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Termes IGN > mathématiques > statistique mathématique > probabilités > théorie des erreurs > valeur aberrante
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Titre : Uncertainty in radar emitter classification and clustering Titre original : Gestion des incertitudes en identification des modes radar Type de document : Thèse/HDR Auteurs : Guillaume Revillon, Auteur ; Charles Soussen, Directeur de thèse ; A. Mohammad-Djafari, Directeur de thèse Editeur : Paris-Orsay : Université de Paris 11 Paris-Sud Centre d'Orsay Année de publication : 2019 Importance : 181 p. Format : 21 x 30 cm Note générale : bibliographie
Thèse de Doctorat de l’Université Paris-Saclay préparée à l’Université Paris-Sud Sciences et Technologies de l’Information et de la Communication (STIC) Spécialité : Traitement du signal et des imagesLangues : Français (fre) Descripteur : [Vedettes matières IGN] Traitement du signal
[Termes IGN] approximation
[Termes IGN] détection du signal
[Termes IGN] écho radar
[Termes IGN] émetteur
[Termes IGN] estimation bayesienne
[Termes IGN] inférence statistique
[Termes IGN] modèle de mélange multilinéaire
[Termes IGN] modulation du signal
[Termes IGN] probabilités
[Termes IGN] valeur aberranteIndex. décimale : THESE Thèses et HDR Résumé : (auteur) In Electronic Warfare, radar signals identification is a supreme asset for decision making in military tactical situations. By providing information about the presence of threats, classification and clustering of radar signals have a significant role ensuring that countermeasures against enemies are well-chosen and enabling detection of unknown radar signals to update databases. Most of the time, Electronic Support Measures systems receive mixtures of signals from different radar emitters in the electromagnetic environment. Hence a radar signal, described by a pulse-to-pulse modulation pattern, is often partially observed due to missing measurements and measurement errors. The identification process relies on statistical analysis of basic measurable parameters of a radar signal which constitute both quantitative and qualitative data. Many general and practical approaches based on data fusion and machine learning have been developed and traditionally proceed to feature extraction, dimensionality reduction and classification or clustering. However, these algorithms cannot handle missing data and imputation methods are required to generate data to use them. Hence, the main objective of this work is to define a classification/clustering framework that handles both outliers and missing values for any types of data. Here, an approach based on mixture models is developed since mixture models provide a mathematically based, flexible and meaningful framework for the wide variety of classification and clustering requirements. The proposed approach focuses on the introduction of latent variables that give us the possibility to handle sensitivity of the model to outliers and to allow a less restrictive modelling of missing data. A Bayesian treatment is adopted for model learning, supervised classification and clustering and inference is processed through a variational Bayesian approximation since the joint posterior distribution of latent variables and parameters is untractable. Some numerical experiments on synthetic and real data show that the proposed method provides more accurate results than standard algorithms. Note de contenu : Introduction
1- State of the art and the selected approach
2- Continuous data
3- Mixed data
4- Temporal evolution data
5- Conclusion and perspectivesNuméro de notice : 25703 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Thèse française Note de thèse : Thèse de Doctorat : Traitement du signal et des images : Paris 11 : 2019 Organisme de stage : Thales, GPI nature-HAL : Thèse DOI : sans Date de publication en ligne : 02/09/2019 En ligne : https://hal.science/tel-02275817 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=94829 Three-point-based solution for automated motion parameter estimation of a multi-camera indoor mapping system with planar motion constraint / Fangning He in ISPRS Journal of photogrammetry and remote sensing, vol 142 (August 2018)
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Titre : Three-point-based solution for automated motion parameter estimation of a multi-camera indoor mapping system with planar motion constraint Type de document : Article/Communication Auteurs : Fangning He, Auteur ; Ayman Habib, Auteur Année de publication : 2018 Article en page(s) : pp 278 - 291 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image
[Termes IGN] appariement d'images
[Termes IGN] carte d'intérieur
