Geographic Information Science and Systems

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Geographic Information Science and Systems

• Talbot Brooks, Director
• Center for Interdisciplinary Geospatial
  Information Technologies
• Kethley Hall, Suite 150
• 662.846.4520

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Overview

• Syllabus
• Lectures
• Labs
• Tonights lecture topics
• What is GIS?
• GIScience vs GISystems
• The Scientific Method and examples of GIS in
  science
• Allied spatial technologies
• Thinking spatially
• The History of GIS

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Lecture

• You MUST take notes for participation credit!!!!
• Powerpoint slides are available at BlackBoard

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Lab

• Problem with lab? SEE YOUR TA FIRST, then come
  see me.
• Read your lab ahead of time
• Show up to all labs
• The lab book is to be used as a supporting
  document. Actual assignments will focus on
  scientific reasoning, critical thinking, problem
  solving and the application of GIS as a science
  and tool.

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A key to success if the computer doesnt do what
you want, DO NOT throw up your arms in disgust
and give up. Work with your TA to reason the
problem out and accomplish the mission!
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GIS An Overview
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Big Picture

• GIS is a marriage between computer information
  science and geography

Computer Science the science concerned with the
systematic and automatic processing of data and
information with the help of computers.
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Definition of Geography

• a science that deals with the description,
  distribution, and interaction of the diverse
  physical, biological, and cultural features of
  the earth's surface (spaces and places).

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Computer Science Some key terms

• datum (plural data) is a structured sequence of
  symbols based on specific rules (syntax). Data
  are transmitted through signals, most often
  electrical in nature (though whats the next
  generation of computers going to use?)
• information is the combination of data and the
  data's meaning (semantics)
• The receiver must know the 'correct' rules for
  interpretation of data in order to extract the
  information from the message.

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Example 1
Signal . . . - - - . . . (3 short, 3 long, 3
short tones) Data If the syntax of Morse code
is known, the signal can be translated into data
SOS Information This message only makes sense
after the receiver interprets (decodes) it, i.e.
after it becomes information 'Save Our Souls'
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Example 2
The datum '1.000' is by itself meaningless.
Contextual information such as 'unit of measure
is hPa', 'air pressure at a height of 2m above
ground' and the expertise of a geoscientist
transforms the datum into information 'this
indicates an area of low pressure'.
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What does GIS stand for?

• Geographic Information Science
• Geographic Information Systems

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Geographic Information Science
the science concerned with the systematic and
automatic processing of spatial data and
information with the help of computers.
Spatial component of information The spatial
reference of a piece of information is a typical
point of interest in geoscientific questions.
Geoscientists are interested in special features
(attributes) of spatial objects, also called
geographic objects.
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Geographic Objects

• Examples of geographic objects from hydrology
  Gauging station, river section, river basin,
  groundwater aquifer
• Geographic objects are defined by their location
  in geographical space
• The absolute position is described by the
  geometry of the object.
• Topology describes the spatial relations between
  objects (relative location).
• The special thematic domain of objects can be
  described by attributes.
• The dynamics of objects are reflected through the
  change of the objects geometry, topology and
  thematic domain through time.

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Spatial is Special!

• "Look for all locations of house fires in
  Cleveland." This task can be completed with the
  help of a normal information system (database).
• "Look for all locations of house fires in
  Cleveland and the distance they are from a fire
  station." This task can only be completed with
  the help of a geographic information system
  (GIS), which has special capabilities allowing it
  to analyze the relationship between geographic
  objects (house fires and fire stations).
• The Urban and Regional Information Systems
  Association (URISA) estimates that 80 of ALL
  data has a spatial basis.

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Examples of GIS use
Where should the new landfill be located?
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Examples of GIS use

• GIS questions Locations - What is at.?

Who owns the lot at 3233 E. College Ave and what
is its zoning?
parcel no. 565-23a area 118,245
sq. ft. owner Triangle Development
address 500 Water St., Pittsburgh
zoning R-3 assessment 950,000
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Examples of GIS use

• GIS questions Objects - Where is?

parcel no. 565-23a area 118,245
sq. ft. owner Triangle Development
address 500 Water St., Pittsburgh
zoning R-3 assessment 950,000
Where are houses located you might consider
buying?
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Examples of GIS use

• GIS questions Patterns - Which things are
  related?

Where have traffic accidents occurred over the
past year at intersections without a traffic
light?
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Examples of GIS use

• GIS questions Models - What if?

What would happen to traffic patterns if a new
Walmart were built here?
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Examples of GIS use

• GIS questions Trends - What has changed
  since?

Where has agricultural land gone to other uses
since 1950?
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The five basic elements of a GIS

• A GIS is a 5-part system
• People
• Data
• Hardware
• Software
• Procedures
• A GIS is only as strong as its weakest link!

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People

• People are the most important part of a GIS
• People define and develop the procedures used by
  a GIS
• People can overcome shortcoming of the other 4
  elements, but not vice-versa

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Data

• Data is the information used within a GIS
• Since a GIS often incorporates data from multiple
  sources, its accuracy defines the quality of the
  GIS.
• GIS quality determines the types of questions and
  problems that may be asked of the GIS

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Hardware

• The type of hardware determines, to an extent,
  the speed at which a GIS will operate.
• Additionally, it may influence the type of
  software used.
• To a small degree, it may influence the
  types/personalities of the people working with
  the GIS.

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Software

• GIS software encompasses not only to the GIS
  package, but all the software used for databases,
  drawings, statistics, and imaging.
• The functionality of the software used to manage
  the GIS determines the type of problems that the
  GIS may be used to solve.
• The software used must match the needs and skills
  of the end user.

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Course Software

• This course will use the latest release of ArcGIS
  (9.2), a product of Environmental Science
  Research Institute.
• ArcGIS replaces ArcView, ArcEditor, and ArcInfo.
  The latter terms now refer to the
  functionality/licensing of ArcGIS.
• For example, an ArcInfo license may be purchased
  with ArcGIS, thus allowing for full
  functionality. An ArcEditor license for ArcGIS
  has less functionality and an ArcView license is
  the least functional.

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ArcGIS

• ArcGIS provides a graphical user interface (GUI)
  for access and manipulation of the GIS.
• It is composed of three basic tools
• ArcCatalogue
• ArcMap
• ArcToolbox

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Procedures

• The procedures used to input, analyze, and query
  data determine the quality and validity of the
  final product.
• The procedures used are simple the steps taken in
  a well defined and consistent method to produce
  correct and reproducible results from the GIS
  system.

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GIS Functions

• Six Functions of a GIS
• Capture data
• Store data
• Query data
• Analyze data
• Display data
• Produce output

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Capturing Data

• A GIS must be able to handle two fundamental data
  types
• Geographic data. This type of data is coordinate
  based and represents the physical distribution of
  elements in the GIS
• Tabular data. This type of data contains the
  attributes, or characteristics, about elements in
  the GIS.
• Most features displayed in a GIS are composites
  of both types of data. For example, a road may
  be drawn using x,y coordinates, but the type of
  road, its name, and construction features are
  stored as tabular data.

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Capturing Data (contd)

• The effectiveness of a GIS strongly relies on the
  input of data.
• Data sources include
• Paper maps (digitized)
• Coordinate input
• Digital data (obtained from outside sources)
• GPS (collected using a GPS system)
• A good GIS should support multiple formats for
  all data types listed above.

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Storing Data

• Geographic GIS data is stored primarily in one of
  2 types
• Raster, which is image based. A raster data
  model assigns values to cells on a computer
  screen which covers a specific location. The
  detail of a raster data set is therefore
  dependant upon the size of the cell used to
  represent a given area (resolution).
• Vector, which is coordinate based model used to
  represent real-world features.

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Querying Data

• A GIS must provide tools by which its users can
  answer questions.
• A query can be based upon the use of the GIS to
  identify a specific feature OR its use to
  identify features based on a specific set of
  conditions.
• Depending on the software used, queries can be as
  simple as point and click or as complicated as
  writing command-line programming code. In other
  words, the type of questions to be asked
  determines the type of GIS to be used.

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Analyzing Data

• A GIS must be capable of answering questions
  regarding the interaction of spatial
  relationships.
• Inherent in analyzing the data is the ability to
  ask the right questions, follow the correct
  procedures, and correctly interpret the results!

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Analyzing Data (contd)

• There are three basic types of analysis
• Proximity analysis queries the GIS about
  distances between objects
• Overlay analysis joins different map layers of a
  GIS together to answer a question
• Network analysis is used to answer questions
  about how a group of objects function together.

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Displaying the Data

• A GIS must allow a flexible environment for its
  users to view the data.
• Data may be displayed in multiple formats, but
  generally is viewed as either a graph, table, or
  map.

