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Uber movement data: a proxy for average one-way commuting times by car / Yeran Sun in ISPRS International journal of geo-information, vol 9 n° 3 (March 2020)  

Public [article]  inISPRS International journal of geo-information > vol 9 n° 3 (March 2020) . - 16 p. Titre : Uber movement data: a proxy for average one-way commuting times by car Type de document : Article/Communication Auteurs : Yeran Sun, Auteur ; Yinming Ren, Auteur ; Xuan Sun, Auteur Année de publication : 2020 Article en page(s) : 16 p. Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale [Termes descripteurs IGN] Boston (Massachusetts) [Termes descripteurs IGN] distribution spatiale [Termes descripteurs IGN] flux [Termes descripteurs IGN] migration pendulaire [Termes descripteurs IGN] objet mobile [Termes descripteurs IGN] origine - destination [Termes descripteurs IGN] planification urbaine [Termes descripteurs IGN] taxi [Termes descripteurs IGN] temps de trajet [Termes descripteurs IGN] trace GPS Résumé : (auteur) Recently, Uber released datasets named Uber Movement to the public in support of urban planning and transportation planning. To prevent user privacy issues, Uber aggregates car GPS traces into small areas. After aggregating car GPS traces into small areas, Uber releases free data products that indicate the average travel times of Uber cars between two small areas. The average travel times of Uber cars in the morning peak time periods on weekdays could be used as a proxy for average one-way car-based commuting times. In this study, to demonstrate usefulness of Uber Movement data, we use Uber Movement data as a proxy for commuting time data by which commuters’ average one-way commuting time across Greater Boston can be figured out. We propose a new approach to estimate the average car-based commuting times through combining commuting times from Uber Movement data and commuting flows from travel survey data. To further demonstrate the applicability of the commuting times estimated by Uber movement data, this study further measures the spatial accessibility of jobs by car by aggregating place-to-place commuting times to census tracts. The empirical results further uncover that 1) commuters’ average one-way commuting time is around 20 min across Greater Boston; 2) more than 75% of car-based commuters are likely to have a one-way commuting time of less than 30 min; 3) less than 1% of car-based commuters are likely to have a one-way commuting time of more than 60 min; and 4) the areas suffering a lower level of spatial accessibility of jobs by car are likely to be evenly distributed across Greater Boston. Numéro de notice : A2020-255 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.3390/ijgi9030184 date de publication en ligne : 24/03/2020 En ligne : https://doi.org/10.3390/ijgi9030184 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95010 [article]

Labelling hierarchy for street maps using centrality measures / Wasim Shoman in Cartographic journal (the), vol 55 n° 1 (February 2018)  

Public [article]  inCartographic journal (the) > vol 55 n° 1 (February 2018) . - pp 68 - 84 Titre : Labelling hierarchy for street maps using centrality measures Type de document : Article/Communication Auteurs : Wasim Shoman, Auteur ; Fatih Gülgen, Auteur Année de publication : 2018 Article en page(s) : pp 68 - 84 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes descripteurs IGN] axe médian [Termes descripteurs IGN] Boston (Massachusetts) [Termes descripteurs IGN] classe d'objets [Termes descripteurs IGN] écriture cartographique [Termes descripteurs IGN] généralisation cartographique automatisée [Termes descripteurs IGN] lisibilité perceptive [Termes descripteurs IGN] placement automatique des écritures [Termes descripteurs IGN] processus d'analyse hiérarchisée floue [Termes descripteurs IGN] représentation multiple [Termes descripteurs IGN] réseau routier [Termes descripteurs IGN] route [Termes descripteurs IGN] Styled Layer Descriptor [Vedettes matières IGN] Généralisation Résumé : (Auteur) This paper proposes a compound hierarchy to be used in cartographic labelling of streets. The main purposes of this hierarchy are to ease navigation of street maps and to provide more understandability and legibility of street features for map users. The hierarchy uses centrality measures along with functional classes of the streets to order features according to their spatial importance in each used zoom level. The calculation of a proper radius, to be employed in the calculations of centrality measures, is based on extracting proper field of view in the map user’s focus status. The used measures are integrated using fuzzy-analytic hierarchy process, yielding proper coefficients to create the hierarchy. The hierarchy is applied for the thinning process and later for using the styled layer descriptor to label street features. Quality constrains are implemented to make the street labels more understandable and readable. Numéro de notice : A2018-257 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1080/00087041.2017.1323151 date de publication en ligne : 19/05/2017 En ligne : https://doi.org/10.1080/00087041.2017.1323151 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=90325 [article]

