Détail d'une collection
Sous-collection Dissertationen
Éditeur :
Collection :
ISSN :
pas d'ISSN
|
Documents disponibles dans la sous-collection (453)
Ajouter le résultat dans votre panier
Visionner les documents numériques
Affiner la recherche Interroger des sources externes
Zur Parametrisierung radialsymmetrischer Dichtemodelle für die Erde / H. Wziontek (2005)
Titre : Zur Parametrisierung radialsymmetrischer Dichtemodelle für die Erde Titre original : [Pour la paramétrisation de modèles denses symétriques pour la Terre] Type de document : Thèse/HDR Auteurs : H. Wziontek, Auteur Editeur : Munich : Bayerische Akademie der Wissenschaften Année de publication : 2005 Collection : DGK - C Sous-collection : Dissertationen num. 587 Importance : 102 p. Format : 21 x 30 cm ISBN/ISSN/EAN : 978-3-7696-5026-6 Note générale : Bibliographie Langues : Allemand (ger) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] croute terrestre
[Termes IGN] densité
[Termes IGN] équation de Poisson
[Termes IGN] masse de la Terre
[Termes IGN] potentiel de pesanteur terrestre
[Termes IGN] vitesseIndex. décimale : 30.40 Géodésie physique Résumé : (Auteur) Even in the frame of a spherical symmetric, non-rotating, linear elastic and isotropic model an independent description of the Earth's density and elastic properties, as usual in most existing models, has no unique solution and thus leads to an over-parametrisation. Whereas the elastic properties can be verified well with the help of seismic traveltimes, the density remains much less determinate. With this work, an adequate description of a normal density distribution based on a physically meaningful, non-empirical parametrisation and an abstraction to the essential physical properties will be presented. Beside the postulate on homogeneity of the chemical composition and phase inside each shell and an adiabatic gradient of temperature, the main assumption is hydrostatic equilibrium, which must be fulfilled in a global sense for the widest parts of the Earth's interior. Under these circumstances the Williamson-Adams-equation holds as a fundamental relation between density and seismic velocities. Deviations from the underlying suppositions can be described, if necessary and appropriate information exists, a priori by the Bullen-Parameter. By the physical relation between density and seismic velocities alone a parametrisation is not given. With the help of a postulate on a pressure-density-relation in historical density laws it is possible to develop a suitable function. A differential equation follows from the Poisson equation for the inner gravitational potential in conjunction with that postulate and the assumption of hydrostatic equilibrium. Its special solutions lead in consistence with seismic data to a parametrisation of the density. Extensive investigations show that only functions in even powers of the radius allow a best and stable fit to the seismic data, while ordinary polynomials most common in use are less eligible for a description of the density. Furthermore, to obtain a stable determination of the density a strict separation of the data-types is unavoidable. From the seismic velocities it is only possible to infer the shape of the density-function within the shells, additional data as the density below the crust-mantle-boundary, the geodetic values for mean mass and mean moment of inertia and the frequencies of the free oscillations are necessary to fix the absolute level in each shell. Under consideration of the aforementioned aspects it is possible to obtain a unique and stable description of a normal density distribution in accordance with seismic and geodetic information. Thus the presented parametrisation can serve as a basis for anomaly analysis in geodesy and geophysics. Numéro de notice : 13274 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Thèse étrangère Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=54953 Exemplaires(2)
Code-barres Cote Support Localisation Section Disponibilité 13274-01 30.40 Livre Centre de documentation Géodésie Disponible 13274-02 30.40 Livre Centre de documentation Géodésie Disponible Atmosphärische und ozeanische Einflüsse auf die Rotation der Erde - Nummerische Untersuchungen mit einem dynamischen Erdsystemmodell / Florian Seitz (2004)
Titre : Atmosphärische und ozeanische Einflüsse auf die Rotation der Erde - Nummerische Untersuchungen mit einem dynamischen Erdsystemmodell Titre original : [Influences atmosphérique et océanographique sur la rotation de la Terre : études numériques avec un modèle dynamique systémique de la Terre] Type de document : Thèse/HDR Auteurs : Florian Seitz, Auteur Editeur : Munich : Bayerische Akademie der Wissenschaften Année de publication : 2004 Collection : DGK - C Sous-collection : Dissertationen num. 578 Importance : 94 p. Format : 21 x 30 cm ISBN/ISSN/EAN : 978-3-7696-5017-4 Note générale : Bibliographie Langues : Allemand (ger) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] atmosphère terrestre
[Termes IGN] circulation atmosphérique
[Termes IGN] circulation océanique
[Termes IGN] marée terrestre
[Termes IGN] modèle dynamique
[Termes IGN] moment cinétique atmosphérique
