Geographic Information Systems
Web GIS
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
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
The Internet
Basics of Web-GIS
Clients
Server(s)
Internet or
Intranet
Optional
Separate data
storage
Data
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
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
Three types of architectures
►
Thin client architecture
►
Medium client architecture
►
Thick client architecture
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
Three types of architectures
Thin client
Medium client
Thick client
Thin client architecture
Thin client architecture ..
►
Client
- Display
- requires a standard browser
►
Server
- Map Render and Element Generator
- out of its databases and applications
Thin client architecture ..
►
Protocol (primarily for data transfer)
- e.g. raster data transfer
►
Uses
- map display
►
Examples:
- Google Map
Medium client architecture
Medium client architecture ..
Medium client architecture ..
►
Client
- Display and Map Render
- requires a plug-in in the web browser
►
Server
- Element Generator
- out of it’s applications and databases
Medium client architecture ..
►
Protocol
- encoded vector
►
Uses
- map display, data query, and simple analysis (measure
distance, draw a polygon)
►
Example:
- Google Earth
Thick client architecture
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
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
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
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
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)
- LBS software (services, base SW)
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)
LBS for Mobiles
Emergency Services
E-911
Road-side service
Directions
Loc-Based Information - Push
Reminders
Traffic / weather alerts
Loc-Based Information - Pull
Concierge
Shopping
City guide
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
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
Conclusion - Trends in GIS
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