Building a shape model
The normal way (Bob's way) is described in a text file called "densify.txt". I have created a script to automate things in a standard way.
- Copy the directory "shape3/support3" and put it in the working directory and call it support
cd <workingDir> cp -r ../shape3/support3 support
- Edit the buildShape.sh file
- Change the suffix to H2-Test1-
- Comment out (#) the line that runs dummer
dumber < tmpRun.txt | tee -a shape.log # normally used
- Remove the comment (#) from the line
- #cp SHAPEFILES/SHAPE.TXT SHAPEFILES/dumb$suffix # used only with initial base model Q=32
- Run the program
- When it is done, it will have already run view_shape (via another script viewShape.sh)
- Look at the files view_01.jpg (01 to 10) and shape.gif
This will create several different resolution shape models, each with a factor of 2 higher resolution. The 512 is the highest resolution model, with 1.6 million vectors.
One you create the high resolution model, you can install it in the directory SHAPEFILES. This is done by removing the symbolic link to SHAPE.TXT and replacing it with the new file that you've created.
ln -s shapeH2-Test1-512 SHAPE.TXT
You can run register and load the shape model to see how the new shape model looks.
- Create a bigmap using the TAG site definition.
bigmap < MTAG15.in
- Display the map
showmap MTAG15 convert MTAG15.pgm mtag15.jpg open mtag15.jpg
You can also view it using other programs
view_map_rgb MTAG15 1 1 2 45 convert view.ppm output1.jpg view_map_stereo MTAG15 convert view.pgm output2.jpg
You can use coverage_p to show how well a region has been tiled.
map_coverage MTAG15 0 .0012 convert coverage_m.pgm coverage.jpg
Building maplets using bigmap
Previously, we created maplets with the initial topography from the shape model. Once we go beyond 75cm (for Bennu), then the bigmap will have the higher resolution, which will be needed. To do this, we "fill" the maplet with the data from the bigmap rather than the shape model.
- 200 200
- .00075 49
- 0 50 .2 .2 0 4
- b - fill with map
- y - list possibilities
- n - Auto pick
Then just continue processing like normal. It is unlikely that you will need to align to a picture. You now have decent topography with albedo, so you should be able to just 'auto align' to get the images aligned -- that is option "1" and submenu "0" auto align
Resetting the albedo in lithos
If you have some topography that isn't good in your template, you may want to replace it. If you can load the data from another maplet, that works well. However, if you cannot, you can remove the template, setting it to 0. Then as you build a template, you are not fighting bad data.
Within lithos and the landmark is already loaded
- a - reset albedo menu
- y - reset slopes
- y - reset albedo
Then you can do several "build templates" (0 0 44)
The RECENT command in LITHOS
There are times when you need to re-enter the same landmark. There is a shortcut in lithos that lets you use the landmark that you were just using, RECENT. You can either type "RECENT", or "R" or "r".
This assumes that you've already worked with a landmark and typed in its full name. You can enter this in at the following menus.
- i - input menu
- o - overlap/limb menu
Overlaps Menu in LITHOS
Overlaps are used by SPC to help constrain a solution. Each maplet will have its edges overlapped by other maplets. SPC will identify which maplets should have overlaps, and then it will share information between them to reduce error.
Overlaps must be set in lithos. This is done in the 'o' menu. This is done as part of the normal scripts that you have been given.
Also in those scripts, they run the overlap menu that has an option to set the limbs. A maplet is set at a limb when any part of its surface is in an images' limb. What lithos does is reviews every image and identifies where the limb is in that image. Once found, it will see if the the maplet should be present. If so, it will record that image as a limb image for the maplet. More info: Attach map to maps or limbs
Steps in SPC (taken from the standard scripts)
o - overlap menu r - use recent landmark y - clear out old data 1 - automatically detect overlaps o - overlap menu r - use recent landmark n - do not remove old data (we want to keep what we just did) 3 - search for limb images n - clear. Do no remove old limb images 1 3 5 - Search parameters.
When you are done, lithos will not have a landmark loaded. Thus, it is useful to reload the landmark
i r n n
When you run bigmap it will generate two files
SIGMAS.TXT -- a text file that lists the residual error. Each time you run it, it will add an entry. The first number is the maximum deviation. The second number is the average deviation.
The residual deviation is computed for every pixel by taking the height value from every maplet that was used to determine the height. In bigmap, it will average those values. The residual (or sigma) is the standard deviation of those heights.