Live From Mars 01 at CMS

Rendering MOLA Data into an Image Map and Surface Plot

When the Mars Global Surveyor reached the Red Planet in September 1997, it assumed an orbit and began "bouncing" a beam of light off the Martian surface by means of the Mars Orbiter Laser Altimeter (MOLA). By measuring the speed at which the reflected pulse returned to the spacecraft, engineers determined with great accuracy the Martian surface topography and elevation.

The original Live From Mars Activity 1.2 - Mapping the Topography of Unknown Surfaces offers a wonderful modeling activity for students on the mathematics and science behind the MOLA. As an extension of the LFM Teacher's Guide directions, students can also render their shoe box measurements into a full color image map and 3-D surface plot, both closely resembling images generated by the actual MOLA instrument.

Software Requirements

Spreadsheet program

NIH Image - Mac (Download free software) or Scion Image - PC (Download free software)

Materials for Activity 1.2

Instructions for Rendering an Image Map

 

1. Record all altimeter rod readings on spreadsheet. Be sure numbers entered represent height of surface, not depth of rod.

2. Upon completion of measurements, highlight and save spreadsheet data as ASCII TEXT.

3. Open NIH Image or Scion Image, go to File menu and import spreadsheet data as TEXT.

4. Go to EDIT and select SCALE AND ROTATE.

5. Enter 25 as a new scale number

6. Click off NEAREST NEIGHBOR interpolation and click on BILINEAR. Click OK

7. Drag down OPTIONS and select COLOR TABLES. Select RAINBOW.

Sample Image Map

Instructions for Rendering a Surface Plot

 

8. Go to Analyze on the menu bar and drag down to Surface Plot.

9. Click off WIREFRAME and click on GRAYSCALE/COLOR.

10. Click OK

Sample Surface Plot

11. Compare the images rendered from shoe box data to actual MOLA images found on the Mars Global Surveyor website.

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