Descripteur
Documents disponibles dans cette catégorie (1523)
![](./images/expand_all.gif)
![](./images/collapse_all.gif)
Etendre la recherche sur niveau(x) vers le bas
Multi-scale spatiotemporal analyses of moose-vehicle collisions: a case study in northern Vermont / Giorgos Mountrakis in International journal of geographical information science IJGIS, vol 23 n°11-12 (november 2009)
![]()
[article]
Titre : Multi-scale spatiotemporal analyses of moose-vehicle collisions: a case study in northern Vermont Type de document : Article/Communication Auteurs : Giorgos Mountrakis, Auteur ; K. Gunson, Auteur Année de publication : 2009 Article en page(s) : pp 1389 - 1412 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale
[Termes IGN] accident de la route
[Termes IGN] analyse spatio-temporelle
[Termes IGN] Cervidae
[Termes IGN] estimation par noyau
[Termes IGN] Mammalia
[Termes IGN] outil d'aide à la décision
[Termes IGN] trafic routier
[Termes IGN] véhicule automobile
[Termes IGN] Vermont (Etats-Unis)Résumé : (Auteur) Moose-vehicle collisions (MVCs) pose a serious safety and environmental concern in many regions of Europe and North America. For example, in the state of Vermont, one-third of all reported MVCs resulted in motorist injury or fatality while collisions have increased from two in 1982 to 164 in 2002. Our work used a MVC dataset from 1983 to 1999 in the Northeastern Highlands of Vermont (four major roads) to perform space, time and spatiotemporal analyses and guide future mitigation strategies. An adapted kernel density estimator was implemented for exploratory analyses to detect high density collision hotspots on roads. The kernel in space showed seven major density peaks which varied in magnitude and spread between roads. The kernel estimator in time for all roads showed an exponentially increasing trend with annual periodicity and a seasonal cyclic component, where the majority of collisions occurred from May to October. Spatiotemporal kernel estimation exhibited discontinuous density hotspots in time and space suggesting changing animal movement patterns across roads. We used an adapted Ripley's K-function to test the hypothesis that MVCs clustering occurred at multiple scales in space, in time and in space-time combined. Statistically significant spatial clustering was evident on all roads at spatial scales from 2 to 10 km. A more consistent clustering in time occurred on all roads at a scale distance of 5 years. Similar to the kernel estimation, annual periodicity was also evident. Positive space-time clustering was present at small spatial (5 km) and temporal scales (2 years) indicating that where MVCs occur is also influenced by when they occur. In retrospect, using multiple road lengths, and the combined kernel estimation and Ripley's K-function in time and space, provided a powerful methodology to study varying spatiotemporal patterns of wildlife collisions along roads. This can greatly assist transportation planners in identifying optimal mitigation strategies along specific roads, such as deciding on location and spatial length for permanent and expensive measures (e.g. crossing structures and associated fencing) versus less permanent and inexpensive structures (e.g. wildlife signage and reduced speed limits). Copyright Taylor & Francis Numéro de notice : A2009-513 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1080/13658810802406132 En ligne : https://doi.org/10.1080/13658810802406132 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30142
in International journal of geographical information science IJGIS > vol 23 n°11-12 (november 2009) . - pp 1389 - 1412[article]Réservation
Réserver ce documentExemplaires(2)
Code-barres Cote Support Localisation Section Disponibilité 079-09071 RAB Revue Centre de documentation En réserve L003 Disponible 079-09072 RAB Revue Centre de documentation En réserve L003 Disponible Positioning localities based on spatial assertions / Y. Liu in International journal of geographical information science IJGIS, vol 23 n°11-12 (november 2009)
![]()
[article]
Titre : Positioning localities based on spatial assertions Type de document : Article/Communication Auteurs : Y. Liu, Auteur ; Q. Guo, Auteur ; J. Wieczorek, Auteur ; Michael F. Goodchild, Auteur Année de publication : 2009 Article en page(s) : pp 1471 - 1501 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale
[Termes IGN] géopositionnement
[Termes IGN] incertitude de position