[Termes IGN] compensation par faisceaux
[Termes IGN] coplanarité
[Termes IGN] élément d'orientation interne
[Termes IGN] modélisation 3D
[Termes IGN] orientation relative
[Termes IGN] Ransac (algorithme)
[Termes IGN] reconstruction 3D
[Termes IGN] structure-from-motion
[Termes IGN] valeur aberranteRésumé : (auteur) Accurate indoor 3D models have become a key prerequisite for various applications. Through state-of-the-art image processing techniques, 3D models can be generated from high quality images captured by off-the-shelf digital cameras. To acquire redundant data and produce real scale models, a multi-camera system can be used. However, dedicated approaches for image-based 3D reconstruction using mapping platforms equipped with multiple cameras have not been fully addressed. Assuming the availability of prior information regarding the platform trajectory, this paper presents a new approach for reliable estimation of system motion parameters between different data acquisition epochs of a multi-camera system. This approach, which assumes planar motion of the utilized platform, provides a three-point closed-form solution. The derived solutions are then incorporated within a modified RANSAC framework for outlier detection/removal. It is worth noting that, different from the existing General Camera Model (GCM)-based solutions, the proposed approach is based on a modified co-planarity model, which is essentially a direct extension of the classic stereo-based relative orientation. Moreover, since the proposed approach only provides a maximum number of four possible solutions for system motion parameters over different epochs, it has better computational efficiency when compared to other existing algorithms. Experimental results from real datasets acquired with different configurations have demonstrated the reliability of the proposed approach in motion parameter estimation for indoor multi-camera mapping systems. Numéro de notice : A2018-297 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2018.06.011 Date de publication en ligne : 01/08/2018 En ligne : https://doi.org/10.1016/j.isprsjprs.2018.06.011 Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=90417
in ISPRS Journal of photogrammetry and remote sensing > vol 142 (August 2018) . - pp 278 - 291[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 081-2018081 RAB Revue Centre de documentation En réserve L003 Disponible 081-2018083 DEP-EXM Revue LASTIG Dépôt en unité Exclu du prêt 081-2018082 DEP-EAF Revue Nancy Dépôt en unité Exclu du prêt The efficiency of different outlier detection approaches in geodetic networks: case study for Pobednik statue / Mehmed Batilović in Geodetski vestnik, vol 62 n° 2 (June 2018)
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Titre : The efficiency of different outlier detection approaches in geodetic networks: case study for Pobednik statue Type de document : Article/Communication Auteurs : Mehmed Batilović, Auteur ; Zoran Sušić, Auteur ; Marko Z. Marković, Auteur ; Marijana Vujinović, Auteur ; Gojko Nikolić, Auteur ; Toša Ninkov, Auteur Année de publication : 2018 Article en page(s) : pp 293 - 305 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Topographie
[Termes IGN] Belgrade
[Termes IGN] fortification
[Termes IGN] méthode robuste
[Termes IGN] réseau de contrôle
[Termes IGN] valeur aberranteRésumé : (auteur) In the paper, the efficacy of two different approaches for outlier detection in geodetic networks is analysed on a test example of a control network for geodetic monitoring of the Pobednik statue in the Kalemegdan Fortress in Belgrade by applying the mean success rate (MSR). Conventional tests and robust methods were applied for detecting outliers. The experimental results indicate that the new approach based on original observations provides higher efficiency of the applied methods than the classical approach for outlier detection in geodetic networks. Numéro de notice : A2018-253 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueNat DOI : 10.15292/geodetski-vestnik.2018.02.293-305 En ligne : https://doi.org/10.15292/geodetski-vestnik.2018.02.293-305 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=90314
in Geodetski vestnik > vol 62 n° 2 (June 2018) . - pp 293 - 305[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 139-2018021 RAB Revue Centre de documentation En réserve L003 Disponible Reduction of ZTD outliers through improved GNSS data processing and screening strategies [Interactive discussion] / Katarzyna Stępniak in Atmospheric measurement techniques, vol 11 n° 3 (March 2018)
