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On-orbit BDS signals and transmit antenna gain analysis for a geostationary satellite / Meng Wang in Advances in space research, vol 69 n° 7 (April 2022)  

Public [article]  inAdvances in space research > vol 69 n° 7 (April 2022) . - pp 2711 - 2723 Titre : On-orbit BDS signals and transmit antenna gain analysis for a geostationary satellite Type de document : Article/Communication Auteurs : Meng Wang, Auteur ; Tao Shan, Auteur ; Lei Liu, Auteur ; et al., Auteur Année de publication : 2022 Article en page(s) : pp 2711 - 2723 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Techniques orbitales [Termes IGN] affaiblissement de la précision [Termes IGN] orbite géostationnaire [Termes IGN] orbite terrestre [Termes IGN] orbitographie [Termes IGN] récepteur BeiDou [Termes IGN] satellite géostationnaire [Termes IGN] signal BeiDou Résumé : (auteur) A Beidou navigation satellite system (BDS) receiver with high sensitivity is embarked in a geostationary orbit (GEO) spacecraft to demonstrate characteristics of BDS signals tracked. This receiver can be compatible with the regional (BDS-2) and global (BDS-3) systems, which have three orbit types: medium Earth orbit (MEO), inclined geostationary orbit (IGSO), and GEO. The on-orbit BDS signal characteristics, including observations quantity, availability, position dilution of precision (PDOP), and carrier-to-noise ratio (C/N0), are presented according to in-flight data. The observations and distribution of C/N0 with respect to nadir angles were analyzed. The average number of the BDS satellites tracked is 4.4, and the average PDOP is 12.0. PDOP improves when the BDS GEO and IGSO observations are involved. The maximum value of C/N0 of the BDS-3 MEO satellites is approximately 49 dB-Hz, which is roughly 2 dB higher than that of the BDS-2 MEO satellites. Most of the C/N0 of the BDS-3 MEO satellite at nadir angles beyond 26° is in the range of 27–34 dB-Hz. We reconstruct the transmit antenna gain for all observed BDS satellites using C/N0 measurements. Moreover, we investigate the main and side lobe characteristics of the BDS satellites in terms of different orbit types and satellite manufacturers. The side lobe signals of the BDS-3 MEO generally have 20–30 dB lower gain than the peak main lobe gain. The side lobe signal performance of the BDS-2 MEO is evidently better than that of the BDS-3 MEO. We give side lobe characteristics analysis of the BDS-3 MEO satellites from two different manufacturers based on the transmit antenna gain reconstructed. Numéro de notice : A2022-230 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1016/j.asr.2022.01.022 Date de publication en ligne : 25/01/2022 En ligne : https://doi.org/10.1016/j.asr.2022.01.022 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=100107 [article]

Remote sensing of precipitation, 1. Volume 1 / Silas Michaelides (2019)  

Public Titre de série : Remote sensing of precipitation, 1 Titre : Volume 1 Type de document : Monographie Auteurs : Silas Michaelides, Éditeur scientifique Editeur : Bâle [Suisse] : Multidisciplinary Digital Publishing Institute MDPI Année de publication : 2019 Importance : 480 p. ISBN/ISSN/EAN : 978-3-03921-286-6 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes IGN] bande K [Termes IGN] bande X [Termes IGN] climatologie [Termes IGN] cyclone [Termes IGN] données GNSS [Termes IGN] données météorologiques [Termes IGN] fréquence [Termes IGN] image GPM [Termes IGN] image radar [Termes IGN] météorologie [Termes IGN] neige [Termes IGN] pluie [Termes IGN] précipitation [Termes IGN] récepteur monofréquence [Termes IGN] satellite géostationnaire [Termes IGN] télédétection en hyperfréquence [Termes IGN] variation saisonnière Résumé : (Editeur) Precipitation is a well-recognized pillar in global water and energy balances. An accurate and timely understanding of its characteristics at the global, regional, and local scales is indispensable for a clearer understanding of the mechanisms underlying the Earth’s atmosphere–ocean complex system. Precipitation is one of the elements that is documented to be greatly affected by climate change. In its various forms, precipitation comprises a primary source of freshwater, which is vital for the sustainability of almost all human activities. Its socio-economic significance is fundamental in managing this natural resource effectively, in applications ranging from irrigation to industrial and household usage. Remote sensing of precipitation is pursued through a broad spectrum of continuously enriched and upgraded instrumentation, embracing sensors which can be ground-based (e.g., weather radars), satellite-borne (e.g., passive or active space-borne sensors), underwater (e.g., hydrophones), aerial, or ship-borne. Numéro de notice : 26511A Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Recueil / ouvrage collectif DOI : 10.3390/books978-3-03921-286-6 En ligne : http://doi.org/10.3390/books978-3-03921-286-6 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97192

Voir aussi

• Remote sensing of precipitation, 2. Volume 2 / Silas Michaelides (2019)  

Remote sensing of precipitation, 2. Volume 2 / Silas Michaelides (2019)  

