distributed gis technology, components, applications and future april 11 2005 yang han

Distributed GISDistributed GIS

Technology, Technology, Components, Components,

Applications and Applications and FutureFuture April 11 2005April 11 2005

Yang HanYang Han

AgendaAgenda Impact of the Internet on GIS Impact of the Internet on GIS GIS Technology: From Centralized to DistributedGIS Technology: From Centralized to Distributed What is Distributed GIS What is Distributed GIS Why do we Need Distributed GIS Why do we Need Distributed GIS Basic Components of Distributed GIS Basic Components of Distributed GIS The Standards for Distributed GISThe Standards for Distributed GIS Applications of Distributed GIS Applications of Distributed GIS Future of Distributed GISFuture of Distributed GIS

Impact of the Impact of the Internet on GISInternet on GIS

Change our lives


The Internet is a modern information system that connects thousands of telecommunication networks and creates an “internetworking” framework. The dramatic success of the Internet and the popular adoption of TCP/IP pushed the development of telecommunication into a new age.


The GIS community also began to utilize the Internet The GIS community also began to utilize the Internet to develop distributed GIS. to develop distributed GIS.

Distributed GIS is a research and application area that Distributed GIS is a research and application area that utilize the Internet and other internetworking systems utilize the Internet and other internetworking systems to facilitate the access, processing, and dissemination to facilitate the access, processing, and dissemination of geographic information and spatial analysis of geographic information and spatial analysis knowledge. knowledge.

The Internet is affecting GIS in three major areas: The Internet is affecting GIS in three major areas: GIS data access GIS data access Spatial information dissemination Spatial information dissemination GIS modeling/processing GIS modeling/processing


The Internet provides GIS users easy access to The Internet provides GIS users easy access to acquire GIS data from different data providers. GIS acquire GIS data from different data providers. GIS data warehouse and digital libraries are two common data warehouse and digital libraries are two common forms of Internet data access systems.forms of Internet data access systems. U.S. Geospatial Data Clearinghouse Activities under U.S. Geospatial Data Clearinghouse Activities under

the Federal Geographic Data Committee (FGDC) has the Federal Geographic Data Committee (FGDC) has been working to build a distributed archive of been working to build a distributed archive of information for universal access (information for universal access (http://www.fgdc.govhttp://www.fgdc.gov) )

Alexandria Digital Library Project funded by the US Alexandria Digital Library Project funded by the US National Science Foundation established the first National Science Foundation established the first distributed library service for spatially referenced data in distributed library service for spatially referenced data in 1994 (1994 (http://www.alexandria.ucsb.edu/http://www.alexandria.ucsb.edu/ ) )

http://www.fgdc.gov/

http://www.alexandria.ucsb.edu/

Impact of the Internet Impact of the Internet on GISon GIS

The Internet also enables the dissemination of GIS The Internet also enables the dissemination of GIS analysis results and spatial information to a much analysis results and spatial information to a much wider audience than does traditional GIS. wider audience than does traditional GIS.

Furthermore, the Internet is becoming a means to Furthermore, the Internet is becoming a means to conduct GIS processing. It enhances the conduct GIS processing. It enhances the accessibility and reusability of GIS analysis tools accessibility and reusability of GIS analysis tools by dynamically downloading or uploading GIS by dynamically downloading or uploading GIS processing components. processing components.


The rapid expansion of low-cost The rapid expansion of low-cost bandwidth on the Internet bandwidth on the Internet

A new generation of Web-enabled A new generation of Web-enabled desktop computers and mobile desktop computers and mobile devices.devices.

GIS Technology: GIS Technology: From Centralized to From Centralized to DistributedDistributed

Mainframe GIS Desktop GIS

Distributed GIS

Mobile GIS

Internet GIS


Mainframe GIS adopted the monolithic coMainframe GIS adopted the monolithic computing model; that is, all programs were imputing model; that is, all programs were in the same mainframe computers. User acn the same mainframe computers. User access to GIS data and analysis functions on cess to GIS data and analysis functions on the mainframe server were through dumb tthe mainframe server were through dumb terminals.erminals.


Desktop GIS relies on GIS programs on the Desktop GIS relies on GIS programs on the desktop computers. It has two categories. desktop computers. It has two categories.