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Effects of urban tree canopy loss on land surface temperature magnitude and timing / Arthur Elmes in ISPRS Journal of photogrammetry and remote sensing, vol 128 (June 2017)  

Public [article]  inISPRS Journal of photogrammetry and remote sensing > vol 128 (June 2017) . - pp 338 - 353 Titre : Effects of urban tree canopy loss on land surface temperature magnitude and timing Type de document : Article/Communication Auteurs : Arthur Elmes, Auteur ; John Rogan, Auteur ; Christopher Williams, Auteur ; et al., Auteur Année de publication : 2017 Article en page(s) : pp 338 - 353 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes descripteurs IGN] analyse diachronique [Termes descripteurs IGN] arbre urbain [Termes descripteurs IGN] densité de la végétation [Termes descripteurs IGN] données lidar [Termes descripteurs IGN] données localisées 3D [Termes descripteurs IGN] étude d'impact [Termes descripteurs IGN] ilot thermique urbain [Termes descripteurs IGN] image Worldview [Termes descripteurs IGN] Massachusetts (Etats-Unis) [Termes descripteurs IGN] température de surface [Termes descripteurs IGN] variation saisonnière [Termes descripteurs IGN] zone urbaine Résumé : (Auteur) Urban Tree Canopy (UTC) plays an important role in moderating the Surface Urban Heat Island (SUHI) effect, which poses threats to human health due to substantially increased temperatures relative to rural areas. UTC coverage is associated with reduced urban temperatures, and therefore benefits both human health and reducing energy use in cities. Measurement of this relationship relies on accurate, fine spatial resolution UTC mapping, and on time series analysis of Land Surface Temperatures (LST). The City of Worcester, Massachusetts underwent extensive UTC loss and gain during the relatively brief period from 2008 to 2015, providing a natural experiment to measure the UTC/LST relationship. This paper consists of two elements to this end. First, it presents methods to map UTC in urban and suburban locations at fine spatial resolution (∼0.5 m) using image segmentation of a fused Lidar/WorldView-2 dataset, in order to show UTC change over time. Second, the areas of UTC change are used to explore changes in LST magnitude and seasonal variability using a time series of all available Landsat data for the study area over the eight-year period from 2007 to 2015. Fractional UTC change per unit area was determined using fine resolution UTC maps for 2008, 2010, and 2015, covering the period of large-scale tree loss and subsequent planting. LST changes were measured across a series of net UTC change bins, providing a relationship between UTC net change and LST trend. LST was analyzed for both monotonic trends over time and changes to seasonal magnitude and timing, using Theil-Sen slopes and Seasonal Trend Analysis (STA), respectively. The largest magnitudes of UTC loss occurred in residential neighborhoods, causing increased exposure of impervious (road) and pervious (grass) surfaces. Net UTC loss showed higher monotonic increases in LST than persistence and gain areas. STA indicated that net UTC loss was associated greater difference between 2008 and 2015 seasonal temperature curves than persistence areas, and also larger peak LST values, with peak increases ranging from 1 to 6 °C. Timing of summer warm period was extended in UTC loss areas by up to 15 days. UTC gain provided moderate LST mitigation, with lower monotonic trends, lower peak temperatures, and smaller seasonal curve changes than both persistence and loss locations. This study shows that urban trees mitigate the magnitude and timing of the surface urban heat island effect, even in suburban areas with less proportional impervious coverage than the dense urban areas traditionally associated with SUHI. Trees can therefore be seen as an effective means of offsetting the energy-intensive urban heat island effect. Numéro de notice : A2017-338 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2017.04.011 En ligne : https://doi.org/10.1016/j.isprsjprs.2017.04.011 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=85506 [article]

