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Analysis of orbital configurations for geocenter determination with GPS and low-Earth orbiters / Da Kuang in Journal of geodesy, vol 89 n° 5 (May 2015)
[article]
Titre : Analysis of orbital configurations for geocenter determination with GPS and low-Earth orbiters Type de document : Article/Communication Auteurs : Da Kuang, Auteur ; Yoaz E. Bar-Sever, Auteur ; Bruce J. Haines, Auteur Année de publication : 2015 Article en page(s) : pp 471 - 481 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] analyse comparative
[Termes IGN] antenne GPS
[Termes IGN] double différence
[Termes IGN] géocentre
[Termes IGN] hauteur ellipsoïdale
[Termes IGN] orbite basse
[Termes IGN] orbitographie par GNSS
[Termes IGN] poursuite de satellite
[Termes IGN] récepteur GPS
[Termes IGN] télémétrie laser sur satelliteRésumé : (auteur) We use a series of simulated scenarios to characterize the observability of geocenter location with GPS tracking data. We examine in particular the improvement realized when a GPS receiver in low Earth orbit (LEO) augments the ground network. Various orbital configurations for the LEO are considered and the observability of geocenter location based on GPS tracking is compared to that based on satellite laser ranging (SLR). The distance between a satellite and a ground tracking-site is the primary measurement, and Earth rotation plays important role in determining the geocenter location. Compared to SLR, which directly and unambiguously measures this distance, terrestrial GPS observations provide a weaker (relative) measurement for geocenter location determination. The estimation of GPS transmitter and receiver clock errors, which is equivalent to double differencing four simultaneous range measurements, removes much of this absolute distance information. We show that when ground GPS tracking data are augmented with precise measurements from a GPS receiver onboard a LEO satellite, the sensitivity of the data to geocenter location increases by more than a factor of two for Z-component. The geometric diversity underlying the varying baselines between the LEO and ground stations promotes improved global observability, and renders the GPS technique comparable to SLR in terms of information content for geocenter location determination. We assess a variety of LEO orbital configurations, including the proposed orbit for the geodetic reference antenna in space mission concept. The results suggest that a retrograde LEO with altitude near 3,000 km is favorable for geocenter determination. Numéro de notice : A2015-347 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-015-0792-6 Date de publication en ligne : 08/02/2015 En ligne : https://doi.org/10.1007/s00190-015-0792-6 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76721
in Journal of geodesy > vol 89 n° 5 (May 2015) . - pp 471 - 481[article]HYCA: A new technique for hyperspectral compressive sensing / G. Martin in IEEE Transactions on geoscience and remote sensing, vol 53 n° 5 (mai 2015)
[article]
Titre : HYCA: A new technique for hyperspectral compressive sensing Type de document : Article/Communication Auteurs : G. Martin, Auteur ; José M. Bioucas-Dias, Auteur ; Antonio J. Plaza, Auteur Année de publication : 2015 Article en page(s) : pp 2819 - 2831 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] capteur hyperspectral
[Termes IGN] compression d'image
[Termes IGN] coordonnées géographiques
[Termes IGN] corrélation
[Termes IGN] image hyperspectrale
[Termes IGN] reconstruction d'imageRésumé : (Auteur) Hyperspectral imaging relies on sophisticated acquisition and data processing systems able to acquire, process, store, and transmit hundreds or thousands of image bands from a given area of interest. In this paper, we exploit the high correlation existing among the components of the hyperspectral data sets to introduce a new compressive sensing methodology, termed hyperspectral coded aperture (HYCA), which largely reduces the number of measurements necessary to correctly reconstruct the original data. HYCA relies on two central properties of most hyperspectral images, usually termed data cubes: 1) the spectral vectors live on a low-dimensional subspace; and 2) the spectral bands present high correlation in both the spatial and the spectral domain. The former property allows to represent the data vectors using a small number of coordinates. In this paper, we particularly exploit the high spatial correlation mentioned in the latter property, which implies that each coordinate is piecewise smooth and thus compressible using local differences. The measurement matrix computes a small number of random projections for every spectral vector, which is connected with coded aperture schemes. The reconstruction of the data cube is obtained by solving a convex optimization problem containing a data term linked to the measurement matrix and a total variation regularizer. The solution of this optimization problem is obtained by an instance of the alternating direction method of multipliers that decomposes very hard problems into a cyclic sequence of simpler problems. In order to address the need to set up the parameters involved in the HYCA algorithm, we also develop a constrained version of HYCA (C-HYCA), in which all the parameters can be automatically estimated, which is an important aspect for practical application of the algorithm. A series of experiments with simulated and real data shows the effectiveness of HYCA and C-HYCA, indicating their potential in real-world applications. Numéro de notice : A2015-520 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2014.2365534 En ligne : https://doi.org/10.1109/TGRS.2014.2365534 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=77527
