SO432, Geographical Information Systems

Exam 2, Fall 2007


Definitions††† 10 @3††††††† 30†† ___________

Short answer††† 5 @ 10††††††† 50†† ___________

Longer answer ††1 @ 20††††††† 20†† ___________

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.


  1. ETOPO5:
  2. Georegistered image:
  3. Generalization:
  4. GUI:
  5. IR:
  6. LIDAR
  7. Soft-copy
  8. SRTM:
  9. Supervised classification:
  10. Temporal resolution:
  11. Topological operations
  12. Topology:


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 Gulf Stream?What would be the most important resolution for you?



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 itójust 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†††††††††††††† ____VectorRaster__________

Shape file†††††† ____VectorRaster__________

Spreadsheet ††† ____VectorRaster__________