Geographic
Information
Systems
ASM 215
Feb 2013
Larry Theller
Schedule
• Wednesday
– GIS lecture
– Disc of homework
• Lab – Thursday GPS
• Feb 28 Lab – ABE 105 or 116 computer
labs
GIS Lecture today
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History
Software details
Current GIS uses
Hot GIS trends
Feb 28 lab
Geographic Information Systems
• GIS means “Geographical Information
System”
– its called SYSTEM because there is
information behind the map.
– You may “ask questions” of the data or
of the map
GIS Evolution
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Map viewing >> Map Analysis
Past: map layers = little files
Now: map layers = huge databases
We use Terabytes of images
Streaming GIS data = music on the web
Web-based tools do not install on your
computer
Example: Map of cholera outbreak,
1854
• (Based on
John
Snow’s
map)
• Other
analysis
examples?
GIS is not CAD
• Difference between CAD and GIS
software:
– you ask questions in GIS
• Three levels of GIS applications:
– Inventory (What is there?)
– Analysis (Answering questions)
– Modeling (Making predictions)
CAD stands for Computer-Aided Design
A GIS is a
software
system that
connects map
layers with
tables of
information.
Tabular Data
Image: ESRI course Learning ArcGIS Desktop 2007
Spatial Analysis is considered the
crux of GIS. Why?
• Spatial analysis is the means of adding
value to geographic data.
• It turns data into information
• Spatial analysis can reveal things that
might otherwise be invisible. It can make
what is implicit explicit.
More about spatial analysis…
• Some methods are highly mathematical.
• All effective spatial analysis requires an
intelligent user, not just a powerful
computer.
• “Spatial analysis is best seen as a
collaboration between the computer and
the human, in which both play vital roles.”
(Geographic Information Systems and
Science, Wiley, 2001)
The GIS analytical process
1. Define the problem
2. Define the criteria
3. Identify the data you
need
4. Plan the analysis
5. Prepare the data for
analysis
6. Execute the analysis
7. Examine and present the
results
A GIS
originally
was software
installed on a
computer
and using
local files as
layers with
attached
tables of
information.
GIS and the internet
• GIS Users quickly adopted the internet for
download of large files
• With satellite-sensors and digital camera
the files soon became gigantic
• Not efficient to copy to every PC in Indiana
This map is
drawing data
from two
streaming
data sources
on the web
and from files
on the hard
drive.
Named streets and property parcel lines
from the Tippecanoe County GIS server
These high-resolution aerial photos
use 8 terabytes of storage at IU,
which is why you do not want to
download files anymore
Streaming High-resolution images
Don’t Download that image
• If you don’t need to change it, maybe you
don’t need to download it
• If you need to change it, edit it or clip out
parts, you need to have your own copy.
• Aerial Photos – Indiana 2005 photos are:
– 8500 gigabyes
– Or 2000 DVD’s
– Sure you want to download that?
Location Business Services:
The geo fence
• You know when a vehicle passes into or
out of a zone.
• Monitor deliveries, service staff,
employees, felons, ambulances, pizza
delivery guy..
– http://gis2.esri.com/showcase/showcase.cf
m
– http://tuxedo.esri.com/geofence/
Web Location Business Services
• Target marketing geographically
–Cell phone yellow pages
• Google and Mapquest,
–Spots on the map, Gas, food, etc.
• eBay
–Nearby items
Mobile GoogleEarth
Google Earth for iPhone
Google Earth for Android
GIS software on your desktop
• ESRI ArcGIS (ArcMap, ArcCatalog)
• Other Commercial : ThinkMap, Autodesk
Map 3D or Civil 3D, MapInfo
• Commercial but free Viewers:
– Google Earth
– ArcGIS Explorer
• Open Source GIS:
– uDIG (user-friendly Desktop Internet GIS)
– Quantun GIS (most full-featureed and free)
uDIG – free and web-oriented
Labels
Scale Bar
Streaming data;
databases,
tables,
shapefiles
uDIG Open Source GIS
Legend
Quantum GIS (free)
Overlay
• Combine spatial and
attribute data from
two or more spatial
data layers
• Union and Intersect
most common
Buffers
• Buffer = region that is less than or equal to a
specified distance from a feature or features
• Can buffer point, line or area feature
• Raster or vector data
Clip, Intersect, and Union
http://www.indianamap.org/
Map Gallery
Online Map
Build my map by adding layers
The Lab Exercise - ArcMap
THE END