[Termes IGN] mouvement du pôle
[Termes IGN] océan
[Termes IGN] ondelette
[Termes IGN] rotation de la Terre
[Termes IGN] terme de Chandler
[Termes IGN] théorème de LiouvilleIndex. décimale : 30.40 Géodésie physique Résumé : (Auteur) Variations of Earth rotation are caused by a multitude of gravitational and geophysical processes in the Earth system. The largest effects are due to tidal deformations of the solid Earth and mass redistributions within the atmosphere and the oceans. In order to study the Earth's reaction on gravitational and geophysical excitations, the dynamic Earth system model DyMEG has been developed. It is based on the balance of angular momentum in the Earth system, which is described by the non-linear Liouville equation. The model is forced by consistent time series of variations of the Earth's tensor of inertia and relative angular momenta which are deduced from atmospheric and oceanic circulation models. In contrast to former investigations, the characteristics of the Earth's free polar motion (Chandler wobble) are not explicitly predetermined with respect to period and damping but reproduced by the model from geometrical and rheological parameters. Therefore the traditional analytical solution is not applicable, and the Liouville equation is solved numerically as an initial value problem. A sensitivity analysis of DyMEG reveals that the solution based on a Runge-Kutta method is reliable from an algorithmic point of view. However, the system is sensitive to the initial conditions of the integration and the rheological model parameters (Love numbers). Forced variations of Earth rotation due to atmospheric and oceanic excitations yield an effect on the free polar motion as rotational deformations of the solid Earth are regarded in DyMEG. Wavelet analyses of the resulting time series for polar motion show that the Chandler wobble from DyMEG is excited by the atmospheric and oceanic mass redistributions over more than two decades. The noise of the excitation series is found to contain sufficient energy to counteract the damping of the Chandler amplitude which is caused by friction. It is assumed that the noise is due to stochastic processes within the atmosphere (weather). The numerical results for polar motion and length-of-day variations from DyMEG are significantly related with geodetic observations. Depending on the quality of the excitations, the correlation coefficients between the model time series and observations amount to 0,99. In addition to the rotational variations, time series of the second degree spherical harmonic coefficients of the Earth's gravity field, which are directly linked to the tensor of inertia, are computed. The mean values of the respective coefficients are in good agreement with recent gravity models. However the validation of their temporal variations is limited as suitable observation time series are not yet available. Numéro de notice : 13278 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Thèse étrangère Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=54957 Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 13278-01 30.40 Livre Centre de documentation Géodésie Disponible Automatische Extraktion urbaner Straßennetze aus Luftbildern / Stefan Hinz (2004)
Titre : Automatische Extraktion urbaner Straßennetze aus Luftbildern Titre original : [Extraction automatique d'un réseau routier urbain à partir de photographies aériennes] Type de document : Thèse/HDR Auteurs : Stefan Hinz, Auteur Editeur : Munich : Bayerische Akademie der Wissenschaften Année de publication : 2004 Collection : DGK - C Sous-collection : Dissertationen num. 580 Importance : 130 p. Format : 21 x 30 cm ISBN/ISSN/EAN : 978-3-7696-5019-8 Note générale : Bibliographie Langues : Allemand (ger) Descripteur : [Vedettes matières IGN] Photogrammétrie numérique
[Termes IGN] extraction automatique
[Termes IGN] milieu urbain
[Termes IGN] orthoimage
[Termes IGN] photographie aérienne
[Termes IGN] prise en compte du contexte
[Termes IGN] réseau routier
[Termes IGN] segmentation d'imageIndex. décimale : 33.30 Photogrammétrie numérique Résumé : (Auteur) In this dissertation, a new approach to automatic road extraction from high resolution aerial imagery taken over urban areas is developed. In order to deal with the high complexity of this type of scenes, the approach integrates detailed knowledge about roads and their context using explicitly formulated scale-dependent models. The knowledge about how and when certain parts of the road and context model are optimally exploited is expressed by an extraction strategy. It is subdivided into three levels: Context-based data analysis (Level 1) comprises the segmentation of the scene into the urban, rural, and forest area as wells as the analysis of context relations (e.g. the determination of shadow areas and the detection of vehicles). Processing continues in urban areas. To determine salient roads (Level 2) the extraction includes the detection of homogeneous ribbons as preliminary road segments in coarse scale, collinear grouping thin bright road markings in fine scale, and the construction of lanes from groups of road markings and road sides. Then, the