The stand-alone desktop GIS has all the GIS The stand-alone desktop GIS has all the GIS functions, user interface, and data in one functions, user interface, and data in one stand-alone computer. stand-alone computer.

The LAN-based desktop GIS usually adopts The LAN-based desktop GIS usually adopts the two-tier client/server model. the two-tier client/server model.

GIS Technology: GIS Technology: From Centralized to From Centralized to DistributedDistributed Distributed GIS represents a dramatic Distributed GIS represents a dramatic

departure from the traditional two-tier departure from the traditional two-tier client/server model. Rather than relying on client/server model. Rather than relying on desktop GIS programs, distributed GIS, desktop GIS programs, distributed GIS, when fully implemented, does not when fully implemented, does not necessarily require the user to install GIS necessarily require the user to install GIS programs on the user’s desktop. It relies on programs on the user’s desktop. It relies on the Internet and wireless networks for data the Internet and wireless networks for data from anywhere with Internet access. from anywhere with Internet access. Internet GIS Internet GIS Mobile GIS Mobile GIS

GIS Technology: GIS Technology: From Centralized to From Centralized to DistributedDistributed The mainframe GIS and desktop GIS are The mainframe GIS and desktop GIS are

traditionally referred to as GISystems, and traditionally referred to as GISystems, and distributed GIS is referred to as distributed GIS is referred to as GIServices. The term service here refers GIServices. The term service here refers to component services; that is, to component services; that is, components with certain functions can be components with certain functions can be downloaded and reassembled together to downloaded and reassembled together to build larger, more comprehensive services build larger, more comprehensive services to perform certain tasks. to perform certain tasks.


Traditional GISystems:Traditional GISystems: Closed, centralized systems that incorporate interfaces, Closed, centralized systems that incorporate interfaces,

programs, and data. programs, and data. System is platform dependent and application dependent. System is platform dependent and application dependent. Migrating traditional GISystems into different operating Migrating traditional GISystems into different operating

systems or platforms is difficult. systems or platforms is difficult. Different GIS applications may require different GIS Different GIS applications may require different GIS

packages and architecture design.packages and architecture design. Every element is embedded inside traditional GISystems Every element is embedded inside traditional GISystems

and cannot be separated from the rest of the architecture. and cannot be separated from the rest of the architecture. Traditional GISystems include mainframe GIS and stand-Traditional GISystems include mainframe GIS and stand-

alone desktop GIS. alone desktop GIS.

GIS Technology: GIS Technology: From Centralized to From Centralized to DistributedDistributed Client/server GISystems or current desktop GIS are Client/server GISystems or current desktop GIS are

based on generic client/server architecture in network based on generic client/server architecture in network design.design. The client-side components are separated from server-side The client-side components are separated from server-side

components. components. Client/server architecture allows distributed clients to access Client/server architecture allows distributed clients to access

a server remotely by using distributed computing techniques a server remotely by using distributed computing techniques or database connectivity techniques. or database connectivity techniques.

The client-side components are usually platform dependent. The client-side components are usually platform dependent. Each client component can access only one specific server Each client component can access only one specific server at one time. at one time.

Different geographic information servers come with different Different geographic information servers come with different client/server connection frameworks, which can not be client/server connection frameworks, which can not be shared. shared.

GIS Technology: GIS Technology: From Centralized to From Centralized to DistributedDistributed Distributed GIServices Distributed GIServices

The most significant difference is the adoption of distributed-The most significant difference is the adoption of distributed-component technology, which can connect to and interact component technology, which can connect to and interact with multiple and heterogeneous systems and platforms and with multiple and heterogeneous systems and platforms and without the constraints of traditional client/server without the constraints of traditional client/server relationship.relationship.

Under a distributed GIServices architecture, there is no Under a distributed GIServices architecture, there is no difference between a client and a server. Each GIS node difference between a client and a server. Each GIS node embeds GIS programs and geodata and can become a embeds GIS programs and geodata and can become a client or a server based on the task at hand.client or a server based on the task at hand.

A client is defined as the requester of a service in a network, A client is defined as the requester of a service in a network, and a server provides a service. and a server provides a service.

A distributed GIServices architecture permits dynamic A distributed GIServices architecture permits dynamic combinations and linkages of data and GIS programs via combinations and linkages of data and GIS programs via networking.networking.


