Find heights

(lithos Main Menu Option 2. Find heights)


This Main Menu option solves for the brightness and slope of each pixel. It includes a variety of options, including stereo and photoclinometry.


When you choose Option 2. Find heights from the Main Menu, you will see this set of Suboptions:


 0. Begin integration
 1. Auto include neighboring maps
 2. Include existing heights
 3. Include shape vectors
 4. Include limb vectors
 5. Include external map
 6. Include differential stereo
 7. Include shadowing
 8. Fill with shape
 9. Include control points
 Q. Exit

0. Begin integration - Provide these inputs:

  1. Weight for the conditioning heights - Always use .025.

Whether to use weight 0.025 or not depends on a number of factors. Often in the first slope to height integration you may want to use a smaller number, 0.01. Also if you have a large number of overlapping maps and the seeds.pgm plot looks very dense, you may want to decrease the weight so as not to over constrain the solution with too many seed heights. Also, if some of the conditioning heights are derived from maps that have poorly determined heights, you should decrease the value of the weight to even less than 0.01. If this does not improve the heights integration, you may skip options 1 and 2 and use option 6 before you perform the heights integration.

  1. Number of iterations - Typically use 30.

  2. After the iterations are finished, enter one of these choices:
    • '0' to go back to the Main Menu
    • '1' to input more iterations
    • '2' to change the weight

1. Auto include neighboring maps - Includes data from surrounding maplets that have been added to the "overlap" list.

2. Include existing heights - Use this option most times. You dn't have to use this option if you include an external map.

3. Include shape vectors - This option is seldom used, perhaps only in the beginning stage of creating the first set of landmarks.

4. Include limb vectors - Constrains the solution by using limb data.

5. Include external map - You can use an external map, often a big map, to provide seed heights for the slope to heights integration.

6. Include differential stereo - This option calculates stereo points at random locations on the maplet. Testing has shown that this option is a good way to keep maplets from tilting at the edges.

7. Include shadowing - This is still an experimental procedure. It will be tried thoroughly when there's significant shadowing in the images used for the map in question.

8. Fill with shape - This option uses the shape model to fill any "holes" in the maplet, if they exist.

9. Include control points - This option is rarely used. It will use landmarks as seed heights.

Q. Exit - Exit to the Main Menu.

Typical Example

The following sample shows how to use 2. Find heights when starting at the Main Menu.

2         <- Find heights option
8         <- Fill w/ shape
2         <- Include existing heights
.01       <- weighting
1         <- Include overlaps
4         <- Include limbs
1, 2.5, 3 <- inputs for limbs
7         <- Include extended shadowing
6         <- include stereo
y         <- use gradients
y         <- use auto heights
0         <- Begin integration
.025      <- weighting
30        <- number of iterations
0         <- End iterations

The following sample output begins with the '0' input for Begin integration:

 gc seeds.pgm

 input weight
 Enter number of iterations
    -0.33759     0.34356    -0.34050     0.41873

 gc slope.pgm

    -0.28767     0.27729    -0.25837     0.36825

 gc slope.pgm

    -0.22599     0.18857    -0.16774     0.26969

 gc slope.pgm

    -0.22600     0.18859    -0.16777     0.26958

 gc slope.pgm

 0. end iterations
 1. more iterations
 2. change weight

 Current landmark = EE0001
SCALE =  0.000100 QSZ =   49
 Lat/Lon/Rad =     -6.800   264.090     0.266
 Region = EE


 check display

Additional Reference

1. Auto include neighboring maps

3. Include shape vectors

4. Include limb vectors

5. Include external map

6. Include differential stereo

7. Include shadowing

9. Include control points

(Compiled by JRW)


Find heights (last edited 2022-03-14 13:37:31 by JohnWeirich)