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
The effect of tropospheric delay on GPS height differences along the Equator / J. Dodo in SaLIS Surveying and land information science, vol 68 n° 3 (September 2008)
[article]
Titre : The effect of tropospheric delay on GPS height differences along the Equator Type de document : Article/Communication Auteurs : J. Dodo, Auteur ; M. Kamarudin, Auteur ; M. Yahya, Auteur Année de publication : 2008 Article en page(s) : pp 145 - 154 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Nivellement
[Termes IGN] antenne GPS
[Termes IGN] correction du signal
[Termes IGN] équateur (géodésie)
[Termes IGN] erreur systématique
[Termes IGN] GPS en mode cinématique
[Termes IGN] hauteur ellipsoïdale
[Termes IGN] Malaisie
[Termes IGN] nivellement par GPS
[Termes IGN] positionnement cinématique en temps réel
[Termes IGN] propagation troposphérique
[Termes IGN] zone équatorialeRésumé : (Auteur) The fundamental issue in GPS positioning is the ability to mitigate all the potential errors and biases in the system. The atmosphere related errors of ionosphere and troposphere constitute one of these potential errors. The tropospheric effect is much more pronounced at the equatorial region due to its hot and wet conditions. This significantly affects the GPS signal due to the variability of the refractive index, which in turn affects the accuracy of GPS positioning, especially in the height components. This paper presents a study conducted in Malaysia located at the equatorial region, to investigate the impact of tropospheric delay on GPS height variation. Five GPS reference stations forming part of the Malaysian real-time kinematic GPS network (MyRTKnet) in Johor were used. RINEX data from these stations were integrated with GPS and ground meteorological data observed from a GPS station located at the Universiti Teknologi Malaysia (UTM), at varying antenna heights for each session of observation in four campaigns with each campaign lasting for three days. A computer program called TROPO.exe was developed based on Saastamoinen tropospheric model. The result shows variations in the height component of GPS measurement with a maximum value of 119.100 cm and a minimum value of 37.990 cm. Similarly, the results show that the tropospheric delay is a distance-dependent error which varies with changes in meteorological condition. Furthermore, the results of simulated data show a decrease in tropospheric delay with increase in antenna height. Copyright SaLIS Numéro de notice : A2008-411 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83665
in SaLIS Surveying and land information science > vol 68 n° 3 (September 2008) . - pp 145 - 154[article]Réservation
Réserver ce documentExemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 121-08031 RAB Revue Centre de documentation En réserve L003 Disponible ADOP in closed form for a hierarchy of multi-frequency single-baseline GNSS models / Dennis Odijk in Journal of geodesy, vol 82 n° 8 (August 2008)
[article]
Titre : ADOP in closed form for a hierarchy of multi-frequency single-baseline GNSS models Type de document : Article/Communication Auteurs : Dennis Odijk, Auteur ; Peter J.G. Teunissen, Auteur Année de publication : 2008 Article en page(s) : pp 473 - 492 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] affaiblissement de la précision
[Termes IGN] ambiguïté entière
[Termes IGN] modèle de diffusion du rayonnement
[Termes IGN] positionnement par GNSS
[Termes IGN] propagation du signal
[Termes IGN] résolution d'ambiguïté
[Termes IGN] signal GNSSRésumé : (Auteur) Successful carrier phase ambiguity resolution is the key to high-precision positioning with Global Navigation Satellite Systems (GNSS). The ambiguity dilution of precision (ADOP) is a well-known scalar measure which can be used to infer the strength of the GNSS model for carrier phase ambiguity resolution. In this contribution we present analytical closed-form expressions for the ADOP. This will be done for a whole class of different multi- frequency single baseline models. These models include the geometry-fixed, the geometry-free and the geometry-based models, respectively. And within the class of geometry-based models, we discriminate between short and long observation time spans, and between stationary and moving receivers. The easy-to-use ADOP expressions can be applied to infer the contribution of various GNSS model factors. They comprise, for instance, the type, the number and the precision of the GNSS observations, the number and selection of frequencies, the presence of atmospheric disturbances, the length of the observation time span and the length of the baseline. Copyright Springer Numéro de notice : A2008-320 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-007-0197-2 En ligne : https://doi.org/10.1007/s00190-007-0197-2 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29313
in Journal of geodesy > vol 82 n° 8 (August 2008) . - pp 473 - 492[article]Réservation
Réserver ce documentExemplaires(2)
