geographic information systems
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Geographic Information Systems. Babu Ram Dawadi, IOE Pulchowk Campus. Definition. A Geographic Information System (GIS) is a computer based system that facilitates the phases of data entry, data analysis and data presentation especially in cases when we are dealing with georeferenced data. - PowerPoint PPT PresentationTRANSCRIPT
Babu Ram Dawadi, IOE Pulchowk Campus
DefinitionA Geographic Information System (GIS) is a
computer based system that facilitates the phases of data entry, data analysis and data presentation especially in cases when we are dealing with georeferenced data.
A Geographic Information System (GIS) is a computer-based mapping tool that enables geographic or spatial data capture, storage, retrieval, manipulation, analysis, modeling and presentation of the real world scenario. Basically, GIS is working on the principle of geography. Geography or GIS is now proving its potential and widely accepted by inter-disciplinary experts at various levels to better manage the earth’s resources.
Def…GIS is a System of computer software,
hardware and data, and personnel to help manipulate, analyze and present information that is tied to a spatial location –spatial location– usually a geographic locationinformation– visualization of analysis of datasystem– linking software, hardware, datapersonnel– a thinking explorer who is key to
the power of GIS
History of GISDecade Milestones for computer-based GIS
1960’s - Canada Geographic Information System (CGIS) developed: national land inventory pioneered many aspects of GIS
- Harvard Lab for Computer Graphics and Spatial Analysis: pioneered software for spatial data handling
- US Bureau of Census developed DIME data format
- ESRI founded
1970’s - CGIS fully operational (and still operational today)
- First Landsat satellite launched (USA)
- CARIS (Computer Aided Resource Information System) founded
- USGS (United States Geological Survey) begins Geographical Information Retrieval and Analysis System (GIRAS) to manage and analyze large land resources databases and Digital Line Graph (DLG) data format
- ERDAS (Earth Resources Data Analysis System) founded
- ODYSSEY GIS launched (first vector GIS)
History of GISDecade Milestones for computer-based GIS
1980’s - ESRI launches ARC/INFO (vector GIS)
- GPS became operational
- US Army Corp of Engineers develop GRASS (raster GIS)
- MapInfo founded
- First SPOT satellite launched (Europe)
- IDRISI Project started (GIS program)
- SPANS GIS produced
- National Center for Geographic Information and Analysis (NCGIA) established in USA
- TIGER digital data
History of GISDecade Milestones for computer-based GIS
1990’s - MapInfo for Windows, Intergraph, Autodesk, others
- ESRI produces ArcView and ARCGIS
- $7+ billion industry
GIS SoftwareThe geoprocessing engines of GISMajor functions
Collect, store, mange, query, analyze and present
Key termsProgram – collections of instructions to
manipulate dataPackage – integrated collection of programsComponent – self-contained, reusable software
building blocks
User Interface Applications
Geographic Tools
Data AccessSpatial
ReferenceVector
DataManager
Raster
Output
Editing
Analysis
CustomizationDisplay
Translation
Autodesk ESRI Intergraph MapInfo Smallworld
Viewer AutoCAD LT
ArcReader GeoMedia Viewer ProViewer Custom
Desktop World ArcView GeoMedia MapInfo Professional
Spatial Intelligence
Profess-ional
AutoCAD / Map
ArcEditorArcInfo
GeoMedia Pro MapInfo Professional
Smallworld GIS
Hand-held OnSite ArcPad IntelliWhere MapXtend Scout
Database Server
GIS Server
ArcSDE Uses Oracle Spatial
SpatialWare Part of Smallworld GIS
Component In several products
MapObjects
Part of GeoMedia MapX, MapJ Part of Smallworld GIS
Internet MapGuide ArcIMS GeoMedia Web Map, GeoMedia Web Enterprise
MapXtreme, MapXSite
Smallworld Internet Applic- ation Server
CAD AutoCAD Map
In several products
In several products
In several products
Part of Smallworld GIS
Number ofUsers
CostInternetViewer
ComponentHand-heldDesktop
Professional
Functionality
• ArcGIS Desktop ApplicationsArcGIS Desktop Applications
• ArcIMS , ArcExplorer, ArcPadArcIMS , ArcExplorer, ArcPad
• MapObjects MapObjects
• Third-Party applicationsThird-Party applications
SQL ServerSQL Server OracleOracle InformixInformix IBM DB2IBM DB2
ArcSDE Services
ArcSDEArcSDE
Data Is Independent of Application
ArcIMSArcIMSArcGISArcGIS
SQL ServerSQL ServerSQL ServerSQL Server
High Availability, High Performance, Secure, Scalable
Web Server
DatabasesDatabases
BrokerBroker
BrowsersBrowsers
Web
ApplicationsApplications
Web Server
DatabasesDatabases
BrokerBroker
BrowsersBrowsers
Web
ApplicationsApplications
ServicesServices
Distributed GIS DevelopmentDistributed GIS Development
New Concept – g.net architecture leveraging emerging web technologies
Web services GIS technology for applications over the web
Mapping Metadata GIS Functionality
Spatial Data sharing and distribution
Extends ArcGIS System concept Desktop Applications Back Office Servers Distributed “Services” via the Internet
GIS Portal
GIS Portal
• Network architecture
(Distributed)
• Loosely Coupled
• Internet Standards
• Many GeoServices
• Many Clients
• Metadata Servers
• Open / Interoperable
• Full GIS capabilities
GIS Users
GIS PortalMetadata
Server
Searc
h Cat
alog
and
Fin
d
Searc
h Cat
alog
and
Fin
d
Publish GIS Data & ServicesPublish GIS Data & Services
Document in CatalogDocument in Catalog
Connect and U
se
Connect and U
se
Checkout and U
se
Checkout and U
se
World Wide Web
Author, Manage, Serve Geographic Information Collections
Author, Manage, Serve Catalogs
GIS GIS ClientsClients
GIS GIS ClientsClients
