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Least-squares prediction in linear models with integer unknowns / Peter J.G. Teunissen in Journal of geodesy, vol 81 n° 9 (September 2007)  

Public [article]  inJournal of geodesy > vol 81 n° 9 (September 2007) . - pp 565 - 579 Titre : Least-squares prediction in linear models with integer unknowns Type de document : Article/Communication Auteurs : Peter J.G. Teunissen, Auteur Année de publication : 2007 Article en page(s) : pp 565 - 579 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie [Termes IGN] collocation par moindres carrés [Termes IGN] estimation statistique [Termes IGN] modèle linéaire Résumé : (Auteur) The prediction of spatially and/or temporal varying variates based on observations of these variates at some locations in space and/or instances in time, is an important topic in the various spatial and Earth sciences disciplines. This topic has been extensively studied, albeit under different names. The underlying model used is often of the trend-signal-noise type. This model is quite general and it encompasses many of the conceivable measurements. However, the methods of prediction based on these models have only been developed for the case the trend parameters are real-valued. In the present contribution we generalize the theory of least-squares prediction by permitting some or all of the trend parameters to be integer valued. We derive the solution for least-squares prediction in linear models with integer unknowns and show how it compares to the solution of ordinary least-squares prediction. We also study the probabilistic properties of the associated estimation and prediction errors. The probability density functions of these errors are derived and it is shown how they are driven by the probability mass functions of the integer estimators. Finally, we show how these multimodal distributions can be used for constructing confidence regions and for cross-validation purposes aimed at testing the validity of the underlying model. Copyright Springer Numéro de notice : A2007-390 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-007-0138-0 En ligne : https://doi.org/10.1007/s00190-007-0138-0 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28753 [article]

Exemplaires(2)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
266-07071	RAB	Revue	Centre de documentation	En réserve L003	Disponible
266-07072	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Quasigeoid evaluation with improved levelled height data for Norway / D.I. Lysaker in Journal of geodesy, vol 81 n° 9 (September 2007)  

Public [article]  inJournal of geodesy > vol 81 n° 9 (September 2007) . - pp 617 - 627 Titre : Quasigeoid evaluation with improved levelled height data for Norway Type de document : Article/Communication Auteurs : D.I. Lysaker, Auteur ; O.C. Omang, Auteur ; Bjørn Ragnvald Pettersen, Auteur ; et al., Auteur Année de publication : 2007 Article en page(s) : pp 617 - 627 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique [Termes IGN] géoïde gravimétrique [Termes IGN] géoïde local [Termes IGN] nivellement par GPS [Termes IGN] Norvège [Termes IGN] rebond post-glaciaire Résumé : (Auteur) GPS-levelling points are widely used to control gravimetric geoid or quasigeoid models. Direct comparison is often interpreted to reveal the accuracy of the gravimetric model, using GPS-levelling as a reference. However, both GPS and levelled heights contain errors, and in order to achieve a centimeter-accuracy geoid, these should be investigated. The Norwegian Height System NN1954 is known to contain large systematic errors due to postglacial land uplift in the area. In this study, the current height system and two revised versions, corrected for uplift, are applied to compute three sets of control quasigeoid heights in the southern part of Norway. These heights are then compared to various Nordic gravimetric quasigeoid models generated during the last two decades. In contradiction to some earlier studies, the accuracy of gravimetric quasigeoid models for this area are found to improve near-linearly with time. This is in accordance with expectations, since both data coverage and computation methods have progressed during this time. However, this study shows the importance of establishing accurate and error-free control data for geoid comparisons. Copyright Springer Numéro de notice : A2007-391 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-006-0129-6 En ligne : https://doi.org/10.1007/s00190-006-0129-6 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28754 [article]

Exemplaires(2)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
266-07071	RAB	Revue	Centre de documentation	En réserve L003	Disponible
266-07072	RAB	Revue	Centre de documentation	En réserve L003	Disponible