Name:
Date:
Data Models Lab Write-up
1. Give an example of how a continuous phenomenon can be represented using the vector data
model.
2.1 Which data models can be stored in a Geodatabase?
2.2 Do CAD data use a different kind of data structure?
3.1 The fact that you can't use spaces in file names or folders has to do with what? (the
software, data model, data structure, or something else)
3.2 What is a "feature class"? What is a "feature type"? (hint: use the Help)
3.3 What is an ArcGIS "coverage" and how is it different from a shapefile?
3.4 What is the main difference between the geodatabase data model and the other data
models?
4. Fill out Tables A and B below based on information from the lab introduction, exercises, course
text, and lecture. Although it would be easiest to do this now, as you've just read out it, you can
do this later.
Table A.
Vector
Briefly describe the
essential
characteristics of
each.
Include the types of
data generally
represented
(i.e. continuous or
discontinuous)
Give an example of
a likely geographic
feature that would
be represented.
Raster
TIN
Table B.
Geodatabases
Historic Software
Origin:
How the data is
stored in the
computer (i.e. does
the data need to be
in a special type of
folder? What files
are required for the
data model?)
In what type of files
are the attributes
stored?
Describe the
topological features
in each data model
What type of data
can be created in
each datamodel?
Coverages
Shapefiles
ArcInfo8
No special folder for
storage. Three files
containing spatial and
attribute data are
required, there may
be other files with
index information.
INFO files
Allows for topological
feature classes,
geometric networks.
Polygon topology
implemented through
on-the-fly topological
editing.
Points, arcs, lines,
linear measurement
system, polygon,
regions, tics, nodes,
annotation
5.1 Use ArcGIS Help to find "coverages, described" to answer the following questions.
a) List the feature classes that a coverage can contain.
b) What is the purpose of an INFO table?
c) What are tic points?
d) What is planar topology?
5.2 Use ArcGIS Help to find "shapefiles, described" to answer the following questions.
e) How many feature classes can a shapefile use?
f) Do shapefiles have planar topology?
6. What are the data models for each of the layers? What geographic feature does each layer
seem to represent? (be as specific as possible)
mystery1 -mystery2 -mystery3 -mystery4 -mystery5 -mystery6 -mystery7 –
7.1 How similar aremystery5and your converted layer?
7.2 Briefly describe the major differences between the two.
7.3 What source data was used to makemystery5?
8. Which of the three layers (sbdem, sbtin, sbcontour) do you think was the original data layer?
Which is "second generation" and which is "third generation"? Why do you think this?
9. Find each of these tools and what data model type(s) (or perhaps other file types) it takes as
input:
a) Clip, Select, Intersect, Buffer, & most other Analysis Tools (all the same answer)
b) Viewshed
c) Buffer Wizard
d) Add Spatial Index
e) Import from SDTS
f) Feature Class to Geodatabase
g) Raster to Other Format
h) Export to Interchange File
i) Join Tables
j) Create Labels
10.1 How many records are there?
10.2 What do FNODE# and TNODE# mean?
10.3 What other attribute information can you recognize or guess at in the table (pick 3
columns)?
11.1
11.2
11.3
11.4
How many counties are there in California?
Why do the AAT, PAT, and RAT have different numbers of records?
Explain the relationship between arc, polygon, and region.ctyin this coverage.
What are the label and tic feature classes for?