in IEEE Transactions on geoscience and remote sensing > vol 53 n° 5 (mai 2015) . - pp 2819 - 2831[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 065-2015051 RAB Revue Centre de documentation En réserve L003 Disponible Three-Corner Hat for the assessment of the uncertainty of non-linear residuals of space-geodetic time series in the context of terrestrial reference frame analysis / Claudio Abbondanza in Journal of geodesy, vol 89 n° 4 (April 2015)
[article]
Titre : Three-Corner Hat for the assessment of the uncertainty of non-linear residuals of space-geodetic time series in the context of terrestrial reference frame analysis Type de document : Article/Communication Auteurs : Claudio Abbondanza, Auteur ; Zuheir Altamimi , Auteur ; T.M. Chin, Auteur ; Richard S. Gross, Auteur ; Michael B. Heflin, Auteur ; J. W. Parker, Auteur ; X. Wu, Auteur Année de publication : 2015 Article en page(s) : pp 313-329 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] co-positionnement
[Termes IGN] corrélation temporelle
[Termes IGN] estimation de cohérence
[Termes IGN] hauteur ellipsoïdale
[Termes IGN] incertitude de position
[Termes IGN] International Terrestrial Reference Frame
[Termes IGN] série temporelle
[Termes IGN] signal GPSRésumé : (auteur) We discuss the application of the Three-Corner Hat (TCH) to time series of space-geodetic station position residuals with the purpose of characterizing the uncertainties of GPS, VLBI, SLR, DORIS for the International Terrestrial Reference Frame (ITRF) determination. Adopting simulations, we show that, in the absence of time-correlated errors, TCH is able to fully recover the nominal uncertainties of groups of observations whose intrinsic precisions are remarkably dissimilar to one another, as is the case for the space-geodetic techniques. When time-correlated errors are predominant, as it happens with GPS, TCH is affected by the increased variance of the observations and its estimates are positively biased. TCH applied to 16 ITRF co-located sites confirms that GPS, albeit affected by time-correlated errors, is the most precise of the space-geodetic techniques. GPS median uncertainties are 1.1, 1.2 and 2.8 mm, for the north, east and height component, respectively. VLBI performs particularly well in the horizontal component, the median uncertainties being ≈2 mm. The height component is ∼3 times larger than the GPS one. SLR and DORIS median uncertainties exceed by far the 7 mm level on all of the three components. Comparing TCH results with station position repeatabilities, we find that the two metrics are in striking agreement for VLBI and DORIS, but not for SLR and GPS. The inconsistencies between TCH and station repeatabilities for co-located GPS and SLR point to the presence of either specific station-dependent biases or low-quality co-locations. Scaling factors derived adopting the ratio between TCH and median formal errors on the positions suggest the station position covariances have to be up-scaled for VLBI, SLR, DORIS and down-scaled for GPS. Numéro de notice : A2015-340 Affiliation des auteurs : LASTIG LAREG+Ext (2012-mi2018) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-014-0777-x Date de publication en ligne : 18/11/2014 En ligne : https://doi.org/10.1007/s00190-014-0777-x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76709
in Journal of geodesy > vol 89 n° 4 (April 2015) . - pp 313-329[article]Precision analysis of Trimble Rtx surveying technology with Xfill function in the context of obtained conversion observations / Robert Krzyzek in Reports on geodesy and geoinformatics, vol 97 (December 2014)
[article]
Titre : Precision analysis of Trimble Rtx surveying technology with Xfill function in the context of obtained conversion observations Type de document : Article/Communication Auteurs : Robert Krzyzek, Auteur Année de publication : 2015 Article en page(s) : pp 47 - 70 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Topographie
[Termes IGN] conversion de données
[Termes IGN] GPS en mode cinématique
[Termes IGN] positionnement cinématique en temps réel
