geographic information systems and science: enabling a location-based technology michael f....
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Geographic Information Systems and Science: Enabling a Location-Based Technology
Geographic Information Systems and Science: Enabling a Location-Based Technology
Michael F. Goodchild
University of California
Santa Barbara
Geographic informationGeographic information
Information that links properties to positions on or near the Earth's surface– the information of maps– but much more besides
The atomic form– <x,z>– point observations, e.g. at weather stations– observations about lines, areas
Three technologiesThree technologies
Earth measurement– the accurate determination of position on
the Earth's surface
/dR
Eratosthenes, 200 BC
Perfect sphere, radius 6378 km
Ellipsoid of rotation, flattening 1/300
Ellipsoid Semi-major axis 1/flatteningAiry 1830 6377563.396 299.3249646Modified Airy 6377340.189 299.3249646Australian National 6378160 298.25Bessel 1841 (Namibia) 6377483.865 299.1528128Bessel 1841 6377397.155 299.1528128Clarke 1866 6378206.4 294.9786982Clarke 1880 6378249.145 293.465Everest (India 1830) 6377276.345 300.8017Everest (Sabah and Sarawak) 6377298.556 300.8017Everest (India 1956) 6377301.243 300.8017Everest (Malaysia 1969) 6377295.664 300.8017Everest (Malaysia, Singapore) 6377304.063 300.8017Everest (Pakistan) 6377309.613 300.8017Modified Fischer 1960 6378155 298.3Helmert 1906 6378200 298.3Hough 1960 6378270 297Indonesian 1974 6378160 298.247International 1924 6378388 297Krassovsky 1940 6378245 298.3GRS 80 6378137 298.257222101South American 1969 6378160 298.25WGS 72 6378135 298.26WGS 84 6378137 298.257223563
Clarke Ellipsoid of 1866
a = 6378206 m
1/f = 294.98
World Geodetic System of 1984
a = 6378137 m
1/f = 298.26
The Global Positioning SystemThe Global Positioning System
Three technologiesThree technologies
Remote sensing– satellite-based– aircraft, drones
• Roofs versus roads
• Road types
• Major/minor roads
• Vegetation cover
• Shadows
• Construction areas
Three technologiesThree technologies
Geographic information systems– digital representation of geographic data– editing, transformation, analysis, modeling,
visualization, decision support– virtually any conceivable task
The Canada Geographic Information System– 1966
The geographic information industriesThe geographic information industries
GPS industry– $1 billion– European Galileo
Data supply industry– remote sensing
• NASA $10 billion• other US civilian agencies $10 billion• military and intelligence $30 billion• 500,000,000,000,000 sq m• petabytes of information online (1PB=1015 bytes)
The geographic information industriesThe geographic information industries
GIS software– desktop, Web, enterprise– $1 billion– ESRI 30%– Intergraph 20%
Location-based services– Web– cellphones
Location-based servicesLocation-based services
Information services– provided by systems that know where they
are– and modify information accordingly
How does a system know where it is?How does a system know where it is?
GPS onboard– cellphone
Triangulation from towers Determined at system build time IP address
What kinds of information?What kinds of information?
Nearby services Visualization of invisible features
– underground– around the corner– in the past– visually impaired user
Location-based gamesLocation-based games
Played on location-enabled devices– cellphones
New directionsNew directions
Social sciences– most early applications were environmental– health, business, social services
Dynamics– from how the world looks to how the world works
SimulationsSimulations
1.8 vehicles per driveway Driver behavior influenced by:
– lane width– slope– view distances– traffic control mechanisms– information feedback– driver aggressiveness
770 homes– clearing times > 30 minutes
2D clip
3D clip
Policy implicationsPolicy implications
Addition of new outlets Better deployment of traffic control
resources Understanding the risk Reduce cars used per household Problems of shut-ins, elderly, latch-key
kids
Putting it all togetherPutting it all together
www.earthviewer.com
ConclusionConclusion
A rapidly growing industry– tightly connected sectors
Applications across the spectrum of human activities– commerce– research– everyday life
Growing familiarity– GIS a widely recognized acronym– in-car navigation, LBS, Web mapping
Exciting new directions