Descripteur
Termes IGN > sciences naturelles > physique > optique > optique physique
optique physiqueSynonyme(s)optique ondulatoire |
Documents disponibles dans cette catégorie (3085)
Ajouter le résultat dans votre panier
Visionner les documents numériques
Affiner la recherche Interroger des sources externes
Etendre la recherche sur niveau(x) vers le bas
Atmospheric correction in time-series SAR interferometry for land surface deformation mapping : A case study of Taiyuan, China / Wei Tang in Advances in space research, vol 58 n° 3 (August 2016)
[article]
Titre : Atmospheric correction in time-series SAR interferometry for land surface deformation mapping : A case study of Taiyuan, China Type de document : Article/Communication Auteurs : Wei Tang, Auteur ; Mingsheng Liao, Auteur ; Peng Yuan, Auteur Année de publication : 2016 Article en page(s) : pp 310 - 325 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications
[Termes IGN] Chine
[Termes IGN] correction atmosphérique
[Termes IGN] données météorologiques
[Termes IGN] image Envisat-ASAR
[Termes IGN] interferométrie différentielle
[Termes IGN] interféromètrie par radar à antenne synthétique
[Termes IGN] retard ionosphèrique
[Termes IGN] retard troposphérique
[Termes IGN] série temporelleRésumé : (auteur) The dominant error source of Synthetic Aperture Radar Interferometry (InSAR) is atmospheric phase screen (APS), resulting in phase delay of the radar signal propagating through the atmosphere. The APS in the atmosphere can be decomposed into stratified and turbulent components. In this paper, we introduced a method to compensate for stratified component in a radar interferogram using ERA-Interim reanalysis products obtained from European Centre for Medium-Range Weather Forecasts (ECMWF). Our comparative results with radiosonde data demonstrated that atmospheric condition from ERA-Interim could produce reasonable patterns of vertical profiles of atmospheric states. The stratified atmosphere shows seasonal changes which are correlated with time. It cannot be properly estimated by temporal high-pass filtering which assumes that atmospheric effects are random in time in conventional persistent scatterer InSAR (PSI). Thus, the estimated deformation velocity fields are biased. Therefore, we propose the atmosphere-corrected PSI method that the stratified delay are corrected on each interferogram by using ERA-Interim. The atmospheric residuals after correction of stratified delay were interpreted as random variations in space and time which are mitigated by using spatial–temporal filtering. We applied the proposed method to ENVISAT ASAR images covering Taiyuan basin, China, to study the ground deformation associated with groundwater withdrawal. Experimental results show that the proposed method significantly mitigate the topography-correlated APS and the estimated ground displacements agree more closely with GPS measurements than the conventional PSI. Numéro de notice : A2016-590 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.asr.2016.05.003 En ligne : http://dx.doi.org/10.1016/j.asr.2016.05.003 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81745
in Advances in space research > vol 58 n° 3 (August 2016) . - pp 310 - 325[article]A high-quality reprocessed ground-based GPS dataset for atmospheric process studies, radiosonde and model evaluation, and reanalysis of HyMeX Special Observing Period / Olivier Bock in Quarterly Journal of the Royal Meteorological Society, vol 142 n° S1 (August 2016)
[article]
Titre : A high-quality reprocessed ground-based GPS dataset for atmospheric process studies, radiosonde and model evaluation, and reanalysis of HyMeX Special Observing Period Type de document : Article/Communication Auteurs : Olivier Bock , Auteur ; Pierre Bosser , Auteur ; Rosa Pacione, Auteur ; Mathieu Nuret, Auteur ; Nadia Fourrié, Auteur ; Ana-Claudia Bernardes Parracho , Auteur Année de publication : 2016 Article en page(s) : pp 56 - 71 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] atmosphère terrestre
[Termes IGN] coordonnées GPS
[Termes IGN] données météorologiques
[Termes IGN] Méditerranée, mer
[Termes IGN] modèle atmosphérique
[Termes IGN] modèle météorologique
[Termes IGN] prévision météorologique
[Termes IGN] radiosondage
[Termes IGN] retard troposphérique zénithal
[Termes IGN] teneur intégrée en vapeur d'eauRésumé : (auteur) In the framework of the Hydrological cycle in the Mediterranean Experiment (HyMeX) project, measurements from more than 1000 ground-based Global Positioning System (GPS) receivers located in the northwestern Mediterranean area are reprocessed using a single piece of GPS software for the period from 1 September 2012 to 31 March 2013. A special screening procedure is developed for the removal of outliers in the GPS Zenith Total Delay (ZTD) data. ZTD data are converted to integrated water vapour (IWV) using surface pressure information from an AROME-WMED operational analysis. The reprocessed ZTD and IWV data are used to assess the accuracy of the near-real time E-GVAP ZTD data assimilated in operational numerical weather prediction systems and to validate the IWV data from the AROME-WMED operational analysis and AROME-WMED reanalysis 1, and from radiosonde observations. The mean differences between E-GVAP and reprocessed ZTD data are not negligible and lie in the range from −3 to +3 mm. The standard deviations of differences are between 4 and 8 mm. The comparisons of