Geoportals are a consolidated web-based solution to provide open spatial data sharing and online geo-information management.Their roles and possible advancements according to the Digital Earth vision and implementatio...Geoportals are a consolidated web-based solution to provide open spatial data sharing and online geo-information management.Their roles and possible advancements according to the Digital Earth vision and implementation require investigations.This paper presents a review of the literature concerning geoportals and serves the following primary purposes.First,various geoportal approaches for discovering and accessing Earth observation data and geo-information,mainly with scientific purposes,are summarized according to their characteristics and functionalities.Second,current major challenges in geoportals are identified in terms of functionalities,technologies,and especially big data support,from geoportal cases of China.Finally,based on lessons learned from the international and Chinese geoportals,solutions and recommendations for the challenges in geoportals are proposed in terms of their architectures,services,and technologies.The results show that geoportals usually provide access to distributed data systems,offering maps,data discovery,and data downloads.Some of them are also capable of offering online analysis and processing service,enhanced semantic search engines,and dynamic visualization tools.The strength of geoportals could lead to a full-fledged online Digital Earth system that could provide better data sharing and dissemination solutions to the challenges posed by big data.展开更多
Geoportals have been the primary source of spatial information to researchers in diverse fields.Recent years have seen a growing trend to integrate spatial analysis and geovisual analytics inside Geoportals.Researcher...Geoportals have been the primary source of spatial information to researchers in diverse fields.Recent years have seen a growing trend to integrate spatial analysis and geovisual analytics inside Geoportals.Researchers could use the Geoportal to conduct basic analysis without offline processing.In practice,domain-specific analysis often requires researchers to integrate heterogeneous data sources,leverage new statistical models,or build their own customized models.These tasks are increasingly being tackled with open source tools in programming languages such as Python or R.However,it is unrealistic to incorporate the numerous open source tools in a Geoportal platform for data processing and analysis.This work provides an exploratory effort to bridge Geoportals and open source tools through Python scripting.The Geoportal demonstrated in this work is the Urban and Regional Explorer for China studies.A python package is provided to manipulate this platform in the local programming environment.The server side of the Geoportal implements a set of service endpoints that allows the package to upload,transform,and process user data and seamlessly integrate them into the existing datasets.A case study is provided that illustrated the use of this package to conduct integrated analyses of search engine data and baseline census data.This work attempts a new direction in Geoportal development,which could further promote the transformation of Geoportals into online analytical workbenches.展开更多
There is a critical need to develop a means for fast,task-driven discovery of geospatial data found in geoportals.Existing geoportals,however,only provide metadata-based means for discovery,with little support for tas...There is a critical need to develop a means for fast,task-driven discovery of geospatial data found in geoportals.Existing geoportals,however,only provide metadata-based means for discovery,with little support for task-driven discovery,especially when considering spatial–temporal awareness.To address this gap,this paper presents a Case-Based Reasoning-supported Geospatial Data Discovery(CBR-GDD)method and implementation that accesses geospatial data by tasks.The advantages of the CBR-GDD approach is that it builds an analogue reasoning process that provides an internal mechanism bridging tasks and geospatial data with spatial–temporal awareness,thus providing solutions based on past tasks.The CBR-GDD approach includes a set of algorithms that were successfully implemented via three components as an extension of geoportals:ontology-enhanced knowledge base,similarity assessment model,and case retrieval nets.A set of experiments and case studies validate the CBR-GDD approach and application,and demonstrate its efficiency.展开更多
International studies of expertise have shown that the difficulty of data access is one of the major hindrances that brakes any effort to conduct studies on groundwater. This research paper is an attempt to address th...International studies of expertise have shown that the difficulty of data access is one of the major hindrances that brakes any effort to conduct studies on groundwater. This research paper is an attempt to address this problematic through developing a technical framework to implement a Spatial Data Infrastructure (SDI) with a view to improving the status of access to data related to groundwater in Morocco, and achieving their interoperability. This prototype is primarily based on international standards (OGC & ISO) such as Web Map Service (WMS), Web Feature Service (WFS), Catalog Web Service (CSW) and Sensor Observation Service (SOS) accompanied by the use of associated specifications such as Geography Markup Language (GML) and Filter Encoding (FE). This platform is considered both as a tool for sharing updated data collected from numerous and divers source providers, and as a tool of web-based GIS for groundwater management, which constitutes the basis for decision making.展开更多