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Titre : Reduction of ZTD outliers through improved GNSS data processing and screening strategies [Interactive discussion] Type de document : Article/Communication Auteurs : Katarzyna Stępniak, Auteur ; Olivier Bock , Auteur ; Pawel Wielgosz, Auteur Année de publication : 2018 Projets : 3-projet - voir note / Article en page(s) : pp 1347 - 1361 Note générale : Bibliographie
This work has been supported by Polish National Science Centre grant no. UMO-2015/19/B/ST10/02758. The study was partially carried out during Short Term Scientific Mission (STSM) in the framework of ES1206 COST Action.Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] Bernese
[Termes IGN] coordonnées GPS
[Termes IGN] double différence
[Termes IGN] erreur systématique
[Termes IGN] Pologne
[Termes IGN] réseau géodésique local
[Termes IGN] réseau géodésique permanent
[Termes IGN] retard troposphérique zénithal
[Termes IGN] série temporelle
[Termes IGN] valeur aberranteRésumé : (Auteur) Though Global Navigation Satellite System (GNSS) data processing has been significantly improved over the years, it is still commonly observed that zenith tropospheric delay (ZTD) estimates contain many outliers which are detrimental to meteorological and climatological applications. In this paper, we show that ZTD outliers in double-difference processing are mostly caused by sub-daily data gaps at reference stations, which cause disconnections of clusters of stations from the reference network and common mode biases due to the strong correlation between stations in short baselines. They can reach a few centimetres in ZTD and usually coincide with a jump in formal errors. The magnitude and sign of these biases are impossible to predict because they depend on different errors in the observations and on the geometry of the baselines. We elaborate and test a new baseline strategy which solves this problem and significantly reduces the number of outliers compared to the standard strategy commonly used for positioning (e.g. determination of national reference frame) in which the pre-defined network is composed of a skeleton of reference stations to which secondary stations are connected in a star-like structure. The new strategy is also shown to perform better than the widely used strategy maximizing the number of observations available in many GNSS programs. The reason is that observations are maximized before processing, whereas the final number of used observations can be dramatically lower because of data rejection (screening) during the processing. The study relies on the analysis of 1 year of GPS (Global Positioning System) data from a regional network of 136 GNSS stations processed using Bernese GNSS Software v.5.2. A post-processing screening procedure is also proposed to detect and remove a few outliers which may still remain due to short data gaps. It is based on a combination of range checks and outlier checks of ZTD and formal errors. The accuracy of the final screened GPS ZTD estimates is assessed by comparison to ERA-Interim reanalysis. Numéro de notice : A2018-065 Affiliation des auteurs : LASTIG LAREG+Ext (2012-mi2018) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.5194/amt-11-1347-2018 Date de publication en ligne : 08/03/2018 En ligne : http://dx.doi.org/10.5194/amt-11-1347-2018 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89407
in Atmospheric measurement techniques > vol 11 n° 3 (March 2018) . - pp 1347 - 1361[article]Algebraic method to speed up robust algorithms: example of laser-scanned point clouds / B. Palancz in Survey review, vol 49 n° 357 (December 2017)
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Titre : Algebraic method to speed up robust algorithms: example of laser-scanned point clouds Type de document : Article/Communication Auteurs : B. Palancz, Auteur ; Joseph L. Awange, Auteur ; T. Lovas, Auteur ; R. Lewis, Auteur ; B. Molnar, Auteur ; et al., Auteur Année de publication : 2017 Article en page(s) : pp 408 - 418 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] bases de Gröbner
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] méthode du maximum de vraisemblance (estimation)
[Termes IGN] Ransac (algorithme)
[Termes IGN] reconstruction d'objet
[Termes IGN] semis de points