GIS Web GIS Web ServicesServices
GIS Web GIS Web ServicesServices
ArcGIS
Used to build
• Data
• Maps
• Models
• Applications
• Metadata
ArcGIS
Used to build
• Data
• Maps
• Models
• Applications
• Metadata
ArcIMS
• Serve GIS
• Data
• Maps
• Apps
ArcIMS
• Serve GIS
• Data
• Maps
• Apps
ArcGIS
• Author and Manage
Metadata
• Build Catalog
ArcGIS
• Author and Manage
Metadata
• Build Catalog
Array of GIS Clients
Access and use GIS data and services
• ArcReader
• Map Objects for Java
• ArcGIS Desktop & Extensions
• ArcPad
Array of GIS Clients
Access and use GIS data and services
• ArcReader
• Map Objects for Java
• ArcGIS Desktop & Extensions
• ArcPad
ArcSDE
Used to manage
• Data
• Metadata
• Transactions
ArcSDE
Used to manage
• Data
• Metadata
• Transactions
ArcSDE
Used to manage and distribute
• Metadata
ArcSDE
Used to manage and distribute
• Metadata
ArcIMS
• Manage Metadata
• Provide Search Services
ArcIMS
• Manage Metadata
• Provide Search Services
MetadatMetadata & a &
Catalog Catalog ServicesServices
MetadatMetadata & a &
Catalog Catalog ServicesServices
3-Stages of GISData preparation and entry: the early stage in
which data about the study phenomenon is collected and prepared to be entered into the system.
Data Analysis: the middle stage in which collected data is carefully reviewed and, for instance, attempts are made to discover patterns
Data Presentation: the final stage in which the results of earlier analysis are presented in an appropriate way
Importance & ApplicationsB: BusinessI: IndustriesG: GovernmentA: AcademyA: AircraftM: Military
Major AreaNatural Resource Management
Wildlife habitat, Wild and scenic rivers, Recreation resources, Floodplains, Wetlands, Agricultural lands, Forests.
Facilities ManagementLocating underground pipes and cables, Balancing loads in electrical networks, Planning facility maintenance
Application contd…Land Management
Zoning and subdivision planning, Land acquisition, Environmental impact policy, Water quality management, Maintenance of ownership.
Info. Based Street NetworkAddress matching, Location analysis or site selection, Development of evacuation plans.
How GIS assume Greater SignificanceWhich is the best route between kalanki and ratnapark
having minimal road intersection with good road and lesser traffic jam during peak hours?
Identify the roads served by Metro water tank in kalanki with a population between 1,000 and 1,500?
Which part of Gandaki zone has less literacy rate with unemployed youth between 20 and 30 years of age?
Where are the potential aquifers located away from agricultural land with good road connectivity within 50 km of Kathmandu for groundwater extraction?
Identify the apartment houses in new road not following building codes to withstand earthquake.
Spatial data and Geoinformationspatial data; we mean data that contains
positional values. Often we can say in more precise phrase geospatial data as a further refinement, which then means spatial data that is geo-referenced
By information, we mean data that has been interpreted by a human being
Geo-information is a specific type of information that involves the interpretation of spatial data.
The real world and representation of GISwe usually are trying to represent some part of the
real world as it is, as it was, or perhaps as we think it will be
A computerized system can help to store such representations.
Static ModelMaps & Databases: at any point in time, they represent a
single state of affairs. Usually developments or changes in the real world are not easily recognized in these models.
Dynamic ModelSimulation
Maps..The best known models of the real world are maps
A map is a miniature representation of some part of the real world
GIS and the map is very closely related to each other
maps can deal with questions/answers relating to basic components of spatial or geographic data: location (geometry), characteristics, (thematic attributes) and time, and their combinations
Map TypesTopographic maps: A topographic map
visualizes, limited by its scale, the Earth’s surface as accurately as possible. This may include infrastructure (egg, railroads and roads), land use (eg, vegetation and built-up areas), relief, hydrology, geographic names and reference grid
Thematic maps: A thematic map represents the distribution of the particular themes; we can distinguish socio-economic theme and the physical themes using these maps.
Spatial Databases A spatial database system is a database system
It offers spatial data types in its data model and query language
It supports spatial data types in its implementation, providing at least spatial indexing and efficient algorithms for spatial join.
a spatial database is a collection of spatially referenced data that acts as a model of reality -a database is a model of reality in the sense that the database represents a selected set or approximation of phenomena -these selected phenomena are deemed important enough to represent in digital form -the digital representation might be for some past, present or future time period (or contain some combination of several time periods in an organized fashion)
Spatial Databases…Spatial DB store representations of geographic
phenomena in the real world to be used in a GIS.
They are special in the sense that they use other techniques that tables to store these representations because it is not easy to represent geographic phenomena using tables.
spatial phenomena exist in a two or three dimensional Euclidean space ( a model of space in which locations are represented as coordinates- (x, y) in 2D; (x, y, z) in 3D- and notions like distance and direction have been defined with the usual formulas).
Spatial DB..A database may contain collection of: