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International Journal of Digital Earth 2017年第7期10卷 675-686页

作者： Michael Jendryke Stephen C.McClure Timo Balz Mingsheng Liao State Key Laboratory of information Engineering in Surveying Mapping and Remote SensingWuhan UniversityWuhanPeople’s Republic of China Collaborative Innovation Center for Geospatial Technology Wuhan UniversityWuhanPeople’s Republic of China

In this geo-statistical analysis of change detection,we illustrate the evolution of the built-up environment in Shanghai at the street-block *** on two TerraSAR-X image stacks with 36 and 15 images,covering the city centre of Shanghai for the time period from 2008 to 2015,a set of coherence images was created using a small baseline *** road network from Open Street Map,a volunteered geographic information product,serves as the input dataset to create street-blocks.A street-block is surrounded by roads and resembles a ground parcel,a real estate property–a cadastral *** coherence information is aggregated to these street-blocks for each observation and the variation is analysed over *** analysis of spatial autocorrelation reveals clusters of similar *** result is a detailed map of Shanghai highlighting areas of *** argue that the aggregation and grouping of synthetic aperture radar coherence image information to real-world entities(street-blocks)is comprehensible and relevant to the urban planning ***,this research is a contribution to the community of urban planners,designers,and government agencies who want to monitor the development of the urban landscape.

关键词： SAR change detection urban area volunteered geographic information

Data trustworthiness and user reputation as indicators of VGI quality

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Geo-Spatial information Science 2018年第3期21卷 213-233页

作者： Paolo Fogliaroni Fausto D’Antonio Eliseo Clementini Department for Geodesy and Geoinformation Vienna University of TechnologyViennaAustria Department of Industrial and information Engineering and Economics University of L’AquilaL’AquilaItaly

volunteered geographic information(VGI)has entered a phase where there are both a substantial amount of crowdsourced information available and a big interest in using it by *** the issue of deciding the quality of VGI without resorting to a comparison with authoritative data remains an open *** article first formulates the problem of quality assessment of VGI *** presents a model to measure trustworthiness of information and reputation of contributors by analyzing geometric,qualitative,and semantic aspects of edits over *** implementation of the model is running on a small data-set for a preliminary empirical *** results indicate that the computed trustworthiness provides a valid approximation of VGI quality.

关键词： volunteered geographic information data quality trustworthiness reputation

SIRENE: A Spatial Data Infrastructure to Enhance Communities' Resilience to Disaster-Related Emergency

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International Journal of Disaster Risk Science 2018年第1期9卷 129-142页

作者： Simone Sterlacchini Gloria Bordogna Giacomo Cappellini Debora Voltolina Institute for the Dynamics of Environmental Processes –National Research Council of Italy (CNR-IDPA) Institute for Electromagnetic Sensing of the Environment –National Research Council of Italy (CNR-IREA)

Planning in advance to prepare for and respond to a natural hazard-induced disaster-related emergency is a key action that allows decision makers to mitigate unexpected impacts and potential damage. To further this aim, a collaborative, modular, and information and communications technology-based Spatial Data Infrastructure(SDI)called SIRENE—Sistema Informativo per la Preparazione e la Risposta alle Emergenze(information System for Emergency Preparedness and Response) is designed and implemented to access and share, over the Internet, relevant multisource and distributed geospatial data to support decision makers in reducing disaster risks. SIRENE flexibly searches and retrieves strategic information from local and/or remote repositories to cope with different emergency phases. The system collects, queries, and analyzes geographic information provided voluntarily by observers directly in the field(volunteered geographic information(VGI) reports) to identify potentially critical environmental conditions. SIRENE can visualize and cross-validate institutional and research-based data against VGI reports,as well as provide disaster managers with a decision support system able to suggest the mode and timing of intervention, before and in the aftermath of different types of emergencies, on the basis of the available information and in agreement with the laws in force at the national andregional levels. Testing installations of SIRENE have been deployed in 18 hilly or mountain municipalities(12 located in the Italian Central Alps of northern Italy, and six in the Umbria region of central Italy), which have been affected by natural hazard-induced disasters over the past years(landslides, debris flows, floods, and wildfire) and experienced significant social and economic losses.

