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Analyse und Vergleich unterschiedlicher Modelle der dreidimensionalen Geodäsie / U. Klein (1997)
Titre : Analyse und Vergleich unterschiedlicher Modelle der dreidimensionalen Geodäsie Titre original : [Analyse et comparaison de différents modèles de la géodésie tridimensionnelle] Type de document : Thèse/HDR Auteurs : U. Klein, Auteur Editeur : Munich : Bayerische Akademie der Wissenschaften Année de publication : 1997 Collection : DGK - C Sous-collection : Dissertationen num. 479 Importance : 123 p. Format : 21 x 30 cm ISBN/ISSN/EAN : 978-3-7696-9519-9 Note générale : Bibliographie Langues : Allemand (ger) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] champ de pesanteur terrestre
[Termes IGN] données GPS
[Termes IGN] équation linéaire
[Termes IGN] géodésie tridimensionnelle
[Termes IGN] levé gravimétrique
[Termes IGN] potentiel de pesanteur terrestre
[Termes IGN] quantité discrèteIndex. décimale : 30.40 Géodésie physique Résumé : (Auteur) The dependence of geodetic observables on the gravity field yields an interaction between the deter-mination of the figure of the earth, of the position of points on its surface, and of the gravity field. The determination of both components must be seen as a uniform problem which is denoted by inte-grated geodesy. It is characterized by the combination of all possible available geometric and physical observables.
The main problem within the integrated adjustment is that the dependence of the various observations on the gravity potential function has a different structure. The observables depend either on the gravity potential itself or on its derivatives. The problem of how to treat the function-dependent parameters in the adjustment leads to different approaches of the integrated geodesy.
In the discrete approach the functionals of the gravity field are considered as discrete deterministic quantities disregarding their common dependence on the underlying function. In every point the coordinates, the disturbing potential and its derivatives have to be estimated as discrete unknowns. The pure geometrical approach is a particular case of this approach if we consider the astronomical coordinates as parameters in the gravity field.
The computed reference potential and its derivatives are the result of a previous data analysis and they are therefore the outcome of random variables which differ from the corresponding true values. So the observations are not the only available information for the model parameter. The prior estimates will be introduced as pseudo-observations of the corresponding parameters affected by errors. This approach is called model with prior information.
In the analytical approach the unknown disturbing potential is modeled as a deterministic function depending on a finite set of unknown discrete parameters. As simple base functions the potentials of point masses can be used. The masses and the positions of the point masses have to be estimated in the adjustment.
An emphasis of this work is the detailed analysis of the listed approaches. Several aspects will be treated. The comprehensive description of the basis is followed by the classification of previous pub--lications. The disposable observations are not sufficient for the clear determination of the choosen geometrical and physical parameters. Therefore a comprehensive rank defect analysis is carried out with the linearized observation equations. The practical applicability of the approaches will be investi--gated with a three-dimensional example. Some information about the sensitivity of the observations referring to the determined quantities and the accessible accuracies is given.
The comparison of the approaches is concentrated essentially to the quality of the determination of coordinates and to the question, how the particular observables affect the determination of the different groups of parameters. The horizontal position of points is mainly determined by GPS observations, measurements of distance or horizontal direction. Zenith distances and GPS observations contribute to the determination of the vertical position of points. Measurements of gravity and potential differences do not influence the determination of the coordinates. The parameters of the gravity field, which are choosen in the different approaches, are determined exclusively by the physical observations.