[Termes IGN] valeur aberranteRésumé : (auteur) Surface reconstruction from point clouds generated by laser scanning technology has become a fundamental task in many fields of geosciences, such as robotics, computer vision, digital photogrammetry, computational geometry, digital building modelling, forest planning and operational activities. Point clouds produced by laser scanning, however, are limited due to the occurrence of occlusions, multiple reflectance and noise, and off-surface points (outliers), thus necessitating the need for robust fitting techniques. In this contribution, a fast, non-iterative and data invariant algebraic algorithm with constant O(1) complexity that fits planes to point clouds in the total least squares sense using Gaussian-type error distribution is proposed. The maximum likelihood estimator method is used, resulting in a multivariate polynomial system that is solved in an algebraic way. It is shown that for plane fitting when datasets are affected heavily by outliers, the proposed algebraic method can be embedded into the framework of robust methods like the Danish or the RANdom SAmple Consensus methods and computed in parallel to provide rigorous algebraic fitting with significantly reduced running times. Compared to the embedded traditional singular value decomposition and principal component analysis approaches, the performance of the proposed algebraic algorithm demonstrated its efficiency on both synthetic data and real laser-scanned measurements. The evaluation of a symbolic algebraic formula is practically independent of the values of its coefficients; however, the computation of the coefficients depends on the complexity of the data. Since the main advantage of the symbolic solution is its non-requirement of numerical iteration, the data complexity will have weak influence on the speed-up. The novelty of the proposed method is the use of algebraic technique in a robust plane fitting algorithm that could be applied to remote sensing data analysis/delineation/classification. In general, the method could be applied to most plane fitting problems in the geoscience field. Numéro de notice : A2017-755 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1080/00396265.2016.1183939 En ligne : https://doi.org/10.1080/00396265.2016.1183939 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89109
in Survey review > vol 49 n° 357 (December 2017) . - pp 408 - 418[article]Detection of inconsistencies in geospatial data with geostatistics / Adriana Maria Rocha Trancoso Santos in Boletim de Ciências Geodésicas, vol 23 n° 2 (abr - jun 2017)PermalinkExterior orientation revisited : a robust method based on lq -norm / Jiayuan Li in Photogrammetric Engineering & Remote Sensing, PERS, vol 83 n° 1 (January 2017)PermalinkNew iterative learning strategy to improve classification systems by using outlier detection techniques / Charlotte Pelletier (2017)PermalinkAn attempt to determine the effect of increase of observation correlations on detectability and identifiability of a single gross error / Witold Proszynski in Geodesy and cartography, vol 65 n° 2 (December 2016)PermalinkOutlier detection by using fault detection and isolation techniques in geodetic networks / U.M. Durdag in Survey review, vol 48 n° 351 (October 2016)PermalinkFinding spatial outliers in collective mobility patterns coupled with social ties / Monica Wachowicz in International journal of geographical information science IJGIS, vol 30 n° 9-10 (September - October 2016)PermalinkIdentification of stable areas in unreferenced laser scans for deformation measurement / Daniel Wujanz in Photogrammetric record, vol 31 n° 155 (September - November 2016)PermalinkGeometrical consistency voting strategy for outlier detection in image matching / Luping Lu in Photogrammetric Engineering & Remote Sensing, PERS, vol 82 n° 7 (juillet 2016)PermalinkComparison of robust estimators for leveling networks in Monte Carlo simulations / Maria Pokarowska in Reports on geodesy and geoinformatics, vol 101 (June 2016)PermalinkMIDAS robust trend estimator for accurate GPS station velocities without step detection / Geoffrey Blewitt in Journal of geophysical research : Solid Earth, vol 121 n° 3 (March 2016)PermalinkPermalinkConvex programming approach to robust estimation of a multivariate Gaussian model / Samuel Balmand (2016)PermalinkPermalinkAnalysis of a GNSS network using the theory of reliability for multiple outliers / M Mustafa Berber in Geodetski vestnik, vol 59 n° 3 (September - November 2015)PermalinkOutlier Detection by means of Monte Carlo Estimation including resistant Scale Estimation / Christian Marx in Journal of applied geodesy, vol 9 n° 2 (June 2015)PermalinkMinimal detectable outliers as measures of reliability / Karl Rudolf Koch in Journal of geodesy, vol 89 n° 5 (May 2015)PermalinkGenerating statistically robust multipath stacking maps using congruent cells / Thomas Fuhrmann in GPS solutions, vol 19 n° 1 (January 2015)PermalinkPermalinkOn the formulation of the alternative hypothesis for geodetic outlier detection / Rüdiger Lehmann in Journal of geodesy, vol 87 n° 4 (April 2013)PermalinkSingle-receiver single-channel multi-frequency GNSS integrity: outliers, slips, and ionospheric disturbances / Peter J.G. Teunissen in Journal of geodesy, vol 87 n° 2 (February 2013)Permalink