Centre de documentation
scientifique

Displacement monitoring performance of relative positioning and Precise Point Positioning (PPP) methods using simulation apparatus / Salih Alcay in Advances in space research, vol 63 n° 5 (1 March 2019)  

Public [article]  inAdvances in space research > vol 63 n° 5 (1 March 2019) . - pp 1697 - 1707 Titre : Displacement monitoring performance of relative positioning and Precise Point Positioning (PPP) methods using simulation apparatus Type de document : Article/Communication Auteurs : Salih Alcay, Auteur ; Sermet Ogutcu, Auteur ; Ibrahim Kalayci, Auteur ; Cemal Ozer Yigit, Auteur Année de publication : 2019 Article en page(s) : pp 1697 - 1707 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale [Termes IGN] déformation de la croute terrestre [Termes IGN] données GPS [Termes IGN] GAMIT [Termes IGN] GIPSY-OASIS [Termes IGN] GLOBK [Termes IGN] positionnement différentiel [Termes IGN] positionnement ponctuel précis [Termes IGN] simulation [Termes IGN] surveillance géologique Résumé : (Auteur) Besides the classical geodetic methods, GPS (Global Positioning System) based positioning methods are widely used for monitoring crustal, structural, ground etc., deformations in recent years. Currently, two main GPS positioning methods are used: Relative and Precise Point Positioning (PPP) methods. It is crucial to know which amount of displacement can be detected with these two methods in order to inform their usability according to the types of deformation. Therefore, this study conducted to investigate horizontal and vertical displacement monitoring performance and capability of determining the direction of displacements of both methods using a developed displacement simulator apparatus. For this purpose, 20 simulated displacement tests were handled. Besides the 24 h data sets, 12 h, 8 h, 4 h and 2 h subsets were considered to examine the influence of short time spans. Each data sets were processed using GAMIT/GLOBK and GIPSY/OASIS scientific software for relative and PPP applications respectively and derived displacements were compared to the simulated (true) displacements. Then statistical significance test was applied. Results of the experiment show that using 24 h data sets, relative method can determine up to 6.0 mm horizontal displacement and 12.3 mm vertical displacement, while PPP method can detect 8.1 mm and 19.2 mm displacements in horizontal and vertical directions respectively. Minimum detected displacements are found to grow larger as time spans are shortened. Numéro de notice : A2019-173 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.asr.2018.11.003 Date de publication en ligne : 13/11/2018 En ligne : https://doi.org/10.1016/j.asr.2018.11.003 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=92625 [article]

Study of the effects on GPS coordinate time series caused by higher-order ionospheric corrections calculated using the DIPOLE model / Liansheng Deng in Geodesy and Geodynamics, vol 8 n° 2 (March 2017)  

Public [article]  inGeodesy and Geodynamics > vol 8 n° 2 (March 2017) . - pp 111 - 119 Titre : Study of the effects on GPS coordinate time series caused by higher-order ionospheric corrections calculated using the DIPOLE model Type de document : Article/Communication Auteurs : Liansheng Deng, Auteur ; Weiping Jiang, Auteur ; Hua Chen, Auteur ; Zhaohan Zhu, Auteur ; Wen Zhao, Auteur Année de publication : 2017 Article en page(s) : pp 111 - 119 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] amplitude [Termes IGN] bruit blanc [Termes IGN] bruit rose [Termes IGN] champ géomagnétique [Termes IGN] correction ionosphérique [Termes IGN] GAMIT [Termes IGN] GLOBK [Termes IGN] série temporelle [Vedettes matières IGN] Traitement de données GNSS Résumé : (auteur) As one of the main error sources in high-precision Global Positioning System (GPS) data processing, higher-order ionospheric (HOI) delays cause significant effects on coordinate time series that cannot be ignored in analyses of long time series. Typically two geomagnetic models, DIPOLE model and International Geomagnetic Reference Field (IGRF) model, are used for calculating HOI corrections. This paper investigates the effects of HOI correction caused by the DIPOLE model on coordinate time series. GPS data from 104 globally distributed International GNSS Service (IGS) stations spanning from January, 1999 to December, 2003 were reprocessed following up-to-date processing strategies utilizing GAMIT and GLOBK software. Two coordinate time series solutions before and after applying HOI corrections using the DIPOLE model were derived for studying the effects in terms of seasonal variations and noise amplitudes. The results show that after applying the HOI corrections calculated with DIPOLE, the noise amplitudes of the coordinate time series increased, especially in the north and east directions, and the increased amplitudes of the flicker noise were larger than those of the white noise. Furthermore, spurious periodic signals that were probably introduced by the HOI corrections from the DIPOLE model were also found. Moreover, an apparent increase was confirmed for the power spectra of most of the stations, especially in the north direction, and the amplitudes of both the annual and semi-annual signals also increased in the north and east directions. It can be inferred that the quality of the external data sources such as the geomagnetic model might be the key factors that lead to the above results. The results also suggest that we should be very careful when the DIPOLE model is used for HOI corrections. Numéro de notice : A2017-235 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1016/j.geog.2017.01.004 En ligne : https://doi.org/10.1016/j.geog.2017.01.004 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=85167 [article]