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Denoising atmospheric radar signals using spectral-based subspace method applicable for PBS wind estimation / V.N. Sureshbabu in IEEE Transactions on geoscience and remote sensing, vol 51 n° 7 Tome 1 (July 2013)
[article]
Titre : Denoising atmospheric radar signals using spectral-based subspace method applicable for PBS wind estimation Type de document : Article/Communication Auteurs : V.N. Sureshbabu, Auteur ; V.K. Anandan, Auteur ; Toshitaka Tsuda, Auteur ; et al., Auteur Année de publication : 2013 Article en page(s) : pp 3853 - 3861 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications
[Termes IGN] décomposition spectrale
[Termes IGN] écho radar
[Termes IGN] filtrage du bruit
[Termes IGN] image radar
[Termes IGN] sous-espace
[Termes IGN] vecteur propreRésumé : (Auteur) This paper mainly focuses on the advantages of subspace-based eigenvector (EV) spectral estimator to improve the power spectrum and the quality of calculations in spectrum parameter estimation. In general, the spectrum produced by most of subspace methods is sharply peaked at the frequency of complex sinusoids. Although subspace methods exhibit the advantage of spectral resolution, the retrieval of the actual spectrum width is not well observed in many cases, compared with standard Fourier estimates. Several simulation works are carried out to determine the unknown order of the signal correlation matrix, which significantly helps in obtaining the equivalent Fourier spectrum using EV along with numerous advantages of the subspace method for better estimation of spectrum parameters. Such advantages are useful in precisely obtaining the atmospheric moments (Doppler frequency, spectrum width, etc.) from the synthesized beams required for wind estimation by the postset beam steering technique. In addition, the systematic improvements done in EV are much useful for complete wind profiling up to ~ 20 km with a temporal resolution of ~ 26 s, which is reported for the first time. Numéro de notice : A2013-367 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2012.2227334 En ligne : https://doi.org/10.1109/TGRS.2012.2227334 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32505
in IEEE Transactions on geoscience and remote sensing > vol 51 n° 7 Tome 1 (July 2013) . - pp 3853 - 3861[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 065-2013071A RAB Revue Centre de documentation En réserve L003 Disponible Ambiguity resolution for triple-frequency geometry-free and ionosphere-free combination tested with real data / K. Wang in Journal of geodesy, vol 87 n° 6 (June 2013)
[article]
Titre : Ambiguity resolution for triple-frequency geometry-free and ionosphere-free combination tested with real data Type de document : Article/Communication Auteurs : K. Wang, Auteur ; Markus Rothacher, Auteur Année de publication : 2013 Article en page(s) : pp 539 - 553 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] combinaison linéaire
[Termes IGN] filtrage du bruit
[Termes IGN] mesurage de la fréquence
[Termes IGN] phase GNSS
[Termes IGN] résolution d'ambiguïté
[Termes IGN] signal BeiDou
[Termes IGN] signal Galileo
[Termes IGN] signal GNSSRésumé : (Auteur) The recent GPS Block IIF satellites SVN62 and SVN63 and the Galileo satellites GIOVE-A, GIOVE-B, PFM and FM2 already send signals on more than two frequencies, and more GNSS satellites will provide tracking data on at least three frequencies in the near future. In this paper, a simplified general method for ambiguity resolution minimizing the noise level for the triple-frequency geometry-free (GF) and ionosphere-free (IF) linear combinations is presented, where differently scaled code noise on the three frequencies was introduced. For the third of three required linear combinations, the most demanding one in triple-frequency ambiguity resolution, we developed a general method using the ambiguity-corrected phase observations without any constraints to search for the optimal GF and IF linear combination. We analytically demonstrate that the noise level of this third linear combination only depends on the three frequencies. The investigation concerning this frequency-dependent noise factor was performed for GPS, Galileo and Compass frequency triplets. We verified the theoretical derivations with real triple-frequency GPS and Galileo data from the Multi-GNSS Experiment (M–GEX) of the International GNSS Service (IGS). The data of about 30 M–GEX stations around the world over 11 days from 29 April 2012 to 9 May 2012 were used for the test. For the third linear combinaton using Galileo E1, E5b and E5a, which is expected to have the worst performance among all the GNSS frequency triplets in our investigation, the formal errors of the estimated ambiguities are in most cases below 0.2 cycles after 400 observation epochs. If more GPS satellites sending signals on three frequencies or more stations tracking Galileo E6 signal are available in the future, an improvement by a factor of two to three can be expected. Numéro de notice : A2013-339 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-013-0630-7 Date de publication en ligne : 09/04/2013 En ligne : https://doi.org/10.1007/s00190-013-0630-7 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32477
in Journal of geodesy > vol 87 n° 6 (June 2013) . - pp 539 - 553[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 266-2013061 SL Revue Centre de documentation Revues en salle Disponible Multiple-spectral-band CRFs for denoising junk bands of hyperspectral imagery / Ping Zhong in IEEE Transactions on geoscience and remote sensing, vol 51 n° 4 Tome 2 (April 2013)
[article]
Titre : Multiple-spectral-band CRFs for denoising junk bands of hyperspectral imagery Type de document : Article/Communication Auteurs : Ping Zhong, Auteur ; Runsheng Wang, Auteur Année de publication : 2013 Article en page(s) : pp 2260 - 2275 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] champ aléatoire de Markov
[Termes IGN] filtrage du bruit
[Termes IGN] image hyperspectrale
[Termes IGN] spectroscopieRésumé : (Auteur) Denoising of hyperspectral imagery in the domain of imaging spectroscopy by conditional random fields (CRFs) is addressed in this work. For denoising of hyperspectral imagery, the strong dependencies across spatial and spectral neighbors have been proved to be very useful. Many available hyperspectral image denoising algorithms adopt multidimensional tools to deal with the problems and thus naturally focus on the use of the spectral dependencies. However, few of them were specifically designed to use the spatial dependencies. In this paper, we propose a multiple-spectral-band CRF (MSB-CRF) to simultaneously model and use the spatial and spectral dependencies in a unified probabilistic framework. Furthermore, under the proposed MSB-CRF framework, we develop two hyperspectral image denoising algorithms, which, thanks to the incorporated spatial and spectral dependencies, can significantly remove the noise, while maintaining the important image details. The experiments are conducted in both simulated and real noisy conditions to test the proposed denoising algorithms, which are shown to outperform the popular denoising methods described in the previous literatures Numéro de notice : A2013-224 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2012.2209656 En ligne : https://doi.org/10.1109/TGRS.2012.2209656 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32362
in IEEE Transactions on geoscience and remote sensing > vol 51 n° 4 Tome 2 (April 2013) . - pp 2260 - 2275[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 065-2013041B RAB Revue Centre de documentation En réserve L003 Disponible Evaluation of the ITRF2008 GPS vertical velocities using satellite antenna z-offsets / Xavier Collilieux in GPS solutions, vol 17 n° 2 (April 2013)
[article]
Titre : Evaluation of the ITRF2008 GPS vertical velocities using satellite antenna z-offsets Type de document : Article/Communication Auteurs : Xavier Collilieux , Auteur ; Ralf Schmid, Auteur Année de publication : 2013 Article en page(s) : pp 237 - 246 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] antenne GNSS
[Termes IGN] centre de phase
[Termes IGN] filtre de Kalman
[Termes IGN] International Terrestrial Reference FrameRésumé : (auteur) We develop a method to evaluate the terrestrial reference frame (TRF) scale rate error using Global Positioning System (GPS) satellite antenna phase center offset (APCO) parameters and apply it to ITRF2008. We search for the TRF in which z-APCO parameters have the smallest drift. In order to provide realistic error bars for the z-APCO drifts, we pay attention to model periodic variations and auto-correlated noise processes in the z-APCO time series. We will show that the GPS scale rate with respect to a frame is, as a first approximation, proportional to the estimated mean z-APCO trend if that frame is used to constrain station positions. Thus, an ITRF2008 scale rate error between - 0.27 and - 0.06 mm/yr depending on the GPS analysis center can be estimated, which demonstrates the high quality of the newly constructed ITRF2008. We will also demonstrate that the traditional estimates of the GPS scale rate from 7-parameter similarity transformations are consistent with our newly derived GPS scale rates with respect to ITRF2008 within two sigmas. We find using International GNSS Service (IGS) products that the traditional approach is relevant for scale rate determination even if some of the z-APCO values supplied by the IGS were not simultaneously calibrated. As the scale rate is related to the accuracy of vertical velocities, our estimates supply a conservative evaluation that can be used for error budget computation. Numéro de notice : A2013-850 Affiliation des auteurs : LASTIG LAREG+Ext (2012-mi2018) Thématique : POSITIONNEMENT Nature : Article DOI : 10.1007/s10291-012-0274-8 Date de publication en ligne : 11/07/2012 En ligne : http://dx.doi.org/10.1007/s10291-012-0274-8 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=80131
