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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)
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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]Levelling co-located GNSS and tide gauge stations using GNSS reflectometry / Alvaro Santamaria Gomez in Journal of geodesy, vol 89 n° 3 (March 2015)
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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)
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Titre : De la navigation "à vue" au calcul des longitudes Type de document : Article/Communication Auteurs : Jean-Yves Sarazin, Auteur Année de publication : 2015 Article en page(s) : pp 66 - 71 Langues : Français (fre) Descripteur : [Vedettes matières IGN] Cartographie ancienne
[Termes IGN] carte marine
[Termes IGN] coordonnées géodésiques
[Termes IGN] longitude
[Termes IGN] mer
[Termes IGN] navigation maritimeRésumé : (Auteur) Tous les plus anciens marins de la planète commencèrent leurs périples sans aucune représentation cartographique des distances et des surfaces à parcourir. Ils progressaient le long d'un littoral, en pratiquant par atavisme la navigation "à vue" des amers naturels ou artificiels, des rochers, collines, tours et fanaux. Il fallut attendre le 13ème siècle et la multiplication des relations commerciales entre l'Orient et l'Occident pour qu'apparaissent les premiers schémas des mers traversées. Numéro de notice : A2015-450 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/POSITIONNEMENT Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=77098
in Carto, le monde en cartes > n° 28 (mars - avril 2015) . - pp 66 - 71[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 154-2015021 RAB Revue Centre de documentation Revues en salle Disponible Detecting 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)
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Titre : Detecting discontinuities in GNSS coordinate time series with STARS: case study, the Bologna and Medicina GPS sites Type de document : Article/Communication Auteurs : Sara Bruni, Auteur ; Susanna Zerbini, Auteur ; Fabio Raicich, Auteur ; et al., Auteur Année de publication : 2014 Article en page(s) : pp 1203 - 1214 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] coordonnées géodésiques
[Termes IGN] coordonnées GPS
[Termes IGN] discontinuité
[Termes IGN] données GNSS
[Termes IGN] série temporelleRésumé : (Auteur) Global navigation satellite systems (GNSS) data are a fundamental source of information for achieving a better understanding of geophysical and climate-related phenomena. However, discontinuities in the coordinate time series might be a severe limiting factor for the reliable estimate of long-term trends. A methodological approach has been adapted from Rodionov (Geophys Res Lett 31:L09204, 2004; Geophys Res Lett 31:L12707, 2006) and from Rodionov and Overland (J Marine Sci 62:328–332, 2005) to identify both the epoch of occurrence and the magnitude of jumps corrupting GNSS data sets without any a priori information on these quantities. The procedure is based on the Sequential t test Analysis of Regime Shifts (STARS) (Rodionov in Geophys Res Lett 31:L09204, 2004). The method has been tested against a synthetic data set characterized by typical features exhibited by real GNSS time series, such as linear trend, seasonal cycle, jumps, missing epochs and a combination of white and flicker noise. The results show that the offsets identified by the algorithm are split into 48% of true-positive, 28% of false-positive and 24% of false-negative events. The procedure has then been applied to GPS coordinate time series of stations located in the southeastern Po Plain, in Italy. The series span more than 15 years and are affected by offsets of different nature. The methodology proves to be effective, as confirmed by the comparison between the corrected GPS time series and those obtained by other observation techniques. Numéro de notice : A2014-570 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-014-0754-4 Date de publication en ligne : 24/08/2014 En ligne : https://doi.org/10.1007/s00190-014-0754-4 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=74757
in Journal of geodesy > vol 88 n° 12 (December 2014) . - pp 1203 - 1214[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 266-2014121 SL Revue Centre de documentation Revues en salle Disponible Cartes 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)PermalinkProjections cartographiques et systèmes de références / Miljenko Lapaine in Cartes & Géomatique, n° 221 (septembre 2014)PermalinkDirect georeferencing of airborne LiDAR data in national coordinates / Yongjun Zhang in ISPRS Journal of photogrammetry and remote sensing, vol 84 (October 2013)PermalinkNetwork RTK: What is the effect of user and CORS height on NRTK performance? / Mark Petovello in Inside GNSS, vol 8 n° 5 (September - October 2013)PermalinkFrom the portolan chart to the latitude chart / Joaquim Alves Gaspar in Cartes & Géomatique, n° 216 (juin 2013)PermalinkCIRCE RHONE : mise en place d'une grille de transformation altimétrique entre les altitudes orthométriques (NGF/Lallemand) et normales (NGF/IGN69) / Paul-Henri Faure in XYZ, n° 134 (mars - mai 2013)PermalinkGéoréférencement tridimensionnel des réseaux de distribution de chaleur de la Communauté Urbaine de Strasbourg / Bruce Beaurepère (2013)PermalinkGlobal height system unification with GOCE: a simulation study on the indirect bias term in the GBVP approach / C. Gerlach in Journal of geodesy, vol 87 n° 1 (January 2013)PermalinkPermalinkThe height datum problem and the role of satellite gravity models / A. Gatti in Journal of geodesy, vol 87 n° 1 (January 2013)PermalinkThe application of the model of coordinate S-transformation for stability analysis of datum points in high-precision GPS deformation monitoring networks / Jiming Guo in Journal of applied geodesy, vol 6 n° 3-4 (November 2012)PermalinkCoordonnées géographiques lambda, phi, h sur l'ellipsoïde de révolution / Patrick Julien in XYZ, n° 130 (mars - mai 2012)PermalinkThe US Gravimetric Geoid of 2009 (USGG2009): model development and evaluation / Y. Wang in Journal of geodesy, vol 86 n° 3 (March 2012)PermalinkPermalinkEvaluation de l'érosion du site de Wankama (Niger) par comparaison de différents MNT / T. Gendre in XYZ, n° 129 (décembre - février 2011)PermalinkUtilisation de la technique du nivellement par GPS pour l'élaboration des surfaces de conversions altimétriques / S. Medjahed in Bulletin des sciences géographiques, n° 26 (octobre 2011)PermalinkAn analytical method to transform geocentric into geodetic coordinates / H. Vermeille in Journal of geodesy, vol 85 n° 2 (February 2011)PermalinkMeasurement accuracy in Network-RTK / R. Emardson in Bulletin of geodesy and geomatics BGG, vol 69 n° 2 - 3 (December 2010)Permalink