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WebGIS. Web & GIS ….WebGIS. Access without purchasing proprietary software Data directly from producer Emerging new market. The challenge of WebGIS. Creating software systems that work any desktop. WebGIS architectures. Server-Side Client-Side Hybrid. Server-Side.
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Web & GIS ….WebGIS • Access without purchasing proprietary software • Data directly from producer • Emerging new market
The challenge of WebGIS • Creating software systems that work any desktop
WebGIS architectures • Server-Side • Client-Side • Hybrid
Server-Side • Definition:End users submit requests for data and analysis to a web server. The server processes the requests and returns data or a solution to the remote client. (Thin Client) • Advantages • High performance server • Eliminate large data sets being sent • More control • Disadvantages • Bandwidth • High performance client machines • Every request must be communicated
Server-side Strategies Server tasks Client tasks Map browsing Display Query Analysis Map drawing Server-side Strategies
Client-Side • Definition:End users can perform some data manipulation and analysis locally on their own machines. (Thick Client) • Advantages • Take advantage of powerful client machines • Greater control of data to the user • Reduced requests sent over the network • Disadvantages • Large of amounts of data and applets sent • Users may not have a powerful machine • Users may not have the training to employ the data and analysis functions properly
Client-side Strategies Server tasks Client tasks Analysis Display Map drawing Map browsing Query Client-side Strategies
Real-time GIS • Variations on the client-side strategy can be used • Involves feeding data directly into the system from sensors • Real-time can used to: • Monitor vehicle location or traffic conditions • Monitor weather and hydrological conditions • Track tagged animals in habitat monitoring • Can deliver data across the Internet without the need for dedicated cable, telephone, or radio feeds
Variations on the client-side strategy • Add GIS functionality to Web browsers • The alternatives are to: • Download and permanently install a "plug-in" • Build capabilities into existing GIS software that runs on the client
Combination and Hybrid Strategies • Pure server-side and client-side strategies have distinct limitations: • Server-side strategies sensitive to Internet bandwidth • Client-side strategies are sensitive to the computational power of the client
Hybrid • Definition: Server and Client processes combined to optimize performance and meet special user needs. • Better Matched Solutions for Computer Capabilities • Smart Task Assignments
Applications • Mass Market ServerSide • Smaller, GIS Savvy Client-Side • Transactions Hybrid Maps on Demand
WebGIS trends • Lower access cost • Provide better customer service • Shared data and GIS functionality • “Pay-for-use" mapping and GIS services
GIS Vendors and Products • Four Major GIS Vendors ESRI Intergraph AutoDesk MapInfo Enterprise Information Solutions, Inc.
ESRI • ArcView IMS • Server-Side strategy • Server platform - Windows 95, 98, NT, Unix • Client software - JavaScript, Java, HTML, Active X • Client platforms - All • Client-side data formats - GIF/JPEG images Enterprise Information Solutions, Inc.
ESRI • MapObjects IMS • Hybrid strategy • Server platform - Windows 95, 98, NT • Client software - ArcExplorer, JavaScript, Java, HTML, Active X • Client platforms - All • Client-side data formats - GIF/JPEG images, ESRI shapefiles Enterprise Information Solutions, Inc.
ESRI • ArcIms • Hybrid strategy • Server platform - Windows 98, NT, Unix • Client software - JavaScript, Java, HTML, Active X • Client platforms - All • Client-side data formats - GIF/JPEG images, ESRI shapefiles Enterprise Information Solutions, Inc.
Intergraph • Geo Media Web Map • Hybrid strategy • Server platform - Windows NT • Client software - Plug-in for Active CGM, ASP, VBScript, HTML, Active X • Client platforms - Windows 95, 98, NT • Client-side data formats - Active CGM Enterprise Information Solutions, Inc.
MapInfo • MapXtreme • Hybrid strategy • Server platform - Windows NT, UNIX, (MapXtreme Java) • Client software - ASP, VB Script, JavaScript, HTML, Active X • Client platforms - All • Client-side data formats - As implemented by developer Enterprise Information Solutions, Inc.
AutoDesk • MapGuide • Hybrid strategy • Server platform • Client software - JavaScript, HTML • Client platforms - All • Client-side data formats - GIF/JPEG images Enterprise Information Solutions, Inc.
Web and GIS Demonstration • Environmental Navigator • Maryland SHA Chart II • Real Time Crime Reporting • Real Estate Property Viewer • TerraServer
Environmental Navigator • http://sirb.awm.dnrec.state.de.us/enweb/ • Goal • Provide information on contaminant sites available in GIS online • Features • Address locator • Contaminant site GIS Viewer • Criteria query
Maryland SHA - Chart II • http://www.sha.state.md.us • Goal • Provide traffic monitor information for the State of Maryland • Features • From Legacy to Hot Java • Web, database, and GIS integration • Ad hoc reporting system
Real Time Crime Reporting • http://www.citymaps.sacto.org • Goal • Provide Real Time Crime Reporting Information for DE • Features • Enterprise Web Client/Server • ActiveX Map Viewer • GPS/Wireless Technologies
Real Estate Property Viewer • http://www.webgis.net • Goal • Provide real estate property information on the Web • Features • Gigabytes of data records • Simple user interface
TerraServer • http://www.terraserver.microsoft.com • Goal • Provide Imagery for property assessment, engineering, traffic planning, personal mapping, etc. • Features • 1m to 1km digital orthoquad imagery • Free imagery downloads • Site finder and lat/long information