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Resolution of GPS carrier-phase ambiguities in Precise Point Positioning (PPP) with daily observations / M. Ge in Journal of geodesy, vol 82 n° 7 (July 2008)  

Public [article]  inJournal of geodesy > vol 82 n° 7 (July 2008) . - pp 389 - 401 Titre : Resolution of GPS carrier-phase ambiguities in Precise Point Positioning (PPP) with daily observations Type de document : Article/Communication Auteurs : M. Ge, Auteur ; Gerd Gendt, Auteur ; Markus Rothacher, Auteur ; et al., Auteur Année de publication : 2008 Article en page(s) : pp 389 - 401 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale [Termes IGN] ambiguïté entière [Termes IGN] double différence [Termes IGN] mesurage de phase [Termes IGN] positionnement par GNSS [Termes IGN] positionnement ponctuel précis [Termes IGN] résolution d'ambiguïté [Termes IGN] simple différence Résumé : (Auteur) Precise Point Positioning (PPP) has been demonstrated to be a powerful tool in geodetic and geodynamic applications. Although its accuracy is almost comparable with network solutions, the east component of the PPP results is still to be improved by integer ambiguity fixing, which is, up to now, prevented by the presence of the uncalibrated phase delays (UPD) originating in the receivers and satellites. In this paper, it is shown that UPDs are rather stable in time and space, and can be estimated with high accuracy and reliability through a statistical analysis of the ambiguities estimated from a reference network. An approach is implemented to estimate the fractional parts of the single-difference (SD) UPDs between satellites in wide- and narrow-lane from a global reference network. By applying the obtained SD-UPDs as corrections to the SD-ambiguities at a single station, the corrected SD-ambiguities have a naturally integer feature and can therefore be fixed to integer values as usually done for the double-difference ones in the network mode. With data collected at 450 stations of the International GNSS Service (IGS) through days 106 to 119 in 2006, the efficiency of the presented ambiguity-fixing strategy is validated using IGS Final products. On average, more than 80% of the independent ambiguities could be fixed reliably, which leads to an improvement of about 27% in the repeatability and 30% in the agreement with the IGS weekly solutions for the east component of station coordinates, compared with the real-valued solutions. Copyright Springer Numéro de notice : A2008-317 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-007-0187-4 En ligne : https://doi.org/10.1007/s00190-007-0187-4 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29310 [article]

Exemplaires(2)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
266-08061	RAB	Revue	Centre de documentation	En réserve L003	Disponible
266-08062	RAB	Revue	Centre de documentation	En réserve L003	Disponible

On weighted total least-squares adjustment for linear regression / Burkhard Schaffrin in Journal of geodesy, vol 82 n° 7 (July 2008)  

Public [article]  inJournal of geodesy > vol 82 n° 7 (July 2008) . - pp 415 - 421 Titre : On weighted total least-squares adjustment for linear regression Type de document : Article/Communication Auteurs : Burkhard Schaffrin, Auteur ; Andreas Wieser, Auteur Année de publication : 2008 Article en page(s) : pp 415 - 421 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Statistiques [Termes IGN] compensation par moindres carrés [Termes IGN] pondération [Termes IGN] régression linéaire [Termes IGN] régression multiple Résumé : (Auteur) The weighted total least-squares solution (WTLSS) is presented for an errors-in-variables model with fairly general variance–covariance matrices. In particular, the observations can be heteroscedastic and correlated, but the variance–covariance matrix of the dependent variables needs to have a certain block structure. An algorithm for the computation of the WTLSS is presented and applied to a straight-line fit problem where the data have been observed with different precision, and to a multiple regression problem from recently published climate change research. Copyright Springer Numéro de notice : A2008-318 Affiliation des auteurs : non IGN Thématique : MATHEMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-007-0190-9 En ligne : https://doi.org/10.1007/s00190-007-0190-9 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29311 [article]

Exemplaires(2)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
266-08061	RAB	Revue	Centre de documentation	En réserve L003	Disponible
266-08062	RAB	Revue	Centre de documentation	En réserve L003	Disponible