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Auteur Oscar L. Colombo |
Documents disponibles écrits par cet auteur (3)
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From Mars to Greenland / Oscar L. Colombo (1992)
Titre : From Mars to Greenland : charting gravity with space and airborne instruments, fields tide methods results, International Association of Geodesy symposium Type de document : Actes de congrès Auteurs : Oscar L. Colombo, Éditeur scientifique Editeur : Berlin, Heidelberg, Vienne, New York, ... : Springer Année de publication : 1992 Collection : International Association of Geodesy Symposia, ISSN 0939-9585 num. 11 Conférence : IAG 1991, 20th general assembly and symposium, From Mars to Greenland : charting gravity with space and airborne instruments, fields tide methods results 11/08/1991 24/08/1991 Vienne Autriche Importance : 358 p. Format : 21 x 30 cm ISBN/ISSN/EAN : 978-3-540-97857-2 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] altimétrie
[Termes IGN] Aristoteles
[Termes IGN] atmosphère terrestre
[Termes IGN] géodésie spatiale
[Termes IGN] Global Positioning System
[Termes IGN] gravimètre supraconducteur
[Termes IGN] Groenland
[Termes IGN] Mars (planète)
[Termes IGN] orbite
[Termes IGN] pesanteur terrestre
[Termes IGN] satellite artificielNuméro de notice : 67653 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Actes Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=37147 Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 67653-01 CG.91 Livre Centre de documentation En réserve M-103 Disponible Altimetry, orbits and tides / Oscar L. Colombo (1984)
Titre : Altimetry, orbits and tides Type de document : Monographie Auteurs : Oscar L. Colombo, Auteur Editeur : Washington : National Aeronautics and Space Administration NASA Année de publication : 1984 Collection : NASA Technical Memorandum Importance : 173 p. Format : 21 x 30 cm Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Techniques orbitales
[Termes IGN] marée océanique
[Termes IGN] orbite képlerienne
[Termes IGN] orbitographie
[Termes IGN] poursuite de satellite
[Termes IGN] surface de la mer
[Termes IGN] vitesse radialeRésumé : (Auteur) This report explains the nature of the orbit error and its effect on the sea surface heights calculated with satellite altimetry. It includes an introduction of the elementary concepts of celestial mechanics required to follow a general discussion of the problem. This leads to a detailcd consideration ot errors in the orbits of satellites with precisely repeating groLind tracks (SEASAT, TOPEX, ERS1, POSEIDON, amongst past and future altimeter satellites). The theoretical conclusions are illustrated with the numerical results of computer simulations. The nature of the errors in this type of orbits is such that this error can be filtered out by using height differences along repeating (overlapping) passes. This makes them particularly valuable for the study and monitoring of changes in the sea surface, such as tides. The report ends with a presentation of some elements of tidal theory, showing how these principles can be combined with those pertinent to the orbit error to make direct maps of the tides using altimetry. Numéro de notice : 18679 Affiliation des auteurs : non IGN Thématique : IMAGERIE/POSITIONNEMENT Nature : Monographie Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=55445 Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 18679-01 21.10 Livre Centre de documentation Technologies spatiales Disponible
Titre : The global mapping of gravity with two satellites Type de document : Rapport Auteurs : Oscar L. Colombo, Auteur Editeur : Delft : Netherlands Geodetic Commission NGC Année de publication : 1984 Collection : Netherlands Geodetic Commission Publications on Geodesy Sous-collection : New series Importance : 253 p. Format : 20 x 27 cm ISBN/ISSN/EAN : 978-90-6132-230-6 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] champ de pesanteur terrestre
[Termes IGN] collocation par moindres carrés
[Termes IGN] équation de Hill
[Termes IGN] gradiométrie
[Termes IGN] mécanique orbitale
[Termes IGN] modèle mathématique
[Termes IGN] orbite défilante
[Termes IGN] poursuite de satellite
[Termes IGN] satellite artificiel
[Termes IGN] simulation
[Termes IGN] vitesse radialeIndex. décimale : 30.60 Géodésie spatiale Résumé : (auteur) This is a report on a method for the detailed and global mapping of the planetary gravitational field using two artificial satellites that carry devices to track each other along the same near-circular, near-polar orbit, separated by a few hundred kilometers and as low as the atmosphere would allow. They are kept a loft, in spite of air drag, by the action of small rocket engines that maintain a proof-mass inside each spacecraft in constant free fall. The signal is the relative line- of-sight velocity of the proof masses, averaged over several seconds.
A specially tailored analytical perturbation theory, where the reference orbit is periodical and obtained by numerical integration in a low-degree zonal reference field, is used here to derive a linearized model for the signal. The 'lumped coefficients' of the perturbations can be calculated very efficiently with a technique that relies heavily on the Fast Fourier Transform algorithm, and whose principle is similar to that of Gauss' method for integrating Lagrange's planetary equations. Computer simulations of the relative motion of the satellites in a field whose potential is the sum of zonal spherical harmonics up to degree 300, suggest that the model is accurate to better than 1% at most frequencies present in the spectrum of the signal. The programs used for the simulations are explained and listed in an appendix.
Detailed consideration is given to a method for estimating from the data all potential coefficients up to a high degree and order (such as 300). This method is based on the choice of a common orbit that closes upon itself after enough days have elapsed to resolve all the unknown coefficients. This orbit gives a rotationally symmetrical distribution of data. After taking care of the non-periodical component of the signal (due to orbit estimation errors and secular resonant effects) by introducing extra unknowns, the normal equations of the adjustment become very sparse. With a suitable ordering of unknowns, it shows an 'arrow' structure, the 'shaft' consisting of diagonal blocks. It is feasible to solve such a system (in spite of its great size) with ordinary modern computers, and also to find the formal accuracies of the results by a partial inversion of the normal matrix.Numéro de notice : 55090 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Rapport de recherche DOI : sans En ligne : https://www.ncgeo.nl/downloads/28Colombo.pdf Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=59760 Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 55090-01 30.60 Livre Centre de documentation Géodésie Disponible