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Integrating interferometric SAR data with levelling measurements of land subsidence using geostatistic / Y. Zhou in International Journal of Remote Sensing IJRS, vol 24 n° 18 (September 2003)
[article]
Titre : Integrating interferometric SAR data with levelling measurements of land subsidence using geostatistic Type de document : Article/Communication Auteurs : Y. Zhou, Auteur ; Alfred Stein, Auteur ; Martien Molenaar, Auteur Année de publication : 2003 Article en page(s) : pp 3547 - 3563 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications
[Termes IGN] bruit blanc
[Termes IGN] Chine
[Termes IGN] déformation de la croute terrestre
[Termes IGN] données de terrain
[Termes IGN] eau souterraine
[Termes IGN] erreur
[Termes IGN] erreur moyenne quadratique
[Termes IGN] extraction du sursol
[Termes IGN] géostatistique
[Termes IGN] image radar moirée
[Termes IGN] intégration de données
[Termes IGN] interferométrie différentielle
[Termes IGN] interféromètrie par radar à antenne synthétique
[Termes IGN] krigeage
[Termes IGN] nivellement
[Termes IGN] précision centimétrique
[Termes IGN] subsidence
[Termes IGN] variogrammeRésumé : (Auteur) Differential Synthetic Aperture Radar (SAR) interferometric (D-InSAR) data of ground surface deformation are affected by several error sources associated with image acquisitions and data processing. In this paper, we study the use of D-InSAR for quantifying land subsidence due to groundwater extraction. We model the data as the sum of a trend, a zeromean stochastic process and white noise. A geostatistical approach combines D-InSAR subsidence data with in situ levelling measurements. The objective of this paper is to correct the errors contained in the D-InSAR measurements by using measurements as the ground data to improve their accuracy. Discrepancies between the true subsidence values and original D-InSAR measurements are analysed at levelling points using variograms and predicted at unvisited points using kriging. The integrated measurements are obtained by subtracting the predicted errors from the original D-InSAR measurements. The proposed method is applied to data collected in the Tianjin (China) area where land subsidence occurs due to groundwater extraction. Results demonstrate the capability of the D-InSAR technique for detecting subsidence at the centimetre level, and of using a limited number of levelling points to improve the accuracy of D-InSAR deformation measurements provided the coherence of images used is high enough. Discrepancies between the true subsidence values and D-InSAR measurements are quantified using the root mean square error (RMSE). RMSE for the original data was equal to 2.8, and 0.8 for the integrated data, whereas the mean error was equal to 2.1 and 0.0, respectively. Numéro de notice : A2003-262 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/0143116021000023880 En ligne : https://doi.org/10.1080/0143116021000023880 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=22557
in International Journal of Remote Sensing IJRS > vol 24 n° 18 (September 2003) . - pp 3547 - 3563[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 080-03181 RAB Revue Centre de documentation En réserve L003 Disponible Optimizing a network-based RTK method for OTF [on-the-fly] positioning / L.P. Fortes in GPS solutions, vol 7 n° 2 (August 2003)
[article]
Titre : Optimizing a network-based RTK method for OTF [on-the-fly] positioning Type de document : Article/Communication Auteurs : L.P. Fortes, Auteur ; M.E. Cannon, Auteur ; et al., Auteur Année de publication : 2003 Article en page(s) : pp 61 - 73 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] covariance
[Termes IGN] erreur
[Termes IGN] filtre de Kalman
[Termes IGN] ionosphère
[Termes IGN] méthode des moindres carrés
[Termes IGN] optimisation (mathématiques)
[Termes IGN] orbite
[Termes IGN] positionnement cinématique en temps réel
[Termes IGN] précision centimétrique
[Termes IGN] résolution d'ambiguïté
[Termes IGN] station de référence
[Termes IGN] valeur efficaceRésumé : (Auteur) Differential GPS is able to provide cm-level positoning accuracies, as long as the carrier phase ambiguities are resolved to integer values. Classical methods are based on the use of a single reference station located in the vicinity of the rover. Due to the spatial decorrelation of the errors, the distance between the reference station and the user is generally limited to within 20-30 km or even less, mainly due to the ionosphere. The MultiRef method, developed at the University of Calgary, uses a network of reference stations to generate regional code and carrier phase corrections, which can be transmitted to users in order to increase the distance over which integer ambiguity resolution is possible. In the original method, the correlated errors, due to the satellite orbits, troposphere, and ionosphere are modeled together using the L1 