Beside the analysis and the comparison of the approaches remains another important aspect. It has to be determined how the geometry of the net is influenced by the type of treating the functionals of the gravity field. The results of this investigation lead to the conclusion that the type of treating the functionals of the gravity field does not affect the geometry of the net. Concerning the quality of the determination of coordinates the analysed approaches can be considered as equivalent.Numéro de notice : 28011 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Thèse étrangère Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=63358 Réservation
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Code-barres Cote Support Localisation Section Disponibilité 28011-01 30.40 Livre Centre de documentation Géodésie Disponible 28011-02 30.40 Livre Centre de documentation Géodésie Disponible Analyse und Optimierung geodätischer Netze nach spektralen Kriterien und mechanische Analogien / R. Jäger (1988)
Titre : Analyse und Optimierung geodätischer Netze nach spektralen Kriterien und mechanische Analogien Titre original : [Analyse et optimisation des réseaux géodésiques d'après des critères spectraux et des analogies mécaniques] Type de document : Thèse/HDR Auteurs : R. Jäger, Auteur Editeur : Munich : Bayerische Akademie der Wissenschaften Année de publication : 1988 Collection : DGK - C Sous-collection : Dissertationen num. 342 Importance : 135 p. Format : 21 x 30 cm ISBN/ISSN/EAN : 978-3-7696-9390-4 Note générale : Bibliographie Langues : Allemand (ger) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] élasticité
[Termes IGN] matrice
[Termes IGN] méthode des éléments finis
[Termes IGN] optimisation (mathématiques)
[Termes IGN] quantité discrète
[Termes IGN] réseau géodésique
[Termes IGN] valeur propreIndex. décimale : 30.10 Systèmes de référence et réseaux géodésiques Résumé : (Auteur) According to the expression 'spectral criterions' this thesis is dealing - within the analysis and optimisation of geodetic networks - with mathematical models describable as eigenvalue problems connected with the variance-covariance matrix of network-coordinates. The eigenvalues and eigenvectors serve as spectral criterions for network analysis and as spectral target functions for network optimisation respectively.
A first network analysis model consists in the comparison of the appropriate variance-covariance matrix with an ideal criterion-matrix, and is based on the general eigenvalue problem of these matrices. Theoretical investigations concerning thereby the problem of choice of datum lead to a unification of hitherto existing approaches in form of a datum-invariant substitutive eigenvalue problem. A second consideration is due to the simple eigenvalue-problem of the variance-covariance matrix of the network-coordinates itself. A therefore developed filter model includes the influence of a weak datum on the spectral criterions as well as a separation between the inner geometry of the regarded network and its absolute foundation. The theoretical studies are completed and further extended by network examples.
The analysis of geodetic networks by means of the simple eigenvalue problem of its variance-covariance matrix of coordinates is closely linked to the kinetics, especially to the eigen-vibrations of elastic mechanical structures. Proceeding from the elastic continuum, the complete foundation of analogies between elastomechanics and geodetic network-compensation by least squares can be carried out in the step of its finite-element-discretisation, being based fundamentally ('fundamental analogies') on equivalent principles, of variations. The well-known analogies between particular corresponding finite elements and geodetic observational types are thereby included and resulting as a special case (denoted as 'direct analogies') of the so cal-led 'principal analogies', which are not at all depending on special types of elements. The principal analogies are forming the central kernel of the treated concept of analogy-foundation. In the sense of a complete analogy-foundation the very principal analogies at the same time represent the link to the way back to the differential equations of the adjoint continuum structures. The differential equations are traced back to their dependence to network-design (pattern), the observational types/elements and their weight-parameterisation). For the purpose of a general derivation of differential equations of regularly designed geodetic networks, there is developed a procedure with an algorithmic nature which is also be applicable to mechanical structures. The mechanical analogies in the matrix equations and differential equations turn out to be useful for the interpretation of the eigenvector-shapes and the eigenvalue-spectrum within the above mentioned geodetic network analysis. For geodetic networks of high density the spectral analysis can advantageously be performed directly by the solution of the differential equations of the (elastic) continuum. The theoretical parts of this chapter are underpinned by appropriate examples.
As inversion of the network analysis with spectral criterions this thesis is (to its second main part) further on dealing with the optimisation on spectral target functions. The chapters of optimisation are introduced by preliminary theoretical research concerning the influence of single observations on the spectral characteristics of a network and with the possibilities of modifying the eigenvalue-spectrum and the eigenvectors by changing observation-weights, design (graph) and nodal point-positions respectively within the network. As for the spectral optimisation concerning 2nd/3rd Order Design and 1st Order Design of point observations, this theoretical framework turns out that the aims of these optimisation-designs can be achieved by target functions limited to the eigenvalues of the above-mentioned eigenvalue problems. The concept of optimisation leads - mathematically spoken - to the problem of solving different associated inverse eigenvalue problems with respect to prescribed target-spectra. For all interesting eigenvalue problems and intended optimisation problems of the above-mentioned designs there can be found a unified iterative solution procedure referring to the normal equations as kernel. The particular eigenvalue problem of optimisation as well as partly required datum-changes are realized by specific transformations within this iteration procedure.
