Geographic Information SystemsGeographic Information Systems

Web GISWeb GIS

What is a Web GIS?What is a Web GIS?► Web GIS is an on-line version of geographic Web GIS is an on-line version of geographic

information systeminformation system

► Using it, GIS data and functions are made available Using it, GIS data and functions are made available over the Internetover the Internet

► It is also called Internet GIS, or Online GISIt is also called Internet GIS, or Online GIS

Client-Server networkClient-Server network

► A client/server network involves a large number A client/server network involves a large number of client computers connecting to a single, central of client computers connecting to a single, central server computer server computer

► Servers usually are high speed computers with Servers usually are high speed computers with robust hardware capacity to handle large robust hardware capacity to handle large volumes of client service requests volumes of client service requests

The InternetThe Internet

Basics of Web-GISBasics of Web-GIS

DatDataa

DatDataa

OptionalSeparate datastorage

Internet orIntranet

Internet orIntranet

Server(s)Clients

How does Web GIS work?How does Web GIS work?

Users (clients) submit requests for maps, data, or Users (clients) submit requests for maps, data, or analysis to a Web serveranalysis to a Web server

The server processes the requests and returns The server processes the requests and returns requested maps, data, or analysis to the clients requested maps, data, or analysis to the clients

Why Web GIS?Why Web GIS?► Avoid the complicated (and often expensive) GIS Avoid the complicated (and often expensive) GIS

software installation in individual client computerssoftware installation in individual client computers

► Users can access GIS database and GIS Users can access GIS database and GIS applications from anywhere through a common applications from anywhere through a common Web browser Web browser

Three types of architectures Three types of architectures

► Thin client architectureThin client architecture

► Medium client architectureMedium client architecture

► Thick client architectureThick client architecture

Three types of architectures Three types of architectures

► Thin client architectureThin client architecture- users only need to display maps - users only need to display maps

► Medium client architectureMedium client architecture- users perform some data manipulation and - users perform some data manipulation and analysis locally on their own computers, in analysis locally on their own computers, in addition to map displayaddition to map display

► Thick client architectureThick client architecture- users perform advanced analysis locally, in - users perform advanced analysis locally, in addition to map display and simple analysisaddition to map display and simple analysis

Three types of architecturesThree types of architectures

Thin clientThin client

Medium clientMedium client

Thick clientThick client

Thin client architectureThin client architecture

Thin client architecture ..Thin client architecture ..

► Client Client - Display- Display

- requires a standard browser- requires a standard browser

► Server Server - Map Render and Element Generator- Map Render and Element Generator- out of its databases and applications- out of its databases and applications

Thin client architecture ..Thin client architecture ..

► Protocol (primarily for data transfer)Protocol (primarily for data transfer)- e.g. raster data transfer- e.g. raster data transfer

► UsesUses- map display- map display

► Examples:Examples:- Google Map- Google Map

Medium client architectureMedium client architecture

Medium client architecture ..Medium client architecture ..

Medium client architecture ..Medium client architecture ..

► Client Client - Display and Map Render- Display and Map Render- requires a plug-in in the web browser- requires a plug-in in the web browser

► Server Server - Element Generator- Element Generator- out of it’s applications and databases - out of it’s applications and databases

Medium client architecture ..Medium client architecture ..

► ProtocolProtocol- encoded vector - encoded vector

► UsesUses- map display, data query, and simple analysis - map display, data query, and simple analysis (measure distance, draw a polygon)(measure distance, draw a polygon)

► Example:Example:- Google Earth- Google Earth

Thick client architectureThick client architecture

Thick client architecture ..Thick client architecture ..

► Client Client - Display, Map Render, Element Generator- Display, Map Render, Element Generator- requires plug-ins and stand alone tools - requires plug-ins and stand alone tools

► Server Server - - - allows for access to its applications and - allows for access to its applications and databases databases

Thick client architecture ..Thick client architecture ..

