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Recursive Gauss-Helmert model with equality constraints applied to the efficient system calibration of a 3D laser scanner / Sören Vogel in Journal of applied geodesy, vol 16 n° 1 (January 2022)  

Public [article]  inJournal of applied geodesy > vol 16 n° 1 (January 2022) . - pp 37 - 57 Titre : Recursive Gauss-Helmert model with equality constraints applied to the efficient system calibration of a 3D laser scanner Type de document : Article/Communication Auteurs : Sören Vogel, Auteur ; Dominik Ernst, Auteur ; Ingo Neumann, Auteur ; et al., Auteur Année de publication : 2022 Article en page(s) : pp 37 - 57 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s) [Termes IGN] contrainte d'intégrité [Termes IGN] étalonnage d'instrument [Termes IGN] filtre de Kalman [Termes IGN] géoréférencement [Termes IGN] modèle de Gauss-Helmert [Termes IGN] positionnement cinématique [Termes IGN] processeur graphique [Termes IGN] télémètre laser aéroporté Résumé : (auteur) Sensors for environmental perception are nowadays applied in numerous vehicles and are expected to be used in even higher quantities for future autonomous driving. This leads to an increasing amount of observation data that must be processed reliably and accurately very quickly. For this purpose, recursive approaches are particularly suitable in terms of their efficiency when powerful CPUs and GPUs are uneconomical, too large, or too heavy for certain applications. If explicit functional relationships between the available observations and the requested parameters are used to process and adjust the observation data, complementary approaches exist. The situation is different for implicit relationships, which could not be considered recursively for a long time but only in the context of batch adjustments. In this contribution, a recursive Gauss-Helmert model is presented that can handle explicit and implicit equations and thus allows high flexibility. This recursive estimator is based on a Kalman filter for implicit measurement equations, which has already been used for georeferencing kinematic multi-sensor systems (MSS) in urban environments. Furthermore, different methods for introducing additional information using constraints and the resulting added value are shown. Practical application of the methodology is given by an example for the calibration of a laser scanner for a MSS. Numéro de notice : A2022-053 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1515/jag-2021-0026 Date de publication en ligne : 15/10/2021 En ligne : https://doi.org/10.1515/jag-2021-0026 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99448 [article]

Multi-frequency quadrifilar helix antennas for cm-accurate GNSS positioning / Lambert Wanninger in Journal of applied geodesy, vol 16 n° 1 (January 2022)  

Public [article]  inJournal of applied geodesy > vol 16 n° 1 (January 2022) . - pp 25 - 35 Titre : Multi-frequency quadrifilar helix antennas for cm-accurate GNSS positioning Type de document : Article/Communication Auteurs : Lambert Wanninger, Auteur ; Melanie Thiemig, Auteur ; Walker Frevert, Auteur Année de publication : 2022 Article en page(s) : pp 25 - 35 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale [Termes IGN] antenne GNSS [Termes IGN] bruit (théorie du signal) [Termes IGN] étalonnage d'instrument [Termes IGN] fréquence multiple [Termes IGN] phase GNSS [Termes IGN] positionnement par GNSS [Termes IGN] précision centimétrique [Termes IGN] signal GNSS [Termes IGN] trajet multiple Résumé : (auteur) For a few years now, GNSS multi-frequency quadrifilar helix antennas (QHA) are available to be used for precise GNSS applications. We performed test measurements with two types of multi-frequency QHA and compared them with a geodetic patch antenna. Although code and carrier phase noise and high-frequent multipath was determined to be larger as compared to the geodetic antenna, the fast-static horizontal coordinate accuracies are on the same level and demonstrate cm-accuracy capability. One of the QHA types exhibited an increased susceptibility to near-field multipath effects which resulted in a degraded accuracy of the vertical coordinate component. Numéro de notice : A2022-054 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1515/jag-2021-0042 Date de publication en ligne : 15/09/2021 En ligne : https://doi.org/10.1515/jag-2021-0042 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99449 [article]