and wide-lane observables. In this paper extensive efforts were carried out towards as optimizing the MultiRef method with the objective of maximizing its performance. Data collected in southeastern Brazil was used in this research. At first, the impact of using covariance function calculated with different data sets was assessed, showing improvement variations of up to 14% in the observation domain compared to using no network corrections, with the exact improvement depending on the data set used in the computation. A new approach, also using least-squares prediction (collation), was proposed to separately model the correlated errors. An additional effort was carried out in the terms of modeling the ionosphere into directional components. Results of the enhanced method showed the same level of improvement as those obtained using the original covariance functions. However, this new approach has advantages with respect to the transmission of the corrections. Finally, an additional step was taken in terms of applying a Kalman filter to the corrections in order to improve their quality. For cases when the corresponding satellite was setting at low elevations, the filter approach improved results up to 44%. A study on the impact of the various covariance functions on the estimated accuracy of the corrections is also included. Numéro de notice : A2003-370 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1007/s10291-003-0054-6 En ligne : https://doi.org/10.1007/s10291-003-0054-6 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26450
in GPS solutions > vol 7 n° 2 (August 2003) . - pp 61 - 73[article]Stability of the surface generated from distributed points of uncertain location / Yukio Sadahiro in International journal of geographical information science IJGIS, vol 17 n° 2 (march 2003)
[article]
Titre : Stability of the surface generated from distributed points of uncertain location Type de document : Article/Communication Auteurs : Yukio Sadahiro, Auteur Année de publication : 2003 Article en page(s) : pp 139 - 156 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Information géographique
[Termes IGN] analyse mathématique
[Termes IGN] analyse visuelle
[Termes IGN] erreur
[Termes IGN] géopositionnement
[Termes IGN] imprécision des données
[Termes IGN] incertitude géométrique
[Termes IGN] stabilité
[Termes IGN] système d'information géographique
[Termes IGN] visualisation de donnéesRésumé : (Auteur) Conversion of a point distribution into a surface is one of the spatial operations used in GIS. This supports the visual analysis of point patterns, which is usually followed by more sophisticated statistical and mathematical analysis. If the location of points is uncertain, however, the surface obtained becomes unstable and consequently the results of analysis may be unreliable. Though unavoidable in spatial data, locational uncertainty has been rather neglected in the context of spatial analysis. To fill this gap, this paper proposes a method for representing and analysing the stability of the surface generated from an uncertain point distribution. The surface stability is represented by a scalar function called the slope stability function. Its definition, calculation procedure, visualization method, and summary indices are proposed. The method is evaluated through an empirical study, and some findings are shown which help us understand the effect of the smoothing parameter, locational uncertainty, and spatial pattern of points on the stability of a surface. Numéro de notice : A2003-093 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1080/713811751 En ligne : https://doi.org/10.1080/713811751 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=22389
in International journal of geographical information science IJGIS > vol 17 n° 2 (march 2003) . - pp 139 - 156[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 079-03021 RAB Revue Centre de documentation En réserve L003 Disponible 079-03022 RAB Revue Centre de documentation En réserve L003 Disponible Creation of digital terrain models using an adaptative Lidar vegetation point removal process / G.T. Raber in Photogrammetric Engineering & Remote Sensing, PERS, vol 68 n° 12 (December 2002)
[article]
Titre : Creation of digital terrain models using an adaptative Lidar vegetation point removal process Type de document : Article/Communication Auteurs : G.T. Raber, Auteur ; J.R. Jensen, Auteur ; S.R. Schill, Auteur ; K. Schuckman, Auteur Année de publication : 2002 Article en page(s) : pp 1307 - 1315 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] carte de la végétation
[Termes IGN] données lidar
[Termes IGN] erreur
[Termes IGN] lasergrammétrie
[Termes IGN] modèle numérique de terrain
