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ITRF 91 and its associated velocity field / Claude Boucher (1992)
Titre : ITRF 91 and its associated velocity field Type de document : Monographie Auteurs : Claude Boucher , Auteur ; Zuheir Altamimi , Auteur ; Laurent Duhem, Auteur Editeur : Paris, Meudon et Nançay : Observatoire de Paris Année de publication : 1992 Collection : IERS Technical note num. 12 Importance : 140 p. Format : 21 x 30 cm Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] interférométrie à très grande base
[Termes IGN] International Earth Rotation Service
[Termes IGN] International Terrestrial Reference Frame
[Termes IGN] transformation de coordonnéesIndex. décimale : 30.10 Systèmes de référence et réseaux géodésiques Numéro de notice : 68919 Affiliation des auteurs : IGN+Ext (2012-2019) Thématique : POSITIONNEMENT Nature : Recueil / ouvrage collectif Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=44775 Réservation
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Code-barres Cote Support Localisation Section Disponibilité 68919-02 30.10 Livre Centre de documentation Géodésie Disponible 68919-01 30.10 Livre Centre de documentation Géodésie Disponible Optimierung geodätischer Netze mit spektralen Zielfunktionen / H. Kaltenbach (1992)
Titre : Optimierung geodätischer Netze mit spektralen Zielfunktionen Titre original : [Optimisation des réseaux géodésiques par les fonctions spectrales recherchées] Type de document : Thèse/HDR Auteurs : H. Kaltenbach, Auteur Editeur : Munich : Bayerische Akademie der Wissenschaften Année de publication : 1992 Collection : DGK - C Sous-collection : Dissertationen num. 393 Importance : 116 p. Format : 21 x 30 cm ISBN/ISSN/EAN : 978-3-7696-9439-0 Note générale : Bibliographie Langues : Allemand (ger) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] analyse spectrale
[Termes IGN] canevas
[Termes IGN] itération
[Termes IGN] matrice de covariance
[Termes IGN] mire parlante
[Termes IGN] problème inverse
[Termes IGN] réseau géodésique
[Termes IGN] système de coordonnées
[Termes IGN] système non linéaire
[Termes IGN] valeur propreIndex. décimale : 30.10 Systèmes de référence et réseaux géodésiques Résumé : (Auteur) The following thesis deals with the optimization of geodetic networks based on spectral target functions. The spectral analysis and optimization is based on the decomposition of the normal equation matrix of the adjustment or on the covariance matrix of the coordinates in the system of eigenvalues and eigenvectors. Chapter two contains some important mathematical background knowledge from the field of direct and inverse eigenvalue problems and the iterative solution of nonlinear systems of equations. Especially some properties of the newton-procedure are discussed, because this method is generally used to solve inverse eigenvalue problems. To apply the Newton-procedure it is necessary to know the derivatives of the eigenvalues and vectors of the considered matrix with respect to the design parameters. The derivatives of an arbitrary (symmetric) matrix are summarized in this chapter.
The spectral analysis of geodetic networks related to aspects of precision and reliability is the subject of chapter three. Some wellknown local and global measures for the precision are summarized shortly. Aspects concerned with the so-called inner geometry of a network and the definition of the coordinate system (datum problem) are mentioned and supplemented by examples.
The optimization with target functions related to the eigenvalue spectrum is the main part of this thesis and the subject analyzed in detail in chapter four. Principally spoken the task is to determine the coordinates of the netpoints and the observation weights in such a manner that the resulting normal equation or covariance matrix has a special target spectrum. This is the definition of the inverse eigenvalue problem. Based on a given start design of a geodetic network the target function is formulated and the inverse eigenvalue problem is solved iteratively. As mentioned above it is necessary to know the derivatives of the eigenvalues with respect to the coordinates and the observation weights. The derivatives can be computed based on the eigenvalue problem for the normal equation matrix or the covariance matrix and furthermore it is necessary to calculate the derivatives of the elements of the normal equation matrix analytically. Problems arising in network optimization like handling the orientation unknowns in direction networks or the consideration of inner geometry and datum definition of a network are discussed. Examples show the effectiveness of the optimization procedure and show how the so-called weak form of geodetic networks can be reduced. The spectral network optimization is a useful tool for understanding properties and behaviour of geodetic networks. The spectral formulation with target eigenvalues allows the solution of first, second and third order design problems in the usual classification of network optimization. The examples are also used to investigate the properties of the iterative solution procedure, especially the rate of convergence or the definiteness of solutions.
In analogy to the eigenvalues, one can define an inverse eigenvector problem : the task is to determine the design parameters -namely the coordinates and the observation weights - in such a way that the normal equation matrix has given eigenvectors. The formulation of solution procedures and the difficulties in formulating suitable target functions for eigenvectors is the topic of chapter five. One application of this topic is the field of deformation analysis, where the task is to achieve the components of the dominant eigenvector in such a manner that they are perpendicular to. the expected direction of the deformations.