in GPS solutions > vol 17 n° 2 (April 2013) . - pp 237 - 246[article]Dual-Polarimetric signatures of vegetation – a case study Biebrza / Dariusz Ziolkowski in Geoinformation issues, vol 5 n° 1 (2013)
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Titre : Dual-Polarimetric signatures of vegetation – a case study Biebrza Type de document : Article/Communication Auteurs : Dariusz Ziolkowski, Auteur ; Iwona Malek, Auteur ; Maria Budzynska, Auteur Année de publication : 2013 Article en page(s) : pp 29 - 41 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications
[Termes IGN] données polarimétriques
[Termes IGN] filtre de déchatoiement
[Termes IGN] image ALOS-PALSAR
[Termes IGN] parc naturel national
[Termes IGN] polarimétrie radar
[Termes IGN] Pologne
[Termes IGN] pouvoir de résolution géométrique
[Termes IGN] végétationRésumé : (auteur) The main objective of the research presented in this article is to analyse the polarimetric characteristics of three main types of natural vegetation occurring in the Biebrza National Park – forests, shrubs and non-forest land communities covering wetlands. The variability of many different polarimetric products of signal decomposition, depending on the type of vegetation, the microwave image acquisition period and the method of their preliminary treatment, was analysed. An attempt was also made to assess how much polari-metric methods can be useful for modelling biophysical parameters of vegetation. The study used six dual-polarized (HH and HV) ALOS satellite images recorded during the growing season in the years 2008, 2009 and 2010. The images were processed in parallel, using different parameters, in order to estimate the impact of the spatial resolution of images and methods of speckle noise filtering on the value of polarimetric characteristics of different types of vegetation. All methods of polarimetric signal decompositions available using ESA POLSARPRO 4.2 software were tested. Three of them, i.e. the Alpha parameter from the H/A/Alpha decomposition (Cloud and Pottier, 1996) containing information about the dominant scattering mechanisms and two types of entropy: the entropy from the H/A/Alpha decomposition and the Shannon Entropy were selected for further analysis. The analysed years differed quite significantly from one another in the agro-meteorological conditions of plant growth. It was a cause of significant differences between the values of polarimetric characteristics in images recorded at the same season but in different years. During the growing season individual products of polarimetric signal decomposition are characterized by different variability. This demonstrates the dependence of different polarimetric characteristics on various biophysical parameters of the environment. It was observed that they are characterized by greater information content than the backscattering coefficient, especially if they are subjected to the process of increasing the resolution (oversampling). They can be used to model the biophysical parameters of vegetation. Numéro de notice : A2013-787 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article DOI : sans En ligne : http://www.igik.edu.pl/upload/File/wydawnictwa/givol5dzimmbmin.pdf Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76832
in Geoinformation issues > vol 5 n° 1 (2013) . - pp 29 - 41[article]New approaches for estimating local point density and its impact on lidar data segmentation / Z. Lari in Photogrammetric Engineering & Remote Sensing, PERS, vol 79 n° 2 (February 2013)PermalinkEstimation of mass change trends in the Earth’s system on the basis of GRACE satellite data, with application to Greenland / C. Siemes in Journal of geodesy, vol 87 n° 1 (January 2013)PermalinkPermalinkPermalinkPermalinkPermalinkHigh-frequency signal and noise estimates of CSR GRACE RL04 / J.A. Bonin in Journal of geodesy, vol 86 n° 12 (December 2012)PermalinkTélédétection de la trame verte arborée en haute résolution par morphologie mathématique / E. Maire in Revue internationale de géomatique, vol 22 n° 4 (décembre 2012 – février 2013)PermalinkNon-Gaussian noises: What about Gaussian vs. non-Gaussian noise in inertial/GNSS integration? / Mark Petovello in Inside GNSS, vol 7 n° 6 (November - December 2012)PermalinkOptimized Kalman filter versus rigorous method in deformation analysis / N. Aharizad in Journal of applied geodesy, vol 6 n° 3-4 (November 2012)Permalink