► ProtocolProtocol- raster, vector, etc. - raster, vector, etc.

► UsesUses- display, data query, and advanced analysis - display, data query, and advanced analysis (overlay, buffer)(overlay, buffer)

► Example:Example:- ArcGIS for Server - ArcGIS for Server

http://www.esri.com/software/arcgis/arcgisserver

Applications – Location-based Applications – Location-based Services (LBS)Services (LBS)

► A location-based service A location-based service

- an information service provided by a device that - an information service provided by a device that knows where it isknows where it is

► LBS include services to identify the location of a LBS include services to identify the location of a person, an object, or a place, such as the nearest person, an object, or a place, such as the nearest ATM machine or the whereabouts of a friendATM machine or the whereabouts of a friend

LBS-capable deviceLBS-capable device

► Any device that includes a GPS capability, such as Any device that includes a GPS capability, such as a laptop or a smartphonea laptop or a smartphone

► Can tack postal parcels, vehicles, coupons, etc. Can tack postal parcels, vehicles, coupons, etc. ► E-commerce, social networks, mobile networksE-commerce, social networks, mobile networks

► Web of things, web of people, web of eventsWeb of things, web of people, web of events

Required technologiesRequired technologies

► Key: determine the location of devicesKey: determine the location of devices

► LBS requires technologies to work togetherLBS requires technologies to work together

- Positioning technologies (GPS) - Positioning technologies (GPS) - Terminal technologies (cell phones)- Terminal technologies (cell phones)- Networking technologies - Networking technologies - Database technologies (indexes, spatio-temporal - Database technologies (indexes, spatio-temporal

DBs)DBs)- LBS software (services, base SW)- LBS software (services, base SW)

Required technologies ..Required technologies ..

- … - … - GIS to - GIS to Provide and administer base map data such as man Provide and administer base map data such as man made structures (streets, buildings) and terrain made structures (streets, buildings) and terrain (mountains, rivers)(mountains, rivers)

Manage point-of-interest data such as location of Manage point-of-interest data such as location of gas stations, restaurants, nightclubs, etc)gas stations, restaurants, nightclubs, etc)

LBS for MobilesLBS for MobilesEmergency ServicesEmergency Services

E-911 E-911

Road-side serviceRoad-side service

DirectionsDirections

Loc-Based Information - PushLoc-Based Information - Push

RemindersReminders

Traffic / weather alertsTraffic / weather alerts

Loc-Based Information - PullLoc-Based Information - PullConciergeConciergeShoppingShoppingCity guideCity guide

LBS for mobiles ..LBS for mobiles ..NavigationNavigation

DDirections prior to tripirections prior to trip

Enroute planning / recommendationsEnroute planning / recommendations

TrackingTracking

Workforce / Vehicle (fleet/stolen/lost)Workforce / Vehicle (fleet/stolen/lost)

FamilyFamily

Location-Enhanced ImagingLocation-Enhanced Imaging

Location info captured with video or soundLocation info captured with video or sound

Send images with mapsSend images with maps

Location SharingLocation Sharing

Friend-finder / landmarksFriend-finder / landmarks

Emergency servicesEmergency services

► Provide one of the strongest motivations for LBSProvide one of the strongest motivations for LBS

► Problem: users of a cellphone is unable to report Problem: users of a cellphone is unable to report his/her current location to enable effective his/her current location to enable effective responseresponse

► A solution: install GPS in the vehicleA solution: install GPS in the vehiclewww.onstar.com

Conclusion - Trends in GISConclusion - Trends in GIS

Potential of Web GISPotential of Web GIS

► Internet users will be able to access GIS Internet users will be able to access GIS applications from their browsers without purchasing applications from their browsers without purchasing proprietary GIS software proprietary GIS software

► WebGIS will make it possible to add GIS WebGIS will make it possible to add GIS functionality to a wide range of network-based functionality to a wide range of network-based applications in business, government, and applications in business, government, and education institutionseducation institutions