Astro 3310 Fall 2015
LAB #4
-----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 subdirectory.
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
2. 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:
3. 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
4. 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
5. 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:
6. 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: