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Analyse und Numerik überbestimmter Randwertprobleme in der Physikalischen Geodäsie / M. Hirsch (1996)
Titre : Analyse und Numerik überbestimmter Randwertprobleme in der Physikalischen Geodäsie Titre original : [Analyse et problème de valeur aux limites numériques surdéterminées en géodésie physique] Type de document : Thèse/HDR Auteurs : M. Hirsch, Auteur Editeur : Munich : Bayerische Akademie der Wissenschaften Année de publication : 1996 Collection : DGK - C Sous-collection : Dissertationen num. 453 Importance : 154 p. Format : 21 x 30 cm ISBN/ISSN/EAN : 3-7696-9596-1 Note générale : Bibliographie Langues : Allemand (ger) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] Aristoteles
[Termes IGN] modèle mathématique
[Termes IGN] problème des valeurs limitesIndex. décimale : 30.40 Géodésie physique Résumé : (Auteur)The determination of the Earth gravity field is a primary objective of geodesy. In order to solve this task, gravity values must be available in global covering and high density; till now this condition is only insufficiently fulfilled. Therefore, great expectations are focused on new developed observation technologies realizing high precision measurements of gravity or gravitational field signals on moved platforms (airplanes, satellites). These processes promise strongly improved qualitative and quantitative information about the gravity field. Moreover, they are much more effective than traditional methods.
This study deals with suitable mathematical modelling of two of these new measurement methods: airborne gravimetry and satellite gradiometry. In particular, the combination between already available gravity information and new observations in a consistent model is investigated. Overdetermined boundary value problems are used for a mathematical description of this task. In contrast to the classical geodetic boundary value problem, the solution of these problems is not uniquely determinable. The sought quantities rather have to be estimated in function spaces. For this reason, the well known BLUE principle was expanded in order to apply it in infinite dimensional spaces. The direct parameter estimation in the overdetermined boundary value problem is not possible, since the equation types are different while the BLUE principle requires an identical equation type. Therefore, a transformation into a homogenous system of integral equations using the theory of pseudodifferential operators (PDO) has to be performed.
Starting from a general formulation of the overdetermined boundary value problem, two special problems are studied; a linear fixed problem to model the local determination of the gravity field by means of airborne gravimetry, and a nonlinear free boundary value problem, describing the global determination of the gravitational field by means of satellite gradiometry. The solution of the nonlinear problem is based upon an imbedding technique by Hormander. Using this imbedding technique the problem can be decomposed into a sequence of linear boundary value problems with the same structure.
In order to be able to solve the problems with an uniform procedure, the problems are transformed in systems of PDO-equations and interpreted as an analogy to the Gauss-Markov-Model. Inversion-free solution formulae are derived for optimal estimation of the sought potential in the space and frequency domains. Using assumptions about stochastic properties of measurement noise, error formulae, describing expected accuracy of the solution, can be obtained.
In order to verify derived solutions, numerical studies are carried out, which can be divided into the following two parts:
In the first part, an overdetermined boundary value problem in local formulation is investigated. This problem is applied for modelling the stabilized downward continuation of airborne gravimeter data. Using three numerical experiments, the possibility of achieving the stabilization of continuation process without a smoothing of the measurements can be proved. This means that the overdetermined boundary value problem is an alternative to the usually applied Tikhonov's regularization, also in numerical case.
The second part discusses the numerical studies of an overdetermined boundary value problem, which has been formulated to determine the global gravitational field in high resolution. First, the numerical experiments are described. This description explains the simulation of the satellite gradiometry mission ARISTOTELES, the data reduction to given boundary surfaces and the error modelling. In the sequel, the successful numerical verification of the derived estimation formulae is covered. A detailed graphical representation illustrates the accuracy potential of the satellite gradiometry data. Further on, analyses of the influence of the polar data gaps and of the aliasing effect are carried out. The obtained results are compared with the results of other authors.Numéro de notice : 28036 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Thèse étrangère Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=63383 Réservation
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Code-barres Cote Support Localisation Section Disponibilité 28036-01 30.40 Livre Centre de documentation Géodésie Disponible 28036-02 30.40 Livre Centre de documentation Géodésie Disponible Lokale, regionale und globale Punktbestimmung mit Dreizeilenbilddaten und Bahninformation der Mars 96-Mission / T. Ohlhof (1996)
Titre : Lokale, regionale und globale Punktbestimmung mit Dreizeilenbilddaten und Bahninformation der Mars 96-Mission Titre original : [Le positionnement local, régional et global de points avec des données 3D et l'information de trajectoire de la mission 1996 de Mars] Type de document : Thèse/HDR Auteurs : T. Ohlhof, Auteur Editeur : Munich : Bayerische Akademie der Wissenschaften Année de publication : 1996 Collection : DGK - C Sous-collection : Dissertationen num. 445 Importance : 136 p. Format : 21 x 30 cm ISBN/ISSN/EAN : 978-3-7696-9488-8 Note générale : Bibliographie Langues : Allemand (ger) Descripteur : [Vedettes matières IGN] Photogrammétrie numérique
[Termes IGN] compensation par bloc
[Termes IGN] compensation par faisceaux
[Termes IGN] image numérique
[Termes IGN] Mars (planète)
[Termes IGN] mission spatiale
[Termes IGN] simulation
[Termes IGN] trajectoire (véhicule non spatial)Index. décimale : 33.30 Photogrammétrie numérique Résumé : (Auteur) For the forthcoming Mars96 mission a procedure for high precision point determination based on an extended, physically consistent bundle block adjustment has been developed and verified using simulated and practical data. The procedure serves to reconstruct the exterior orientation of the two stereo cameras HRSC (High Resolution Stereo Camera) and WAOSS (Wide-Angle Optoelectronic Stereo Scanner), to improve the existing Mars control network in accuracy and density, and to determine non-photogrammetric model parameters, e.g. the Mars rotation parameters, more accurately.
The Russian Mars96 spacecraft is scheduled for launch in October 1996. The German stereo cameras HRSC and WAOSS are some of the most important instruments of the spacecraft. They will be operated in a highly elliptic Mars orbit to image the planetary surface at local, regional and global scale. From the recorded imagery the terrain surface will be reconstructed 3-dimensionally by photogrammetric means.
The photogrammetric evaluation of the HRSC/WAOSS data starts with the precise reconstruction of the exterior orientation of the images and the determination of ground points on Mars within the scope of a bundle block adjustment. Besides image information represented by a large amount of conjugate points which are measured automatically, control information is required for point determination. Due to the lack of accurate ground control points and navigation systems like GPS or INS, orbit and attitude determination of the Mars96 spacecraft are of high importance.
The mathematical model of bundle block adjustment is based on the collinearity equations. Due to the dynamical mode of image acquisition, each image line has its own exterior orientation with 6 unknown orientation parameters. Since the existing image and control information is not sufficient to estimate all unknowns, the 6 orientation parameters are treated as unknowns only for so-called orientation points, which are introduced at certain time intervals, e.g. once for every 100th or 1000th readout cycle. In between, the orientation parameters of each image line are expressed as polynomials of the parameters of the neighbouring orientation points.
While this approach reduces the number of unknown orientation parameters to a reasonable amount, it has several disadvantages:
/
Any physical relation between the exterior orientation at subsequent orientation points is neglected
entirely, since the positions are modeled by piecewise polynomials and not by orbital constraints.
The statistical properties of the position data derived from orbit determination are improperly considered in the bundle adjustment.
The positional exterior orientation parameters estimated in the bundle adjustment do not permit an interpretation in terms of physical parameters.
In order to avoid these disadvantages, a new appraoch has been developed, which guarantees that all exposure stations of the cameras are lying on a physically consistent trajectory. To this end, the position parameters, which have been estimated so far at arbitrary orientation points, are now replaced by the 6 parameters of the epoch state vector and additional orbit model parameters. In addition, epoch state vector and orbit model para-meters are introduced into the bundle adjustment as direct observations with their full covariance information. Statistically, the resulting estimation procedure is equivalent to a combined orbit determination and bundle adjustment from radio tracking data and 3-line image data.
Computer simulations on point determination have been performed to obtain a survey of the attainable accuracy at local, regional and global levels. Since WAOSS will image the entire planet, a closed block covering the entire Martian surface may be processed under ideal circumstances. Because of the extraordinary strength of the closed block and based on the complete image, orbit, attitude and ground control information, 70 m accuracy in X, Y and Z can be achieved. Moreover, the Mars rotation parameters can be improved by factor 2-4. It can be stated that the synergy effect of image and orbit information is most effective, if many orbital arcs are processed simultaneously in a block of high geometric strength.
The new approach was tested also with practical data. Image data of the multi-line camera MOMS-02 and TDRSS tracking data, both acquired during the German D2 mission, were evaluated together. An empirical accuracy of 12m (0.9 pixel) in X, Y and Z was obtained with only 4 groups of ground control points. Thus the efficiency of the rigorous bundle adjustment approach integrating orbital constraints has been proved with practical data. For that reason, it will be routinely used for the MOMS-2P/PRIRODA mission to be launched in spring 1996.Numéro de notice : 28044 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Thèse étrangère Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=63391 Réservation
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Code-barres Cote Support Localisation Section Disponibilité 28044-01 33.30 Livre Centre de documentation Photogrammétrie - Lasergrammétrie Disponible 28044-02 33.30 Livre Centre de documentation Photogrammétrie - Lasergrammétrie Disponible Zur Bahndynamik niedrigfliegender Satelliten / M. Scheinert (1996)
Titre : Zur Bahndynamik niedrigfliegender Satelliten Titre original : [Sur l'orbite dynamique des satellites à basse altitude] Type de document : Thèse/HDR Auteurs : M. Scheinert, Auteur Editeur : Munich : Bayerische Akademie der Wissenschaften Année de publication : 1996 Collection : DGK - C Sous-collection : Dissertationen num. 435 Importance : 140 p. Format : 21 x 30 cm ISBN/ISSN/EAN : 978-3-7696-9478-9 Note générale : Bibliographie Langues : Allemand (ger) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] Aristoteles
[Termes IGN] champ de pesanteur terrestre
[Termes IGN] données GPS
[Termes IGN] équation de Hill
[Termes IGN] équation différentielle
[Termes IGN] gradiométrie
[Termes IGN] orbite
[Termes IGN] orbite circulaire
[Termes IGN] poursuite de satellite
[Termes IGN] système linéaireIndex. décimale : 30.40 Géodésie physique Résumé : (Auteur) The satellite missions ARISTOTELES and STEP, under discussion for some years, would give the chance to determine the gravitational field of the Earth with high accuracy and up to the short-wave domain. This is due to the expected highly sensitive observations of gravitational gradients fend tracking information obtained by GPS.
The goal of the hereby presented dissertation is to investigate especially the potentiality of the GPS tracking data to solve the coefficients of the long-wave domain in particular.
The theory of Hill's equations forms an excellent tool to analyse the orbit perturbations of the satellites moving in nearly polar, nearly circular orbits of very low altitude. The derivation of the linear perturbation theory is dealt with in detail. Special attention is given to the formulation of differential equations and their analytical and numerical solution.
On the basis of the linear theory numerical simulations were carried out which proofed the impossibility to solve the long-wave domain completely from tracking data of only one of the discussed satellites. But the orbit analysis allows to set up a so-called Tailored Model in each case which may support and complete the processing of the gradiometry data. Further applications of a Tailored Model, gained from an orbit analysis of ARISTOTELES or STEP, resp., are possible, e.g. in the fields of satellite altimetry or of the development of global Earth's gravity models which uses data of satellites in many different orbits.Numéro de notice : 28054 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Thèse étrangère Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=63401 Réservation
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Code-barres Cote Support Localisation Section Disponibilité 28054-01 30.40 Livre Centre de documentation Géodésie Disponible 28054-02 30.40 Livre Centre de documentation Géodésie Disponible Determination of gridded mean sea surface from Topex, ERS-1 and Geosat altimeter data / Y. Yi (1995)
Titre : Determination of gridded mean sea surface from Topex, ERS-1 and Geosat altimeter data Type de document : Monographie Auteurs : Y. Yi, Auteur Editeur : Colombus (Ohio) : Ohio State University Année de publication : 1995 Collection : Department of Geodetic Science and Surveying Reports num. 434 Importance : 93 p. Format : 21 x 27 cm Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] ERS
[Termes IGN] GEOSAT
[Termes IGN] hauteurs de mer
[Termes IGN] modélisation
[Termes IGN] niveau moyen des mers
[Termes IGN] TOPEXIndex. décimale : 30.52 Marégraphie et niveau moyen des mers Résumé : (Auteur) A mean sea surface (MSS) grid model on a 1°/16 grid was developed using one year mean sea surface height (SSH) data of the Topex, Geosat and 35-day repeat ERS-1 altimeter satellites. The first cycle data of 168-day repeat ERS-1 were also included. The MSS data represent average heights of the ocean surface above the Topex/Poseidon reference ellipsoid during Topex repeat cycles 17 through 53.
The one year mean SSH data of each satellite were computed by time-averaging SSH values of all available cycles at fixed points on the reference track. The inverted barometer (IB) correction had been applied to all SSH data before they were reduced to reference tracks correcting for the geoid gradients. The ocean tide correction of the Topex SSH data used in this study had been improved over the Cartwright and Ray 1990 model in a preliminary analysis which estimated residual signals of four major ocean tide constituents along with additional modeling of the annual and semiannual variations and the global secular SSH change. As a by-product of this preliminary data analysis, a sea level rise rate of 2.3 mm/yr. was obtained from Topex SSH data for cycles 4 through 58 after correcting for the drift rate of Topex altimeter. A gridding method of the least squares collocation was used with a covariance function based on the second-order Markov process.
Global test comparisons of several recently developed MSS grid models showed that the MSS model determined in this study had the best agreement with the SSH and along-track SSH gradient data of Topex, Geosat and ERS-1 satellites. The MSS grid model determined in this study, however, contains the artifact of cross-track gradients which show the visual pattern of satellite ground tracks in regions with strong ocean variability. The artificial cross-track gradients of this MSS model can create errors of about 0.2 - 0.3 cm of MSS gradient correction for the ocean-wide Topex data. Another version of the MSS model corresponding to the SSH data without the IB correction was also produced but it was found that the MSS model with the IB correction is preferred.Numéro de notice : 12107 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Monographie Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=54536 Réservation
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Code-barres Cote Support Localisation Section Disponibilité 12107-01 30.52 Livre Centre de documentation Géodésie Disponible DORIS and IERS terrestrial reference frame : open questions and comments / Pascal Willis (1995)
Titre : DORIS and IERS terrestrial reference frame : open questions and comments Type de document : Article/Communication Auteurs : Pascal Willis , Auteur Editeur : Paris : Institut Géographique National - IGN (1940-2007) Année de publication : 1995 Collection : Publications du LAREG Sous-collection : Communications Conférence : ITRF 1995, workshop 08/05/1995 09/05/1995 Saint-Mandé France Importance : 14 p. Format : 21 x 30 cm Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] DORIS
[Termes IGN] International Terrestrial Reference Frame
[Termes IGN] système de référence géodésique
[Termes IGN] TOPEXIndex. décimale : 30.10 Systèmes de référence et réseaux géodésiques Numéro de notice : 12305 Affiliation des auteurs : LAREG (1991-2011) Thématique : POSITIONNEMENT Nature : Communication DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=64257 Réservation
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Code-barres Cote Support Localisation Section Disponibilité 12305-01 30.10 Tiré à part Centre de documentation Géodésie Disponible 12305-02 30.10 Tiré à part Centre de documentation Géodésie Disponible La gestion des données en sciences de la Terre et de l'environnement / Centre national d'études spatiales (1995)PermalinkEstimation of sea dynamic topography, ocean tides, and secular changes from Topex altimeter data / Y.M. Wang (1994)PermalinkThe application of spaceborne atmospheric limb sounding and global change monitoring / W.G. Melbourne (1994)PermalinkEarly results from the Topex-Poseidon GPS precise orbit determination demonstration / Willy I. Bertiger (01/03/1993)Permalinkvol 97 n° E10 - October 1992 - Magellan at Venus Part 2 (Bulletin de Journal of geophysical research : Oceans) / R.S. SaundersPermalinkvol 97 n° E8 - Aout 1992 - Magellan at Venus Part 1 (Bulletin de Journal of geophysical research : Oceans) / R.S. SaundersPermalinkEtude des systèmes de référence terrestres liés au projet Topex-Poseidon / Pascal Willis (01/06/1992)PermalinkComparaisons de systèmes de référence terrestres à partir de données d'orbites de satellites, application au projet franco-américain Topex-Poséidon / F. Cadot (1992)PermalinkFrom Mars to Greenland / O. Colombo (1992)PermalinkJoint IAPSO-IOC workshop on sea level measurements and quality control / Intergovernmental oceanographic commission (1992)PermalinkSatellites et capteurs / Jean Cassanet (1990)PermalinkThe anticipated role of the large format camera in future Earth observation strategies / M. Heric in Geocarto international, vol 4 n° 4 (December 1989 - February 1990)PermalinkSpace shuttle large format camera coverage of areas in Africa : a review of the mission and the photographs acquired / J.D. Greer in Geocarto international, vol 4 n° 2 (June - August 1989)PermalinkCovariance propagation from GEM-L2 and GRIM-3M1P to TOPEX and ERS-1 orbits / J. Klokocnik (1989)Permalinkvol 35 n° 2 - March 1988 - SIR-B experiments in Japan (Bulletin de Journal of the Radio Research Laboratory) / Ministry of posts and telecommunicationsPermalinkParticipation à la reconstruction des trajectoires des ballons de Vénus de la mission Vega par interférométrie différentielle à très grande base, VLBI / A. Ortega-Molina (1988)PermalinkFrom high thrust to low thrust : application of advanced optimisation methods to mission analysis / M.C. Bartholomew-Biggs in ESA journal, vol 11 n° 1 (01/01/1987)PermalinkPrecise orbit computation, gravity model adjustment and altimeter data processing for the ERS-1 altimetry mission / K.F. Wakker (1987)PermalinkRapport d'expérimentation de la campagne Spacelab, IGN, DFVLR / R. Charton (1986)PermalinkUnited States and western Europe cooperation in planetary exploration / Joint working group on cooperation in planetary exploration (1986)Permalink