[Termes IGN] modèle conceptuel de données
[Termes IGN] probabilités
[Termes IGN] raisonnement spatial
[Termes IGN] relation spatiale
[Termes IGN] segmentation sémantique
[Termes IGN] système d'information géographiqueRésumé : (Auteur) In practice, descriptive localities are often communicated using named places and spatial relationships. Uncertainty associated with such descriptions of localities is inevitable, and knowledge of such uncertainty is normally not explicit. When translating descriptive localities into spatially explicit ones, it is critical to circumscribe locations and to estimate the associated uncertainty based on a set of appropriate spatial relationships. In conventional research on qualitative spatial reasoning (QSR), spatial relationships are modeled using formal logic. Unfortunately, QSR cannot deal with the uncertainty of a position. In this paper, based on the conceptual model of spatial assertions, we introduce the uncertainty field model to represent the probability distribution of a point locality. Using probability operations, we can combine a set of assertions to position a locality. Conflicts among assertions for a single locality can be detected based on the resulting field. Since spatial relationships play an important role in the uncertainty of target objects, we investigate conceptually the uncertainty fields associated with various types of spatial relationships (for example, topological, directional and metric). In a concrete application, these uncertainty fields can be customized and used without altering the proposed framework. Copyright Taylor & Francis Numéro de notice : A2009-517 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1080/13658810802247114 En ligne : https://doi.org/10.1080/13658810802247114 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30146
in International journal of geographical information science IJGIS > vol 23 n°11-12 (november 2009) . - pp 1471 - 1501[article]Réservation
Réserver ce documentExemplaires(2)
Code-barres Cote Support Localisation Section Disponibilité 079-09071 RAB Revue Centre de documentation En réserve L003 Disponible 079-09072 RAB Revue Centre de documentation En réserve L003 Disponible Sensivity analysis of a decision tree classification to input data errors using a general Monte Carlo error sensitivity model / Zhi Huang in International journal of geographical information science IJGIS, vol 23 n°11-12 (november 2009)
![]()
[article]
Titre : Sensivity analysis of a decision tree classification to input data errors using a general Monte Carlo error sensitivity model Type de document : Article/Communication Auteurs : Zhi Huang, Auteur ; S.W. Laffan, Auteur Année de publication : 2009 Article en page(s) : pp 1433 - 1452 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] analyse de sensibilité
[Termes IGN] carte de la végétation
[Termes IGN] classification par arbre de décision
[Termes IGN] erreur de classification
[Termes IGN] erreur de positionnement
[Termes IGN] image Landsat-TM
[Termes IGN] incertitude des données
[Termes IGN] méthode de Monte-Carlo
[Termes IGN] modèle numérique de terrainRésumé : (Auteur) We analysed the sensitivity of a decision tree derived forest type mapping to simulated data errors in input digital elevation model (DEM), geology and remotely sensed (Landsat Thematic Mapper) variables. We used a stochastic Monte Carlo simulation model coupled with a one-at-a-time approach. The DEM error was assumed to be spatially autocorrelated with its magnitude being a percentage of the elevation value. The error of categorical geology data was assumed to be positional and limited to boundary areas. The Landsat data error was assumed to be spatially random following a Gaussian distribution. Each layer was perturbed using its error model with increasing levels of error, and the effect on the forest type mapping was assessed. The results of the three sensitivity analyses were markedly different, with the classification being most sensitive to the DEM error, than to the Landsat data errors, but with only a limited sensitivity to the geology data error used. A linear increase in error resulted in non-linear increases in effect for the DEM and Landsat errors, while it was linear for geology. As an example, a DEM error of as small as +2% reduced the overall test accuracy by more than 2%. More importantly, the same uncertainty level has caused nearly 10% of the study area