Code-barres Cote Support Localisation Section Disponibilité 266-08071 RAB Revue Centre de documentation En réserve L003 Disponible 266-08072 RAB Revue Centre de documentation En réserve L003 Disponible Estuarine shoreline change detection using Japanese ALOS PALSAR HH and JERS-1 L-HH SAR data in the Albemarle-Pamlico Sounds, North Carolina, USA / Y. Wang in International Journal of Remote Sensing IJRS, vol 29 n° 15-16 (August 2008)
[article]
Titre : Estuarine shoreline change detection using Japanese ALOS PALSAR HH and JERS-1 L-HH SAR data in the Albemarle-Pamlico Sounds, North Carolina, USA Type de document : Article/Communication Auteurs : Y. Wang, Auteur ; T. Allen, Auteur Année de publication : 2008 Article en page(s) : pp 4429 - 4442 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications
[Termes IGN] analyse diachronique
[Termes IGN] bande L
[Termes IGN] Caroline du Nord (Etats-Unis)
[Termes IGN] détection de changement
[Termes IGN] données polarimétriques
[Termes IGN] érosion côtière
[Termes IGN] estuaire
[Termes IGN] image ALOS-PALSAR
[Termes IGN] image JERS
[Termes IGN] polarimétrie radar
[Termes IGN] trait de côteRésumé : (Auteur) An edge extraction model has been developed that uses multitemporal satellite synthetic aperture radar data to delineate shorelines in estuaries. Using Japanese ALOS PALSAR HH data acquired in December 2006 and JERS-1 L-HH SAR data in December 1994, we mapped shorelines of the outer Pamlico Peninsula, Dare County, North Carolina, USA, spanning 12 years. To assess the validity and accuracy of the delineation, we compared (a) 1994 shorelines versus those derived from the 1993 digital orthophotographs, and (b) 2006 shorelines versus field data collected in February 2007. With promising results, we then analysed and quantified the shoreline changes between 1994 and 2006 on the north, east, and south sides of the Peninsula. Virtually no discernible changes on the north and south sides were found. However, significant landward migration in the middle to southern portion on the east shore was observed. Spatial retreat of shorelines varied greatly, with the maximum rate averaged over a span of 12 years exceeding 11 m year?-1? The results support further monitoring of shorelines in estuaries using active remote sensing and the potential for the methodology developed to identify erosional hotspots. Copyright Taylor & Francis Numéro de notice : A2008-528 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/01431160801932525 En ligne : https://doi.org/10.1080/01431160801932525 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29598
in International Journal of Remote Sensing IJRS > vol 29 n° 15-16 (August 2008) . - pp 4429 - 4442[article]Integration of multitemporal/polarization C-band SAR data sets for land-cover classification / N. Park in International Journal of Remote Sensing IJRS, vol 29 n° 15-16 (August 2008)
[article]
Titre : Integration of multitemporal/polarization C-band SAR data sets for land-cover classification Type de document : Article/Communication Auteurs : N. Park, Auteur ; K.H. Chi, Auteur Année de publication : 2008 Article en page(s) : pp 4667 - 4688 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications
[Termes IGN] analyse en composantes principales
[Termes IGN] angle d'incidence
[Termes IGN] bande C
[Termes IGN] carte agricole
[Termes IGN] image Envisat-ASAR
[Termes IGN] image radar
[Termes IGN] image Radarsat
[Termes IGN] intégration de données
[Termes IGN] occupation du sol
[Termes IGN] polarimétrie radarRésumé : (Auteur) This paper investigates the potential of multitemporal/polarization C-band SAR data for land-cover classification. Multitemporal Radarsat-1 data with HH polarization and ENVISAT ASAR data with VV polarization acquired in the Yedang plain, Korea are used for the classification of typical five land-cover classes in an agricultural area. The presented methodologies consist of two analytical stages: one for feature extraction and the other for classification based on the combination of features. Both a traditional SAR signal property analysis-based approach and principal-component analysis (PCA) are applied in the feature extraction stage. Special concerns are in the interpretation of each principal component by using principal-component loading. The tau model applied as a decision-level fusion methodology can provide a formal framework in which the posteriori probabilities derived from different sensor data can be combined. From the case study results, the combination of PCA-based features showed improved classification accuracy for both Radarsat-1 and ENVISAT ASAR data, as compared with the traditional SAR signal property analysis-based approach. The integration of PCA-based features based on multiple polarization (i.e. HH from Radarsat-1, and both VV and VH from ENVISAT ASAR) and different incidence angles contributed to a significant improvement of discrimination capability for dry fields which could not be properly classified by using only Radarsat-1 or ENVISAT ASAR data, and thus showed the best classification accuracy. The results of this case study indicate that the use of multiple polarization SAR data with a proper feature extraction stage would improve classification accuracy in multitemporal SAR data classification, although further consideration should be given to the polarization and incidence angle dependency of complex land-cover classes through more experiments. Numéro de notice : A2008-530 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/01431160801947341 En ligne : https://doi.org/10.1080/01431160801947341 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29600
