introducing arcgis chapter 1. objectives understand the architecture of the arcgis program. become...

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!!!!