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Interpolating atmospheric water vapor delay by incorporating terrain elevation information / B. Xu in Journal of geodesy, vol 85 n° 9 (September 2011)  

Public [article]  inJournal of geodesy > vol 85 n° 9 (September 2011) . - pp 555 - 564 Titre : Interpolating atmospheric water vapor delay by incorporating terrain elevation information Type de document : Article/Communication Auteurs : B. Xu, Auteur ; Z.W. Li, Auteur ; Jianjun Zhu, Auteur Année de publication : 2011 Article en page(s) : pp 555 - 564 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement du signal [Termes IGN] dégradation du signal [Termes IGN] écho radar [Termes IGN] interféromètrie par radar à antenne synthétique [Termes IGN] interpolation spatiale [Termes IGN] modèle numérique de surface [Termes IGN] propagation du signal [Termes IGN] signal GPS [Termes IGN] vapeur d'eau Résumé : (Auteur) In radio signal-based observing systems, such as Global Positioning System (GPS) and Interferometric Synthetic Aperture Radar (InSAR), the water vapor in the atmosphere will cause delays during the signal transmission. Such delays vary significantly with terrain elevation. In the case when atmospheric delays are to be eliminated from the measured raw signals, spatial interpolators may be needed. By taking advantage of available terrain elevation information during spatial interpolation process, the accuracy of the atmospheric delay mapping can be considerably improved. This paper first reviews three elevation-dependent water vapor interpolation models, i.e., the Best Linear Unbiased Estimator in combination with the water vapor Height Scaling Model (BLUE + HSM), the Best Linear Unbiased Estimator coupled with the Elevation-dependent Covariance Model (BLUE + ECM), and the Simple Kriging with varying local means based on the Baby semi-empirical model (SKlm + Baby for short). A revision to the SKlm + Baby model is then presented, where the Onn water vapor delay model is adopted to substitute the inaccurate Baby semi-empirical model (SKlm + Onn for short). Experiments with the zenith wet delays obtained through the GPS observations from the Southern California Integrated GPS Network (SCIGN) demonstrate that the SKlm + Onn model outperforms the other three. The RMS of SKlm + Onn is only 0.55 cm, while those of BLUE + HSM, BLUE + ECM and SKlm + Baby amount to 1.11, 1.49 and 0.77 cm, respectively. The proposed SKlm + Onn model therefore represents an improvement of 29–63% over the other known models. Numéro de notice : A2011-374 Affiliation des auteurs : non IGN Thématique : IMAGERIE/POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-011-0456-0 Date de publication en ligne : 08/03/2011 En ligne : https://doi.org/10.1007/s00190-011-0456-0 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31153 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
266-2011091	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Improved filtering parameter determination for the Goldstein radar interferogram filter / Z.W. Li in ISPRS Journal of photogrammetry and remote sensing, vol 63 n° 6 (November - December 2008)  

Public [article]  inISPRS Journal of photogrammetry and remote sensing > vol 63 n° 6 (November - December 2008) . - pp 621 - 634 Titre : Improved filtering parameter determination for the Goldstein radar interferogram filter Type de document : Article/Communication Auteurs : Z.W. Li, Auteur ; X.L. Ding, Auteur ; et al., Auteur Année de publication : 2008 Article en page(s) : pp 621 - 634 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications [Termes IGN] cohérence des données [Termes IGN] filtrage du bruit [Termes IGN] filtre de Goldstein [Termes IGN] image radar moirée [Termes IGN] radar à antenne synthétique Résumé : (Auteur) Phase noise in a radar interferogram is directly related to interferometric coherence and the look number of the interferogram. Therefore an optimal radar interferogram filter should incorporate information on both interferometric coherence and look number. We present a modification to the commonly used Goldstein filter by suggesting an improved determination of the filtering parameter. Experimental results with both simulated and real data sets show that the new filter offers much better results when used to filter radar interferograms. Copyright ISPRS Numéro de notice : A2008-435 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2008.03.001 En ligne : https://doi.org/10.1016/j.isprsjprs.2008.03.001 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29504 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
081-08061	SL	Revue	Centre de documentation	Revues en salle	Disponible

Ground subsidence monitoring in Hong Kong with satellite SAR interferometry / X.L. Ding in Photogrammetric Engineering & Remote Sensing, PERS, vol 70 n° 10 (October 2004)  

Public [article]  inPhotogrammetric Engineering & Remote Sensing, PERS > vol 70 n° 10 (October 2004) . - pp 1151 - 1156 Titre : Ground subsidence monitoring in Hong Kong with satellite SAR interferometry Type de document : Article/Communication Auteurs : X.L. Ding, Auteur ; G.X. Liu, Auteur ; Z.W. Li, Auteur ; Z.L. Li, Auteur ; Y.Q. Chen, Auteur Année de publication : 2004 Article en page(s) : pp 1151 - 1156 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications [Termes IGN] Hong-Kong [Termes IGN] image radar moirée [Termes IGN] interferométrie différentielle [Termes IGN] interféromètrie par radar à antenne synthétique [Termes IGN] risque naturel [Termes IGN] subsidence [Termes IGN] surveillance géologique Résumé : (Auteur) Ground settlement has long been a problem in Hong Kong, as most usable land in Hong Kong was reclaimed from the sea. Ground settlement may affect building structures and underground facilities such as water supply and sewage systems built on the land. Measurements of ground settlement can provide valuable data for assessing the impacts of ground settlement and for improving designs of future land reclamation projects. Experiments have been carried out to assess the performance of INSAR in the environment of Hong Kong especially the temporal decorrelations of SAR images and the potential atmospheric effects on INSAR measurements, and to use INSAR to study the ground settlement problem in Hong Kong. This study finds that the temporal decorrelation is an important problem in the heavily vegetated rugged areas as usually expected, and that the atmospheric effects can be very significant at times. Ground settlements measured over the airport and a residential area are presented. It can be seen from the results that both of the areas are still settling significantly in any years after the reclamation. Numéro de notice : A2004-362 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.14358/PERS.70.10.1151 En ligne : https://doi.org/10.14358/PERS.70.10.1151 Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26889 [article]