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NR 621: GIS on The Web. Jim Graham Spring 2009. Dynamic Web Pages (server). Client. Server. Internet. Database. Browser. Web Server. Web Script. HTML File. HTML File. Image File. Image File. GIS Web Servers. Client. Server. Internet. Database. Browser. Web Server. Web Script.
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NR 621: GIS on The Web Jim Graham Spring 2009
Dynamic Web Pages (server) Client Server Internet Database Browser Web Server Web Script HTML File HTML File Image File Image File
GIS Web Servers Client Server Internet Database Browser Web Server Web Script HTML File HTML File Image File Image File GIS Server GIS Files
GIS On the Web Closed Servers Client Software Open Servers Internet Map Quest Map Quest Google Maps Google Maps GODM Client i3 GODM Server GoogleEarth Keyhole KML Files ArcExplorer ArcMap World Wind JPL
Key Issues • Parameters: • Schedule • Resources ($, people, equipment) • Features • Performance • Data: Large amounts can kill performance • 3 Decisions: • Client features • Web Server (GIS Server, Scripting, Database) • Data configuration
Solutions • Small amounts of data, static: • Files (Shapefiles and TIFFs) to download • KML files on a web site for GoogleEarth • Shapefiles with a GIS web server • Medium amounts of data, query/search, periodic updates: • GIS web server with spatial database • Large amounts of data, flexible, immediate updates: • Custom solution with spatial database
Web-based clients: GoogleMaps MapQuest GODM Client GoogleEarth Plug-in ArcIMS (HTML, Java) Internet-based clients: ArcExplorer ArcMap GoogleEarth World Wind VirtualEarth Client OSes: Windows Macintosh Linux UNIX Browsers: IE FireFox Safari Chrome? Client Support
Key Client-Side Questions • Required features: • Web pages with 2d content? • Querying (search)? • 3d visualization? • Web-based (GoogleEarth plug-in)? • Application based (GoogleEarth)? • Recommendation: • 2D web site w/search • GoogleEarth support with KML files
OS: Windows Linux UNIX Web Server Apache Internet Information Server Framework/Language: ASP: VBScript ASP: Jscript VB.NET C#.NET PHP Java Python Cold Fusion Server Alternatives
Server Criteria • We don’t have IT to support anything but windows • IIS is easier to support than Apache and this can be changed later if desired • Scripting Alternatives: • PHP: Fast, easy, OpenSource • ASP/VBScript: Fast, easy • Question: Is OpenSource and issue for sponsors? (Don’t think they care)
GIS Web Serving • All can use Shapefiles and external raster files. The issue is the Map Server and the Database • ArcIMS w/SQL Server • ArcIMS w/ArcSDE and SQL Server • Oracle Spatial • Map Server w/PostreSQL and PostGIS • GODM Server w/SQL Server • ERMapper (rasters only)
GIS Server Alternatives • Shapefiles -> Spatial Database • Rasters -> JPEG and/or PNG tile files • Alternatives: • Map Server w/PostgreSQL & PostGIS • GODM w/SQL Server(?) • ArcIMS w/ArcSDE & SQL Server • Issues: • High-resolution polylines • Large extent • Querying (Symbology?) • Updates
GODM Solution • Client Environments: • Custom client with various backgrounds and projections: GoogleMaps, MapQuest, NASA, i3 • GoogleEarth w/KML files • Server: • GODM Server w/Custom spatial data format (topological) inside SQL Server