SO432, Geographical
Information Systems
Short
answer 5 @ 10 50
___________
Total 100 ___________
Read the directions
carefully. You have a selection of
questions for all parts of the exam.
Carefully select which questions you will answer, and only answer the
correct number of questions.
Quality of your answers is
important. For full credit you should
use correct terminology, and show that you understand the concepts involved.
Definitions: define 10 of
these terms with a concise sentence that clearly shows your understanding of
the term: Each is worth three points.
Answer 5 of the 7 short answer questions. Each is worth 10 points.
1. When NGA and its predecessor agencies decided
to make all their DEMs with spacing in arc seconds, did they make a good
decision? Why or why not?

2. The two maps above depict two possible ways
to store digital topography, and draw contour lines through the data. The elevation points are labeled, and the
contour lines are the thicker lines. What
are the differences between the two methods, and the advantages and
disadvantages of each?
3. We have discussed the spatial resolution of
both satellite imagery and digital elevation models. If you could have 30 m imagery and a 1 m DEM,
or 1 m imagery and a 30 m DEM, which would you rather have and why?
4. What can you do to increase the signal to noise
ratio in a satellite, and how would you use this information if you wanted to
create a satellite system to monitor temperatures of the
5. Why are shape files important for GIS, and
what important considerations would you have to consider before you sent one to
someone else to use?
6. What steps are required to digitize a paper
map to create a vector data base? Which
would you consider to be the hardest, and why?
7. Why is stereo imagery important for GIS, and
what do we have to do to create stereo imagery?
Long answer questions. This is worth 20 points, and you must answer it.
(5)
You found the map on the first page of the exam on the internet, and it will be
perfect for a paper you are writing for a Poli Sci elective. You would like to use this map as a GIS base
map. What will you have to do to use the
image (it is a JPEG, and you have no metadata or other GIS geek-speek
information to go with it—just an honest image of a map). Would you be able to click on a state and get
the number of electoral votes, or final all the states with more than 10
electoral votes?
(5)
If you found that the same web site also had the same data as an ESRI shape
file, would getting just the SHP file be a better or worse choice? Why or why not?
(5)
If you found the data in an Excel spreadsheet with the State Name, a FIPS code,
and the number of electoral votes, would that be usable to create a map like
this?
(5)
Would this data be best used in GIS as a raster or a vector data set? Why?
Which
type would each of the three options above be?
JPEG ____Vector Raster__________
Shape
file ____Vector Raster__________
Spreadsheet
____Vector Raster__________