IWV from AROME-WMED analyses and the reprocessed GPS data show high quality of the analyses where operational GPS data are assimilated and lower quality where no GPS data are assimilated. Small but significant biases are found in the radiosonde data during daytime (−0.5 to +1.4 kg m−2), but their origin is not determined so far. Thanks to the high spatial density of the reprocessed GPS stations, both the large-scale and small-scale variations in IWV can be documented. The case of HyMeX Intensive Observing Period 8 is presented as an example of a heavy precipitation event. This work suggests that improved quality of the humidity fields can be expected of the future AROME-WMED reanalysis 2 as a result of the assimilation of the reprocessed GPS data. Numéro de notice : A2016-938 Affiliation des auteurs : LASTIG LAREG+Ext (2012-mi2018) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1002/qj.2701 Date de publication en ligne : 04/11/2015 En ligne : http://dx.doi.org/10.1002/qj.2701 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83370
in Quarterly Journal of the Royal Meteorological Society > vol 142 n° S1 (August 2016) . - pp 56 - 71[article]Radiometric correction of airborne radar images over forested terrain with topography / Marc Simard in IEEE Transactions on geoscience and remote sensing, vol 54 n° 8 (August 2016)
[article]
Titre : Radiometric correction of airborne radar images over forested terrain with topography Type de document : Article/Communication Auteurs : Marc Simard, Auteur ; Bryan V. Riel, Auteur ; Michael Denbina, Auteur ; Scott Hensley, Auteur Année de publication : 2016 Article en page(s) : pp 4488 - 4500 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications
[Termes IGN] canopée
[Termes IGN] correction radiométrique
[Termes IGN] évaluation des données
[Termes IGN] forêt
[Termes IGN] homomorphisme
[Termes IGN] image aérienne
[Termes IGN] image radar
[Termes IGN] réflectivité
[Termes IGN] reliefRésumé : (Auteur) Radiometric correction of radar images is essential to produce accurate estimates of biophysical parameters related to forest structure and biomass. We present a new algorithm to correct radiometry for 1) terrain topography and 2) variations of canopy reflectivity with viewing and tree-terrain geometry. This algorithm is applicable to radar images spanning a wide range of incidence angles over terrain with significant topography and can also take into account aircraft attitude, antenna steering angle, and target geometry. The approach includes elements of both homomorphic and heteromorphic terrain corrections to correct for topographic effects and is followed by an additional radiometric correction to compensate for variations of canopy reflectivity with viewing and tree-terrain geometry. The latter correction is based on lookup tables and enables derivation of biophysical parameters irrespective of viewing geometry and terrain topography. We evaluate the performance of the new algorithm with airborne radar data and show that it performs better than classical homomorphic methods followed by cosine-based corrections. Numéro de notice : A2016-885 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2016.2543142 En ligne : http://dx.doi.org/10.1109/TGRS.2016.2543142 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83049
in IEEE Transactions on geoscience and remote sensing > vol 54 n° 8 (August 2016) . - pp 4488 - 4500[article]Soil moisture retrieval in agricultural fields using adaptive model-based polarimetric decomposition of SAR data / Lian He in IEEE Transactions on geoscience and remote sensing, vol 54 n° 8 (August 2016)
[article]
Titre : Soil moisture retrieval in agricultural fields using adaptive model-based polarimetric decomposition of SAR data Type de document : Article/Communication Auteurs : Lian He, Auteur ; Rocco Panciera, Auteur Année de publication : 2016 Article en page(s) : pp 4445 - 4460 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications
[Termes IGN] bande L
[Termes IGN] biomasse
[Termes IGN] cultures
[Termes IGN] décomposition d'image
[Termes IGN] données polarimétriques
[Termes IGN] filtre adaptatif
[Termes IGN] humidité du sol
[Termes IGN] image radar moirée
[Termes IGN] polarimétrie radarRésumé : (Auteur) The aim of this paper was to estimate soil moisture in agricultural crop fields from fully polarimetric L-band synthetic aperture radar (SAR) data through the polarimetric decomposition of the SAR coherency matrix. A nonnegative-eigenvalue-decomposition scheme, together with an adaptive volume scattering model, is extended to an adaptive model-based decomposition (MBD) (Adaptive MBD) model for soil moisture retrieval. The Adaptive MBD can ensure nonnegative decomposed scattering components and allows two parameters (i.e., the mean orientation angle and a degree of randomness) to be determined to characterize the volume scattering. Its performance was tested using airborne SAR data and coincident ground measurements collected over agricultural fields in southeastern Australia and compared with previous MBD methods (i.e., the Freeman three-component decomposition using the extended Bragg model, the Yamaguchi three-component decomposition, and an iterative generalized hybrid decomposition). The results obtained with the newly proposed decomposition scheme agreed well with expectations based on observed plant structure and biomass levels. The new method was superior in tracking soil moisture dynamics with respect to previous decomposition methods in our study area, with root-mean-square error of soil moisture estimations being 0.10 and 0.14 m3/m3, respectively, for surface and double-bounce components. However, large variability in the achieved soil moisture accuracy was observed, depending on the presence of row structures in the underlying soil surface. Numéro de notice : A2016-884 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2016.2542214 En ligne : https://doi.org/10.1109/TGRS.2016.2542214 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83048