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Output

• A GIS must have the means to output the data in
  usable formats
• Common forms of output include
• Images
• Documents
• Paper maps
• The internet
• Files for use in other applications

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Examples

• Government
• http//gis.greenwoodsc.gov/giswebsite/default.htm
• Climate
• http//www.cpc.ncep.noaa.gov/
• Engineering
• http//www.onuma.com/services/VancouverStorm.php

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What jobs use GIS?

• Examples of application of automated methods
  include a wide range engineering
  mining natural resource management
  agriculture planning (all govt levels)
  etc...

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GIS can be found in most any field

• but generally can be grouped into four basic
  categories
• NATURAL RESOURCE MANAGEMENT
• Forest Wildlife
• Hydrological
• Minerals
• URBAN REGSIONAL MANAGEMENT
• Land Use Planning/Environmental Impact
• Public Works
• Emergency Response
• Legal Records

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• COMMERCIAL
• Market Area Analysis
• Site Selection
• Routing
• AGRICULTURAL MANAGEMENT
• Field Records
• Animal Management
• Climate Change / Human Impact

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Discussion

• How does GIS apply to your area of study or
  career?

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What do I need to know to have a career in
geographic information science?

• Theory and concepts
• How to think spatially
• How to ask questions spatially
• Software training
• How computers store spatial information
• How to answer spatial questions

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Allied Spatial Technologies
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Related technologies
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Global Positioning System
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Remote Sensing
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Computer Assisted Drawing (Computer Aided
Drafting)

• Function database development
• Strengths easy method of data input many data
  sources in this format
• Weaknesses not general tied to external
  descriptive data complex data

• Improvements better linkages with attribute data
  and with GIS software

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Spatial Analysis and Modeling

• Function manipulation of spatial data to gain
  insight to geographic processes to make
  predictions about spatial patterns
• Strengths improves the ability to understand
  spatial patterns

• weakness difficult to use not easily integrated
  into software
• improvements GUI, interoperability

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Cartography
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Visualization
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Related technologies (Summary)
Scanning GPS CAD Remote sensing
Spatial analysis Modeling
DBMS
Cartography Visualization
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Required GIS and Related Skills

• Systems Engineering
• Geodesy
• Geography
• DBMS
• Project Planning
• Project Management
• Creativity

• GPS
• C
• Photogrammetry
• Economics
• Application Development
• Project Life Cycle
• GIS Software

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Technical Skills Required by a Geographer

• GIS knowledge
• Ability to use design package software
• Statistics
• AUTOCAD
• Spreadsheets LOTUS, EXCEL, etc

• Management knowledge
• Use of development tools (Visual Basic)
• Cartography
• Writing
• Air photography and remote sensing

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Getting started

• Read
• Experiment with the software
• Talk to GIS users
• Talk with me
• Talk to each other
• Pay attention

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GIScience vs GISystems

• Whats the difference?
• Is he just being picky?

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GISystems

• Use of hardware, software, people, procedures,
  and data

GIScience

• Theory behind how to solve spatial problems with
  computers

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What is GIS?

• Literal
• Functional
• Component

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What is GIS literal definition?

• Geographic relating to the surface of the earth
• Information Knowledge derived from study,
  experience, or instruction
• System a group of interacting, interrelated, or
  interdependent elements forming a complex whole
• Science the observation, identification,
  description, experimental investigation, and
  theoretical explanation of phenomena

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What is a GIS functional definition

• inputting, storing, manipulating, analyzing, and
  reporting data describing places

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The GIS pipeline
Data gathering (input)
Data storage and specification
Data use and analysis
Data output
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Component definition

• An organized collection of computer hardware,
  software, geographic data, procedures, and
  personnel designed to handle all phases of
  geographic data capture, storage, analysis,
  query, display, and output.

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• Components of a GIS.

people
procedures
data
hardware
software
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Six functions of GISystems

• Capture data
• Store data
• Query data
• Analyze Data
• Display Data
• Produce Output

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GIS combines data at a location to provide a
better understand of that place. It serves as a
tool to model reality.
http//www.gis.com/whatisgis/whatisgis.pdf
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GIScience

• The current state of GIS as a system does not
  always provide the best or most informed methods
  of problem solving
• These research-oriented problems stem from how we
  choose to represent features geographically,
  store and analyze data, visualize information,
  measure location (geodesy), and model our world.

