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Introduction

Discover how GIS and the Internet merged to create web-based technology, enabling Location Based Services. Learn about the evolution of the Internet, Web Technology, Standards, Web-Based Mapping, and Open-Source GIS. Explore neogeography, free software movement, and applications in Internet web-mapping, intranet web-mapping, geoportals, and more.

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Introduction

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  1. Introduction • GIS was originally the preserve of large (mainframe) computers, but in the 1990s it became feasible on desktop PCs. • The growth of the World Wide Web in the 1990s provided mass access to the Internet. • It made sense for these two technologies to merge to create web-based GIS. • GIS and the Internet also permit the expansion of Location Based Services (LBS). • Today we will look at GIS and the Internet.

  2. History Of The Internet • The Internet can be traced back to ARPANET in 1969. • It really took off in the 1980s, but still entailed a steep learning curve. • The World Wide Web developed by Tim Berners Lee in 1991 and user-friendly web browsers such as NCSA Mosaic changed all that.

  3. Web Technology • Web pages are basically text files with embedded HTML tags. • Early pages were static, but various technologies developed to make them more dynamic. • These technologies scould be either server-side (e.g. ASP or CGI) or client-side (e.g. Java applets). • Web 2.0 allows end-users to add their own content without programming skills (e.g. blogs, wikis, social networking)

  4. Standards • Standards are necessary to permit communication between different platforms. • Important standards bodies include: • W3C (World Wide Web Consortium) • HTML4, HTML5, XML, XHTML • OGC (Open Geospatial Consortium) • GML, WMS, WCS, WFS • FGDC (Federal Geospatial Data Consortium) • NSDI • Other • NSS (ISDI) • EU (INSPIRE)

  5. Web-Based Mapping • Degrees of complexity: • Static maps • Dynamic maps • Simple interactive maps • User-specified themes • User-added content • Web-based GIS

  6. Issues For Developers • Server-side or client-side • Accommodate local data • Data protection • Live data • Database interaction (attribute data) • Database interaction (spatial data) • Multiple sources • Scalability • Functionality • Browser compatibility

  7. Neogeography • Web sites such as Google Earth and Google Maps have opened up web map creation to the ‘general public’. • This has many positives: heightened awareness of the importance of space; ability to tap into a vast ‘knowledge database’; can combine oformation for diverse sources to create mashups (e.g. http://www.healthmap.org/) • Also some negatives: loss of accuracy; cluttering by trivia; ownership issues.

  8. Free Software • The internet allows programmers to cooperate on projects – free software movement. • Two meanings of free: • Gratis (no charge) – e.g. ArcReader • Libre (open source) – e.g. Linux • Linux/GNU: Richard Stallman (GNU), Linus Torvalds • Other examples: Apache, OpenOffice.org, R, MySQL, PostGreSQL, Python, Perl, PHP, Moodle

  9. Open-Source GIS • Desktop GIS: • GRASS (Geographic Resources Analysis Support System). Traditionally UNIX-only but now available for Windows. • Quantum GIS (QGIS) • Web-Based GIS: • Can be assembled from a variety of open-source tools: e.g. Firefox, Apache, UMN Mapserver, GeoServer, MySQL, PostgreSQL/PostGIS, GDAL/OGR, PROJ.4, R and R-spatial, GRASS, Zope, Python.

  10. Applications • Internet web-mapping • Intranet web-mapping • Geoportals • Application service providers • Location based services

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