Transcript Overview - CyberInfrastructure and Geospatial Information

Overview of Geog 480
Guofeng Cao
CyberInfrastructure and Geospatial Information Laboratory
Department of Geography
National Center for Supercomputing Applications (NCSA)
University of Illinois at Urbana-Champaign
Course Description
• This course is intended to introduce students to basic
principles in the rapidly growing field of Geographic
Information Science (GIScience) and commonly used
methods in spatial analysis. The course will be held in a
lecture format combined with hands-on projects. The
emphasis is on the concepts and principles that underlie
the development of GIS and its intelligent use. The
knowledge that students gain in this course will be general
and will not be limited to a specific GIS product.
Survey
Name, major, year
What do you expect to learn from this class?
GIS experiences (courses taken, projects participated, etc.)
Programming experiences (programming languages,
databases, and etc)
• Open Source experiences
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o Unix/linux like operating system?
• Note: Don’t be scared, it would be totally fine if you don’t
have such experiences.
Class Information
• Instructor: Guofeng Cao (http://www.cigi.uiuc.edu/guofeng)
o Lectures: Tues/Thurs 3:30pm-4:50pm (Davenport Hall 338)
o Office Hours: Tues/Thus: 2:00pm -3:30pm (Davenport Hall 316)
• Prerequisites:
o Geog 379 or consent of instructor
o General Background: Knowledge on GIS, Cartography, Database and information
system will help understand the course materials.
• Course website:
o http://www.cigi.uiuc.edu/guofeng/geog480.htm
• Textbook:
o Worboys, M. and Duckham, M. 2004. GIS – A Computing Perspective, Second
Edition. New York, NY: CRC Press.
o Smith, M. D, Longley, P. and Goodchild, M. F. 2012. Geospatial Analysis – A
Comprehensive guide
(free)
o Other reference materials
Course Work
• Two midterm exams: 40% (20% each)
• Course projects:
o The project will be divided into four stages, and report of each stage plus lecture
related problems considered as four assignments (15% each * 4 = 60%); the first stage
starts from end of week3
o The project will be evaluated based on (1) technical innovation, (2) thoroughness of the
work, and (3) clarity of presentation
o Team composition: teams must include no more than 4 students and 2 graduate
students
Topic Coverage of Geog 480
• Concepts of GIS (Textbook: Chap. 1 – 9)
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Database
Spatial concepts
Geospatial Data Models
Representations
Spatial Analysis
Spatial Query
Architecture
Interface
Spatial Uncertainty
• Hands-on Tutorials on open source GIS
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Why bother using open source tools?
PostGIS (open source spatial database)
Geoserver (open source geospatial data sharing)
OpenLayers (free maps for the web )
Research Frontiers in GIScience
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Spatiotemporal dynamics
Social media analysis
Volunteer geographic information
Spatiotemporal statistics (data mining)
Semantic geospatial web
“Big” spatiotemporal data
Cyberinfrastructure-enabled GIS (CyberGIS)
High performance spatiotemporal computing
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Useful links
• Cyberinfrastructure and Geospatial Information Laboratory
• CyberGIS Speaker Series
• ESRI International User Conference
o July 8 - 12 , San Diego Convention Center
o Student Assistantship Program
• Includes registration, accommodation, meals,
• Apply online: http://www.esri.com/careers/students/user-conference-studentassistants
• ESRI Summer Internship Program
Introduction
What is GIS
• Information systems: an association of people, machines,
data, and procedures working together to collect, manage,
and distribute information of importance to individuals or
organizations
• Geographic information system (GIS): a computer-based
information system that enables capture, modeling,
storage, retrieval, sharing, manipulation, and presentation
of geographically referenced data
• Geographic Information Science (GISc, or GISci, GIScience):
studies the theory behind the development, use and
application of GIS
• Geospatial data: geographically referenced data
Elements of GIS
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Databases elements
Data Processing element
Data storage and retrieval element
Data sharing element
Data presentation element
Spatial reasoning element
Accuracy, precision, and reliability
Spatiotemporal element
Data and information
• Context: the structure of interrelationships between data
and how data is collected, processed, used, and understood
within an application
o Understanding the data model and the limitations of data, are
elements of the context for data
• Data is only useful, taking on value as information, within
its context
information = data + context
The Nature of Geographic Data
• Spatial (and temporal) Context: “Everything is related to
everything else, but near things are more related than
distant things”
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Waldo Tobler’s First Law (TFL) of geography
nearby things are more similar than distant things
phenomena vary slowly over the Earth's surface
Compare time series
The Nature of Geographic Data
• Implications of Tobler’s First Law:
o We can do samplings and fill the gap using estimation procedures (e.g. weather
stations)
o Spatial patterns
o Image a world without TFL:
• White noise
• No polygons (how to draw a polygon on a white noise map?)
The Nature of Geographic Data
• Spatial Heterogeneity
o Earth’s surface is non-stationary
o Laws of physical sciences remain constant, virtually everything else changes
• Elevation,
• Climate, temperatures
• Social conditions
o Global model might be inconsistent with regional models:
• Spatial Simpson’s Paradox
The Nature of Geographic Data
• Fractal Behavior
o What happens as scale of map changes?
o Coast of Maine
• Implications:
o Volume of geographic features tends to be underestimated
• Lengths of lines
• Surface areas
• End of this topic