1. Geographic Information Systems Web GIS

2. What is a Web GIS? ► Web GIS is an on-line version of geographic information system ► Using it, GIS data and functions are made available over the Internet ► It is also called Internet GIS, or Online GIS

3. Client-Server network ► A client/server network involves a large number of client computers connecting to a single, central server computer ► Servers usually are high speed computers with robust hardware capacity to handle large volumes of client service requests

4. The Internet

5. Basics of Web-GIS DataData Optional Separate data storage Internet or Intranet Internet or Intranet Server(s) Clients

6. How does Web GIS work?  Users (clients) submit requests for maps, data, or analysis to a Web server  The server processes the requests and returns requested maps, data, or analysis to the clients

7. Why Web GIS? ► Avoid the complicated (and often expensive) GIS software installation in individual client computers ► Users can access GIS database and GIS applications from anywhere through a common Web browser

8. Three types of architectures ► Thin client architecture ► Medium client architecture ► Thick client architecture

9. Three types of architectures ► Thin client architecture - users only need to display maps ► Medium client architecture - users perform some data manipulation and analysis locally on their own computers, in addition to map display ► Thick client architecture - users perform advanced analysis locally, in addition to map display and simple analysis

10. Three types of architectures Thin client Medium client Thick client

11. Thin client architecture

12. Thin client architecture.. ► Client - Display - requires a standard browser - requires a standard browser ► Server - Map Render and Element Generator - out of its databases and applications

13. Thin client architecture.. ► Protocol (primarily for data transfer) - e.g. raster data transfer ► Uses - map display ► Examples: - Google Map

14. Medium client architecture

15. Medium client architecture..

16. ► Client - Display and Map Render - requires a plug-in in the web browser ► Server - Element Generator - out of it’s applications and databases

17. Medium client architecture.. ► Protocol - encoded vector ► Uses - map display, data query, and simple analysis (measure distance, draw a polygon) ► Example: - Google Earth

18. Thick client architecture

19. Thick client architecture.. ► Client - Display, Map Render, Element Generator - requires plug-ins and stand alone tools ► Server - - allows for access to its applications and databases

20. Thick client architecture.. ► Protocol - raster, vector, etc. ► Uses - display, data query, and advanced analysis (overlay, buffer) ► Example: - ArcGIS for Server http://www.esri.com/software/arcgis/arcgisserver http://www.esri.com/software/arcgis/arcgisserverhttp://www.esri.com/software/arcgis/arcgisserver

22. Applications – Location-based Services (LBS) ► A location-based service - an information service provided by a device that knows where it is ► LBS include services to identify the location of a person, an object, or a place, such as the nearest ATM machine or the whereabouts of a friend

23. LBS-capable device ► Any device that includes a GPS capability, such as a laptop or a smartphone ► Can tack postal parcels, vehicles, coupons, etc. ► E-commerce, social networks, mobile networks ► Web of things, web of people, web of events

24. Required technologies ► Key: determine the location of devices ► LBS requires technologies to work together - Positioning technologies (GPS) - Terminal technologies (cell phones) - Networking technologies - Database technologies (indexes, spatio-temporal DBs) DBs) - LBS software (services, base SW)

25. Required technologies.. - … - GIS to Provide and administer base map data such as man made structures (streets, buildings) and terrain (mountains, rivers) Manage point-of-interest data such as location of gas stations, restaurants, nightclubs, etc)

26. LBS for Mobiles Emergency Services E-911 Road-side service Directions Loc-Based Information - Push Reminders Traffic / weather alerts Loc-Based Information - Pull ConciergeShopping City guide

27. LBS for mobiles.. Navigation Directions prior to trip Enroute planning / recommendations Tracking Workforce / Vehicle (fleet/stolen/lost) Family Location-Enhanced Imaging Location info captured with video or sound Send images with maps Location Sharing Friend-finder / landmarks

28. Emergency services ► Provide one of the strongest motivations for LBS ► Problem: users of a cellphone is unable to report his/her current location to enable effective response ► A solution: install GPS in the vehicle www.onstar.com

29. Conclusion - Trends in GIS

30. Potential of Web GIS ► Internet users will be able to access GIS applications from their browsers without purchasing proprietary GIS software ► WebGIS will make it possible to add GIS functionality to a wide range of network-based applications in business, government, and education institutions