 283 Note générale : bibliographie
This study was supported by CNES (Centre National d’Etudes Spatiales) through the TOSCA committee and is IPGP contribution number 3701.Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] champ de pesanteur terrestre
[Termes IGN] données GOCE
[Termes IGN] facteur d'échelle
[Termes IGN] gradient de gravitation
[Termes IGN] manteau terrestre
[Termes IGN] méthode de Monte-Carlo
[Termes IGN] potentiel de pesanteur terrestre
[Termes IGN] viscositéRésumé : (auteur) Joint analysis of the seismic velocities and geoid, gravity and gravity gradients are used to constrain the viscosity profile within the mantle as well as the lateral density variations. Recent ESA's Gravity field and steady-state Ocean Circulation Explorer measurements of the second-order derivatives of the Earth's gravity potential give new possibilities to determine these mantle properties. Using a simple mantle model and seismic tomography results, we investigate how the gravitational potential, the three components of the gravity vector and the gravity gradients can bring information on the radial viscosity profile and on the mantle mass anomalies. We start with lateral density variations in the Earth's mantle based either on slab history or deduced from seismic tomography. The main uncertainties are: for the latter case, the relationship between seismic velocity and density—the so-called density/velocity scaling factor—and for the former case, the variation with depth of the density contrast between the cold slabs and the surrounding mantle. We perform a Monte Carlo search for the viscosity and the density/velocity scaling factor profiles within the mantle, which allows to fit the observed geoid, gravity and gradients of gravity. We compute the posterior probability distribution of the unknown parameters, and find that the gravity gradients improve the estimate of the scaling factor within the upper mantle, because of their sensitivity to the masses within the upper mantle, whereas the geoid and the gravity better constrain the scaling factor in the lower mantle. In the upper mantle, it is less than 0.02 in the upper part and about 0.08–0.14 in the lower part, and it is significantly larger for depths greater than 1200 km (about 0.32–0.34). In any case, the density/velocity scaling factor between 670 and 1150 km depth is not well constrained. We show that the viscosity of the upper part of the mantle is strongly correlated with the viscosity of the lower part of the mantle and that the viscosity profile is characterized by a decrease in the lower part of the upper mantle (about 1020–2 × 1020 Pa s) and by an increase (about 1023–2 × 1023 Pa s) at the top of the lower mantle (between 670 and 1150 km). The viscosity of the mantle below 1150 km depth is well estimated in our Monte Carlo search and is about 1022–4 × 1022 Pa s. Numéro de notice : A2016--192 Affiliation des auteurs : LASTIG LAREG+Ext (2012-mi2018) Autre URL associée : vers HAL Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1093/gji/ggw002 Date de publication en ligne : 16/02/2016 En ligne : https://doi.org/10.1093/gji/ggw002 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91843
in Geophysical journal international > vol 205 n° 1 (April 2016) . - pp 257 - 283[article]A local approach to optimize the scale parameter in multiresolution segmentation for multispectral imagery / F. Cánovas-García in Geocarto international, vol 30 n° 7 - 8 (August - September 2015)PermalinkAutomated parameterisation for multi-scale image segmentation on multiple layers / L. Drăguț in ISPRS Journal of photogrammetry and remote sensing, vol 88 (February 2014)PermalinkConcise derivation of extensive coordinate conversion formulae in the Gauss-Krüger projection / Kazushige Kawase in Bulletin of the GeoSpatial Information authority of Japan, vol 60 (March 2013)PermalinkModeling the scale dependences of topological relations between lines and regions induced by reduction of attributes / S. Du in International journal of geographical information science IJGIS, vol 24 n°11-12 (december 2010)PermalinkIntroducing scale parameters for adjusting area objects in GIS based on least squares and variance component estimation / X. Tong in International journal of geographical information science IJGIS, vol 23 n°11-12 (november 2009)PermalinkPermalinkA cost-scale factor relationship for topographic mapping / S. Laroche in CISM Journal, vol 43 n° 4 (December 1989)PermalinkThe factor of scale in remote sensing / Curtis E. Woodcock in Remote sensing of environment, vol 21 n° 3 (01/04/1987)PermalinkMaßstabskontrollen in der Elsaß-Lothringischen Dreieckskette 1977-1979 ; Die Feldmessungen in der Elsaß-Lothringischen Dreieckskette ; Die Meßergebnisse von 1977-1979 und ein Vergleich mit den Messungen von 1877 ; Die Basis Oberhergheim 1804-1877-1979 / H. Grosse (1981)PermalinkGemeinschaftsarbeit 1972-74, Maßstabskontrolle des Deutschen Hauptdreiecksnetzes im rheinisch-hessischen Raum. Elektromagnetische Streckenmessungen / K. Hensel (1975)Permalink