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For example

• A house may be represented 3 different ways in a
  GIS
• As a point on a map
• As an area (the footprint of the house)
• As a grouping of cells in an image (raster data)

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RASTER AND VECTOR DATA MODELS
REAL WORLD
1 2 3 4 5 6
7 8 9 10
1 2 3 4 5 6 7 8 9 10
GRID RASTER
VECTOR
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Discussion

• Which model works best?

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The best of both worlds

• In the real world, GIS generally is practiced
  in one of three functional areas
• Pure research
• Use inspired research
• Applications
• Each area is dependant upon the other for
  inspiration and survival
• The vast majority of money and jobs lie in use
  inspired research and applications.

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The Scientific Method

• Examples of GIS in Science

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Example and discussion

• What is global climate change and what are its
  implications for urbanized areas?

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The scientific method

• Current knowledge is used to formulate a research
  question.
• The question is refined into a hypothesis that
  may be experimentally tested
• An experiment is run using appropriate and
  accepted methodology and data is captured
• The resulting data is analyzed and contextualized
  to prove or disprove the hypothesis
• Conclusions are drawn from proving/disproving of
  the hypothesis. These conclusions are used to
  support the development of another research
  question and the process repeats.

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The facts about carbon dioxide (CO2) and urban
areas

• CO2 is a significant greenhouse gas
• Changes to the global carbon cycle
• The proportion of the global population living in
  urban areas is increasing
• A significant portion of CO2 emitted into the
  atmosphere comes from urban areas
• Changes in policy regarding CO2 emissions will
  most likely have the largest impact in urban areas

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Phoenix, Arizona a living laboratory

• Phoenix is unique because it has a moderately
  dense population area surrounded by a very
  sparsely populated area
• There is little to no transition in population
  density as you move from urban to rural areas

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Research question

• What are the effects of population on local
  carbon dioxide concentrations?

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Hypothesis

• Urban areas with population densities greater
  than 5000 people per square mile will exhibit
  higher than average carbon dioxide concentrations
• The concentration of carbon dioxide will
  fluctuate with time of day in correlation with
  rush hours

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Measuring CO2 concentrations in metro-Phoenix
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Adapted from Idso, Brooks, et al. 2001
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GISystems Research Objective

• How can we estimate carbon dioxide levels at
  locations where no data were collected (analysis
  completed by E. Wentz, ASU Dept. of Geography)?

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Sources of CO2

• Soils
• Vehicle Emissions
• Power Plants
• Human Respiration
• Landfills
• Airplanes

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Average Weekday Traffic
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Population
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Employment
85,000 points
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Vegetation
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Regression results
CO2 a Urbanization Vegetation
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Morning CO2
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Afternoon CO2
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What is the concentration of CO2 in downtown
Phoenix in the morning?
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Research question

• What effect does increased local CO2 and
  urbanization have on quality of life?
• Quality of life can be described many ways.
  After sweating my hair out and paying 450 a
  month for summer air conditioning bills on a
  student budget, I was dialed in on temperature.

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Diurnal temperature range

• Problem Reporting of changes in annual average
  temperature does not adequately describe climate
  change
• Initial analysis of record setting temperatures
  indicates that climate change in the Phoenix area
  is much more dramatic than indicated by the
  reported 1.6 degree change in average temp.

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Hypothesis

• Increased carbon dioxide and urbanization
  decrease daily temperature ranges.

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Year of occurrence for daily record high and low
temp. at Phx WSFO
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Year of occurrence for daily record high and low
temp. at Maricopa
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The History of GIS

• GIS is not really a new idea

With information from http//www.geog.ubc.ca/cours
es/klink/gis.notes/ncgia/u23.htmlSEC23.5.1
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Early GIS

• A GIS can be conceptualized as the use of
  overlays placed upon a base map.
• GIS-type systems pre-date the invention of the
  computer
• For example, deaths of cholera were mapped using
  overlays by Dr. John Snow in 1854. It allowed
  him to find that victims were all drinking from a
  common well.
• Maps of the Battle of Yorktown were drawn by
  Louis-Alexandre Berthier using hinged glass
  overlays.

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Enter the computer

• With the advent of the computer, a new tool was
  added to the arsenal available to designers,
  cartographers, and engineers.
• The invention of Computer Aided Design (CAD)
  allowed for the display of vector maps with lines
  on a computer screen in the late 1950s and early
  1960s.
• Data was stored in binary file formats with dot
  representations for points, lines, and arc.
• This data model could make little or no use of
  attribute data.

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Enter the computer (contd)

• The computer allowed for a change in basic
  cartographic technique because it allowed for
  more complex analysis of geographic information
  at relatively fast rates.
• The Dept. of Geography at the University of
  Washington pioneered the way to modern GIS.

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University of Washington GIS Gurus

• Nystuen - fundamental spatial concepts -
  distance, orientation, connectivity
• Tobler - computer algorithms for map projections,
  computer cartography
• Bunge - theoretical geography - geometric basis
  for geography - points, lines and areas
• Berry's Geographical Matrix of places by
  characteristics (attributes) - regional studies
  by overlaying maps of different themes -
  systematic studies by detailed evaluation of a
  single layer

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Canada Geographic Information System

• First modern GIS developed in 1960, Roger
  Tomlinson was key developer
• use of scanning for input of high density area
  objects
• maps had to be redrafted (scribed) for scanning
• note scribing is as labor intensive as
  digitizing
• vectorization of scanned images
• geographical partitioning of data into "map
  sheets" or "tiles" but with edgematching across
  tile boundaries
• partitioning of data into themes or layers

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CGIS (contd)

• use of absolute system of coordinates for entire
  country with precision adjustable to resolution
  of data
• number of digits of precision can be set by the
  system manager and changed from layer to layer
• internal representation of line objects as chains
  of incremental moves in 8 compass directions
  rather than straight lines between points
  (Freeman chain code)
• coding of area object boundaries by arc, with
  pointers to left and right area objects

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CGIS (contd)

• first "topological" system with planar
  enforcement in each layer, relationships between
  arcs and areas coded in the database
• separation of data into attribute and locational
  files
• "descriptor dataset" (DDS) and "image dataset"
  (IDS)
• concept of an attribute table
• implementation of functions for polygon overlay,
  measurement of area, user-defined circles and
  polygons for query

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The Harvard Lab

• Full name - Harvard Laboratory For Computer
  Graphics And Spatial Analysis
• Howard Fisher, moved from Chicago to establish a
  lab at Harvard, initially to develop
  general-purpose mapping software - mid 1960s
• Harvard Lab for Computer Graphics and Spatial
  Analysis had major influence on the development
  of GIS until early 1980s, still continues at
  smaller scale
• Harvard software was widely distributed and
  helped to build the application base for GIS
• Many pioneers of newer GIS "grew up" at the
  Harvard lab

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Harvard Contributions

• Nearly a half dozen GIS applications during the
  1960s
• Howard Fisher - initiated Lab, development of
  SYMAP
• William Warntz - succeeded Fisher as Director
  until 1971, developed techniques, theories of
  spatial analysis based on computer handling of
  spatial data
• Scott Morehouse - move to ESRI was key link
  between ODYSSEY and the development of ARC/INFO

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The US Bureau of the Census

• Need for a method of assigning census returns to
  correct geographical location
• Address matching to convert street addresses to
  geographic coordinates and census reporting zones
  
• With geographic coordinates, data could be
  aggregated to user-specified custom reporting
  zones
• Need for a comprehensive approach to census
  geography
• Reporting zones are hierarchically related (e.g.
  enumeration districts nest within census tracts)
• 1970 was the first geocoded census
• DIME files were the major component of the
  geocoding approach

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Jack climbs the beanstalk

• Jack Dangermond founded Environmental Systems
  Research Institute in 1969 based on techniques,
  ideas being developed at Harvard Lab and
  elsewhere
• 1970s period of slow growth based on various
  raster and vector systems
• Early 1980s release of ARC/INFO
• Successful implementation of CGIS idea of
  separate attribute and locational information
• Successful marriage of standard relational
  database management system (INFO) to handle
  attribute tables with specialized software to
  handle objects stored as arcs (ARC) - a basic
  design which has been copied in many other
  systems

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• Created "toolbox", command-driven,
  product-oriented user interface
• Modular design allowed elaborate applications to
  be built on top of toolbox
• ARC/INFO was the first GIS to take advantage of
  new super-mini hardware
• GIS could now be supported by a platform which
  was affordable to many resource management
  agencies
• Emphasis on independence from specific platforms,
  operating systems
• Initial successes in forestry applications, later
  diversification to many GIS markets
• Expansion to 40 million company by 1988
• Releases cheap version of GIS for the
  multitudes called ArcView during the early 1990s
  (and thus shapefiles were born)

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• Made the leap to spatial databases with the
  release of ArcGIS 8.0 in 2000
• ESRI is now the largest privately held company in
  the world
• ESRI has 80 of the large-market GIS industry and
  approximately 40 of all other GIS users

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The way home...