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GIS & Internet. Introduction to Internet GIS. Contents. Concept System architecture Technology Language Servers. Internet GIS. ?. GIS. Internet. A Giant Computer Network. Internet. Wendy. Esri-sweden.com. www. Documents. HTML. Hypertext. Browser. Web Page. Web Site.
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GIS & Internet Introduction to Internet GIS
Contents • Concept • System architecture • Technology • Language • Servers
Internet GIS ? GIS Internet
A Giant Computer Network Internet
Wendy Esri-sweden.com
www Documents HTML Hypertext Browser Web Page Web Site Web Server
Services and Applications File Transfer Protocol Worldwide discussion groups Menu-based indexes Indexing Search Wide Area Information Server
Communication Activities Faster Cheaper Digital
Same network tools Same user tools Same manager tools Internet vs. Intranet Network in one organization Networks inmanyorganizations No difference!
Internet • A giant network • Communication & information • Services & application Summary
GIS ?
GIS --- A collection of Computer h’ware & s’ware Capture Storage Retrieval Display Software Operation Hardware Spatial Data
GIS Internet Internet GIS (Web GIS) WWW + Gopher Email Telnet ... FTP
Mobile GIS • Access and use of GIS data and functions through mobile and wireless devices -mobile laptop computers - PDAs ( Palm Pilots and pocket PC devices) - Web-accessible smart phones • Users Fieldworkers Consumers of location-based services
Mobile GIS Services Telecommunication Service Providers air interfaces networking routing other communication services a wireless network linkage facility equipment Mobile GIS Service Providers GIS Services
Mobile GIS Client Server TSP Internet Wireless Network TCP/IP Web GIS Data Internet-enabled mobile devices Wireless Network ISP
GIS Impact Internet
As powerful as Monkey King Powerful More User Flexible Server-Centric Interoperaility Mobile
Features • Integrated Client/Server network system • Interactive • Distributed • Dynamic • Cross-platform • Graphical hypertext information system
Contents • Concept • System architecture • Technology • Language • Server
Server Client TCP/IP Network Architecture C/S HTTP
Server-Side Client-Side Web Browser Application Server Request Data Server Return HTML/Map Web Server Map Server Internet GIS Architecture
Internet GIS Components • Client • Server
Client • Concept • A requesting program or user in a client/server relationship • Browser, IE, Navigator • Types • HTML: simple client. • DHML • Plug-in • Java Applets • ActiveX
Components • Client • Server • Web Server • Application Server • Map Server • Data Server
Web Server (HTTP server) • A Server process running at a web site that sends out web pages in response to HTTP requests from remote browsers • Communicates directly with the Viewer
Web Server (HTTP server) Types: Microsoft Internet Information Server (IIS) Netscape Enterprise Server iPlanet Apache
Map Server • Key component Fulfil spatial queries conducts spatial analysis generates and delivers maps
HTTP HTML Each may require different query of structure and format Web Server Map Server AppServer
Application Server (Appserver) • A glue program or middleware that connects the Web server and server-side applications such as a map server • Acts as a translator or connector between the Web server and the map server
Data Server • A component that contains and delivers data across a common interface to any client • Three database middleware ODBC JDBC OLE DB
Summary Web Server Internet GIS Map Server Client Server AppServer Data Server
Contents • Concept • System architecture • Technology • Language • Server
Technology • CGI • API • Plug-ins • ActiveX Controls • Java Applets
2 3 1 Send Values Invoke Request CGI Script GIS Server Web Server Client Response Translate Result Return Results 6 5 4 CGI • Common Gateway Interface • A standard for running external programs from Server and passing the data to the client browser.
Application programm Operating system API API • Application Program Interface • By which an application program accesses operating system and other services
Plug-ins • Small applications • Extending Web browser • Supporting GIS data
Request GIS Data WWW Browser WWW Server Send GIS Data Understand data type? No Search for plug-ins Or helper programs locally Download & Install Plug-ins from Server No yes GIS data displayed
ActiveX Controls • A type of COM component • Build on OLE standard • Extend Capability of Browser
Request GIS Data WWW Browser WWW Server Object Send ActiveX Controls And Data Object GIS Controls And Data Display
Java Applets • A small program written in Java language • Can be sent along with a Web page to a user • Java applets can perform interactive animations, immediate calculations, or other simple tasks
WWW Server (Java Applet) Request GIS Data WWW Browser Object Send Java Applets And Data Object GIS Applet and And GIS Data Display
Java Applets ActiveX controls Platform Independent Limited to Windows environment Risk is damage software & data in Local machine Safe
Summary Client Server Plug-ins ActiveX Controls Java Applets CGI API
Contents • Concept • System architecture • Technology • Language • Server
Languages • HTML • VRML • XML • GML