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Deflection of vertical effect on direct georeferencing in aerial mobile mapping systems: A case study in Sweden / Mohammad Bagherbandi in Photogrammetric record, vol 37 n° 179 (September 2022)  

Public [article]  inPhotogrammetric record > vol 37 n° 179 (September 2022) . - pp 285 - 305 Titre : Deflection of vertical effect on direct georeferencing in aerial mobile mapping systems: A case study in Sweden Type de document : Article/Communication Auteurs : Mohammad Bagherbandi, Auteur ; Arash Jouybari, Auteur ; Faramarz Nilfouroushan, Auteur ; et al., Auteur Année de publication : 2022 Article en page(s) : pp 285 - 305 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Photogrammétrie [Termes IGN] couplage GNSS-INS [Termes IGN] déviation de la verticale [Termes IGN] Earth Gravity Model 2008 [Termes IGN] ellipsoïde de référence [Termes IGN] géoréférencement direct [Termes IGN] photogrammétrie aérienne [Termes IGN] quasi-géoïde [Termes IGN] Suède [Termes IGN] système de numérisation mobile Résumé : (auteur) GNSS/INS applications are being developed, especially for direct georeferencing in airborne photogrammetry. Achieving accurately georeferenced products from the integration of GNSS and INS requires removing systematic errors in the mobile mapping systems. The INS sensor's uncertainty is decreasing; therefore, the influence of the deflection of verticals (DOV, the angle between the plumb line and normal to the ellipsoid) should be considered in the direct georeferencing. Otherwise, an error is imposed for calculating the exterior orientation parameters of the aerial images and aerial laser scanning. This study determines the DOV using the EGM2008 model and gravity data in Sweden. The impact of the DOVs on horizontal and vertical coordinates, considering different flight altitudes and camera field of view, is assessed. The results confirm that the calculated DOV components using the EGM2008 model are sufficiently accurate for aerial mapping system purposes except for mountainous areas because the topographic signal is not modelled correctly. Numéro de notice : A2022-937 Affiliation des auteurs : non IGN Thématique : IMAGERIE/POSITIONNEMENT Nature : Article DOI : 10.1111/phor.12421 Date de publication en ligne : 25/07/2022 En ligne : https://doi.org/10.1111/phor.12421 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102683 [article]

A global vertical datum defined by the conventional geoid potential and the Earth ellipsoid parameters / Hadi Amin in Journal of geodesy, vol 93 n°10 (October 2019)  

Public [article]  inJournal of geodesy > vol 93 n°10 (October 2019) Titre : A global vertical datum defined by the conventional geoid potential and the Earth ellipsoid parameters Type de document : Article/Communication Auteurs : Hadi Amin, Auteur ; Lard Erik Sjöberg, Auteur ; Mohammad Bagherbandi, Auteur Année de publication : 2019 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique [Termes IGN] champ de pesanteur terrestre [Termes IGN] coordonnées cartésiennes géocentriques [Termes IGN] ellipsoïde de référence [Termes IGN] géoïde [Termes IGN] géoïde gravimétrique [Termes IGN] harmonique ellipsoïdale [Termes IGN] modèle de géopotentiel [Termes IGN] surface de la mer [Termes IGN] système de référence altimétrique [Termes IGN] système de référence géodésique Résumé : (auteur) The geoid, according to the classical Gauss–Listing definition, is, among infinite equipotential surfaces of the Earth’s gravity field, the equipotential surface that in a least squares sense best fits the undisturbed mean sea level. This equipotential surface, except for its zero-degree harmonic, can be characterized using the Earth’s global gravity models (GGM). Although, nowadays, satellite altimetry technique provides the absolute geoid height over oceans that can be used to calibrate the unknown zero-degree harmonic of the gravimetric geoid models, this technique cannot be utilized to estimate the geometric parameters of the mean Earth ellipsoid (MEE). The main objective of this study is to perform a joint estimation of W0, which defines the zero datum of vertical coordinates, and the MEE parameters relying on a new approach and on the newest gravity field, mean sea surface and mean dynamic topography models. As our approach utilizes both satellite altimetry observations and a GGM model, we consider different aspects of the input data to evaluate the sensitivity of our estimations to the input data. Unlike previous studies, our results show that it is not sufficient to use only the satellite-component of a quasi-stationary GGM to estimate W0. In addition, our results confirm a high sensitivity of the applied approach to the altimetry-based geoid heights, i.e., mean sea surface and mean dynamic topography models. Moreover, as W0 should be considered a quasi-stationary parameter, we quantify the effect of time-dependent Earth’s gravity field changes as well as the time-dependent sea level changes on the estimation of W0. Our computations resulted in the geoid potential W0 = 62636848.102 ± 0.004 m2 s−2 and the semi-major and minor axes of the MEE, a = 6378137.678 ± 0.0003 m and b = 6356752.964 ± 0.0005 m, which are 0.678 and 0.650 m larger than those axes of GRS80 reference ellipsoid, respectively. Moreover, a new estimation for the geocentric gravitational constant was obtained as GM = (398600460.55 ± 0.03) × 106 m3 s−2. Numéro de notice : A2019-608 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-019-01293-3 Date de publication en ligne : 12/09/2019 En ligne : https://doi.org/10.1007/s00190-019-01293-3 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=94791 [article]