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Satellite constellation with direct radio measurements for atmospheric studies : WATS mission case / G. Alberti in International Journal of Remote Sensing IJRS, vol 25 n° 18 (September 2004)
[article]
Titre : Satellite constellation with direct radio measurements for atmospheric studies : WATS mission case Type de document : Article/Communication Auteurs : G. Alberti, Auteur ; G.B. Amata, Auteur ; F. Amisano, Auteur Année de publication : 2004 Article en page(s) : pp 3703 - 3730 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Missions spatiales
[Termes IGN] Agence spatiale européenne
[Termes IGN] antenne
[Termes IGN] distribution spatiale
[Termes IGN] étude de faisabilité
[Termes IGN] mission spatiale
[Termes IGN] onde radioélectrique
[Termes IGN] orbite basse
[Termes IGN] positionnement par GNSS
[Termes IGN] radiooccultation
[Termes IGN] rayonnement électromagnétique
[Termes IGN] rayonnement radioélectrique
[Termes IGN] récepteur
[Termes IGN] réfraction atmosphérique
[Termes IGN] stratosphère
[Termes IGN] teneur en vapeur d'eau
[Termes IGN] transmission de données
[Termes IGN] troposphère
[Termes IGN] vapeur d'eau
[Termes IGN] vent
[Termes IGN] Water Vapour and Wind in Atmospheric Troposphere and StratosphereRésumé : (Auteur) This paper shows the main results of a pre-feasibility study commissioned by the European Space Agency (ESA) in the framework of the Earth Explorer Core Mission programme. The analysed mission is called WATS (Water vapour and wind in Atmospheric Troposphere and Stratosphere) and aims to monitor variations and changes in the global atmospheric water vapour distribution and lower-stratosphere/upper-troposphere winds. Starting from a set of scientific requirements, the present work shows the main results of the mission analysis in terms of the number and spatial distribution of possible measurements. By performing trade-off with respect to expected values, the number of satellites forming the constellation has been fixed as well as the main orbital parameters, also taking into account degradations within the maximum expected mission lifetime. To assess the accuracy of the final measurement, a suitable performance model has been established that takes into account the effects of both the radio propagation of the signal through the atmosphere and the instrument receiving chain. The results obtained by running such a performance model are presented and discussed in order to assess the main system parameters mainly in terms of minimum transmitted power. Following, a sensitivity analysis is presented that shows the effects of antenna pointing error, receiver gain fluctuation, effective antenna size and pre-detection bandwidth. Numéro de notice : A2004-357 Affiliation des auteurs : non IGN Thématique : IMAGERIE/POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/01431160410001680392 En ligne : https://doi.org/10.1080/01431160410001680392 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26884
in International Journal of Remote Sensing IJRS > vol 25 n° 18 (September 2004) . - pp 3703 - 3730[article]Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité 080-04161 RAB Revue Centre de documentation En réserve L003 Exclu du prêt Single frequency processing of atmospheric radio occultations / M. De La Torre Juarez in International Journal of Remote Sensing IJRS, vol 25 n° 18 (September 2004)
[article]
Titre : Single frequency processing of atmospheric radio occultations Type de document : Article/Communication Auteurs : M. De La Torre Juarez, Auteur ; E.R. Kursinski, Auteur ; et al., Auteur Année de publication : 2004 Article en page(s) : pp 3731 - 3734 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image
[Termes IGN] atmosphère terrestre
[Termes IGN] correction ionosphérique
[Termes IGN] dégradation du GPS
[Termes IGN] données GPS
[Termes IGN] radiooccultation
[Termes IGN] rapport signal sur bruit
[Termes IGN] réfraction atmosphérique
[Termes IGN] signal GPSRésumé : (Auteur) Tracking of the radio signals broadcast by the Global Positioning System (GPS) satellites as they are occulted from a GPS receiver by the Earth's atmosphere can provide high resolution vertical profiles of atmospheric refractivity, temperature and water vapour. Most implementations of this radio occultation technique use two GPS frequencies to correct for ionospheric effects. However, during most soundings, one of the frequencies is degraded by the introduction of the so-called Anti-Spoofing (AS) encryption mode. A retrieval method is discussed in this work for periods when only one of the two frequency signals has good quality. This method uses only the frequency with higher signal-to-noise ratio. We illustrate the quality of the atmospheric profiles obtained from such single frequency retrievals using GPS/MET data from the periods where the AS was turned off and the two frequencies were available. The results enable us to ensure the quality of a climate record of thousands of radio occultations collected by GPS/MET during the period with AS encryption, and the data processing of future missions with similar constraints, like IOX, can be performed. Numéro de notice : A2004-358 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/0143116031000156800 En ligne : https://doi.org/10.1080/0143116031000156800 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26885