Public Titre de série : Remote sensing of precipitation, 2 Titre : Volume 2 Type de document : Monographie Auteurs : Silas Michaelides, Éditeur scientifique Editeur : Bâle [Suisse] : Multidisciplinary Digital Publishing Institute MDPI Année de publication : 2019 Importance : 318 p. ISBN/ISSN/EAN : 978-3-03921-288-0 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes IGN] climatologie [Termes IGN] cyclone [Termes IGN] données GNSS [Termes IGN] fréquence [Termes IGN] image GPM [Termes IGN] image radar [Termes IGN] météorologie [Termes IGN] Pakistan [Termes IGN] pluie [Termes IGN] positionnement ponctuel précis [Termes IGN] prédiction [Termes IGN] récepteur monofréquence [Termes IGN] satellite géostationnaire [Termes IGN] télédétection en hyperfréquence [Termes IGN] télédétection spatiale [Termes IGN] Tibet [Termes IGN] variation saisonnière [Termes IGN] vitesse de déplacement Résumé : (Editeur) Precipitation is a well-recognized pillar in global water and energy balances. An accurate and timely understanding of its characteristics at the global, regional, and local scales is indispensable for a clearer understanding of the mechanisms underlying the Earth’s atmosphere–ocean complex system. Precipitation is one of the elements that is documented to be greatly affected by climate change. In its various forms, precipitation comprises a primary source of freshwater, which is vital for the sustainability of almost all human activities. Its socio-economic significance is fundamental in managing this natural resource effectively, in applications ranging from irrigation to industrial and household usage. Remote sensing of precipitation is pursued through a broad spectrum of continuously enriched and upgraded instrumentation, embracing sensors which can be ground-based (e.g., weather radars), satellite-borne (e.g., passive or active space-borne sensors), underwater (e.g., hydrophones), aerial, or ship-borne. Numéro de notice : 26511B Affiliation des auteurs : non IGN Thématique : IMAGERIE/POSITIONNEMENT Nature : Recueil / ouvrage collectif DOI : 10.3390/books978-3-03921-288-0 En ligne : http://doi.org/10.3390/books978-3-03921-288-0 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97195

Voir aussi

• Remote sensing of precipitation, 1. Volume 1 / Silas Michaelides (2019)  

CCD-Astrometrie von Objekten des geostationären Ringes / M. Ploner (1996)

Public Titre : CCD-Astrometrie von Objekten des geostationären Ringes Titre original : [Astrométrie CCD des objets de l'anneau géostationnaire] Type de document : Rapport Auteurs : M. Ploner, Auteur Editeur : Vienne [Autriche] : Technische Universität Wien Année de publication : 1996 Collection : Geowissenschaftliche Mitteilungen, ISSN 1811-8380 num. 46 Importance : 133 p. Format : 21 x 30 cm Note générale : Bibliographie Langues : Allemand (ger) Descripteur : [Vedettes matières IGN] Géodésie physique [Termes IGN] astrométrie [Termes IGN] campagne d'observations [Termes IGN] chambre DTC [Termes IGN] champ de pesanteur terrestre [Termes IGN] orbitographie [Termes IGN] Pascal [Termes IGN] satellite géostationnaire [Termes IGN] satellite météorologique [Termes IGN] transformation de coordonnées Index. décimale : 30.40 Géodésie physique Résumé : (Auteur) The motions of artificial satellites are influenced by gravitational and non-gravitational perturbations. Of special interest among the gravitational perturbations is the anisotropy of the earth's gravitational field. Orbits of geostationary satellites are extremely sensitive to perturbations caused by the earth's equatorial ellipticity, which is described by the coefficients C22 and S22 in the harmonic series expansion of the geopotential. These coefficients cause resonant perturbations, which lead to a librating motion of geostationary objects around two defined points of the earth's equator. These points are located at longitude east 75' and longitude west 105' of Greenwich. The period of the librating motion varies between 1000 and 2000 days, changes in the semi-major axis can reach up to 35 km. On the other hand, these large variations allow for a very exact calculation of the above mentioned terms by means of observing geostationary satellites over a period of only a few weeks. Meteosat satellites are extremely useful for this type of study, because in contrast to communication satellites, orbit manoeuvres are carried out only every 2 or 3 months. In the course of this project, the Zeiss BNIK 75 ballistic camera of the Graz-Lustbühel satellite observation centre was adapted for CCD observations. Instead of the automatic plate-changing device, the CCD camera SITe 1024B (1024*1024 pixel, pixel size 24µm, backside illuminated, 1 pixel = 6.6") was mounted. Thanks to a special shuttering technique, the epoch registration of the observations can be carried out with an accuracy of a few microseconds. After installing the hardware, a two-month observation campaign of the satellites Meteosat 5 and Meteosat 6 as well as the Russian satellites Gorizont 11 and Statsionar-raduga 8 was carried out. Whereas, due to orbital manoeuvres, the orbits of the Meteosat satellites are very close to the theoretical geostationary orbit, the latter mentioned satellites have not been controlled for a quite long time. Inevitably this causes an increasing motion leading away from their geostationary orbit. They also are marked by heavy tumbling movements. The astrometric evaluation of the observations was carried out with the help of the program CCD. Its development was - besides the hardware installation - one of the main tasks of this project. This Windows application, which is written in Borland Pascal 7.0, permits the use of different polynomes for the transformation of the measured coordinates into tangent coordinates and makes use of various fit algorithms (Gaussian, Laplace and Cauchy distributions) for the calculation of the object coordinates. Usually the star tracker is switched off when observations of geostationary satellites are carried out. Therefore special attention has to be paid to the determination of the starting and final point of star trails. The reference stars can be selected from the PPM and the GSC catalogue. The calculated coordinates of the measured objects either refer to the true date and equinox or to the mean date and equinox (J2000.0). The orbit integration program ORBDET of the Astronomical Institute of the University of Berne was used for the calculation of the osculating orbital elements and the direct solar radiation pressure of all satellites. The residuals of the two Meteosat satellites did not show any remaining signals. The average deviation of a single observation was 0.5" for these extremely faint objects, which corresponds to less than 1/10 of the pixel size. This high accuracy was a consequence of calculating the satellite coordinates by fitting a two-dimensional Gaussian distribution. The situation concerning Gorizont 11 and Statsionar-raduga 8 is different. Significant signals were found in the residuals, which can be explained by extreme difficulties in establishing an appropriate model for the direct solar radiation pressure. While Meteosat satellites have a simple cylindrical shape, the Russian satellites are marked by large solar panels. The establishment of a model for the direct solar radiation pressure is further complicated because of the heavy tumbling movements. Finally, the geopotential coefficients C22 and S22 were calculated from observations of the satellites Meteosat 5 and 6. The results show an extremely low deviation from the corresponding numbers of the well-known gravity model JGM-3). By combining this data with observations made by the satellite observation centre Zimmerwald (Switzerland), the accuracy of the coefficients C22 and S22 could be further increased. The calculations result in the following values for the two normalized coefficients : C22 = 2.43923E-06 ± 3.9OE-10 S22 = -1.4003IE-06 ± 9.77E-11 The results show that CCD observations of geostationary satellites can contribute considerably to the determination of the above mentioned parameters. A further increase in accuracy is to be expected by the use of the Hipparcos star catalogue, which is going to be available in summer 1997. Numéro de notice : 55044 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Rapport d'étude technique Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=59754

