Astro 3310 Fall 2015

LAB #4

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Please copy this document to the REPORT sub-directory from the expanded LAB4_Data_Package_FA15.tar.gz. Then, edit it to write your answers in all the "______" areas. When finished, create a tar.gz archive of the REPORT directory and all of its contents, then scp the file to datafarm.astro.cornell.edu and place it in:

/data/Courses/A3310/FA15/”your netid”/LAB4/

Remember that you will only get credit for the files that you put in the REPORT sub-directory and copy to datafarm. Please make sure that you keep a Matlab workbook with all of the commands you used to answer the questions in the lab. Feel free to comment and organize your workbook so that it will be easy for us to follow your algorithms when we execute the code. If you generate any functions for the lab, ensure that they are also in the REPORT sub-directory and properly called from the workbook file. For you convenience, there is a template for the workbook file already in the REPORT sub-directory.

YOUR NAME: ______Your NetID: ______

I. Image Processing

  1. Briefly describe the various forms and processes you see in the Narrow Angle image, using both it and the context MOC image. Label a few of the features that you see on a figure and paste it into your write up.

Hint: What are the depressions in the context image? What material is the narrow angle image cutting through? What are the dark streaks in the narrow angle image?

Answer:

II. Altimetry and Topographic Analysis: Photoclinometry

  1. Why is photoclinometry only valid along track that cutacross the image parallel to the illumination direction?

Hint: Think about how photoclinometry determines surface slope.

Answer:

  1. How and why does the photoclinometry function ‘pclin.m’ fail when the albedo and shadow illumination parameter are far from reality? Make a few plots to demonstrate what happens are you vary these parameters and paste them below.

Hint: Think about how photoclinometry works and look at the equations that make up the algorithms in ‘pclin.m’

Answer:

II. Altimetry and Topographic Analysis: Laser Altimetry

  1. What is the total relief along the default mola track? What are the maximum slopes seen along the track? Are all of the high points in the image at the same elevation? Are the slopes consistent with loose sediment (as opposed to bedrock)?

Hint: Make a plot and label a few of the main points (max/min height and max slope). Loose sediment will have slopes less than ~30 degrees (angle of repose). Bedrock can have slopes approaching 90 degrees at cliff faces.

Answer:

II. Altimetry and Topographic Analysis: Stereo Imagery

  1. Use ‘proftool3’ to determine whether the layers exposed along the edge of the cliff are roughly horizontal or not.

Hint: Make a plot of the topography along a bedding layer and look at the min/max elevation trends. It would be useful to incorporate a plot into your answer.
Answer:

  1. Determine the angle of the slope streaks that can be seen throughout the narrow angle image. Make a figure showing the profile of a few of them. What are the maximum and minimum elevations of the slope streaks that you studied?

Hint: Determine the slope at a few points along the profile of the streaks and report the maximum value.

Answer: