Lecture 2 (Introduction: Systems, Science, and Studies) Flashcards Preview

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What is geography?

Geography is the science of place and space and an integrative spatial science that attempts to explain and to predict the spatial distribution and variation and physical features on the earth’


What do geographers study?

Geographers study how and why things differ from place to place,
as well as how spatial patterns change through time.


Geographic Information

Geographic information is information about places on the
Earth's surface (buildings in a city, individual trees in a forest, climate
of large region, and population density of an entire country)


Geographic Information Systems (GISs)

Definition: GISs are computer-based systems for storing and processing geographic
information. They are tools that
improve the efficiency and
effectiveness of handling
information about geographic
objects and events.


Three Ss of GIScience Technology

giS (Geographic Information Systems)
rS (Remote Sensing) - Use of satellites and aircrafts to capture information about the earth's surface.
gpS (Global Positioning System) - a system of earth-orbiting satellites to provide precise location (< 30cm) on the earth's surface.


Five Ms of Applied GIS




- Emphasis on useful technology and tools for both specialist and general-purpose applications.
- Information systems are used to manipulate, summarize, query, edit, visualize - generally, to work with information stored in computer databases.
How does a GIS user know that the results obtained are accurate?
What principles might help a GIS user to design a better map?
How can location-based services be used to help users to navigate and understand human and natural environment?



- Illustrates the fundamental issues and science approaches raised by the use of GIS and related technologies (See Technical Box 1.7).
- Is the science needed to keep technology at the cutting edge.
- Coined by Michael Goodchild in 1992 (article).



- Systematic study of the use of geographic information (i.e., institution, standard, procedures).


Six Components of GIS

People, Software, Data/ Database, Procedures/ Management, Hardware *NETWORK*



- Most fundamental part to communicate and share information among the other components.
- Internet becomes as a vehicle for delivering GIS applications.
- The Internet is core to most aspects of GIS use, and the days of standalone GISystems are mostly over.



The device - users directly interact
with the GIS operations -> the device’s screen displays the returning information for allowing us to verify the outputs



- It can run locally in the user’s machine.
- GIS software packages have become quite sophisticated and can capture and implements general knowledge to handle all the
requirements of standard GIS projects.


Data/ Database

- consists of a digital representation of selected
aspects of some specific data of the earth’s surface or near surface.
- built to provide information to some problem-solving or scientific purposes.



- GIS databases can range in size from a
megabyte to a petabyte or more.
- 1 megabyte - 1 000 000 - Single dataset in a small project database.
- 1 gigabyte - 1 000 000 000 - Entire street network of a large city or small country.
- 1 terabyte - 1 000 000 000 000 - Elevation of entire Earth surface recorded at 30m intervals.
- 1 petabyte - 1 000 000 000 000 000 - Satellite image of entire earth surface at 1m resolution.
- 1 exabyte - 1 000 000 000 000 000 000 - A future 3-D representation of entire Earth at 10m resolution?
NOTE: bytes are counted in powers of two. One kilobyte is 1024 not 1000.


Procedure/ Management

- An organization must establish procedures, lines
of report, control points,and other mechanisms for ensuring that its GIS activities meet the needs of the organization (i.e., stay within budgets and
maintain high quality.)



- Design
- Program
- Maintain
- Supply with data
- Interpret the results
- Knowledge - data source, scale, accuracy, and software procedure.
- CRITICAL SPATIAL THINKING - filter the message of spatial data.


Brief History of GIS

1960 - 1970s Innovation
- First GIS (computerized map measuring system) - Canada Geographic Information System (CGIS) 1964, Roger Tomlinson (father of GIS)
- DIME ( Dual Independent Map Encoding) US Bureau of Census (storing Geographic data)
- First vector GIS (Harvard Laboratory for Computer Graphics and Spatial Analysis (ODYSSEY GIS in 1974).
- Major vendors started (e.g. ESRI, Intergraph)
- Landsat satellite launched (1972)
- The Center for Geographic Analysis at Harvard


First Earth Observing Satellite

Landsat 1: 1972-1978
Landsat 2: 1975-1982
Landsat 3: 1978-1983
Landsat 4: 1982-2001 data downlink capability failed in 1993
Landsat 5: 1984-2013
Landsat 6: failed launch, 1993
Landsat 7: 1999-
LDCM: Launched on Feb. 11, 2013/ Pan: 15-m/ Multispectral Bands: 30-m


Modern History of GIS

1980-1990s Commercialization
- Commercial GIS Software (e.g. ArcInfo) - Designed for minicomputer and based on the vector.
- First GIS textbooks
- First global data sets


2000s Exploitation

- Internet becomes major delivery vehicle.
- More than 1 million active users
- $7 billion business profit
- Industry growing more than 10% per year
- Launch of Google Earth in 2006
- Web 2.0 (Second generation of Internet) - GIS could computing system
GIS Technologies are increasingly common in today's applications.


Views of GIS SWs

- Three key parts of GIS software systems
- User Interfaces
(Command lines, Graphic User Interface (GUIs)

- Tools (Functions)
- Data Manager (Databases)


User Interface

Dos Command Line Interface


Graphic User Interface (GUIs)

A Rich Neighbor Named Xerox


Why GIS Matters

- Almost everything happens somewhere.
- Knowing WHERE some things happen is critically important.
- Geographic LOCATION - important attribute for activities, strategies, and plans.
- GEOGRAPHIC PROBLEMS - Aspect of location ( Information used to solve them/ Solutions themselves)


Information on the World

- Knowledge about PROCESS more valuable than FORM, because it can be used to PREDICT
- How the world looks - FORM
How the world works - PROCESS



- Understanding the science behind applications will help: interpretaion of results, understanding how the results carry out.
- GIS software is developing fast: Major development areas - internet, hand-held, FREE!