As concerns the final representation of some results of the spectral estimation method, a first attention is - above mechanical aspects - paid to the theoretically founded accordance between the results obtained by classical optimisation and those of spectral optimisation in 2nd/3rd Order Design of classical observation types (applying thereby the corresponding model of the general eigenvalue problem due to a criterion matrix). The second point of interest is mainly dedicated to the results and network examples concerning 1st Order Design appearing as the problem of determining optimum supporting-point observations in geodetic networks; this is quite a dual problem between pure 1st Order Design (optimum positions of these points) and 2nd/3rd Order Design (optimum weights of these point-observations).
The optimisation concerning point observations is representing a new component within geodetic network optimisation. Besides the problem of ideal positions for linking free networks (for ex-ample railway network-chains) to points of the superior network, this kind of optimisation is actually getting more and more important with regard to the quest/ion of finding out best positions for supporting classical terrestrial networks by GPS-point-positioning.Numéro de notice : 28104 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Thèse étrangère Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=63451 Réservation
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Code-barres Cote Support Localisation Section Disponibilité 28104-01 30.10 Livre Centre de documentation Géodésie Disponible 28104-02 30.10 Livre Centre de documentation Géodésie Disponible Quadratic discrete optimization / Z. Bingcai (29/03/1987)
contenu dans Technical papers 1987, ASPRS-ACSM annual convention : ASPRS 53rd annual meeting, ACSM 47th annual meeting, Volume 3. Surveying / American society for photogrammetry and remote sensing (1987)
Titre : Quadratic discrete optimization Type de document : Article/Communication Auteurs : Z. Bingcai, Auteur Editeur : Bethesda [Maryland - Etats-Unis] : American Society for Photogrammetry and Remote Sensing ASPRS Année de publication : 29/03/1987 Importance : pp 52 - 60 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie
[Termes IGN] équation
[Termes IGN] optimisation (mathématiques)
[Termes IGN] quantité discrète
[Termes IGN] réseau de second ordre
[Termes IGN] réseau géodésiqueNuméro de notice : C1987-112 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Communication Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=65297 Categorical data analysis for geographers and environmental scientists / N. Wrigley (1985)
Titre : Categorical data analysis for geographers and environmental scientists Type de document : Guide/Manuel Auteurs : N. Wrigley, Auteur Editeur : Londres : Longman Group Année de publication : 1985 Importance : 392 p. Format : 21 x 27 cm ISBN/ISSN/EAN : 978-0-582-30127-6 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale
[Termes IGN] analyse de données
[Termes IGN] analyse spatiale
[Termes IGN] distribution de Poisson
[Termes IGN] distribution, loi de
[Termes IGN] quantité discrète
[Termes IGN] régressionNuméro de notice : 55477 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Manuel de cours Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=48337 Réservation
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Code-barres Cote Support Localisation Section Disponibilité 55477-01 37.20 Livre Centre de documentation Géomatique Disponible Entwurf digitaler zweidimensionaler nichtrekursiver Filter / Dieter Fritsch (1982)
Titre : Entwurf digitaler zweidimensionaler nichtrekursiver Filter Titre original : [Elaboration d'un filtre numérique non récursif à deux dimensions] Type de document : Thèse/HDR Auteurs : Dieter Fritsch, Auteur Editeur : Munich : Bayerische Akademie der Wissenschaften Année de publication : 1982 Collection : DGK - C Sous-collection : Dissertationen num. 275 Importance : 68 p. Format : 21 x 30 cm ISBN/ISSN/EAN : 978-3-7696-9327-0 Note générale : Bibliographie Langues : Allemand (ger) Descripteur : [Vedettes matières IGN] Traitement du signal
[Termes IGN] approximation
[Termes IGN] filtre de Wiener
[Termes IGN] filtre numérique
[Termes IGN] fréquence
[Termes IGN] impulsion
[Termes IGN] méthode des moindres carrés
[Termes IGN] phase
[Termes IGN] quantité discrète
[Termes IGN] transformation de Fourier
[Termes IGN] transformation en ZIndex. décimale : 24.20 Traitement du signal Numéro de notice : 28139 Affiliation des auteurs : non IGN Thématique : IMAGERIE/POSITIONNEMENT Nature : Thèse étrangère Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=63486 Réservation
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Code-barres Cote Support Localisation Section Disponibilité 28139-01 24.20 Livre Centre de documentation Physique Disponible Reconstruction of functions from discrete mean values / Helmut Moritz (1966)Permalink