关键词： Data retrieval Decision support system Disaster management Italy Spatial data infrastructure Susceptibility/hazard and risk maps volunteered geographic information

An exploratory analysis of usability of Flickr tags for land use/land cover attribution

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Geo-Spatial information Science 2019年第1期22卷 12-22页

作者： Yingwei Yan Michael Schultz Alexander Zipf Institute of Geography Heidelberg UniversityHeidelbergGermany

This study explored the land use/land cover(LULC)separability by the machine-generated and user-generated Flickr photo tags(*** auto-tags and the user-tags,respectively),based on an authoritative LULC dataset for San Diego County in the United *** types of LULCs were derived from the authoritative *** was observed that certain types of the reclassified LULCs had abundant tags(*** parks)or a high tag density(*** commercial lands),compared with the less populated ones(*** agricultural lands).Certain highly weighted terms of the tags derived based on a term frequency–inverse document frequency weighting scheme were helpful for identifying specific types of the LULCs,especially for the commercial recreation lands(*** zoos).However,given the 10 sets of tags retrieved from the corresponding 10 types of LULCs,one set of tags(all the tags located at one specific type of the LULCs)could not fully delineate the corresponding LULC due to semantic overlaps,according to a latent semantic analysis.

关键词： Land use/land cover Flickr quantitative semantics volunteered geographic information

Digital Earth from vision to practice:making sense of citizen-generated content

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International Journal of Digital Earth 2012年第5期5卷 398-416页

作者： M.Craglia F.Ostermann L.Spinsanti Digital earth and reference data unit european commission joint research centreispraitaly

The vision of Digital Earth(DE)put recently forward under the auspices of the International Society for DE extends the paradigm of spatial data infrastructures by advocating an interactive and dynamic framework based on near-to-real time information from sensors and *** paper contributes to developing that vision and reports the results of a two-year research project exploring the extent to which it is possible to extract information useful for policy and science from the large volumes of messages and photos being posted daily through social *** the noted concerns about the quality of such data in relation to that provided by authoritative sources,the research has developed a semi-automatic workflow to assess the fitness for purpose of data extracted from Twitter and Flickr,and compared them to that coming from official sources,using forest fires as a case *** findings indicate that we were able to detect accurately six of eight major fires in France in the summer of 2011,with another four detected by the social networks but not reported by our official source,the European Forest Fire information *** findings and the lessons learned in handling the very large volumes of unstructured data in multiple languages discussed in this study provide useful insights into the value of social network data for policy and science,and contribute to advancing the vision of DE.

关键词： Digital Earth social networks volunteered geographic information data quality

volunteered remote sensing data generation with air passengers as sensors

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International Journal of Digital Earth 2021年第2期14卷 158-180页

作者： Chisheng Wang Yongquan Wang Leyang Wang Zhongwen Hu Shaobiao Zhang Shuanglong Wang Wenqun Xiu Hongxing Cui Dan Wang Qingquan Li Key Laboratory for Geo-Environmental Monitoring of Great Bay Area Ministry of Land and ResourcesShenzhen UniversityShenzhenPeople’s Republic of China Key Laboratory of Urban Land Resources Monitoring and Simulation Ministry of Land and ResourcesShenzhenPeople’s Republic of China Faculty of Geomatics East China University of TechnologyNanchangPeople’s Republic of China Shenzhen Urban Public Safety and Technology Institute ShenzhenPeople’s Republic of China Shenzhen Integrated Geotechnical Investigation&Surveying Co.Ltd ShenzhenPeople’s Republic of China

Remote sensing satellites are playing very important roles in diverse earth observation ***,long revisit period,high cost and dense cloud cover have been the main limitations of satellite remote sensing for a long *** paper introduces the novel volunteered passenger aircraft remote sensing(VPARS)concept,which can partly overcome these *** obtaining aerial imaging data from passengers using a portable smartphone on a passenger aircraft,it has various advantages including low cost,high revisit,dense coverage,and partial anti-cloud,which can well complement conventional remote sensing *** paper examines the concept of VPARS and give general data processing framework of *** cases were given to validate this processing *** preliminary applications on land cover classification and economic activity monitoring validate the applicability of the VPARS ***,we examine the issues about data maintenance,potential applications,limitations and *** conclude the VPARS can benefit both scientific and industrial communities who rely on remote sensing data.