in International Journal of Remote Sensing IJRS > vol 25 n° 18 (September 2004) . - pp 3731 - 3734[article]Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité 080-04161 RAB Revue Centre de documentation En réserve L003 Exclu du prêt Geophysical distributions of occultations of GPS satellites viewed from a low Earth orbiting satellite / D.M. O'Brien (1998)
Titre : Geophysical distributions of occultations of GPS satellites viewed from a low Earth orbiting satellite Type de document : Monographie Auteurs : D.M. O'Brien, Auteur ; Paul Tregoning, Auteur Editeur : Aspendale : CSIRO Atmospheric Research Année de publication : 1998 Collection : CSIRO Atmospheric research technical paper num. 39 Importance : 31 p. Format : 21 x 29 cm ISBN/ISSN/EAN : 978-0-643-06345-7 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] affaiblissement géométrique de la précision
[Termes IGN] antenne GPS
[Termes IGN] atmosphère terrestre
[Termes IGN] constellation GPS
[Termes IGN] distribution spatiale
[Termes IGN] météorologie
[Termes IGN] orbite basse
[Termes IGN] radiooccultation
[Termes IGN] récepteur GPS
[Termes IGN] satellite artificiel
[Termes IGN] satellite GPSIndex. décimale : 30.84 Applications de géodésie spatiale à l'atmosphère Résumé : (Auteur) The infrastructure of the Global Positioning System (GPS), with a minimum of twenty four satellites in precisely determined orbits, each transmitting on two radio frequencies of approximately 1.58 GHz and 1.23 GHz, opens new opportunities for meteorology through radio occultation. A small satellite in low earth orbit (LEO) carrying a GPS receiver will see the satellites of the GPS constellation rise and set behind the earth. From measurements of the Doppler shifts of the radio waves during occultations of the GPS satellites, it is possible to deduce the bending of the radio waves in the atmosphere of the Earth, and hence determine the density profile of the atmosphere. The method is unaffected by cloud, does not involve radiometric calibration like other remote sensing methods, and provides density soundings over the entire globe. This technical paper examines the spatial distributions of occultations for four different GPS antenna configurations on the LEO and for orbits of the LEO ranging from equatorial to polar. It is found that the most uniform spatial distribution of occultations occurs for orbits with inclinations near 60° and 120°. In addition, probability distributions are computed for the number of GPS satellites in view and the geometric dilution of precision, the latter being a measure of the accuracy with which the orbit of the LEO may be determined. Because underflight of a GPS satellites by the LEO offer an opportunity to determine the structure of the ionosphere along radial lines from the LEO to the GPS satellite, the paper also computes the frequency of underflights and their spatial distributions. Numéro de notice : 66783 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Monographie Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=61660 Réservation
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Code-barres Cote Support Localisation Section Disponibilité 66783-01 30.84 Livre Centre de documentation Géodésie Disponible The application of spaceborne atmospheric limb sounding and global change monitoring / W.G. Melbourne (1994)
Titre : The application of spaceborne atmospheric limb sounding and global change monitoring Type de document : Monographie Auteurs : W.G. Melbourne, Auteur ; E.S. Davis, Auteur ; C.B. Duncan, Auteur ; G.A. Hajj, Auteur ; G.A. Hardy, Auteur ; et al., Auteur Editeur : Pasadena : Jet Propulsion Laboratory JPL Année de publication : 1994 Collection : JPL Publications num. 94-18 Importance : 150 p. Format : 21 x 30 cm Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] atmosphère terrestre
[Termes IGN] changement climatique
[Termes IGN] météorologie
[Termes IGN] mission spatiale
[Termes IGN] orbite basse
[Termes IGN] positionnement par GPS
[Termes IGN] radiooccultation
[Termes IGN] sonde spatiale
[Termes IGN] surveillance météorologiqueIndex. décimale : 30.84 Applications de géodésie spatiale à l'atmosphère Numéro de notice : 67385 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Monographie Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=61743 Réservation
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Code-barres Cote Support Localisation Section Disponibilité 67385-01 30.84 Livre Centre de documentation Géodésie Disponible 67385-02 30.84 Livre Centre de documentation Géodésie Disponible