NR 621: GIS on The Web

Jim Graham

Spring 2009

Dynamic Web Pages (server)

Browser

Client Server

Web Server

HTML File

Image File

HTML File

Image File

Database

Web Script

Internet

GIS Web Servers

Browser

Client Server

Web Server

HTML File

Image File

HTML File

Image File

Database

Web Script

Internet

GIS Files

GIS Server

GIS On the Web

Map Quest

Client Software Closed Servers

Google Maps

GoogleEarth

Internet

GODM Server

JPL

ArcExplorer

ArcMap

World Wind

GODM Client

KML Files

Keyhole

i3

Open Servers

Google Maps

Map Quest

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

Client Support• 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?

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

Server Alternatives• 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 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