关键词： volunteered geographic information remote sensing handheld cameras passenger aircraft

Assessing quality of volunteer crowdsourcing contributions:lessons from the Cropland Capture game

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International Journal of Digital Earth 2016年第4期9卷 410-426页

作者： Carl F.Salk Tobias Sturn Linda See Steffen Fritz Christoph Perger Ecosystems Services and Management Program International Institute for Applied Systems AnalysisLaxenburgAustria Southern Swedish Forest Research Center Swedish University of Agricultural SciencesAlnarpSweden

volunteered geographic information(VGI)is the assembly of spatial information based on public *** VGI has proliferated in recent years,assessing the quality of volunteer-contributed data has proven challenging,leading some to question the efficiency of such *** this paper,we compare several quality metrics for individual volunteers’*** data were the product of the‘Cropland Capture’game,in which several thousand volunteers assessed 165,000 images for the presence of cropland over the course of 6 *** compared agreement between volunteer ratings and an image’s majority classification with volunteer self-agreement on repeated images and expert *** also examined the impact of experience and learning on *** self-agreement was nearly always higher than agreement with majority classifications,and much greater than agreement with expert validations although these metrics were all positively *** quality showed a broad trend toward improvement with experience,but the highest accuracies were achieved by a handful of moderately active contributors,not the most active *** results emphasize the importance of a universal set of expert-validated tasks as a gold standard for evaluating VGI quality.

关键词： crowdsourcing volunteered geographic information cropland data quality image classification Geo-Wiki

A data fusion-based framework to integrate multi-source VGI in an authoritative land use database

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International Journal of Digital Earth 2021年第4期14卷 480-509页

作者： Lanfa Liu Ana-Maria Olteanu-Raimond Laurence Jolivet Arnaud-le Bris Linda See LASTIG Univ Gustave EiffelENSGIGNSaint-MandeFrance International Institute for Applied Systems Analysis(IIASA) LaxenburgAustria

Updating an authoritative Land Use and Land Cover(LULC)database requires many *** geographic information(VGI)involves citizens in the collection of data about their spatial *** is a growing interest in using existing VGI to update authoritative *** paper presents a framework aimed at integrating multi-source VGI based on a data fusion technique,in order to update an authoritative land use *** VGI data source is considered to be an independent source of information,which is fused together using Dempster-Shafer Theory(DST).The framework is tested in the updating of the authoritative land use data produced by the French National Mapping *** data sets were collected from several in-situ and remote campaigns run between 2018 and 2020 by contributors with varying *** data fusion approach achieved an overall accuracy of 85.6%for the 144 features having at least two contributions when the confidence threshold was set to *** the heterogeneity and limited amount of VGI used,the results are promising,with 99%of the LU polygons updated or *** results show the potential of using multi-source VGI to update or enrich authoritative LU data and potentially LULC data more generally。

关键词： Data fusion DempsterShafer Theory land use OCSGE volunteered geographic information

Data democracy–increased supply of geospatial information and expanded participatory processes in the production of data

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International Journal of Digital Earth 2015年第9期8卷 679-693页

作者： Max Craglia Lea Shanley European Commission Joint Research CentreIspraItaly Gaylord Nelson Institute for Environmental Studies University of WisconsinMadisonWIUSA

The global landscape in the supply,co-creation and use of geospatial data is changing very rapidly with new satellites,sensors and mobile devices reconfiguring the traditional lines of demand and supply and the number of actors *** this paper we chart some of these technology-led developments and then focus on the opportunities they have created for the increased participation of the public in generating and contributing information for a wide range of uses,scientific and *** all this information is open or geospatial,but sufficiently large portions of it are to make it one of the most significant phenomena of the last *** fact,we argue that while satellite and sensors have exponentially increased the volumes of geospatial information available,the participation of the public is transformative because it expands the range of participants and stakeholders in society using and producing geospatial information,with opportunities for more direct participation in science,politics and social action.

关键词： citizen science volunteered geographic information geospatial data

On predicting and improving the quality of Volunteer geographic information projects

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International Journal of Digital Earth 2016年第2期9卷 134-155页

作者： Gloria Bordogna Paola Carrara Laura Criscuolo Monica Pepe Anna Rampini CNR IREANational Research Council of ItalyInstitute for Environmental Remote SensingMilanoItaly

Initiatives that rely upon the contributions of volunteers to reach a specific goal are growing more and more with the success of Web 2.0–interactive *** scientific projects are testing and exploiting volunteers’collaboration,but the quality of information obtained with this approach is often *** paper offers a rich overview of many scientific projects where geographic contributions are committed to volunteers,to the aim of defining strategies to improve information *** describing real examples of Volunteer geographic information(VGI),the contribution establishes a categorization based on the characteristics of the information,tasks,and scopes of the *** a discussion on the relationships of categories and VGI quality,the paper analyses techniques to improve the quality of volunteered information according to the moment of its assessment(i.e.,ex ante,ex post,or both with respect to information creation).The paper outlines the main limitations of the different approaches and indicates some guidelines for future developments.

关键词： volunteered geographic information Citizen Science information quality quality improvement