ApplicationCharacteristics

Mainframe GIS Desktop GIS Distributed GIS

Architectural models

Monolithic Ethernet era client/server

(two-tier)

Web client/server(three-tier or n-tier)

Client Dumb terminals Desktop computers Web client

Client Interface ----- Fat Graphic User Interface (GUI) clients

Web browsers, JavaBeans, ActiveX controls

Networks Local area networks LANs or WANs The Internet

Server Mainframe Data servers Web servers, application server, GIS server, and data servers

Number of accessible servers

One One or limited few Thousands or more

What is Distributed What is Distributed GIS?GIS? Internet GISInternet GIS

Distributed GISDistributed GIS

Web-based GISWeb-based GIS

Web GIS Web GIS

What is Distributed What is Distributed GIS?GIS?

The Internet is any network composed of multiple, The Internet is any network composed of multiple, geographically dispersed networks through geographically dispersed networks through communication devices and a common set of communication devices and a common set of communication protocols. communication protocols.

The World Wide Web is a networking application The World Wide Web is a networking application supporting a HTTP that runs on top of the supporting a HTTP that runs on top of the Internet. The Internet is not synonymous with the Internet. The Internet is not synonymous with the World Wide Web. World Wide Web.

The Internet refers to the network infrastructure, The Internet refers to the network infrastructure, while the Web refers to one of many applications while the Web refers to one of many applications that run on top of the Internet. that run on top of the Internet.


Internet GIS Web-based GISInternet GIS Web-based GIS

The Internet WWW


Distributed GIS is defined as a network-centric Distributed GIS is defined as a network-centric GIS tool that uses the Internet or a wireless net-GIS tool that uses the Internet or a wireless net-information, disseminating spatial information and information, disseminating spatial information and conducting GIS analysis. conducting GIS analysis. The client devices could be desktop computers, laptop The client devices could be desktop computers, laptop

computers, PDAs, or mobile phones. computers, PDAs, or mobile phones. The servers could be distributed in multiple locations. The servers could be distributed in multiple locations. Protocols could be HTTP, WAP, FTP, Common Object Protocols could be HTTP, WAP, FTP, Common Object

Request Broker Architecture (CORBA) protocols, and Request Broker Architecture (CORBA) protocols, and ODBC libraries. ODBC libraries.


Distributed GIS

Wireless GIS

Internet GIS

Web-based GIS

Other Internet GIS

What is Distributed What is Distributed GIS?GIS? Distributed GIS is an Integrated Distributed GIS is an Integrated

Client/Server Computing System Client/Server Computing System Distributed GIS is a Web-Based Interactive Distributed GIS is a Web-Based Interactive

System System Distributed GIS is a Distributed and Distributed GIS is a Distributed and

Dynamic System Dynamic System Distributed GIS is Cross-Platform and Distributed GIS is Cross-Platform and

Interoperable Interoperable


Distributed GIS is an Integrated Client/Server Distributed GIS is an Integrated Client/Server Computing SystemComputing System Distributed GIS applies the dynamic client/server concept Distributed GIS applies the dynamic client/server concept

on performing GIS data sharing and analysis tasks. on performing GIS data sharing and analysis tasks. The connections between the client and server are The connections between the client and server are

established according to a communication protocol, mainly established according to a communication protocol, mainly TCP/IP. TCP/IP.

Depending on the amount of processes performed on the Depending on the amount of processes performed on the client side, the client could be “thick” or “thin”. client side, the client could be “thick” or “thin”.

In addition, the concepts of client and server are relative; In addition, the concepts of client and server are relative; any computer could be both a server if it provides services any computer could be both a server if it provides services to other computers and a client if it requests services from to other computers and a client if it requests services from other computers.other computers.


Distributed GIS is a Web-Based Interactive System Distributed GIS is a Web-Based Interactive System The distributed GIS relies on the WWW and its add-ons to The distributed GIS relies on the WWW and its add-ons to

provide interactively between the user and the distributed provide interactively between the user and the distributed GIS programs. GIS programs.

In addition to the interactivity provided by HTML, XML, or In addition to the interactivity provided by HTML, XML, or WAP, distributed GIS can also handle vector-based GIS WAP, distributed GIS can also handle vector-based GIS data. It enables users to manipulate GIS data and maps data. It enables users to manipulate GIS data and maps interactively over the Internet or wireless networks. interactively over the Internet or wireless networks.