in IEEE Transactions on geoscience and remote sensing > vol 54 n° 8 (August 2016) . - pp 4445 - 4460[article]A comparative analysis of measurement noise and multipath for four constellations: GPS, BeiDou, GLONASS and Galileo / Changsheng Cai in Survey review, vol 48 n° 349 (July 2016)
[article]
Titre : A comparative analysis of measurement noise and multipath for four constellations: GPS, BeiDou, GLONASS and Galileo Type de document : Article/Communication Auteurs : Changsheng Cai, Auteur ; Chang He, Auteur ; Rock Santerre, Auteur ; et al., Auteur Année de publication : 2016 Article en page(s) : pp 287 - 295 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] analyse comparative
[Termes IGN] code GNSS
[Termes IGN] constellation BeiDou
[Termes IGN] constellation Galileo
[Termes IGN] constellation GLONASS
[Termes IGN] constellation GPS
[Termes IGN] phase
[Termes IGN] rapport signal sur bruit
[Termes IGN] trajet multipleRésumé : (auteur) With the rapid development of BeiDou system (BDS) and steady progress of Galileo system, the current GNSS (Global Navigation Satellite System) constellations consist of GPS, GLONASS, BeiDou and Galileo. The real signals from the four constellations have been available, which allows us to analyse and compare their measurement noises and multipath effects. In this study, a zero-baseline test is conducted using two ‘Trimble NetR9’ receivers to assess and compare the noises and multipath of measurements on multiple frequencies from the four satellite systems. The zero-baseline double difference approach is utilised to analyse the receiver noises. The code multipath combination and triple-frequency carrier phase combination approaches are exploited to analyse a comprehensive effect of the multipath and noises on the code and carrier phase measurements, respectively. Based on the analysis of the zero-baseline dataset, the results indicate that the code measurement noise levels range from 5 to 25 cm while the carrier phase noise levels vary within 0.9–1.5 mm for different frequencies and constellations. The code multipath and noise (CMN) level for GLONASS is the largest with a root mean square (RMS) value of 39 cm on both G1 and G2 frequencies whereas the Galileo code measurements exhibit a smallest level on the E5 frequency with a RMS value of only 10 cm. The RMS of the carrier phase multipath and noises (PMN) ranges from 1.3 to 2.6 mm for BeiDou and Galileo satellites. By contrast, the triple-frequency carrier phase combinations from the GPS Block IIF satellites demonstrate a much larger RMS value of 5.6 mm owing to an effect of inter-frequency clock biases. Numéro de notice : A2016-625 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1179/1752270615Y.0000000032 En ligne : https://doi.org/10.1179/1752270615Y.0000000032 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81843
in Survey review > vol 48 n° 349 (July 2016) . - pp 287 - 295[article]Direction-of-arrival estimation of VHF signals recorded on the international space station and simultaneous observations of optical lightning / Hiroshi Kikuchi in IEEE Transactions on geoscience and remote sensing, vol 54 n° 7 (July 2016)PermalinkA general variational framework considering cast shadows for the topographic correction of remote sensing imagery / Huifang Li in ISPRS Journal of photogrammetry and remote sensing, vol 117 (July 2016)PermalinkGeneralized terrain topography in radar scattering models / Mariko S. Burgin in IEEE Transactions on geoscience and remote sensing, vol 54 n° 7 (July 2016)PermalinkGNSS multipath detection using three-frequency signal-to-noise measurements / Philip R.R. Strode in GPS solutions, vol 20 n° 3 (July 2016)PermalinkMultiple spectral similarity metrics for surface materials identification using hyperspectral data / Rama Rao Nidamanuri in Geocarto international, vol 31 n° 7 - 8 (July - August 2016)PermalinkA new method for specular and diffuse pseudorange multipath error extraction using wavelet analysis / Giovanni Pugliano in GPS solutions, vol 20 n° 3 (July 2016)PermalinkRange imaging of E-region field-aligned irregularities by using a multifrequency technique : validation and initial results / Jenn-Shyong Chen in IEEE Transactions on geoscience and remote sensing, vol 54 n° 7 (July 2016)PermalinkCharacterization of ionospheric variability in TEC using EOF and wavelets over low-latitude GNSS stations / J.R.K. Kumar Dabbakuti in Advances in space research, vol 57 n° 12 (June 2016)PermalinkSpectral band selection for urban material classification using hyperspectral libraries / Arnaud Le Bris in ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences, vol III-7 (July 2016)PermalinkHybrid online mobile laser scanner calibration through image alignment by mutual information / Mourad Miled in ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences, vol III-1 (July 2016)Permalink