1 MESSAGE EXCHANGE FOR Web Service-Based Mapping Services AHMET SAYAR INDIANA UNIVERSITY COMMUNITY GRIDS LAB. COMPUTER SCIENCE DEPARTMENT August 17, 2005

2 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

3 GIS – OGC - WMS OGC 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.

4 WMS request-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) Loading … Capabilities Map Factory getCapabilities getFeatureInfo WMS Client WMS layers getMap Raster Caverage Feature vector data Map layers WCS WFS WMS

5 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)

6 From OGC to Service based GIS 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. WEB Services representation with three major functionalities of nodes publish find bind

7 Mapping Request Messages OGC to Web Service Mapping steps  Define interfaces (wsdl)  Define request format (schema files)  Create client stubs for invocation. (via wsdl)

8 Structured Requests in SOAP Envelope WMS Case GETCAPABILITIES GETMAP

9 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)

10 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)

11 California Faults (Earthquake) Visualization Demo Visualization and Analysis of Seismic Data for Turkey

12 Pattern-Informatics Visualization Demo Visualization and Analysis of Seismic Data for Turkey

13 More Information Crisisgrid (GIS project at IU-CGL) home page:  Service-based visualization demo:  ewmap.jsp ewmap.jsp Publications: 

14 Questions/Comments Any questions and/or comments? Thanks!