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Proceedings of the workshop Accurate orbit determination and observations of high Earth satellites for geodynamics / A. Elipe (1995)

Public Titre : Proceedings of the workshop Accurate orbit determination and observations of high Earth satellites for geodynamics Type de document : Actes de congrès Auteurs : A. Elipe, Éditeur scientifique ; P. Paquet, Éditeur scientifique Editeur : Luxembourg : Conseil de l'Europe Année de publication : 1995 Collection : Cahiers du Centre Européen de Géodynamique et de Séismologie num. 10 Conférence : ECGS 1994, workshop Accurate orbit determination and observations of high Earth satellites for geodynamics 17/10/1994 19/10/1994 Walferdange Grand Duché du Luxembourg Importance : 137 p. Format : 16 x 23 cm ISBN/ISSN/EAN : 978-2-87977-033-8 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Techniques orbitales [Termes IGN] orbite géostationnaire [Termes IGN] orbitographie [Termes IGN] satellite artificiel [Termes IGN] satellite géostationnaire [Termes IGN] système de référence céleste [Termes IGN] système de référence géodésique Numéro de notice : 55426 Affiliation des auteurs : non IGN Thématique : IMAGERIE/POSITIONNEMENT Nature : Actes Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=35739

Exemplaires(1)

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55426-01	CG.94	Livre	Centre de documentation	Congrès	Disponible

A method for the mapping of the apparent ground brightness using visible images from geostationary satellites / G. Moussu in International Journal of Remote Sensing IJRS, vol 10 n° 7 (July 1989)  

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The contribution of satellite information to operational weather forcasting : achievements and objectives in the 1990's / J. Reiff in International Journal of Remote Sensing IJRS, vol 9 n°10-11 (October-November 1988)  

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Cloud cover distribution in Indonesia / Jean-Philippe Gastellu-Etchegorry in International Journal of Remote Sensing IJRS, vol 9 n° 7 (July 1988)  

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Predictive models for remotely-sensed data acquisition in Indonesia / Jean-Philippe Gastellu-Etchegorry in International Journal of Remote Sensing IJRS, vol 9 n° 7 (July 1988)  

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Results of the dane-county land records projects / B.J. Niemann in Photogrammetric Engineering & Remote Sensing, PERS, vol 53 n° 10 Tome 1 (october 1987)  

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Cartographie de l'inertie thermique et de l'humidité sur l'Afrique par satellite géostationnaire : identification de quelques points critiques de l'étude : [présenté au] Colloque de la Commission 7 (France) sur l'infrarouge thermique et les hyperfréquences, Grignon, 11 mai 1978 / M. Vieillefosse in Bulletin [Société Française de Photogrammétrie et Télédétection], n° 71 - 72 (Juillet 1978)

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