lanes are further grouped into larger road objects, so-called road segments. During road network completion (Level 3), road segments detected in overlapping images are fused and gaps in the extraction are iteratively closed by hypothesizing and verifying connections between previously extracted road segments. To this end, local as well as global criteria exploiting the network characteristics are used. The result of network completion are roads that connect junctions or endpoints. A key feature of the presented approach is the incorporation of a scheme for self-diagnosis. With this scheme each hypothesis generated during extraction is internally evaluated so that its relevance for further processing can be assessed. This facilitates decisions inherently appearing during the extraction process. The results achieved with the approach show that the implemented system is able to extract roads in complex environments, i.e. the extraction is also possible when the appearance of roads is heavily affected by other objects. Based on an external evaluation of the results, the system is validated, and advantages but also remaining deficiencies are discussed. Numéro de notice : 13279 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Thèse étrangère Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=54958 Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 13279-01 33.30 Livre Centre de documentation Photogrammétrie - Lasergrammétrie Disponible Das stochastische Modell bei der VLBI-Auswertung / V. Tesmer (2004)
Titre : Das stochastische Modell bei der VLBI-Auswertung Titre original : [Le modèle stochastique dans l'exploitation de l'interférométrie à très longue base] Type de document : Thèse/HDR Auteurs : V. Tesmer, Auteur Editeur : Munich : Bayerische Akademie der Wissenschaften Année de publication : 2004 Collection : DGK - C Sous-collection : Dissertationen num. 573 Importance : 105 p. Format : 21 x 30 cm ISBN/ISSN/EAN : 978-3-7696-5012-9 Note générale : Bibliographie Langues : Allemand (ger) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] corrélation
[Termes IGN] covariance
[Termes IGN] interférométrie à très grande base
[Termes IGN] modèle de Gauss-Markov
[Termes IGN] modèle stochastique
[Termes IGN] positionnement par ITGB
[Termes IGN] varianceIndex. décimale : 30.63 Télémétrie laser sur satellite, Télémétrie laser sur lune, VLBI Résumé : (Auteur) Previous improvements of parameter estimations using the observations of Very Long Baseline Interferometry (VLBl) were mainly achieved by refining the functional representation of the geometric-physical properties of the observations. Further progress in this field mostly implicates big efforts and is not possible with any precision. In contrast, the stochastic properties of the observations (due to functionally not ascertainable influences) have not been handled with much care so far. Therefore, this work deals with a qualitative description of deficits of VLBI observations' stochastic model as well as the quantification of these deficits by means of estimation of variance and covariance components. The estimated components represent the entirety of VLBI observations as much as possible. Shortcomings were found to be mainly station and elevation dependent. It is demonstrated that standard VLBI solutions can be improved using a refined stochastic model for the observations. Numéro de notice : 13203 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Thèse étrangère Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=54913 Exemplaires(2)
Code-barres Cote Support Localisation Section Disponibilité 13203-01 30.63 Livre Centre de documentation Géodésie Disponible 13203-02 30.63 Livre Centre de documentation Géodésie Disponible Ein integritätswahrendes Messsystem für kinematische Anwendungen / W. Stempfhuber (2004)
Titre : Ein integritätswahrendes Messsystem für kinematische Anwendungen Titre original : [Un système de mesure intégré pour des applications cinématiques] Type de document : Thèse/HDR Auteurs : W. Stempfhuber, Auteur Editeur : Munich : Bayerische Akademie der Wissenschaften Année de publication : 2004 Collection : DGK - C Sous-collection : Dissertationen num. 576 Importance : 128 p. Format : 21 x 30 cm ISBN/ISSN/EAN : 978-3-7696-5015-0 Note générale : Bibliographie Langues : Allemand (ger) Descripteur : [Vedettes matières IGN] Navigation et positionnement
[Termes IGN] agriculture de précision
[Termes IGN] étalonnage d'instrument
[Termes IGN] GPS en mode cinématique
[Termes IGN] GPS en mode différentiel
[Termes IGN] guidage de véhicules
[Termes IGN] lever tachéométrique
[Termes IGN] positionnement cinématique en temps réel
[Termes IGN] tachéomètre électroniqueIndex. décimale : 30.70 Navigation et positionnement Résumé : (Auteur) By combining individual components with intelligent analytical algorithms, modern measuring systems such as robot tacheometer or the " Global Positioning System, (GPS) " allow many new areas of application in modern engineering surveying. Use of this equipment is initially limited to static, quasi-static or stop-and-go techniques. Today, these efficient measuring sensors are used increasingly for kinematic measuring tasks.
