What is a GIS

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What is a GIS?
Tom Wesp ESRI-San Antonio twesp_at_esri.com
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What is a GIS?

• Government Information System?
• No!
• Latin for It was raining outside so I couldnt
  go to the beach, here I am?
• No! But, that's a good answer!

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So what is a ...

• Geographic
• Information
• System

G I S
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What Do We Know About GIS?

• G Stands for Geographic
• GIS Has Something to do With Maps
• GIS Has Something to do With Computers

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The Next Thing We Know...

• We are Dealing With New Concepts
• We are Dealing With New Technologies
• Whatever it is, its Most Likely Expensive

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What is GIS? (The Personal Definition)
Software for ManagingSpatial (Mappable)
Information
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What Do We Know About Maps?
What Do We Know About Maps?
Types of Maps (Familiar Examples)

• Street Maps
• Environmental Maps
• Census Maps
• Satellite Imagery

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What Do We Know About Maps?
Information on a Typical Map

• Location of an Object
• Information About an Object

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What Do We Know About Maps?
Problems Using Maps

• Objects Can be Off the Map
• Information Can be Missing or Out of Date
• What You See is What You Get (Static)

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How GIS Works

• Map features represent objects in the real world
• Relationships between features are maintained by
  the GIS. (Location, size, shape, distance)
• Attributes (information) about the map features
  are stored in spreadsheets or databases.
• Themes link attributes and map features
  together.
• Collections of Themes form a GIS database.

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How GIS Works
Attributes (Data)
Maps


Answers!
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How GIS Works
Features
Attributes
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Themes share the same geographic space
Fire Hydrants (Points)
Streams (Lines)
City Limits (Polygons)
Streets (Lines)
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Geographic Data
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Descriptive Data
Chris Buhi 1757 Millbrook Ln 28226 Y
2 Christian Carlson 1761 Millbrook Ln 28226 Y
1 Chris McGuire 1765 Millbrook Ln 28226 Y
2 Dale Loberger 1776 Millbrook Ln 28226 N
6 Donna Buccini 1780 Millbrook Ln 28226 Y
2 Doug Ruppel 1537 Sandberry Dr 28226 Y
1 Gary Waters 1541 Sandberry Dr 28226 Y
3 Holly Williams 1200 Yamasee Dr 28210 Y
4 Jim Wojcik 980 Harrowfield Rd 28226 N
1 Jo-Ann Brown 1812 Millbrook Ln 28226 N
2 Joe Rubisch 1090 Overhill Dr 28112 Y
4 Larry Young 1108 Kings Canyon Dr 28226 Y
3 Lee Ross 1605 Bosham Ln 28226 Y 2 Marcia
Austin 1429 Quail Wood Dr 28226 Y 2 Mary Jo
Fraley 1432 Quail Wood Dr 28226 Y 1 Mike
Dyer 1430 Quail Wood Dr 28226 Y 3 Mike
Rhoades 1332 Cameron Forest Dr 28173 Y 3 Mike
Sweeney 1327 Red Hickory Ln 28173 Y 2 Paul
Gallimore 1429 Buckeye Ct 28173 Y 2
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Geographic Information
N 6
Donna Buccini 1780 Millbrook Ln Y 2
.ancaster
Jo-Ann Bro 1812 Millbr Y 2
Millbrook Lane
Christian Carlson 1761 Millbrook Ln Y 1
Chris McGuire 1765 Millbrook Ln Y
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Spatial Representations
.ancaster
POINTS
POLYGON
LINES
Millbrook Lane
ANNOTATION
NODES
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Geographic Representations

• POLYGON a closed area formed by one or more
  lines (eg. parcels, soil types, political
  boundaries, city limits, and census tracts)
• LINE a feature defined by connecting a series of
  coordinates or through a geometric description
  (eg. streams, street centerlines, parcel surveys,
  water lines, and gas mains)

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Geographic Representations

• POINT a feature defined by a single coordinate
  (eg. maintenance hole covers, well locations,
  light poles, eagle nests, survey monuments)
• NODES features located at the intersection of
  two lines (eg. street intersections, pipe joins)
• ANNOTATION a text string placed on a map as a
  graphic description (eg. street names, and parcel
  or index numbers)