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Crowdsourcing functions of the living city from Twitter and Foursquare data / Xiaolu Zhou in Cartography and Geographic Information Science, vol 43 n° 5 (November 2016)  

Public [article]  inCartography and Geographic Information Science > vol 43 n° 5 (November 2016) . - pp 393 - 404 Titre : Crowdsourcing functions of the living city from Twitter and Foursquare data Type de document : Article/Communication Auteurs : Xiaolu Zhou, Auteur ; Liang Zhang, Auteur Année de publication : 2016 Article en page(s) : pp 393 - 404 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale [Termes descripteurs IGN] analyse spatio-temporelle [Termes descripteurs IGN] Boston (Massachusetts) [Termes descripteurs IGN] Chicago (Illinois) [Termes descripteurs IGN] dimension temporelle [Termes descripteurs IGN] données issues des réseaux sociaux [Termes descripteurs IGN] données localisées des bénévoles [Termes descripteurs IGN] géoétiquetage [Termes descripteurs IGN] planification urbaine [Termes descripteurs IGN] réseau social [Termes descripteurs IGN] système d'information géographique [Termes descripteurs IGN] ville Résumé : (Auteur) Urban functions are closely related to people’s spatiotemporal activity patterns, transportation needs, and a city’s business distribution and development trends. Studies investigating urban functions have used different data sources, such as remotely sensed imageries, observation, photography, and cognitive maps. However, these data sources usually suffer from low spatial, temporal, and thematic resolution. This article attempts to investigate human activities to understand urban functions through crowdsourcing social media data. In this study, we mined Twitter and Foursquare data to extract and analyze six types of human activities. The spatiotemporal analysis revealed hotspots for different activity intensities at different temporal resolution. We also applied the classified model in a real-time system to extract information of various urban functions. This study demonstrates the significance and usefulness of social sensing in analyzing urban functions. By combining different platforms of social media data and analyzing people’s geo-tagged city experience, this article contributes to leverage voluntary local knowledge to better depict human dynamics, discover spatiotemporal city characteristics, and convey information about cities. Numéro de notice : A2016-690 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/URBANISME Nature : Article DOI : 10.1080/15230406.2015.1128852 En ligne : https://doi.org/10.1080/15230406.2015.1128852 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=82018 [article]

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Extraction of structural and dynamic properties of forests from polarimetric-interferometric SAR data affected by temporal decorrelation / Marco Lavalle in IEEE Transactions on geoscience and remote sensing, vol 53 n° 9 (September 2015)  

