Describe Block 8 - Geometry/Residuals here.## page was renamed from Block 6A - Lat/Lon Tiling V0

Block 8 - Geometry Residuals

Description

Geometry is a very power and necessary tool in SPC in order to update the spacecraft position. Once done, the position and pointing of the spacecraft is significantly improved so that the calculations with residuals is more accurate.

Assumptions

• You have invoked a Bourne-Again Shell (bash) on ormacsrv1.lpl.arizona.edu

User inputs

• None

Procedure

Step 1- Ensure Stability

Ensure that there are no major problems with the shape model.

• Correlations of all landmarks are fixed. You can run support/batchCheck <fileList> to check this. This runs lithos and checked each landmark's images' correlation and stars. You can also use support/evalLog.sh. This would be required to be done after an iteration, based on the <landmark>.OOT log files.

• Landmarks have sufficient images (3)
• Images have sufficient landmarks (3)

echo 5 .005 .0002 | residuals      # 5 is static, .005 should be 5*acceptable RMS error, .0002 is the pixel size of the highest resolution image
grep ">>" RESIDUALS.TXT

• Review the output.

• Run lithos on that list of landmarks, most likely by hand to fix whatever issues there are.

Step 2 - Prep for geometry

• Backup your working directory

rsync --exclude=*DAT -hapvP . <path>backup-<date>

Step 3 - Run Geometry

Running geometry is pretty simple, but it is very powerful. In this case, we will do an update of the central vector first. It is unlikely that it is needed because lithosP usually does this a lot, but it doesn't hurt. Then we run camera pointing, SCOBJ, which moves the spacecraft and its pointing. This updates the SUMFILES.

geometry
   1: landmark vectors.
   2: camera pointing, scobj
   0: end. 

 input operation list
120

 enter number of iterations
15
 use limbs for pointing? (y/n)
y
 continue? (y/n)
n

Step 4 - Review

echo 5 .005 .0002 | residuals      # 5 is static, .005 should be 5*acceptable RMS error, .0002 is the pixel size of the highest resolution image
grep ">>" RESIDUALS.TXT
grep ">" MAPINFO.TXT

• If you have errors in RESIDUALS.TXT, you will need to look for the specifics with RESIDUALS.TXT itself. If the error is in an overlap (it only lists 6 characters), you can ignore this.
• You should expect many more errors in MAPINFO.TXT, and when you go into the landmark, you won't be able to find a problem. For this step, focus on the worst values