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Spatial Information Systems (SIS) COMP 30110. Dr. Michela Bertolotto School of Computer Science and Informatics, UCD Room B2.21, michela.bertolotto@ucd.ie. Spatial Information Systems (SIS). Outline of the course: Spatial information system: concepts and applications
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Spatial Information Systems (SIS) COMP 30110 Dr. MichelaBertolotto School of Computer Science and Informatics, UCD Room B2.21, michela.bertolotto@ucd.ie
Spatial Information Systems (SIS) Outline of the course: Spatial information system: concepts and applications Spatial data: definitions, formats, models, queries Traditional GIS vs SDBMS DB issues in GIS/SIS Geometric problems and algorithms in GIS/SIS Research issues in GIS/SIS Lecture notes will be at: http://www.csi.ucd.ie/staff/mbertolotto/home/lecture-notes30110.htm
Spatial Information Systems (SIS) Suggested readings: “Database issues in GIS” N. Adam and A. Gangopadhyay, Kluwer Academic Publishers, 1997 “Spatial databases – A tour”, S. Shekhar and S. Chawla, Prentice Hall, 2003 “Spatial databases – with applications to GIS”, P. Rigaux, M. Scholl, A. Voisard, Morgan Kaufmann Publishers, 2002 “Geographical Information Systems”, Chang, McGraw-Hill, 2002 “Geographic Information Systems and Science”, P.Longley, D.J. Maguire,M.F. Goodchild, D.W. Rhind(Eds.), 2002
Spatial Information Systems (SIS) COMP 30110 Introduction
Spatial information systems (SIS) “SIS is a computer software, hardware, data, and personnel to help manipulate, analyze and present information that is tied to a spatial location”
Terminology Spatial data: data with an associated spatial location (with respect to a given reference frame) Geographic data/geo-spatial data: data whose underlying reference frame is the earth’s surface NOTE: spatial data and geographic data often used interchangeably GIS/SIS: often used interchangeably SDBMS: a DBMS for storing and manipulating spatial data GIScience: new discipline studying geographic information in theory and practice (includes GIS) GIServices: more recent
(Geo)-Spatial data • Maps • Terrain data Examples: NOTE: The earth’s surface is not the only reference frame for spatial data (e.g., a silicon chip can be a frame of reference) • Satellite images • Aerial photos
Spatial data “explosion” Huge amounts of spatial data available e.g. NASA’s Earth Observation System generates one terabyte of data every day 80% of all data available has a spatial component recently the interest in exploiting this spatial component has arisen; need to integrate spatial information handling functionality within a wide variety of contexts
Geographic Information Systems Geographic Information Systems (GIS) represent the main technology motivating interest in developing spatially enabled systems GISs provide convenient mechanisms for analysing and visualising geographic data (i.e., data whose underlying reference space is the earth’s surface) Initially developed for expert users for complex calculations/queries Rich set of functions to analyse geographic data: powerful tools Starting to integrate in a wide range of applications to exploit spatial component of data
Main GIS Vendors ESRI (Arcview/ArcInfo, …) MapInfo Corp. (MapInfo, …) Intergraph (GeoMedia,…) Autodesk (Autodesk Map sw/AutoCAD, …) Laser-Scan (different packages) ... Freely available sw packages: GRASS OpenMap Virtual Globes: Google Earth, etc
Classical spatial information applications Mapmaking Cartography Digital photogrammetry Traditionally: GIS only for expert users
New spatial information applications Emergency response planning Simulating environmental effects Urban development Public transportation monitoring Wayfinding and planning (route planning, etc.) Location-based services Crime tracking GIS for everybody?
Spatial vs Non-Spatial All data in an organisation is stored and managed via a DBMS Classical DBMSs are not capable of storing spatial information What is spatial data and what is “special” about it? Non-spatial data vs spatial data Non-spatial queries vs spatial queries And more…
NOTE When we talk about spatial data, we mean data that has a spatial component Both spatial and non-spatial (i.e., descriptive, or also alphanumeric, attribute) aspects are associated with this kind of data For example, a river will have attribute information associated with it (such as its name and length) together with its geometric description (the spatial component) Often we talk about spatial data to mean its spatial component (also called extent)
Spatial queries • Examples: • - “What are the two post offices nearest to Dun Laoghaire dart station?” (proximity query) • - “In what county is Bray?” (containment query) • - “What are Italy’s neighbouring countries” (adjacency query) • - “What Italian regions are crossed by the river Po?” (intersection/overlap query) • Etc…
Non-spatial queries • Examples: • - “What is the population of Dublin City?” • - “How long is the river Shannon?” • (assuming that population and length are attributes stored for city and river, respectively) • These are standard DB queries that request to retrieve the value of some attribute. Spatial queries, on the other hand, require different type of computations.