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DMC geometry analysis and virtual image characterisation / R. Alamus in Photogrammetric record, vol 23 n° 124 (December 2008 - February 2009)
[article]
Titre : DMC geometry analysis and virtual image characterisation Type de document : Article/Communication Auteurs : R. Alamus, Auteur ; W. Kornus, Auteur Année de publication : 2008 Conférence : ISPRS 2007, High-Resolution Earth Imaging for Geospatial Information workshop 29/05/2007 01/06/2007 Hanovre Allemagne Article en page(s) : pp 353 - 371 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s)
[Termes IGN] aérotriangulation automatisée
[Termes IGN] auto-étalonnage
[Termes IGN] chambre à grand format
[Termes IGN] compensation par faisceaux
[Termes IGN] DMC
[Termes IGN] erreur systématique
[Termes IGN] espace image
[Termes IGN] géométrie de l'image
[Termes IGN] géoréférencement
[Termes IGN] modélisation géométrique de prise de vue
[Termes IGN] points homologues
[Termes IGN] précision géométrique (imagerie)
[Termes IGN] rapport base hauteur
[Termes IGN] résiduRésumé : (Auteur) Since the advent of the first large format digital aerial cameras, high expectations have been placed on their performance. The dream of obtaining aerial images virtually free of geometric errors and with greater radiometric quality is getting close. Nevertheless, systematic image residuals, unexpected height errors in aerial triangulation and the need for additional self-calibration parameters have been reported since 2005. In this paper a preliminary analysis of the theoretical accuracies in aerial triangulation using the Zeiss/Intergraph (Z/I) Digital Mapping Camera (DMC) and an analogue camera is conducted, motivated by those recent reports. This analysis considers a mathematical model where the image has conical geometry and is free of systematic errors. The influence on the propagated block accuracy of the base-to-height ratio, image pointing precision (both manual and automatic), GPS observations for projection centres and of pass/tie point density is studied. Moreover, the expected accuracy in the aerial triangulation of analogue images using current procedures (having regard to the a priori accuracy for image pointing, ground control measurement and GPS and pass/tie point density) is computed. The goal of this theoretical study is to find the requirements for aerial triangulation with DMC data which would yield the same or an even higher level of accuracy than that obtained with analogue data under the same conditions. The paper continues with a check on the conclusions of this theoretical analysis, using real data-sets and aerial triangulation set-up, which fit with the theoretical analysis. The results prove that the expected theoretical accuracy in aerial triangulation is only obtained if an appropriate self-calibration parameter set is considered in the bundle block adjustment and/or if good GPS observations are available. These requirements result from the unfavourable propagation from unmodelled systematic error in the DMC image blocks. Some authors have detected systematic residuals in the order of one-tenth of a pixel rms in DMC image space. For this reason, investigations are being carried out on systematic error characterisation, distribution in image space and stability over time and flying height, and systematic error modelling, using self-calibration parameter sets and applying correction grids. Finally, conclusions are drawn from the investigations. Copyright RS&PS + Blackwell Publishing Numéro de notice : A2008-417 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1111/j.1477-9730.2008.00504.x En ligne : https://doi.org/10.1111/j.1477-9730.2008.00504.x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29488
in Photogrammetric record > vol 23 n° 124 (December 2008 - February 2009) . - pp 353 - 371[article]
[article]
Titre : On detecting spatial outliers Type de document : Article/Communication Auteurs : D. Chen, Auteur ; C.T. Lu, Auteur ; Y. Kou, Auteur ; et al., Auteur Année de publication : 2008 Article en page(s) : pp 455 - 475 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Bases de données localisées
[Termes IGN] exploration de données géographiques
[Termes IGN] méthode robuste
[Termes IGN] qualité des données
[Termes IGN] valeur aberranteRésumé : (Auteur) The ever-increasing volume of spatial data has greatly challenged our ability to extract useful but implicit knowledge from them. As an important branch of spatial data mining, spatial outlier detection aims to discover the objects whose non-spatial attribute values are significantly different from the values of their spatial neighbors. These objects, called spatial outliers, may reveal important phenomena in a number of applications including traffic control, satellite image analysis, weather forecast, and medical diagnosis. Most of the existing spatial outlier detection algorithms mainly focus on identifying single attribute outliers and could potentially misclassify normal objects as outliers when their neighborhoods contain real spatial outliers with very large or small attribute values. In addition, many spatial applications contain multiple non-spatial attributes which should be processed altogether to identify outliers. To address these two issues, we formulate the spatial outlier detection problem in a general way, design two robust detection algorithms, one for single attribute and the other for multiple attributes, and analyze their computational complexities. Experiments were conducted on a real-world data set, West Nile virus data, to validate the effectiveness of the proposed algorithms. Copyright Springer Numéro de notice : A2008-379 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/INFORMATIQUE Nature : Article DOI : 10.1007/s10707-007-0038-8 En ligne : https://doi.org/10.1007/s10707-007-0038-8 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29372
in Geoinformatica > vol 12 n° 4 (December 2008) . - pp 455 - 475[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 057-08041 RAB Revue Centre de documentation En réserve L003 Disponible The impact of errors in polar motion and nutation on UT1 determinations from VLBI Intensive observations / Axel Nothnagel in Journal of geodesy, vol 82 n° 12 (December 2008)
[article]
Titre : The impact of errors in polar motion and nutation on UT1 determinations from VLBI Intensive observations Type de document : Article/Communication Auteurs : Axel Nothnagel, Auteur ; D. Schnell, Auteur Année de publication : 2008 Article en page(s) : pp 863 - 869 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] compensation
[Termes IGN] données ITGB
[Termes IGN] écart type
[Termes IGN] erreur systématique
[Termes IGN] mouvement du pôle
[Termes IGN] nutation
[Termes IGN] temps universelRésumé : (Auteur) The earth’s phase of rotation, expressed as Universal Time UT1, is the most variable component of the earth’s rotation. Continuous monitoring of this quantity is realised through daily single-baseline VLBI observations which are interleaved with VLBI network observations. The accuracy of these single-baseline observations is established mainly through statistically determined standard deviations of the adjustment process although the results of these measurements are prone to systematic errors. The two major effects are caused by inaccuracies in the polar motion and nutation angles introduced as a priori values which propagate into the UT1 results. In this paper, we analyse the transfer of these components into UT1 depending on the two VLBI baselines being used for short duration UT1 monitoring. We develop transfer functions of the errors in polar motion and nutation into the UT1 estimates. Maximum values reach 30 [?s per milliarcsecond] which is quite large considering that observations of nutation offsets w.r.t. the state-of-the-art nutation model show deviations of as much as one milliarcsecond. Copyright Springer Numéro de notice : A2008-470 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-008-0212-2 En ligne : https://doi.org/10.1007/s00190-008-0212-2 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29539
in Journal of geodesy > vol 82 n° 12 (December 2008) . - pp 863 - 869[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 266-08111 RAB Revue Centre de documentation En réserve L003 Disponible 266-08112 RAB Revue Centre de documentation En réserve L003 Disponible West African Monsoon observed with ground-based GPS receivers during African Monsoon Multidisciplinary Analysis (AMMA) / Olivier Bock in Journal of geophysical research : Atmospheres, vol 113 n° D21 (16 November 2008)
[article]
Titre : West African Monsoon observed with ground-based GPS receivers during African Monsoon Multidisciplinary Analysis (AMMA) Type de document : Article/Communication Auteurs : Olivier Bock , Auteur ; Marie-Noëlle Bouin , Auteur ; Erik Doerflinger, Auteur ; Philippe Collard, Auteur ; Florian Masson, Auteur ; Rémi Meynadier, Auteur ; Samuel Nahmani , Auteur ; et al., Auteur Année de publication : 2008 Projets : AMMA & AMMA-2 / Janicot, Serge Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] Afrique occidentale
[Termes IGN] circulation atmosphérique
[Termes IGN] données GPS
[Termes IGN] erreur systématique
[Termes IGN] humidité de l'air
[Termes IGN] modèle de simulation
[Termes IGN] mousson
[Termes IGN] phénomène atmosphérique
[Termes IGN] précipitation
[Termes IGN] vapeur d'eau
[Termes IGN] variation saisonnièreRésumé : (auteur) A ground-based GPS network has been established over West Africa in the framework of African Monsoon Multidisciplinary Analysis (AMMA) in tight cooperation between French and African institutes. The experimental setup is described and preliminary highlights are given for different applications using these data. Precipitable water vapor (PWV) estimates from GPS are used for evaluating numerical weather prediction (NWP) models and radiosonde humidity data. Systematic tendency errors in model forecasts are evidenced. Correlated biases in NWP model analyses and radiosonde data are evidenced also, which emphasize the importance of radiosonde humidity data in this region. PWV and precipitation are tightly correlated at seasonal and intraseasonal timescales. Almost no precipitation occurs when PWV is smaller than 30 kg m−2. This limit in PWV also coincides well with the location of the intertropical discontinuity. Five distinct phases in the monsoon season are determined from the GPS PWV, which correspond either to transition or stationary periods of the West African Monsoon system. They may serve as a basis for characterizing interannual variability. Significant oscillations in PWV are observed with 10- to 15-day and 15- to 20-day periods, which suggest a strong impact of atmospheric circulation on moisture and precipitation. The presence of a diurnal cycle oscillation in PWV with marked seasonal evolutions is found. This oscillation involves namely different phasing of moisture fluxes in different layers implying the low-level jet, the return flow, and the African Easterly Jet. The broad range of timescales observed with the GPS systems shows a high potential for investigating many atmospheric processes of the West African Monsoon. Numéro de notice : A2008-656 Affiliation des auteurs : LAREG+Ext (1991-2011) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1029/2008JD010327 Date de publication en ligne : 05/11/2008 En ligne : https://doi.org/10.1029/2008JD010327 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=98266
in Journal of geophysical research : Atmospheres > vol 113 n° D21 (16 November 2008)[article]Correction of humidity bias for Vaïsala RS80 sondes during AMMA 2006 Observing Period / Mathieu Nuret in Journal of Atmospheric and Oceanic Technology, vol 25 n° 11 (November 2008)
[article]
Titre : Correction of humidity bias for Vaïsala RS80 sondes during AMMA 2006 Observing Period Type de document : Article/Communication Auteurs : Mathieu Nuret, Auteur ; Jean-Philippe Lafore, Auteur ; Françoise Guichard, Auteur ; Jean-Luc Redelsperger, Auteur ; Olivier Bock , Auteur ; Anna Agusti-Panareda, Auteur ; Jean-Blaise N’Gamini, Auteur Année de publication : 2008 Article en page(s) : pp 2152 - 2158 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] Afrique occidentale
[Termes IGN] données GPS
[Termes IGN] données météorologiques
[Termes IGN] erreur systématique
[Termes IGN] humidité de l'air
[Termes IGN] mousson
[Termes IGN] radiosondageRésumé : (autuer) During the African Monsoon Multidisciplinary Analyses (AMMA) program, which included a special observing period that took place over West Africa in 2006, a major effort was devoted to monitor the atmosphere and its water cycle. The radiosonde network was upgraded and enhanced, and GPS receivers deployed. Among all sondes released in the atmosphere, a significant number were Vaisala RS80-A sondes, which revealed a significant dry bias relative to Vaisala RS92 (a maximum of 14% in the lower atmosphere, reaching 20% in the upper levels). This paper makes use of a simple but robust statistical approach to correct the bias. Comparisons against independent GPS data show that the bias is almost removed at night, whereas for daytime conditions, a weak dry bias (5%) still remains. The correction enhances CAPE by a factor of about 4 and, thus, becomes much more in line with expected values over the region. Numéro de notice : A2008-570 Affiliation des auteurs : LAREG+Ext (1991-2011) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1175/2008JTECHA1103.1 Date de publication en ligne : 01/11/2008 En ligne : https://doi.org/10.1175/2008JTECHA1103.1 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=103427
in Journal of Atmospheric and Oceanic Technology > vol 25 n° 11 (November 2008) . - pp 2152 - 2158[article]Formulation of distortion error for the line-of-sight (LOS) vector adjustment model and its role in restitution of SPOT imagery / Hyung-Sup Jung in ISPRS Journal of photogrammetry and remote sensing, vol 63 n° 6 (November - December 2008)PermalinkDevelopment and testing of a generic sensor model for pushbroom satellite imagery / T. Weser in Photogrammetric record, vol 23 n° 123 (September - November 2008)PermalinkOrientation and self-calibration of ALOS PRISM imagery / S. Kocaman in Photogrammetric record, vol 23 n° 123 (September - November 2008)PermalinkThe 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)PermalinkMonitoring post-mining subsidence in the North-Pas-de-Calais coal basin (France): interferometric SAR results and levelling / Daniel Raucoules in Geocarto international, vol 23 n° 4 (August - September 2008)PermalinkOn weighted total least-squares adjustment for linear regression / Burkhard Schaffrin in Journal of geodesy, vol 82 n° 7 (July 2008)PermalinkA GNSS odometer: how far have we come? / Andreas Wieser in GPS world, vol 19 n° 4 (April 2008)PermalinkSeeking the Pareto front for multiobjective spatial optimization problems / B. Huang in International journal of geographical information science IJGIS, vol 22 n° 4-5 (april 2008)PermalinkA method to test differences between additional parameter sets with a case study in terrestrial laser scanner self-calibration stability analysis / Derek D. Lichti in ISPRS Journal of photogrammetry and remote sensing, vol 63 n° 2 (March - April 2008)PermalinkA robust biased estimator for exterior orientation of linear array pushbroom satellite imagery / Y. Zhang in Geomatica, vol 62 n° 1 (March 2008)PermalinkAdjusting for long term anomalous trends in NOAA's Global Vegetation Index datasets / L. Jiang in IEEE Transactions on geoscience and remote sensing, vol 46 n° 2 (February 2008)PermalinkPhase unwrapping for SAR interferometry based on an ant colony optimization algorithm / Z.Q. Wei in International Journal of Remote Sensing IJRS, vol 29 n°3-4 (February 2008)PermalinkAide-mémoire de géostatistique linéaire / P. Chauvet (2008)PermalinkPermalinkAnalyse des séries temporelles de positions des stations de géodésie spatiale : application au repère international de référence terrestre (ITRF) / Xavier Collilieux (2008)PermalinkAnomalous harmonics in the spectra of GPS position estimates / Jim Ray in GPS solutions, vol 12 n° 1 (January 20008)PermalinkCapture de layers durant une session dans un globe virtuel / G. Mazabraud (2008)PermalinkEtude sur la restitution fine de l'axe de visée d'un instrument optronique embarqué / Adeline Coupé (2008)PermalinkEvaluation et amélioration des performances de la chaine MNT P+XS SPOT5 / Jean Figuerola (2008)PermalinkPermalink