Users can perform GIS functions such as map rendering, Users can perform GIS functions such as map rendering, spatial queries, and spatial analysis using a Web browser spatial queries, and spatial analysis using a Web browser or other Internet-based client programs.or other Internet-based client programs.


Distributed GIS is a Distributed and Dynamic Distributed GIS is a Distributed and Dynamic System System Geospatial data are usually distributed across different Geospatial data are usually distributed across different

departments within an organization and among departments within an organization and among organizations, either on intranets or on the Internet. organizations, either on intranets or on the Internet. Distributed GIS can potentially query and extract these Distributed GIS can potentially query and extract these distributed databases rather than simply downloading the distributed databases rather than simply downloading the data directly into the end users’ local machines to data directly into the end users’ local machines to combine with local data.combine with local data.

Distributed GIS clients should be able to search, Distributed GIS clients should be able to search, download, and assemble analysis tools on demand. The download, and assemble analysis tools on demand. The clients have control over the functions required for a clients have control over the functions required for a particular task. particular task.


Distributed GIS is Cross-Platform and Interoperable Distributed GIS is Cross-Platform and Interoperable Distributed GIS can be accessed across platforms Distributed GIS can be accessed across platforms

regardless of what operating system the user is running. regardless of what operating system the user is running. The clients of distributed GIS tend to be able to run in a The clients of distributed GIS tend to be able to run in a variety of computing environments and platforms. variety of computing environments and platforms.

To be able to access and share remote GIS data and To be able to access and share remote GIS data and functions, distributed GIS programs require high functions, distributed GIS programs require high interoperability. The Open Geodata Interoperability interoperability. The Open Geodata Interoperability Specification and Geography Markup Language (GML) by Specification and Geography Markup Language (GML) by the OpenGIS Consortium (OGC) are attempting to lay the the OpenGIS Consortium (OGC) are attempting to lay the ground rules for GIS interoperability.ground rules for GIS interoperability.

Why do we Need Why do we Need Distributed GISDistributed GIS

Uniqueness of Geographic Information on Uniqueness of Geographic Information on the Internetthe Internet HeterogeneousHeterogeneous

Format, resolutions, scales, times, and domainsFormat, resolutions, scales, times, and domains The power of GIS operations/functionsThe power of GIS operations/functions

The value of geographic information will increase The value of geographic information will increase dramatically by providing GIS users with the dramatically by providing GIS users with the capability of GIS operations.capability of GIS operations.

Why do we Need Why do we Need Distributed GISDistributed GIS The disadvantage of the traditional GISThe disadvantage of the traditional GIS

The high price of GIS software package. The high price of GIS software package. Inaccessibility to the Desktop GIS from Inaccessibility to the Desktop GIS from

locations other than the computer on which locations other than the computer on which the desktop GIS software is installed. the desktop GIS software is installed.

Difficult to customize. Difficult to customize. Proprietary technology and the lack of Proprietary technology and the lack of

interoperability.interoperability.

Why do we Need Why do we Need Distributed GISDistributed GIS Management PerspectiveManagement Perspective

Globalization of geographic Globalization of geographic information access and distribution.information access and distribution.

Decentralization of geographic Decentralization of geographic information management and update information management and update

Why do we Need Why do we Need Distributed GISDistributed GIS User Perspective User Perspective

The need of distributed GIS processing to The need of distributed GIS processing to cope with increasing size and variety of cope with increasing size and variety of geospatial data sets geospatial data sets

The need for customizable GIS modules for The need for customizable GIS modules for software package specialization software package specialization

The demand for location-based information The demand for location-based information from the general public due to the popularity from the general public due to the popularity of the Internet and mobile devices of the Internet and mobile devices

Why do we Need Why do we Need Distributed GISDistributed GIS

ImplementationImplementation Installation is not necessaryInstallation is not necessary

Basic Components of Basic Components of Distributed GISDistributed GIS

Client

Client

Client

Web Server with Application

ServerMap Server Data Server

Basic Components of Basic Components of Distributed GISDistributed GIS The ClientThe Client

HTMLHTML

HTML-based client has very limited user HTML-based client has very limited user interactivity. It is particularly inadequate for interactivity. It is particularly inadequate for users to interface with maps and spatial users to interface with maps and spatial objects. objects.


