Centre de documentation
scientifique

Geopotential models of the Earth from satellite tracking, altimeter and surface gravity observations / F.J. Lerch (1992)

Public Titre : Geopotential models of the Earth from satellite tracking, altimeter and surface gravity observations : GEM-T3 and GEM-T3S Type de document : Monographie Auteurs : F.J. Lerch, Auteur ; R.S. Nerem, Auteur ; B.H. Putney, Auteur ; T.L. Felsentreger, Auteur ; B.V. Sanchez, Auteur Editeur : Washington : National Aeronautics and Space Administration NASA Année de publication : 1992 Collection : NASA Technical Memorandum Importance : 119 p. Format : 21 x 30 cm Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique [Termes IGN] champ de pesanteur terrestre [Termes IGN] données altimétriques [Termes IGN] géodésie spatiale [Termes IGN] levé gravimétrique [Termes IGN] modèle de géopotentiel [Termes IGN] orbitographie [Termes IGN] poursuite de satellite [Termes IGN] satellite d'observation de la mer [Termes IGN] surface de la mer [Termes IGN] surface topographique Index. décimale : 30.40 Géodésie physique Résumé : (Auteur) Improved models of the Earth's gravitational field have been developed from conventional tracking data (GEM-T3S) and from a combination of satellite tracking, satellite altimeter and surface gravirnetric data (GEM-T3). This combination model represents a significant improvement in the modeling of the gravity field at half-wavelengths of 300 km and longer. Both models are complete to degree and order 50. The GEM-T3 model provides more accurate computation of satellite orbital effects as well as giving superior geoidal representation from that achieved in any previous Goddard Earth Model. A description of the models, their development and an assessment of their accuracy is presented. The GEM-T3 model used altimeter data from GEOS-3 (1975-76), Seasat (1978) and Geosat (1986-87) in estimating the orbits, geoid and dynamic height fields. Other satellite tracking data are largely the same as was used to develop GEM-12, but contain certain important improvements in data treatment and expanded laser tracking coverage. Over 1300 arcs of tracking data from 31 different satellites have been used in the solution. Reliable estimates of the model uncertainties via error calibration and optimal data weighting techniques are discussed. Numéro de notice : 18474 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Monographie Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=55397

Exemplaires(2)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
18474-02	30.40	Livre	Centre de documentation	Géodésie	Disponible
18474-01	21.00	Livre	Centre de documentation	Technologies spatiales	Disponible

The determination of the orbit of the Japanese satellite "AJISAI" and the GEM-T1 and GEM-T2 gravity field models / B.V. Sanchez (1990)

Public Titre : The determination of the orbit of the Japanese satellite "AJISAI" and the GEM-T1 and GEM-T2 gravity field models Type de document : Monographie Auteurs : B.V. Sanchez, Auteur Editeur : Washington : National Aeronautics and Space Administration NASA Année de publication : 1990 Importance : 20 p. Format : 21 x 30 cm Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique [Termes IGN] Ajisai [Termes IGN] altimétrie satellitaire par radar [Termes IGN] champ de pesanteur terrestre [Termes IGN] données laser [Termes IGN] orbitographie [Termes IGN] TOPEX-Poseidon [Termes IGN] valeur efficace Index. décimale : 30.40 Géodésie physique Résumé : (Auteur) The Japanese Experimental Geodetic Satellite "Ajisai was launched on August 12. 1986. In response to the TOPEX-POSEIDON mission requirements, the GSFC Space Geodesy Branch and its associates are producing improved models of the Earth's gravitational field. With the launch of Ajisai, we now have precise laser data which can be used to test many current gravity models. The testing of the various gravity field models show improvements of more than 70 percent in the orbital fits when using GEM-Tl and GEM-T2 relative to results obtained with the earlier GEM-10B model. The GEM-T2 orbital fits are at the 13-cm level (RMS). The results of the tests with the various versions of the GEM-Tl model indicate that the addition of satellite altimetry and surface gravity anomalies as additional data types should improve future gravity field models. Numéro de notice : 18037 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Monographie Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=55331

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
18037-01	30.40	Livre	Centre de documentation	Géodésie	Disponible