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MESSAGE EXCHANGE FOR Web Service-Based Mapping Services. AHMET SAYAR INDIANA UNIVERSITY COMMUNITY GRIDS LAB. COMPUTER SCIENCE DEPARTMENT August 17, 2005. Motivation. GIS OGC Web-Services SOA Grids GIS-Grids Bridging GIS-Grids to other GIS networks Case Study for Message Exchange
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MESSAGE EXCHANGEFOR Web Service-Based Mapping Services AHMET SAYAR INDIANA UNIVERSITY COMMUNITY GRIDS LAB. COMPUTER SCIENCE DEPARTMENT August 17, 2005
Motivation • GIS • OGC • Web-Services • SOA Grids GIS-Grids • Bridging GIS-Grids to other GIS networks • Case Study for Message Exchange • OGC Mapping service - WMS
GIS – OGC - WMS • Geographical Information Systems (GIS) introduce methods, services and environments to visualize, manipulate, analyze and display geospatial data.. • Creation of standards and recommendations for geospatial information and services. • OGC (Open Geospatial Consortium ) • ISO/TC211 • W3C (World Wide Web Consortium) • Web Map Server (WMS) is OGC compatible GIS mapping service.
WMSrequest-response point of view • Provides data as layers and lists supported layers in capabilities file. Capabilities file is an xml file, schema is defined by OGC. • WMS provides 3 functionalities. GetCapabilities and GetMap is mandatory GetFeatureInfo is optional. (Basic WMS, Queryable WMS) Raster Caverage WCS Capabilities getCapabilities layers Feature vector data Loading … getMap WFS Map Factory getFeatureInfo WMS Map layers WMS WMS Client
WEB SERVICES • Web Services • WSDL, XML, SOAP, UDDI • human to machine vs. machine to machine • Advantages • Operating system neutral • Platform neutral • Language neutral • Seamless integrations of services. • Easy to extend • Uses open standards (HTTP, XML)
From OGC to Service based GIS WEB Services representation with three major functionalities of nodes • Major GIS Services • WFS • WMS • WRS (Catalog-Information services) • Issues handled • Message formats • Service interfaces • Transport protocols WMS will be case study for explaining Messaging formats and communication handling in Web Service based Mapping Services. bind publish find
Mapping Request MessagesOGC to Web Service • Mapping steps • Define interfaces (wsdl) • Define request format (schema files) • Create client stubs for invocation. (via wsdl)
Structured Requests in SOAP EnvelopeWMS Case GETCAPABILITIES GETMAP
Proxy-Cascading WMS • Proxy - cascading WMS : • As part of Crisigrid –each server is implemented as web services. • As an outsider of the HttpGET/POST (Servlet) based OGC GIS networks • As part of the HttpGET/POST (Servlet) based OGC GIS networks • Clients don’t have to know which layers provided by which type of services (Web Service based or servlet based)
Quality of Services for WMS – Ongoing Work • Data Transferring • Streaming with NaradaBrokering (NB) • Data Processing • XML Pull parsing • Scientific Visualization • Parallel processing. • Computational Scientific Algorithms. (ex. Seismic contour plots)
California Faults (Earthquake) Visualization Demo Visualization and Analysis of Seismic Data for Turkey
Pattern-Informatics Visualization Demo Visualization and Analysis of Seismic Data for Turkey
More Information • Crisisgrid (GIS project at IU-CGL) home page: • http://www.crisisgrid.org/ • Service-based visualization demo: • http://complexity.ucs.indiana.edu:5050/PiWmsClient/newmap.jsp • Publications: • http://grids.ucs.indiana.edu/ptliupages/publications/
Questions/Comments • Any questions and/or comments? • Thanks!