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MESSAGE EXCHANGEFOR Web Service-Based Mapping Services

AHMET SAYARAHMET SAYARINDIANA UNIVERSITY INDIANA UNIVERSITY COMMUNITY GRIDS LAB.COMMUNITY GRIDS LAB.COMPUTER SCIENCE DEPARTMENTCOMPUTER SCIENCE DEPARTMENT

August 17, 2005

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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

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GIS – 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.

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WMSWMSrequest-response point of viewrequest-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)

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CapabilitiesCapabilities

Map FactoryMap Factory

getCapabilities

getFeatureInfo

WMS Client WMS

layerslayersgetMap

Raster Caverage

Feature vector data

Map layers

WCSWCS

WFSWFS

WMSWMS

browser

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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)

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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.

WMS(requestor)

WFS(publisher)

WRS(registry)

WEB Services representation with three major functionalities of nodes

publish

find

bind

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Mapping Request MessagesOGC to Web Service

Mapping steps Define interfaces (wsdl) Define request format (schema files) Create client stubs for invocation. (via wsdl)

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Structured Requests in SOAP EnvelopeWMS Case

GETCAPABILITIES

GETMAP

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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)

HTTP

SOAP

ISWFS

`

CapabilitiesIntegrator

MapIntegrator

WS

DL

Req

ues

t H

and

ler

WMS

WFS

WRWFS

WRS

Service Oriented

HTTP

HTTP

SOAPOr

HTTP List of layers

and maps

getCapabilitiesgetMap

getFeatureInfo

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Quality of Services for WMS Quality of Services for WMS – Ongoing Work– Ongoing Work

Data Transferring Streaming with NaradaBrokering (NB)

Data Processing XML Pull parsing

Scientific Visualization Parallel processing. Computational Scientific Algorithms. (ex. Seismic

contour plots)

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California Faults (Earthquake) Visualization Demo

Visualization and Analysis of Seismic Data for Turkey

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Pattern-Informatics Visualization Demo Visualization and

Analysis of Seismic Data for Turkey

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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/n

ewmap.jsp

Publications: http://grids.ucs.indiana.edu/ptliupages/publications/

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Questions/Comments

Any questions and/or comments?

Thanks!