The ClientThe Client DHTMLDHTML Uses client-side scripting like JavaScript or VBScript to make the plain Uses client-side scripting like JavaScript or VBScript to make the plain

HTML dynamicHTML dynamic ActiveX controlsActiveX controls General component ware that can plug into any application that supports General component ware that can plug into any application that supports

Microsoft’s Object Linking and Embedding (OLE) standard.Microsoft’s Object Linking and Embedding (OLE) standard. Java Applets Java Applets Reside at the Web server and are downloaded from the server and Reside at the Web server and are downloaded from the server and

executed on the client at runtime. They allow the user to interact directly executed on the client at runtime. They allow the user to interact directly with the spatial features on the map. with the spatial features on the map.

Plug-insPlug-ins Software executables that run on the browser to extend the capabilities Software executables that run on the browser to extend the capabilities

of Web browsers. of Web browsers.


Web Server and Application ServerWeb Server and Application Server Web Server (HTTP Server) Web Server (HTTP Server) Respond requests from Respond requests from

clientsclients Sending existing HTML document or ready-made Sending existing HTML document or ready-made

map images to the client map images to the client Sending Java applets or ActiveX controls to the Web Sending Java applets or ActiveX controls to the Web

client client Passing requests to other programs and invoking Passing requests to other programs and invoking

other programs such as CGI that could process the other programs such as CGI that could process the queries queries


Web Server and Application ServerWeb Server and Application Server Application ServerApplication Server Translator or connector Translator or connector

between the Web server and the map serverbetween the Web server and the map server Establishing, maintaining, and terminating the Establishing, maintaining, and terminating the

connection between the Web server and the map connection between the Web server and the map server server

Interpreting client requests and passing them to Interpreting client requests and passing them to the map server the map server

Managing the concurrent requests and balancing Managing the concurrent requests and balancing loads among map servers and data servers loads among map servers and data servers

Managing the state, transaction, and securityManaging the state, transaction, and security


Map Server (GIS Server, spatial server)Map Server (GIS Server, spatial server) A major workhorse component that fulfills spatial queries, A major workhorse component that fulfills spatial queries,

conducts spatial analysis, and generates, and delivers conducts spatial analysis, and generates, and delivers maps to the client based on the user’s request.maps to the client based on the user’s request. Filtered feature data that are sent to the client program Filtered feature data that are sent to the client program

for user manipulating for user manipulating A simple map image in a graphic format, such as GIF A simple map image in a graphic format, such as GIF

or JPEG, or a graphic element map that is composed or JPEG, or a graphic element map that is composed of discernible map elements with predefined colors, of discernible map elements with predefined colors, styles, legends, and so on.styles, legends, and so on.


Data ServerData Server Serves data, spatial and nonspatial, in a relational or Serves data, spatial and nonspatial, in a relational or

nonrelational database structure. nonrelational database structure. A client application such as a Web client or a map server A client application such as a Web client or a map server

gains access to the database through the SQL. gains access to the database through the SQL. Therefore, a database server is often referred to as a Therefore, a database server is often referred to as a SQL server. SQL server.

Database middleware is often used to access different Database middleware is often used to access different databases. There are three major database middleware: databases. There are three major database middleware: ODBC, Java Database Connectivity (JDBC), and Object ODBC, Java Database Connectivity (JDBC), and Object Linking and Embedded Database (OLE DB) ActiveX Linking and Embedded Database (OLE DB) ActiveX Data Object (ADO). Through SQL, ODBC, or JDBC Data Object (ADO). Through SQL, ODBC, or JDBC drive, the client application can query, retrieve, and even drive, the client application can query, retrieve, and even modify database records in the database servermodify database records in the database server


Client

Client

Client

Web Server with Application

Server

Map Server Data Server


thin client architecturethin client architecture

VS. VS.

thick client architecturethick client architecture


Major advantages of this model are:1. Central control2. Easy for data managing4. Generally cheaper5. Integration possibilities

Disadvantages are:1. Response time low2. Less interactive3. Vector data does not appear in client side

Thin


Thick

Major advantages of this model are:1. Images are not restricted to GIS and JPEG

2. Vector data can be used3. More functions are available on the client

sideAnd disadvantages to this architecture are:

1. Platform and browsers are incompatible2. Users are required to install additional

software

The Standards for The Standards for Distributed GISDistributed GIS Open GIS by Open GIS Open GIS by Open GIS

Consortium (OGC) Consortium (OGC) ISO/TC 211 by Technical ISO/TC 211 by Technical

Committee tasked by the Committee tasked by the International Organization for International Organization for Standardization (ISO) Standardization (ISO)

The Standards for The Standards for Distributed GISDistributed GIS

The main goals of OGC are the full integration of The main goals of OGC are the full integration of geospatial data and geoprocessing resources in geospatial data and geoprocessing resources in mainstream computing and the widespread use mainstream computing and the widespread use of interoperable geoprocessing software and of interoperable geoprocessing software and geodata products throughout the information geodata products throughout the information infrastructure.infrastructure.

ISO/TC 211 emphasizes a service-oriented view ISO/TC 211 emphasizes a service-oriented view of geoprocessing technology and a balanced of geoprocessing technology and a balanced concern for information, application, and system.concern for information, application, and system.


The OGC, a broad-based alliance of government The OGC, a broad-based alliance of government agencies, research organizations, software developers, agencies, research organizations, software developers, and systems integrators, is engaged in a multi-year and systems integrators, is engaged in a multi-year effort to define open GIS and to develop a set of effort to define open GIS and to develop a set of requirements, standards, and specifications which requirements, standards, and specifications which support it. support it.

The overall goal is to encourage software developers The overall goal is to encourage software developers and integrators to adhere to these requirements, and and integrators to adhere to these requirements, and through time create tools, databases, and through time create tools, databases, and communications systems that maximize the utility of communications systems that maximize the utility of systems and resources and take advantage of systems and resources and take advantage of technological advancestechnological advances..

OGC

The Standards for The Standards for Distributed GISDistributed GIS Major areas of research and development within Major areas of research and development within

OGIS include defining a geodata type hierarchy OGIS include defining a geodata type hierarchy that comprises simple and complex features, that comprises simple and complex features, maps and coverages, images, and field datasets maps and coverages, images, and field datasets (and specifying the relevant interfaces); (and specifying the relevant interfaces); developing a consistent approach to metadata to developing a consistent approach to metadata to support data collections and browsing; enabling support data collections and browsing; enabling the concept of ‘‘information communities’’ which the concept of ‘‘information communities’’ which share common definitions, information semantics, share common definitions, information semantics, and data dictionaries/thesauri; and defining the and data dictionaries/thesauri; and defining the basic data structures required for implementation.basic data structures required for implementation.

OGC

The Standards for The Standards for Distributed GISDistributed GIS The three broad requirements for Open The three broad requirements for Open

GIS GIS Interoperable applications Interoperable applications Shared data space Shared data space Heterogeneous resource browserHeterogeneous resource browser

An open GIS architecture must provide rAn open GIS architecture must provide robust methods for accessing multiple forobust methods for accessing multiple forms of data using multiple software enviroms of data using multiple software environments. nments.

OGC


Open GeoData Interoperability Specification Open GeoData Interoperability Specification (OGIS)(OGIS) initiated by the Open Systems Foundationinitiated by the Open Systems Foundation a comprehensive object based framework to a comprehensive object based framework to

support distributed access to geodata and support distributed access to geodata and geoprocessing resourcesgeoprocessing resources

The OGC was set up to oversee the The OGC was set up to oversee the development of the OGISdevelopment of the OGIS

OGC

The Standards for The Standards for Distributed GISDistributed GIS Geography Markup Language (GML)

GML is an XML encoding for the modeling, transport and storage of geographic information including both the spatial and non-spatial properties of geographic features.

The key concepts used by GML to model the world are drawn from the OGC Abstract Specification

OGC

The Standards for The Standards for Distributed GISDistributed GISOGC

Applications of Applications of Distributed GISDistributed GIS Data Sharing Data Sharing

Put the raw data in the original format along Put the raw data in the original format along with the metadata in their own Web site. with the metadata in their own Web site.

Join a data clearinghouse network or a GIS Join a data clearinghouse network or a GIS data portal and list your data using the same data portal and list your data using the same standard or protocol of that data standard or protocol of that data clearinghouse network or GIS data portal. clearinghouse network or GIS data portal.

Put data in a standard format like GML and Put data in a standard format like GML and make it available on the Web. make it available on the Web.