To make an algorithm for network optimization a suitable tool in network planning, it is inevitable to consider some practical aspects. In the first order design, namely the determination of the coordinates of the netpoints, it is obvious that the rate of displacement of the points is limited by the local topography. One cannot move the points arbitrarily without loosing connections between the points. Therefore it is obvious to introduce the possible rate of displacement of the points as restrictions into the optimization algorithm. The same is valid for the observation weigths in a weight optimization (second order design). To take into account aspects of reliability we have to formulate upper bounds for the weights because observations with very high weights compared with other observations usually have low redundancy. Therefore in the adjustment gross errors can be found with a low probability, but unknown errors can distort the results significantly. If we take into account these practical aspects within the iterative solution procedure of the inverse eigenvalue problem we get a problem of minimizing a certain target function with additional restrictions in the form of equations and unequations. There are several methods in optimization theory for solving such problems. Chapter six of the present thesis deals with this topic. Again examples are used to supplement the theoretical investigations.Numéro de notice : 61414 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Thèse étrangère Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=60937 Réservation
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Code-barres Cote Support Localisation Section Disponibilité 61414-01 30.10 Livre Centre de documentation Géodésie Disponible 61414-02 30.10 Livre Centre de documentation Géodésie Disponible Untersuchungen verschiedener Höhensysteme, dargestellt an einer Testschleife in Rheinland-Pfalz / M. Leismann (1992)
Titre : Untersuchungen verschiedener Höhensysteme, dargestellt an einer Testschleife in Rheinland-Pfalz Titre original : [Études de différents systèmes d'altitudes, représentés par une boucle de test en Rhénanie-Palatinat] Type de document : Monographie Auteurs : M. Leismann, Auteur ; R. Klees, Auteur ; H. Beckers, Auteur Editeur : Munich : Bayerische Akademie der Wissenschaften Année de publication : 1992 Collection : DGK - B Sous-collection : Angewandte Geodäsie num. 296 Importance : 97 p. Format : 21 x 30 cm - cont. 7 planches ISBN/ISSN/EAN : 978-3-7696-8580-0 Note générale : Bibliographie Langues : Allemand (ger) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] altitude normale
[Termes IGN] hauteur ellipsoïdale
[Termes IGN] positionnement par GPS
[Termes IGN] Rhénanie-Palatinat (Allemagne)
[Termes IGN] système de référence altimétriqueIndex. décimale : 30.10 Systèmes de référence et réseaux géodésiques Résumé : (Auteur) This report deals with the examination of several height systems for practical and scientific purposes. It starts with a short introduction to the height problem including the formulation of a catalog of demands coming from science, administration, planning and economy. Section 2 contains some foundations about the gravity field of a level ellipsoid, the theoretical closing error that would be obtained by errorless levelling from a starting point, around a level circuit, and back to the starting point and methods for gravity reduc-tions. In section 3 the different height systems being part of our examination are defined. Besides the geo-potential numbers and the dynamic heights we especially consider the orthometric heights and their differ-ent realizations restricting ourselves to those systems which can be determined from levelling and gravity measurements only; for other orthometric heights like Niethammer, Mader and Mueller we summarize the most important facts taken from known publications. Besides, we consider several normal heights, the so called spheroidal-orthometric heights presently used in Germany and the ellipsoidal heights as the only strictly geometrically defined height system. In section 4 we describe the properties of the different height systems and compare them with the catalog of demands mentioned before. The numerical calculations presented in section 5 are based on a closed 420 km levelling line located in the southwestern part of Germany with heights between 60 m and 700 m.
The results show that none of the considered height systems meets all the requirements listed in section 1. That is why we propose the use of two systems; one for purposes placing the dynamic interpretation of heights in the foreground and the other to cover all the geometric tasks most important for piirely geodetic purposes and coming up from modern satellite techniques like NAVSTAR/GPS and inertial methods.