to change its initial class assignment at each perturbation, on average. A spatial assessment of the sensitivities indicates that most of the pixel changes occurred within those forest classes expected to be more sensitive to data error. In addition to characterising the effect of errors on forest type mapping using decision trees, this study has demonstrated the generality of employing Monte Carlo analysis for the sensitivity and uncertainty analysis of categorical outputs that have distinctive characteristics from that of numerical outputs. Copyright Taylor & Francis Numéro de notice : A2009-515 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article DOI : 10.1080/13658810802634949 En ligne : https://doi.org/10.1080/13658810802634949 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30144
in International journal of geographical information science IJGIS > vol 23 n°11-12 (november 2009) . - pp 1433 - 1452[article]Réservation
Réserver ce documentExemplaires(2)
Code-barres Cote Support Localisation Section Disponibilité 079-09071 RAB Revue Centre de documentation En réserve L003 Disponible 079-09072 RAB Revue Centre de documentation En réserve L003 Disponible The application of GPS precise point positioning technology in aerial triangulation / Xiuxiao Yuan in ISPRS Journal of photogrammetry and remote sensing, vol 64 n° 6 (November - December 2009)
![]()
[article]
Titre : The application of GPS precise point positioning technology in aerial triangulation Type de document : Article/Communication Auteurs : Xiuxiao Yuan, Auteur ; Jianhong Fu, Auteur ; Hongxing Sun, Auteur ; Charles K. Toth, Auteur Année de publication : 2009 Article en page(s) : pp 541 - 550 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Photogrammétrie numérique
[Termes IGN] aérotriangulation numérique
[Termes IGN] analyse comparative
[Termes IGN] compensation par faisceaux
[Termes IGN] erreur aléatoire
[Termes IGN] erreur systématique
[Termes IGN] GPS en mode différentiel
[Termes IGN] positionnement ponctuel précisRésumé : (Auteur) In traditional GPS-supported aerotriangulation, differential GPS (DGPS) positioning technology is used to determine the 3-dimensional coordinates of the perspective centers at exposure time with an accuracy of centimeter to decimeter level. This method can significantly reduce the number of ground control points (GCPs). However, the establishment of GPS reference stations for DGPS positioning is not only labor-intensive and costly, but also increases the implementation difficulty of aerial photography. This paper proposes aerial triangulation supported with GPS precise point positioning (PPP) as a way to avoid the use of the GPS reference stations and simplify the work of aerial photography. Firstly, we present the algorithm for GPS PPP in aerial triangulation applications. Secondly, the error law of the coordinate of perspective centers determined using GPS PPP is analyzed. Thirdly, based on GPS PPP and aerial triangulation software self-developed by the authors, four sets of actual aerial images taken from surveying and mapping projects, different in both terrain and photographic scale, are given as experimental models. The four sets of actual data were taken over a flat region at a scale of 1:2500, a mountainous region at a scale of 1:3000, a high mountainous region at a scale of 1:32000 and an upland region at a scale of 1:60000 respectively. In these experiments, the GPS PPP results were compared with results obtained through DGPS positioning and traditional bundle block adjustment. In this way, the empirical positioning accuracy of GPS PPP in aerial triangulation can be estimated. Finally, the results of bundle block adjustment with airborne GPS controls from GPS PPP are analyzed in detail. The empirical results show that GPS PPP applied in aerial triangulation has a systematic error of half-meter level and a stochastic error within a few decimeters. However, if a suitable adjustment solution is adopted, the systematic error can be eliminated in GPS-supported bundle block adjustment. When four full GCPs are emplaced in the corners of the adjustment block, then the systematic error is compensated using a set of independent unknown parameters for each strip, the final result of the bundle block adjustment with airborne GPS controls from PPP is the same as that of bundle block adjustment with airborne GPS controls from DGPS. Although the accuracy of the former is a little lower than that of traditional bundle block adjustment with dense GCPs, it can still satisfy the accuracy requirement of photogrammetric point determination for topographic mapping at many scales. Numéro de notice : A2009-495 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2009.03.006 En ligne : https://doi.org/10.1016/j.isprsjprs.2009.03.006 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30124