Public [article]  inIEEE Transactions on geoscience and remote sensing > vol 53 n° 9 (September 2015) . - pp 4752 - 4767 Titre : Extraction of structural and dynamic properties of forests from polarimetric-interferometric SAR data affected by temporal decorrelation Type de document : Article/Communication Auteurs : Marco Lavalle, Auteur ; S. Hensley, Auteur Année de publication : 2015 Article en page(s) : pp 4752 - 4767 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications [Termes descripteurs IGN] bande L [Termes descripteurs IGN] cohérence spectrale [Termes descripteurs IGN] décorrélation [Termes descripteurs IGN] estimation de quantité [Termes descripteurs IGN] hauteur des arbres [Termes descripteurs IGN] Massachusetts (Etats-Unis) [Termes descripteurs IGN] Pol-INSAR [Termes descripteurs IGN] polarimétrie radar Résumé : (Auteur) This paper addresses the important yet unresolved problem of estimating forest properties from polarimetric-interferometric radar images affected by temporal decorrelation. We approach the problem by formulating a physical model of the polarimetric-interferometric coherence that incorporates both volumetric and temporal decorrelation effects. The model is termed random-motion-over-ground (RMoG) model, as it combines the random-volume-over-ground (RVoG) model with a Gaussian-statistic motion model of the canopy elements. Key features of the RMoG model are: 1) temporal decorrelation depends on the vertical structure of forests; 2) volumetric and temporal coherences are not separable as simple multiplicative factors; and 3) temporal decorrelation is complex-valued and changes with wave polarization. This third feature is particularly important as it allows compensating for unknown levels of temporal decorrelation using multiple polarimetric channels. To estimate model parameters such as tree height and canopy motion, we propose an algorithm that minimizes the least square distance between model predictions and complex coherence observations. The algorithm was applied to L-band NASA's Uninhabited Aerial Vehicle Synthetic Aperture Radar data acquired over the Harvard Forest (Massachussetts, USA). We found that the RMS difference at stand level between estimated RMoG-model tree height and NASA's lidar Laser Vegetation and Ice Sensor tree height was within 12% of the lidar-derived height, which improved significantly the RMS difference of 37% obtained using the RVoG model and ignoring temporal decorrelation. This result contributes to our ability of estimating forest biomass using in-orbit and forthcoming polarimetric-interferometric radar missions. Numéro de notice : A2015-524 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2015.2409066 date de publication en ligne : 13/04/2015 En ligne : https://doi.org/10.1109/TGRS.2015.2409066 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=77535 [article]

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Estimating the vehicle-miles-traveled implications of alternative metropolitan growth scenarios: A Boston example / Joseph Ferreira Jr in Transactions in GIS, vol 17 n° 5 (October 2013)  

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A symmetry detector for map generalization and urban-space analysis / Jan‐Henrik Haunert in ISPRS Journal of photogrammetry and remote sensing, vol 74 (Novembrer 2012)

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Retracing the past: recovering 19th century benchmarks to measure shoreline change along the outer shore of Cape Cod, Massachusetts / S. Mague in Cartography and Geographic Information Science, vol 39 n° 1 (January 2012)  

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Range of categorical associations for comparison of maps with mixed pixels / Robert Gilmore Pontius in Photogrammetric Engineering & Remote Sensing, PERS, vol 75 n° 8 (August 2009)

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Gestion forestière et eau potable. Quelques exemples à travers le monde / Catherine Deck ; Claude Barthelon in Rendez-vous techniques, n° 22 (automne 2008)

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Can error explain map differences over time? / Robert Gilmore Pontius in Cartography and Geographic Information Science, vol 33 n° 2 (April 2006)

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RUSLE [revised universal soil loss equation] applied in a GIS framework: calculating the LS factor and deriving homogenous patches for estimating soil loss / L.A. Lewis in International journal of geographical information science IJGIS, vol 19 n° 7 (august 2005)

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Comparison of the structure and accuracy of two land change models / Robert Gilmore Pontius in International journal of geographical information science IJGIS, vol 19 n° 2 (february 2005)

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Automated subpixel photobathymetry and water quality mapping / R.L. Huguenin in Photogrammetric Engineering & Remote Sensing, PERS, vol 70 n° 1 (January 2004)

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Detailed urban land-use and land-cover mapping using large format camera photographs : an evaluation / C.P. Lo in Photogrammetric Engineering & Remote Sensing, PERS, vol 56 n° 2 (february 1990)

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Use of Thematic Mapper data for the detection of forest damage caused by the pear thrips / J.E. Vogelmann in Remote sensing of environment, vol 30 n° 3 (01/12/1989)

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Thematic Mapper detection of changes in the leaf area of closed canopy pine plantations in central Massachusetts / S.R. Herwitz in Remote sensing of environment, vol 30 n° 2 (November 1989)

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Surfaces de référence liées aux marées / H.A. Marmer (1952)

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Météorologie du relief terrestre / A. Baldit (1937)

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