CEEn 531 - Water Resources Engineering

Dr. Nelson

Homework Assignment 4

After running the respective tutorial, read the following set of questions and write half a page paragraph about what you have learned from this lesson. At this point, you should be able to answer these questions or at least have them help you in writing your paragraph.

Post this paragraph, along with a screen capture, or two,  developed from the results of the tutorial, to your CE531 homework page, then email the TA (include the URL to your homework page).

Always try to make your assignment page look as nice and professional as possible.

Images and Coordinate Systems

  1. What is the basic structure of image files from WMS perspective? And how can we obtain an image?
  2. What is geo-referencing? And why do we need to do it before we start using images?
  3. You are trying to tile 2 images together, and features do not line up, what could be wrong?
  4. Suppose you want to obtain an image that you can clearly see your house in, which scale would probably be better 1:1,000 or 1:250,000? Illustrate your answer.
  5. Why do we need to have geographic coordinates converted to planimetric coordinates before we do any hydrologic analysis?
  6. Go to http://emrl.byu.edu/gsda and then to the TerraServer.  Download both the topographic map and aerial photo for your home town. Include in your web screen captures of the registered images in WMS and report the Geographic and UTM NAD 83 coordinates of the center of your town.

Extra Questions:

Here are some extra questions for you to think about. 

  1. What is the basic difference between manual registration and in-file or pre-set registration?
  2. How is an aerial photograph useful for hydrologic simulations?
  3. Why do we need to tile some images together?
  4. Show one images of your home town that you obtained through the web.
  5. List at least 2 coordinate systems along with their identifying features.
  6. How can you read UTM-NAD83? (what does it stand for?)
  7. We want to analyze a watershed in hand where DEM, soil and land use data are in different coordinate systems. How would we think conceptually about doing it? Do you think WMS is capable of doing so?