Different applications for the precise description of the movement track and for optimizing the horizontal and vertical availability require a combination of these measuring sensors, which operate separately. Normally both these measuring instruments cannot be combined without changing hardware or software (firmware). This thesis presents a method that allows a synchronization of independent measuring systems without a common basis through a comprehensive observation of all factors of disturbance and influence. Calibration of terrestrial and global measuring sensors for kinematic applications is also discussed in detail.
With respect to the description of dynamic movement processes, a calibration of this kind of kinematic measuring sensors requires an expansion of conventional geodetic strategies. Based on static characteristics, these sensors must be tested using kinematic testing methods relating to the type, size and behavior of target points affected by measuring uncertainty. In addition, the real time capability of the measuring system and the synchronization of individual subsystems must be verified and, if required, minimized by corresponding calibration functions.
The result is a hybrid measuring system for kinematic applications that, independent of the type of movement, allows a precise derivation of the movement path based on discrete measuring points on a millimeter scale. For example, these hybrid measuring systems can be employed for the following: 1- as a high precision positioning system for navigation and control of process flows in road and railways track construction (machine guidance), 2- for special applications involving maximum availability and accuracy requirements for land and water vehicles or aircraft, 3- as a reference system to verify the feasible accuracy of positioning and application techniques, and 4- to analyze technical reaction times of partial and overall systems in the precision farming sector.
The descriptions of selected applications in this thesis are limited to testing of section specific land use with the " Landwirtschaftlichen BUS System LBS, (DIN 9684 and ISO 11783) " with respect to position accuracy, precision, quality, and size of disturbances occurring. Investigations have been partly funded by a joint research project within the " Forschungsverbund Agrarökosysteme München, (FAM) " research alliance, which took place at the Chair for Geodesy in cooperation with the Department for Bio Resources and Land Use Technology, Crop Production Engineering (both at the Technical University of Munich).Numéro de notice : 13276 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Thèse étrangère Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=54955 Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 13276-01 30.70 Livre Centre de documentation Géodésie Disponible Identifizierung konsistenter Datengruppen am Beispiel der Kongruenzuntersuchung geodätischer Netze / Frank Neitzel (2004)PermalinkKonzeption und Umsetzung eines Informationssystems zur geodätischen Deformationsanalyse / J. Zimmermann (2004)PermalinkModellierung von Oberflächen mit Diskontinuitäten / Andrzej Borkowski (2004)PermalinkSimultane Schätzung von Topographie und Dynamik polarer Gletscher aus multi-temporalen SAR Interferogrammen / F.J. Meyer (2004)PermalinkAnalyse und Optimierung geodätischer Messanordnungen unter besonderer Berücksichtigung des Intervallansatzes / S. Schön (2003)PermalinkPermalinkAutomatische Extraktion von Straßen aus digitalen Luftbildern / Andreas Baumgartner (2003)PermalinkPermalinkBauaufnahme als Modellierungsaufgabe / U. Weferling (2003)PermalinkHierarchical real-time recognition of compound objects in images / M. Ulrich (2003)Permalink