in ISPRS Journal of photogrammetry and remote sensing > vol 64 n° 6 (November - December 2009) . - pp 541 - 550[article]Réservation
Réserver ce documentExemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 081-09061 RAB Revue Centre de documentation En réserve L003 Disponible A GIS-based stochastic approach to generating daytime population distributions for vehicle route planning / K. Lau in Transactions in GIS, vol 13 n°5-6 (October/december 2009)
![]()
[article]
Titre : A GIS-based stochastic approach to generating daytime population distributions for vehicle route planning Type de document : Article/Communication Auteurs : K. Lau, Auteur Année de publication : 2009 Article en page(s) : pp 481 - 502 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications SIG
[Termes IGN] itinéraire
[Termes IGN] Melbourne
[Termes IGN] milieu urbain
[Termes IGN] modèle stochastique
[Termes IGN] planification urbaine
[Termes IGN] répartition géographique
[Termes IGN] réseau routier
[Termes IGN] surveillance routière
[Termes IGN] transport routierRésumé : (Auteur) This article explores the use of daytime population distributions for vehicle route planning in urban environments when proximity to population is a major consideration. A GIS-based stochastic geocoding algorithm is proposed to generate daytime population distribution patterns using travel survey data. Metropolitan Melbourne in Australia is used as a test case with data collected from the Victorian Activity and Travel Survey between 1994 and 1999. The advantage of employing daytime population distributions for vehicle route planning is then illustrated taking dangerous goods delivery and mobile billboard advertising as examples. Analysis suggests that the proposed algorithm generates population distribution patterns with finer spatial and temporal details than that obtained using other estimation methods. The algorithm also eliminates the problem of over- or under-estimation of population associated with previous attempts using travel survey data and therefore provides more accurate results. Copyright Blackwell Publishing Numéro de notice : A2009-525 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1111/j.1467-9671.2009.01175.x En ligne : https://doi.org/10.1111/j.1467-9671.2009.01175.x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30154
in Transactions in GIS > vol 13 n°5-6 (October/december 2009) . - pp 481 - 502[article]Improving the GNSS positioning stochastic model in the presence of ionospheric scintillation / M. Aquino in Journal of geodesy, vol 83 n° 10 (October 2009)
PermalinkOn the topographic bias in geoid determination by the external gravity field / Lard Erik Sjöberg in Journal of geodesy, vol 83 n° 10 (October 2009)
PermalinkSmall-footprint laser scanning simulator for system validation, error assessment, and algorithm development / Antero Kukko in Photogrammetric Engineering & Remote Sensing, PERS, vol 75 n° 10 (October 2009)
PermalinkApplication of a model to the evaluation of flood damage / Fabio Luino in Geoinformatica, vol 13 n° 3 (September 2009)
PermalinkError budget of Lidar systems and quality control of the derived data / A. Habib in Photogrammetric Engineering & Remote Sensing, PERS, vol 75 n° 9 (September 2009)
PermalinkEstimation du volume de bois exploitable en montagne par scanner laser aeoporté (Lidar) / Nicolas Clouet in Géomatique expert, n° 70 (01/09/2009)
PermalinkSystematic biases in DORIS-derived geocenter time series related to solar radiation pressure mis-modeling / Marie-Line Gobinddass in Journal of geodesy, vol 83 n° 9 (September 2009)
PermalinkAccuracy assessment of the GPS-based slant total electron content / C. Brunini in Journal of geodesy, vol 83 n° 8 (August 2009)
PermalinkAirborne Lidar: in-flight accuracy estimation / Philipp Schaer in GPS world, vol 20 n° 8 (August 2009)
PermalinkAn absolute calibration site for radar altimeters in the continental domain: Lake Issykkul in Central Asia / J.F. Cretaux in Journal of geodesy, vol 83 n° 8 (August 2009)
Permalink