[Termes IGN] végétationRésumé : (Auteur) Commercial small-footprint lidar remote sensing has become an established tool for the creation of digital terrain models (DTMs). Unfortunately, even ofter the application of lidar vegetation point removal algorithms, vertical DTM error is not uniform and varies according to land cover. This paper presents the results of the application of an adaptive lidar vegetation removal process to a raw lidar dataset of a small area in North Carolina. This process utilized an existing lidar vegetation point removal algorithm in which the parameters were adaptively adjusted based on a vegetation map. The vegetation map was derived through the exclusive use of the lidar dataset, making the process independent of ancillary data. The vertical error and surface form of the resulting DTM were then compared to DTMs created using traditional techniques. The results indicate that the adaptive method produces a superior DTM. Numéro de notice : A2002-299 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article DOI : sans En ligne : https://www.asprs.org/wp-content/uploads/pers/2002journal/december/2002_dec_1307 [...] Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=22210
in Photogrammetric Engineering & Remote Sensing, PERS > vol 68 n° 12 (December 2002) . - pp 1307 - 1315[article]Error assessment of grid-based flow routing algorithms used in hydrological models / Q. Zhou in International journal of geographical information science IJGIS, vol 16 n° 8 (december 2002)
[article]
Titre : Error assessment of grid-based flow routing algorithms used in hydrological models Type de document : Article/Communication Auteurs : Q. Zhou, Auteur ; X. Liu, Auteur Année de publication : 2002 Article en page(s) : pp 819 - 842 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Photogrammétrie numérique
[Termes IGN] erreur
[Termes IGN] modèle hydrographique
[Termes IGN] modèle numérique de surface
[Termes IGN] pente
[Termes IGN] ruissellementRésumé : (Auteur) This paper reports an investigation on the accuracy of gridbased routing algorithms used in hydrological models. A quantitative methodology has been developed for objective and dataindependent assessment of errors generated from the algorithms that extract hydrological parameters from gridded DEM. The generic approach is to use artificial surfaces that can be described by a mathematical model, thus the 'true' output value can be predetermined to avoid uncertainty caused by uncontrollable data errors. Four mathematical surfaces based on all ellipsoid (representing convex slopes), an inverse ellipsoid (representing concave slopes), saddle and plane were generated and the theoretical 'true' value of the Specific Catchment Area (SCA) at any given point on the surfaces could be computed using mathematical inference. Based on these models, tests were made on a number of algorithms for SCA computation. The actual output values from these algorithms on the convex, concave, saddle and plane surfaces were compared with the theoretical 'true' values, and the errors were then analysed statistically. The strengths and weaknesses of the selected algorithms are also discussed. Numéro de notice : A2002-261 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1080/13658810210149425 En ligne : https://doi.org/10.1080/13658810210149425 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=22172
in International journal of geographical information science IJGIS > vol 16 n° 8 (december 2002) . - pp 819 - 842[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 079-02081 RAB Revue Centre de documentation En réserve L003 Disponible Large deviation theorems for weighted sums applied to a geographical problem / Olivier Bonin in Journal of Applied Probability, vol 39 n° 2 (01/06/2002)PermalinkMinimum mean square error space-varying filtering of interferometric SAR data / Gianfranco Fornaro in IEEE Transactions on geoscience and remote sensing, vol 40 n° 1 (January 2002)PermalinkOn the estimation of radar polarization orientation shifts induced by terrain slopes / Jong-Sen Lee in IEEE Transactions on geoscience and remote sensing, vol 40 n° 1 (January 2002)PermalinkOn the accuracy of kinematic carrier phase GPS for airborne mapping / A.M. Bruton in Geomatica, vol 55 n° 4 (December 2001)PermalinkDasymetric mapping and areal interpolation: implementation and evaluation / C.L. Eicher in Cartography and Geographic Information Science, vol 28 n° 2 (April 2001)PermalinkError simulation in geographical databases: introducing controlled uncertainty in vector geographical information / Olivier Bonin in GIM international, vol 15 n° 3 (March 2001)PermalinkGeographic Information Systems and science / Paul A. Longley (2001)PermalinkPositional and shape quality of areal entities in geographic databases: quality information aggregation versus measures classification / Atef Bel Hadj Ali (2001)PermalinkAssessment of error in digital vector data using fractal geometry / Matt Duckham in International journal of geographical information science IJGIS, vol 14 n° 1 (january 2000)PermalinkError propagation in environmental modelling with GIS / Gerard B.M. Heuvelink (2000)Permalink