Applications of Distributed Applications of Distributed GISGIS Geospatial Information DisseminationsGeospatial Information Disseminations

Easier to disseminate information such as Easier to disseminate information such as land use plans, zoning information, land use plans, zoning information, environmental information, and traffic environmental information, and traffic information. information.

Foster information sharing and exchange Foster information sharing and exchange among different departments within an among different departments within an agency or across agencies agency or across agencies

Applications of Distributed Applications of Distributed GISGIS Online Data Processing Online Data Processing

Move analysis tools from desktop to onlineMove analysis tools from desktop to online User-friendly Web browsers interface makes User-friendly Web browsers interface makes

the GIS analysis tools easier to use the GIS analysis tools easier to use Component-based distributed GIS Component-based distributed GIS

architecture allows the development of architecture allows the development of interoperable geospatial analysis tools as interoperable geospatial analysis tools as individual and sellable geoprocessing individual and sellable geoprocessing components components

Applications of Distributed Applications of Distributed GISGIS Location-Based Services (LBSs)Location-Based Services (LBSs)

real-time information real-time information Mobile GIS + GPSMobile GIS + GPS

Future of Distributed GISFuture of Distributed GIS Future Impact Future Impact

Future Impact on the GIS IndustryFuture Impact on the GIS Industry Distributed GIServices will exploit the reusability and Distributed GIServices will exploit the reusability and

compatibility of GIS software and data objects compatibility of GIS software and data objects Design of distributed GIServices can help the GIS Design of distributed GIServices can help the GIS

industry migrate gradually from legacy systems and industry migrate gradually from legacy systems and adopt new technologies adopt new technologies

Distributed GIServices will change the development Distributed GIServices will change the development strategies of GIS software vendors and will transform strategies of GIS software vendors and will transform the current monopolized GIS market into an open, the current monopolized GIS market into an open, competitive environment competitive environment

Future of Distributed Future of Distributed GISGIS Future Impact Future Impact

Future Impact on Geographers Future Impact on Geographers Geographers and spatial scientists can build more Geographers and spatial scientists can build more

realistic model to solve their research problems by realistic model to solve their research problems by combine the GIS components and models in distributed combine the GIS components and models in distributed GIServices GIServices

Distributed GIServices will help scientists and Distributed GIServices will help scientists and geographers focus on the domain of problems rather geographers focus on the domain of problems rather than the mechanism of system implementation than the mechanism of system implementation

The flexible data approach and the operational The flexible data approach and the operational metadata scheme in distributed GIServices will help metadata scheme in distributed GIServices will help geographers utilize on-line information more efficiently geographers utilize on-line information more efficiently and facilitate the reusability of geospatial data for and facilitate the reusability of geospatial data for geographic research geographic research

Future of Distributed Future of Distributed GISGIS Future Impact Future Impact

Future Impact on the PublicFuture Impact on the Public Provide transparent, ubiquitous GIProvide transparent, ubiquitous GI

Services in daily life Services in daily life Deliver real-time, integrated servicDeliver real-time, integrated servic

es for emergency events es for emergency events

Future of Distributed Future of Distributed GISGIS Other research topicsOther research topics

GeoportalsGeoportals InteroperabilityInteroperability Web Service technologyWeb Service technology

InteroperabilityInteroperability Interoperability is the ability of a system, or

components of a system, to provide information portability and inter-application cooperative process control.

Two geographical databases X and Y can interoperate if X can send requests for services R to Y on a mutual understanding of R by X and Y, and Y can return responses S to X based on a mutual understanding of S as responses to R by X and Y

Standard

GeoportalGeoportal A technical definition of the word ‘‘portal’’

is ‘‘a web site considered to be an entry point to other web locations’’

Append the term ‘‘geo,’’ and the result might be as follows. Geoportal: a web site that presents an entry point to geographic content on the web or, more simply, a web site where geographic content can be discovered.

MetadataMetadata

GeoportalGeoportal The US Federal Geographic Data

Committees (FGDC) Clearinghouse web sites represent one of the earliest spatial data infrastructure (SDI) web portal initiatives. The FGDC portals were driven by the first US presidential requirement to support the sharing of geographic information, the National Spatial Data Infrastructure or NSDI

QuestionQuestions?s?

distributed gis technology, components, applications and future april 11 2005 yang han

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