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Introducing ArcGISChapter 1
Objectives Understand the architecture of the ArcGIS
program. Become familiar with the types of data files
used in ArcGIS. Learn how to explore data files using
ArcCatalog.
Storing Map Data Vector vs. Raster x, y coordinates (sometimes z) Attribute
Information represented (i.e., soil type)
Georeferenced Tied to a specific location on the Earth’s surface
Vector Model Features
X, Y coordinates Points Lines Polygons
Vector Model Point
1 x, y coordinate Line
2 x, y coordinates Nodes
Polygon More than 2 x, y coordinates Vertex (vertices)
Vector Model Feature Classes
1 type of geometry Share a table containing
their attributes Have like attributes
Vector Model FID (feature identification code) Thematic mapping
Displaying features based on their value
Vector Model Storing feature classes
Shapefiles (shp) One feature class
Coverages
More storage… Feature Datasets
Roads Traffic lights Railroads Gas stations
Fact of the day….
A regular hen's egg has about 7,000 tiny pores in its shell.
Two basic models… Topological
Stores spatial relationships
between features in addition
to their x, y coordinates. Spaghetti
Stores spatial features as
a series of x, y coordinates Does not store topological
relationships
Benefits of Vector Stores with high degree of
precision Flexibility Mapmaking Compact storage Certain types of analysis
Drawbacks of Vector Does not store continuous
information well Elevation, precipitation, etc.
Time consuming analysis
for some types
Raster Model
Raster Model Grid-cell Row and column Land use Resolution
Higher=more precise Lower=less precise
Two types of Raster Discrete
Few values repeat themselves Roads
Continuous Range smoothly from
one location to another Elevation
Benefits of Raster Continuous data Analysis are simple to
perform Map algebra
Algebraic expression
Drawbacks to Raster Precision vs. storage Ability to store
attributes To store geology and
infiltration values, need two rasters
ArcGIS overview ArcMap
Display, analyze, edit
spatial data ArcCatalog
Viewing and maintaining
spatial data files ALWAYS use to delete,
copy, rename, move files
ArcToolbox Collection of tools and
functions More can be
downloaded
Data Files Shapefiles
Only one feature class Points, lines, polygons Green icons Must contain:
.shp The main file that stores
the feature geometry .shx
The file that stores the index of the feature geometry
.dbf The database of
attributes
Coverages Oldest Multiple feature sets
.adf (arc data file) Yellow icons
Geodatabases Multiple feature classes Include tables Rules
Stop light must be on road
2 types: Personal
Ind. & Microsoft Access
Enterprise Groups and editing
Database connections Permits users to log in
and utilize data from an enterprise geodatabase.
Layer Files Does not contain
spatial data How it should be
displayed Store symbols
Rasters Binary format
Tables Unassociated with
spatial data set Standalone tables .dbf (dBase format)
Others Grids
Raster format Internet Servers
Image=print Feature=download
TINs Triangulated Irregular
Networks 3-D
CAD drawings Created in CAD can be
read by ArcGIS Cannot be edited unless
converted
Metadata Data about data Who created? Time relevant? Coordinate system? What the fields
mean?
Context Menus Right click on name
Left click on symbol
Right click on symbol
Object Properties
Arc Catalog ALWAYS used to
copy, delete, rename, modify spatial data.
Viewing files
Preview tab Geography or Table
Metadata Decode what the
information is telling you!!!
ArcToolbox About 30 tools Develop your own
tools ModelBuilder
Thank you for your time….
I know that it has been a LOOOONNGG day, but you will get to practice, I promise!!!!