in International Journal of Remote Sensing IJRS > vol 29 n° 15-16 (August 2008) . - pp 4667 - 4688[article]Sea ice deformation state from Synthetic Aperture Radar Imagery: part 2 Effects of spatial resolution and noise level / W. Dierking in IEEE Transactions on geoscience and remote sensing, vol 46 n° 8 (August 2008)
[article]
Titre : Sea ice deformation state from Synthetic Aperture Radar Imagery: part 2 Effects of spatial resolution and noise level Type de document : Article/Communication Auteurs : W. Dierking, Auteur ; J. Dall, Auteur Année de publication : 2008 Article en page(s) : pp 2197 - 2207 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications
[Termes IGN] bande C
[Termes IGN] bande L
[Termes IGN] filtrage du bruit
[Termes IGN] glace de mer
[Termes IGN] image aérienne
[Termes IGN] image ALOS-PALSAR
[Termes IGN] image Envisat-ASAR
[Termes IGN] image ERS-SAR
[Termes IGN] image radar
[Termes IGN] pouvoir de résolution géométrique
[Termes IGN] radargrammétrie
[Termes IGN] rapport signal sur bruitRésumé : (Auteur) C- and L-band airborne synthetic aperture radar (SAR) imagery acquired at like- and cross-polarizations over sea ice under winter conditions is examined with the objective to study the discrimination between level ice and ice deformation features. High-resolution low-noise data were analyzed in the first paper. In this second paper, the main topics are the effects of spatial resolution and signal-to-noise ratio. Airborne high-resolution SAR scenes are used to generate a sequence of images with increasingly coarser spatial resolution from 5 to 25 m, keeping the number of looks constant. The signal-to-noise ratio is varied between typical noise levels for airborne imagery and satellite data. Areal fraction of deformed ice and average deformation distance are determined for each image product. At L-band, the retrieved values of the areal fraction get larger as the image resolution is degraded. The areal fraction at C-band remains constant. The retrieved average distance between deformation features increases both at C- and L-bands as the image resolution gets coarser. The influence of noise becomes noticeable if its level is equal or larger than the average intensity backscattered from the level ice. The retrieval of deformation parameters using simulated images that resemble ERS-2 SAR, Envisat ASAR, and ALOS PALSAR data products is discussed. Basic differences between real and simulated ERS-2 SAR images are analyzed. Copyright IEEE Numéro de notice : A2008-398 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2008.917267 En ligne : https://doi.org/10.1109/TGRS.2008.917267 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29487
in IEEE Transactions on geoscience and remote sensing > vol 46 n° 8 (August 2008) . - pp 2197 - 2207[article]Voir aussiRéservation
Réserver ce documentExemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 065-08081 RAB Revue Centre de documentation En réserve L003 Disponible Image-based 3D surface reconstruction by combination of photometric, geometric, and real-aperture methods / Pablo d' Angelo in ISPRS Journal of photogrammetry and remote sensing, vol 63 n° 3 (May - June 2008)PermalinkAssimilation of remote sensed data for improved latent and sensible heat flux prediction: a comparative synthetic study / R. Pipunic in Remote sensing of environment, vol 112 n° 4 (15/04/2008)PermalinkMulti-sensor model-data fusion for estimation of hydrologic and energy flux parameters / L. Renzullo in Remote sensing of environment, vol 112 n° 4 (15/04/2008)PermalinkUse of a Kalman filter for the retrieval of surface BRDF coefficients with a time-evolving model based on the ECOCLIMAP land cover classification / O. Samain in Remote sensing of environment, vol 112 n° 4 (15/04/2008)PermalinkDigital aerial cameras / Mathias Lemmens in GIM international, vol 22 n° 4 (April 2008)Permalink3D vegetation mapping using small-footprint full-waveform airborne laser scanners / W. Wagner in International Journal of Remote Sensing IJRS, vol 29 n° 5 (March 2008)PermalinkAssessment of the influence of flying altitude and scan angle on biophysical vegetation products derived from airborne laser scanning / F. Morsdorf in International Journal of Remote Sensing IJRS, vol 29 n° 5 (March 2008)PermalinkA comparison of illumination geometry-based methods for topographic correction of QuickBird images of an undulant area / J. Wu in ISPRS Journal of photogrammetry and remote sensing, vol 63 n° 2 (March - April 2008)PermalinkImproving long-range RTK: getting a better handle on the biases / D. Kim in GPS world, vol 19 n° 3 (March 2008)PermalinkLes interactions entre espèces d'arbres dans les mélanges illustrées par le cas des feuillus et des conifères dans les forêts de montagne / Richard Michalet in Revue forestière française, vol 60 n° 2 (mars - avril 2008)Permalink