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Height biases of SRTM DEM related to EGM96: from a global perspective to regional practice / A. Üstün in Survey review, vol 50 n° 358 (January 2018)  

Public [article]  inSurvey review > vol 50 n° 358 (January 2018) . - pp 26 - 35 Titre : Height biases of SRTM DEM related to EGM96: from a global perspective to regional practice Type de document : Article/Communication Auteurs : A. Üstün, Auteur ; R. A. Abbak, Auteur ; E. Zeray Öztürk, Auteur Année de publication : 2018 Article en page(s) : pp 26 - 35 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique [Termes IGN] Earth Gravity Model 1996 [Termes IGN] erreur systématique [Termes IGN] géoïde local [Termes IGN] géoïde terrestre [Termes IGN] hauteur ellipsoïdale [Termes IGN] MNS SRTM [Termes IGN] Turquie Résumé : (auteur) It is investigated to what extent EGM96 affects the accuracy of digital elevation model (DEM) produced from the shuttle radar topography mission (SRTM). Global and regional analysis of EGM96 compared with EGM2008 indicate that locally there are large differences distorting to the accuracy level of SRTM DEM. In the absolute sense, the overall geoid differences throughout arc-degree tiles reach −5 m in the northeast and 2–3 m in the southern parts of Turkey. A numerical investigation over the test profiles of 200–700 km length running at various directions proves that a possible vertical datum change from EGM96 to EGM2008 yields systematically more accurate height information with an improvement of up to 2.5 m. A GPS-levelling traverse of about 900 km length points out some key patterns of this recovery. Consequently, a correction for the present version of SRTM DEM should be considered in critical implementations of Earth sciences like geoid or water flow modelling, especially for areas where EGM96 shows weak performance. Numéro de notice : A2018-176 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1080/00396265.2016.1218159 Date de publication en ligne : 22/08/2016 En ligne : https://doi.org/10.1080/00396265.2016.1218159 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89820 [article]

The use of low-cost, single-frequency GNSS receivers in mapping surveys / M. Tsakiri in Survey review, vol 50 n° 358 (January 2018)  

Public [article]  inSurvey review > vol 50 n° 358 (January 2018) . - pp 46 - 56 Titre : The use of low-cost, single-frequency GNSS receivers in mapping surveys Type de document : Article/Communication Auteurs : M. Tsakiri, Auteur ; A. Sioulis, Auteur ; George Piniotis, Auteur Année de publication : 2018 Article en page(s) : pp 46 - 56 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement [Termes IGN] coût [Termes IGN] Grèce [Termes IGN] positionnement cinématique en temps réel [Termes IGN] récepteur GNSS [Termes IGN] récepteur monofréquence [Termes IGN] test de performance Résumé : (auteur) The emergence of low-cost, navigation-type receivers capable to provide carrier-phase data (the so-called high-sensitivity carrier-phase positioning) has been steadily growing over the recent years. The aim of this study was to evaluate the positioning performance of a high-sensitivity receiver in a network real-time kinematic environment for mapping surveying applications. Specifically, using as rover receiver the u-blox NEO-7P module and the low-cost antenna Tallysman TW2410, sets of data were collected for the purpose of mapping surveying. The external accuracy of the obtained solutions is considered using different positioning techniques and the internal indicators of the system during real-time kinematic (RTK) positioning are assessed. The assessment indicates that in benign environments this type of receivers produce results that are comparable to RTK positioning using geodetic receivers and with a significantly lower cost. Numéro de notice : A2018-177 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1080/00396265.2016.1222344 Date de publication en ligne : 16/09/2016 En ligne : https://doi.org/10.1080/00396265.2016.1222344 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89821 [article]

Introduction to multiple regression equations in datum transformations and their reversibility / Andrew Carey Ruffhead in Survey review, vol 50 n° 358 (January 2018)  

Public [article]  inSurvey review > vol 50 n° 358 (January 2018) . - pp 82 - 90 Titre : Introduction to multiple regression equations in datum transformations and their reversibility Type de document : Article/Communication Auteurs : Andrew Carey Ruffhead, Auteur Année de publication : 2018 Article en page(s) : pp 82 - 90 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux [Termes IGN] régression multiple [Termes IGN] système de référence local [Termes IGN] système de référence mondial [Termes IGN] transformation de coordonnées Résumé : (auteur) This paper provides an introduction to multiple regression equations as a method of performing geodetic datum transformations. The formulae are particularly useful when there are non-linear distortions that need to be built into the transformation model. However, the equations take the form of a one-way transformation, usually a local geodetic datum to a global datum. The standard procedure for applying the equations to obtain the reverse transformation only gives approximate results relative to the original model. This paper quantifies the problem and describes three methods for computing the reverse transformation (or inverse transformation) more accurately. Numéro de notice : A2018-178 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1080/00396265.2016.1244143 Date de publication en ligne : 31/10/2016 En ligne : https://doi.org/10.1080/00396265.2016.1244143 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89822 [article]