[Termes IGN] transformation de coordonnéesRésumé : (auteur) As a result of traditional geodetic surveying we usually achieve observations which are then used for calculating rectangular coordinates onto a plane along with precision evaluation. In this article the surveying methods are presented in which the situation is different. Test measurements were carried out, consisting in the measurement of a fragment of detailed control network in RTK (Real Time Kinematic) and RTX (Real Time Extended) mode with xFill function. First, the rectangular coordinates onto a plane (through the transformation of data ellipsoidal) were obtained, on the basis of which the conversion observations were determined and they were compared with each other, as well as with reference parameters - conversion observations out of detailed control network adjustment with use of the method of least squares. The results of the study allow to verify the precision and application possibilities of conversion observations obtained thanks to Trimble RTX technology with xFill function. Application of this surveying method in typical geodetic tasks is fully justifiable. Nevertheless, it is recommendable to be aware of the correlations of absolute or relative values obtained in RTX procedure to reference parameters, which in turn will enable conclusive verification of the possibilities of Trimble RTX technology application in certain geodetic surveys. Numéro de notice : A2014-700 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.2478/rgg-2014-0011 En ligne : https://doi.org/10.2478/rgg-2014-0011 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=75405
in Reports on geodesy and geoinformatics > vol 97 (December 2014) . - pp 47 - 70[article]Levelling co-located GNSS and tide gauge stations using GNSS reflectometry / Alvaro Santamaria Gomez in Journal of geodesy, vol 89 n° 3 (March 2015)
[article]
Titre : Levelling co-located GNSS and tide gauge stations using GNSS reflectometry Type de document : Article/Communication Auteurs : Alvaro Santamaria Gomez, Auteur ; Christopher S. Watson, Auteur ; Médéric Gravelle, Auteur ; et al., Auteur Année de publication : 2015 Article en page(s) : pp 241 - 258 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] analyse comparative
[Termes IGN] erreur systématique
[Termes IGN] étalonnage d'instrument
[Termes IGN] hauteur ellipsoïdale
[Termes IGN] marée océanique
[Termes IGN] marégraphe
[Termes IGN] nivellement
[Termes IGN] point de liaison (géodésie)
[Termes IGN] propagation troposphérique
[Termes IGN] rapport signal sur bruit
[Termes IGN] réflectance de surface
[Termes IGN] réflectométrie par GNSS
[Termes IGN] signal GPSRésumé : (auteur) The GNSS reflectometry technique provides geometric information on the environment surrounding the GNSS antenna including the vertical distance to a reflecting surface. We use sea-surface reflections of GPS signals, recorded as oscillations in signal-to-noise ratio (SNR), to estimate the GNSS to tide gauge (TG) levelling tie, and thus the ellipsoidal heights of the TG. We develop approaches to isolate SNR data dominated by sea-surface reflections and to remove SNR frequency changes caused by the dynamic sea surface. Comparison with in situ levelling at eight sites reveals mean differences at the centimetre level for satellites above 12∘ elevation, with four sites showing differences of 3 cm or smaller. These differences include errors in the in situ levelling, in the antenna calibration model and in the TG measurements, and so represent an upper bound on our technique’s error. Data sampling (1 or 30 s) does not significantly affect the results. We detect systematic errors at the decimetre level related to satellite elevations below 12∘ and to sea-surface height and also differences between results from the L1 and L2 GPS signals larger than 15 cm at two sites. These systematic errors remain unexplained; differences between GPS signals are attributed to receiver-dependent differences in the SNR measurements, while the elevation-dependent error is attributed to unmodelled phase effects such as those caused by tropospheric refraction and sea-surface roughness. Using our approach, we identify a levelling offset of 1.5 cm related to a TG sensor change, illustrating our technique’s value for TG reference monitoring. Numéro de notice : A2015-337 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-014-0784-y Date de publication en ligne : 20/12/2014 En ligne : https://doi.org/10.1007/s00190-014-0784-y Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76705
in Journal of geodesy > vol 89 n° 3 (March 2015) . - pp 241 - 258[article]De la navigation "à vue" au calcul des longitudes / Jean-Yves Sarazin in Carto, le monde en cartes, n° 28 (mars - avril 2015)PermalinkLa mesure du niveau de la mer par bouées GPS : l'expérience multi-capteurs de l'île d'Aix / Gaël André in Navigation aérienne, maritime, spatiale, terrestre, vol 62 n° 246 (janvier 2015)PermalinkPermalinkDetecting discontinuities in GNSS coordinate time series with STARS: case study, the Bologna and Medicina GPS sites / Sara Bruni in Journal of geodesy, vol 88 n° 12 (December 2014)PermalinkTransformation model selection by multiple hypotheses testing / Rüdiger Lehmann in Journal of geodesy, vol 88 n° 12 (December 2014)PermalinkCartes pour l'orientation et la découverte d'objets cachés / Lazlo Zentai in Cartes & Géomatique, n° 221 (septembre 2014)PermalinkCoordinate questions in the web environment / A. Favretto in Cartographica, vol 49 n° 3 (September 2014)PermalinkL'information géographique / Bengt Rystedt in Cartes & Géomatique, n° 221 (septembre 2014)PermalinkA practical target recognition system for close range photogrammetry / M.R. Shortis in Photogrammetric record, vol 29 n° 147 (September - November 2014)PermalinkProjections cartographiques et systèmes de références / Miljenko Lapaine in Cartes & Géomatique, n° 221 (septembre 2014)Permalink