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Arc-Node Topology
2732
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433
432
107
435
434
24
477
125
33
438
37
480
2641
478
41
2642
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Arc-Node Topology
2732
FNODE TNODE LPOLY RPOLY LENGTH PARCEL
39 37 0 2641 540.12 477 48 37
2641 2642 297.45 478 39 48 2641
2651 140.33 479 37 41 0 2642
153.56 480
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433
432
107
435
434
24
477
125
33
438
37
480
2641
478
41
2642
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Polygon-Arc Topology
2732
FNODE TNODE LPOLY RPOLY LENGTH PARCEL
39 37 0 2641 540.12 477 48 37
2641 2642 297.45 478 39 48 2641
2651 140.33 479 37 41 0 2642
153.56 480
12
433
432
107
435
434
24
477
PARCEL ARC LIST 2641 477, 478, 479 2642
478, 480, 481, 482
125
33
438
37
480
2641
478
41
2642
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Table Relationships
2732
AREA PERIM PARCEL PARCEL-ID
PIN -8654365 96432.5 1 0 0 65567.54
75343.2 2 2641 536274 43576.22
46512.9 3 2642 541280 46533.71
50264.2 4 2643 539291
12
433
432
107
435
434
24
477
PIN OWNER ADDRESS 536274 Christian
Carlson 1761 Mi 541280 Chris Mguire 1765
Mi 539291 Dale Loberger 1767 Mi
125
33
438
37
480
2641
478
41
2642
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Geographic View of Data
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Attribute Table
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Integration of Geographic and Attribute Data
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GIS Software Functions

• Data Entry
• Digitizing, Data Conversion, Attribute Entry
• Data Management
• Efficient, Nonredundant Storage
• Data Manipulation and Analysis
• Projection Management
• Buffers and Overlays
• Query and Selection
• Map Updating
• Graphic and Attribute Editing
• Display and Output
• Cartographic Design, Plotting, Reporting

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Asking questions getting answers

• Find attributes by selecting features
• Find features by selecting attributes
• What is the relationship of features?
• How far is it?
• How big is it?
• What is nearby?
• What if ....?

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Benefits of Using GIS

• Typical Benefits of Using Automation (Cost
  Savings)
• Better Data Management (More Efficient
  Storage and Updating)
• Faster Information Access (Better Decisions)
• Operational Efficiencies
• New Applications

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GIS for Decision Support
Site Selection
Planning
Routing
Policies
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GIS as an Integration Technology
Data
Work Activities
Organization
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Technologies Affecting GIS
Faster/Cheaper Computing
G.P.S.
Image Processing
High Resolution Space Imaging
GIS Technologies
Multi-Media
Modeling
Communications/Networks
JD-PUG-Houston-96jr
3
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GIS Is a Lot More Than Just Technology
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People
Software
Data
GIS
Procedures
Hardware
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What is GIS? (The Systems Definition)

• Hardware
• Computers
• Networks
• Graphic Devices
• Software
• GIS Software
• Database Software
• OS Software
• Network Software
• Data
• Vector Data
• Raster Data
• Image Data
• Attribute Data

• People
• Administrators
• Managers
• GIS Technicians
• Application Experts
• End Users
• Consumers
• Approaches
• Guidelines
• Specifications
• Standards
• Procedures

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Who uses GIS?
Conservation
Emergency Services
Military
Education
Environmental Protection
Cartography
Hydrology
Utilities
GIS
Oil and Gas
Land Records
Transportation
Ecology/ Biology
Land Use Planning
Earth Sciences
Natural Resources
Forestry
Local Government
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Information From Many Sources Can Be
Integrated for Problem Solving

• Land Use

Legal
Other
Environmental
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New Partnerships
Private Co.s
Networks
Government

• Schools

Libraries
Citizens
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GIS in the Enterprise
Professional GIS
Desktop GIS
API
Shared GeoData
Open GIS
Embedded GIS
CAD-Based GIS
Internet GIS
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Data Integration
GIS
CAD
Coverage
Shape File
GRID
Image
SDE
Other
Direct Data Read
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GIS Same data. many uses
Crime Analysis Dispatch
Fire Incidents Run Maps/Plug Maps
Fire
Police
Business License Sales Tax Hotel / Motel
Finance
Streets Parcels Land Use Zoning
Pavement Water Sewer Storm
Land Use Zoning General Plan
Planning
Public Works Utilities
Public
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GIS Worldwide Core Business(Software)
Market share
Source Daratech
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ESRI Regional Offices, Affiliates and
International Distributors
International Affiliates United Kingdom South
Asia Germany Australia Sweden Canada France Spai
n Italy
Regional Offices Washington, D.C San Antonio
Minneapolis Anchorage St. Louis
Charlotte Olympia Denver Boston
International Distributors over 75 countries
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ESRI Solutions
Consumer
Data Management
Desktop GIS
Professional GIS
PC ARC/INFO
Map Objects
ARC/INFO
BusinessMAP
Data Automation Kit
SDE
ArcCAD
ArcView
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ArcView
Virtual Table
Shape
DBF
TIFF
Arc/Info
RLC
DWG
BIL/BIP
DGN
Erdas
MIF
SQL
Sun
Library
ODBC
Oracle
JPEG
Text
SDE
Image Catalog
Excel
Informix
ASCII
Sybase
1-2-3
Access
Spatial Data
Ingres
Tabular Data
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ArcExplorer
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ESRIs Home Page
www.esri.com

• Expansive Guide to ESRI Software and Services

ESRI-OVERVIEW-96-JR
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