SO432, Geographical Information Systems

Exam 2, Fall 2006


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. Georegistered image:
  2. DTED Level 2:
  3. IR:
  4. LIDAR
  5. Radiometric resolution:
  6. Simplification:
  7. Soft-copy
  8. SRTM:
  9. Topological operations
  10. Unsupervised classification:
  11. USGS Level 2 DEM:
  12. WIMP:


Answer 5 of the 7 short answer questions.  Each is worth 10 points.


1.  When USGS decided to create DEMs to match its map quadrangles, which would have better matched the paper maps: using UTM or geographic coordinates?  What are the advantages and disadvantages of each?  Which did USGS originally use for the DEMs, and which does USGS now consider the best solution?



2.  The two maps above depict two possible ways to store digital topography, and draw contour lines through the data.  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.  What are the considerations in deciding what resolution you would like to have?  If you could only have high resolution for one of the two data sets, which would you prefer and why?  Make and defend any assumptions necessary to answer the question.













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 satellite system to monitor football practices in New York before next month’s football game?



5.  You want to create a database with annual rainfall in the United States.  Should you store this as a vector or raster data set?  What would be the difference between the two, and how would that affect what you could display on the map to show the pattern of rainfall?  Be specific in your answer.


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 above on the internet, and it will be perfect for your final project.  You would like to use this map as a 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 energy cost?



(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 average cost per kWh, 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.