This article presents research and development of an interoperable platform to facilitate, monitor and coordinate groundwater data sharing. This system was orchestrated by a number of services described by Open Geospa...This article presents research and development of an interoperable platform to facilitate, monitor and coordinate groundwater data sharing. This system was orchestrated by a number of services described by Open Geospatial Consortium (OGC) such as Sensor Observation Service (SOS) and other services for the use of mapping data, Web Feature Services (WFS), Web Map Service (WMS), and catalogue services (CSW). An important activity for our project was the establishment of a portal for geographic data and services. Geoportal developed for this project will promote and facilitate access to groundwater data and share theme more openly. Otherwise our system has been designed to provide a powerful tool that enhances the ability of regional staff to monitor near real-time groundwater data (i.e.?piezometric level) and as a result will help provide a more effective response to environmental upsets.展开更多
A spatial web portal(SWP)provides a web-based gateway to discover,access,manage,and integrate worldwide geospatial resources through the Internet and has the access characteristics of regional to global interest and s...A spatial web portal(SWP)provides a web-based gateway to discover,access,manage,and integrate worldwide geospatial resources through the Internet and has the access characteristics of regional to global interest and spiking.Although various technologies have been adopted to improve SWP performance,enabling high-speed resource access for global users to better support Digital Earth remains challenging because of the computing and communication intensities in the SWP operation and the dynamic distribution of end users.This paper proposes a cloud-enabled framework for high-speed SWP access by leveraging elastic resource pooling,dynamic workload balancing,and global deployment.Experimental results demonstrate that the new SWP framework outperforms the traditional computing infrastructure and better supports users of a global system such as Digital Earth.Reported methodologies and framework can be adopted to support operational geospatial systems,such as monitoring national geographic state and spanning across regional and global geographic extent.展开更多
文摘Geoportals are a consolidated web-based solution to provide open spatial data sharing and online geo-information management.Their roles and possible advancements according to the Digital Earth vision and implementation require investigations.This paper presents a review of the literature concerning geoportals and serves the following primary purposes.First,various geoportal approaches for discovering and accessing Earth observation data and geo-information,mainly with scientific purposes,are summarized according to their characteristics and functionalities.Second,current major challenges in geoportals are identified in terms of functionalities,technologies,and especially big data support,from geoportal cases of China.Finally,based on lessons learned from the international and Chinese geoportals,solutions and recommendations for the challenges in geoportals are proposed in terms of their architectures,services,and technologies.The results show that geoportals usually provide access to distributed data systems,offering maps,data discovery,and data downloads.Some of them are also capable of offering online analysis and processing service,enhanced semantic search engines,and dynamic visualization tools.The strength of geoportals could lead to a full-fledged online Digital Earth system that could provide better data sharing and dissemination solutions to the challenges posed by big data.
文摘Geoportals have been the primary source of spatial information to researchers in diverse fields.Recent years have seen a growing trend to integrate spatial analysis and geovisual analytics inside Geoportals.Researchers could use the Geoportal to conduct basic analysis without offline processing.In practice,domain-specific analysis often requires researchers to integrate heterogeneous data sources,leverage new statistical models,or build their own customized models.These tasks are increasingly being tackled with open source tools in programming languages such as Python or R.However,it is unrealistic to incorporate the numerous open source tools in a Geoportal platform for data processing and analysis.This work provides an exploratory effort to bridge Geoportals and open source tools through Python scripting.The Geoportal demonstrated in this work is the Urban and Regional Explorer for China studies.A python package is provided to manipulate this platform in the local programming environment.The server side of the Geoportal implements a set of service endpoints that allows the package to upload,transform,and process user data and seamlessly integrate them into the existing datasets.A case study is provided that illustrated the use of this package to conduct integrated analyses of search engine data and baseline census data.This work attempts a new direction in Geoportal development,which could further promote the transformation of Geoportals into online analytical workbenches.