In our opinion, from all the examined height systems the normal heights of Molodensky are the best compro-mise for all users leading to the best compensation between all the requirements. This height system is in contrast to the presently used spheroidal-orthometric system path independent, i.e. independent of the levelling route. In relation to the geopotential numbers and the dynamic heights they have a geometric interpretation, i.e. they define the distance of a point on the earth's surface from the quasigeoid, a surface differing from the geoid by some few centimeters or decimeters; only in some high mountain regions differ-ences up to 2 meters are possible. Its main advantage is especially in comparison with orthometric heights - that it is free from any hypotheses about the variation of gravity within the earth's crust and the isostatic compensation depth so that the accuracy of normal heights depends only on the accuracy of the measured gravity values and the levelling. Compared with the orthometric heights they suffer from the fact that the quasigeoid is not an equipotential surface of the earth's gravity field making the understanding of the heights possibly difficult for some practitioners. The corrections being taken into account to transform the results of levelling into normal heights and normal height differences are comparable to those for orthome-tric heights but greater than the spheroidal-orthometric corrections. But, for most of the practitioners they are not so hard to accept as the very large dynamic corrections. A disadvantage compared with dynamic heights is the fact that surfaces of equal normal heights are not identical with equipotential surfaces of the earth's gravity field. But the differences are very small and have to be considered only in some special cases like hydrologic projects where sometimes high accuracies are required. For geodetic purposes the geometric interpretation of heights is placed in the foreground, particularly in view of the great progress in satellite geodesy especially satellite positioning techniques like NAVSTAR/GPS and inertia! methods so that three dimensional geodesy will become more and more important even for local applications. In that sense ellipsoidal heights should be used as the fundamental geometric height system and should be incorporated into existing geodetic data bases.Numéro de notice : 28219 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Monographie Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=63565 Réservation
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Code-barres Cote Support Localisation Section Disponibilité 28219-01 30.10 Livre Centre de documentation Géodésie Disponible 28219-02 30.10 Livre Centre de documentation Géodésie Disponible An introduction to urban Geographic Information Systems / W. Huxhold (1991)
Titre : An introduction to urban Geographic Information Systems Type de document : Guide/Manuel Auteurs : W. Huxhold, Auteur Editeur : Oxford, Londres, ... : Oxford University Press Année de publication : 1991 Importance : 337 p. Format : 16 x 24 cm - cont. glossaire ISBN/ISSN/EAN : 978-0-19-506535-0 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes d'information géographique
[Termes IGN] analyse spatiale
[Termes IGN] base de données urbaines
[Termes IGN] données localisées
[Termes IGN] milieu urbain
[Termes IGN] mise à jour cartographique
[Termes IGN] modèle topologique de données
[Termes IGN] norme d'échange de données localisées
[Termes IGN] système d'information géographique
[Termes IGN] système de coordonnées
[Termes IGN] système de gestion de base de données
[Termes IGN] ville
[Termes IGN] zonage (urbanisme)Numéro de notice : 44077 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/INFORMATIQUE Nature : Manuel Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=47697
Titre : Connaissance des temps 1992 : éphémérides astronomiques 1992 Type de document : Dictionnaire / Usuel Auteurs : Bureau des longitudes, Auteur Editeur : Paris : Bureau des longitudes BDL Année de publication : 1991 Collection : Connaissance des Temps, ISSN 0181-3048 Importance : 124 p. Format : 21 x 30 cm ISBN/ISSN/EAN : 978-2-11-080609-3 Langues : Français (fre) Descripteur : [Vedettes matières IGN] Astronomie fondamentale
[Termes IGN] calendrier
[Termes IGN] coordonnées
[Termes IGN] éphémérides de satellite
[Termes IGN] Lune
[Termes IGN] méridien
[Termes IGN] planète
[Termes IGN] satellite naturel
[Termes IGN] soleil (étoile)
[Termes IGN] système de référence géodésique
[Termes IGN] tempsNuméro de notice : 59984 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Usuel En ligne : https://gallica.bnf.fr/ark:/12148/bpt6k9780535n Format de la ressource électronique : URL Gallica Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=36140 Differential geodesy / Martin Hotine (1991)PermalinkDifferentielle Verschiebungen und Drehstreckungen in dreidimensionalen Koordinatensystemen / D. Ehlert (1991)PermalinkEin klassifizierender Beitrag zur Abbildungstheorie und numerischen Genauigkeit von geodätischen Datumsübergängen / R. Schreiber (1991)PermalinkEine analytische Lösung kanonischer Gleichungen der geodätischen Linie zur Transformation ellipsoidischer Flächenkoordinaten / J. Klotz (1991)PermalinkErfassung unsteter Oberflächen aus digitalen Bilddaten durch Flächen- und Kantenzuordnung / R. Li (1990)PermalinkGPS / H.L. Mitchell (1990)PermalinkMéthodes modernes en géodésie : contributions au séminaire DVW, 12-14 Avril 1989, 1. Volume 1 / A. Schodlbauer (1990)PermalinkMéthodes modernes en géodésie : contributions au séminaire DVW, 12-14 Avril 1989, 2. Volume 2 / A. Schodlbauer (1990)PermalinkPlanetary mapping / R. Greeley (1990)PermalinkRéférences de coordonnées tridimensionnelles, bidimensionnelles et altimétriques et unités de coordonnées / IGN (1990)Permalink