基金supported by the National Key Research and Development Program of China[grant number 2016YFB0502204]Opening research fund of State Key Laboratory of Information Engineering in Surveying,Mapping and Remote Sensing[grant number(16)Key04]+1 种基金Opening fund of Guangxi Key Laboratory of Earth Surface Processes and Intelligent Simulation(Guangxi Teachers Education University)[grant number 2015GXESPKF02]National Natural Science Foundation of China[grant number 41401524].
文摘There is a critical need to develop a means for fast,task-driven discovery of geospatial data found in geoportals.Existing geoportals,however,only provide metadata-based means for discovery,with little support for task-driven discovery,especially when considering spatial–temporal awareness.To address this gap,this paper presents a Case-Based Reasoning-supported Geospatial Data Discovery(CBR-GDD)method and implementation that accesses geospatial data by tasks.The advantages of the CBR-GDD approach is that it builds an analogue reasoning process that provides an internal mechanism bridging tasks and geospatial data with spatial–temporal awareness,thus providing solutions based on past tasks.The CBR-GDD approach includes a set of algorithms that were successfully implemented via three components as an extension of geoportals:ontology-enhanced knowledge base,similarity assessment model,and case retrieval nets.A set of experiments and case studies validate the CBR-GDD approach and application,and demonstrate its efficiency.
文摘International studies of expertise have shown that the difficulty of data access is one of the major hindrances that brakes any effort to conduct studies on groundwater. This research paper is an attempt to address this problematic through developing a technical framework to implement a Spatial Data Infrastructure (SDI) with a view to improving the status of access to data related to groundwater in Morocco, and achieving their interoperability. This prototype is primarily based on international standards (OGC & ISO) such as Web Map Service (WMS), Web Feature Service (WFS), Catalog Web Service (CSW) and Sensor Observation Service (SOS) accompanied by the use of associated specifications such as Geography Markup Language (GML) and Filter Encoding (FE). This platform is considered both as a tool for sharing updated data collected from numerous and divers source providers, and as a tool of web-based GIS for groundwater management, which constitutes the basis for decision making.
文摘This article presents research and development of an interoperable platform to facilitate, monitor and coordinate groundwater data sharing. This system was orchestrated by a number of services described by Open Geospatial Consortium (OGC) such as Sensor Observation Service (SOS) and other services for the use of mapping data, Web Feature Services (WFS), Web Map Service (WMS), and catalogue services (CSW). An important activity for our project was the establishment of a portal for geographic data and services. Geoportal developed for this project will promote and facilitate access to groundwater data and share theme more openly. Otherwise our system has been designed to provide a powerful tool that enhances the ability of regional staff to monitor near real-time groundwater data (i.e.?piezometric level) and as a result will help provide a more effective response to environmental upsets.
基金Research reported is partially supported by NSF[grant numbers PLR-1349259 and IIP-1338925],FGDC[grant number G13PG00091],and NASA[grant number NNG12PP37I].
文摘A spatial web portal(SWP)provides a web-based gateway to discover,access,manage,and integrate worldwide geospatial resources through the Internet and has the access characteristics of regional to global interest and spiking.Although various technologies have been adopted to improve SWP performance,enabling high-speed resource access for global users to better support Digital Earth remains challenging because of the computing and communication intensities in the SWP operation and the dynamic distribution of end users.This paper proposes a cloud-enabled framework for high-speed SWP access by leveraging elastic resource pooling,dynamic workload balancing,and global deployment.Experimental results demonstrate that the new SWP framework outperforms the traditional computing infrastructure and better supports users of a global system such as Digital Earth.Reported methodologies and framework can be adopted to support operational geospatial systems,such as monitoring national geographic state and spanning across regional and global geographic extent.
