RESIDUALS.TXT
Compiled by KD
Description
RESIDUALS.TXT is a report created by residuals that looks for bad landmarks.
A basic description of the information in RESIDUALS.TXT.
- The post-fit residuals between predicted and actual control point positions in all images are captured in the residuals file
- The post-fit residuals between predicted and actual control point difference between adjacent, overlapping maplets are captured in the residuals file
- Outliers in both quantities are flagged automatically based on input threshold criteria
A more in depth list explaining the information in the RESIDUALS.TXT file is shown below.
- In between the dot rows:
- The name of a landmark
- T (landmark has a map with it) or F (flat landmark, no image)
- Resolution
- Lat of landmark
- Wlon of landmark
- Radius
- Below the dot rows with the landmark name above them:
- For each image:
- 1st column - picture name
- 2nd column - PX residual (# of pixels in image resolution)
- 3rd column - LN residual (# of pixels in image resolution)
- 4th column - magnitude of PX and LN residuals (# of pixels in image resolution)
- 5th column - the estimate linear residual (km)
- For each overlap:
- 1st column - overlap name
- 2nd column - X residual (km)
- 3rd column - Y residual (km)
- 4rd column - Z residual (km)
- 5th column - estimate linear residual (km)
- For each limb apperation:
- 1st column - picture name
- 2nd column - PX residual (# of pixels in image resolution)
- 3rd column - LN residual (# of pixels in image resolution)
- 4th column - magnitude of PX and LN residuals (# of pixels in image resolution)
- 5th column - the estimate linear residual (km)
- For each image:
- Below the images, overlaps, and limbs list for a landmark:
- Landmark name
- magnitude of RMS linear residual for landmark
- Below the single dot row at the very bottom of the image:
- Observations - how many IMAGEFILES, overlaps, and limbs for all landmarks
- RMS RESIDUAL - overall RMS linear residual in meters.
The user should note that residuals are the difference between observed landmark positions and those predicted by the solution (SPC).
Observed landmark positions are exactly as the name suggests, positions of a landmark found by observing pictures from the spacecraft of the object.
Predicted landmark positions are those found by SPC observing simulated images of the shape model generated.
Think of simulated images being taken at the updated SUMFILE positions and attitudes until the simulated image is as close to the actual image as possible.
Thus, when the RMS between landmark residuals is as low as possible the updated SUMFILE position is the new estimate for spaccraft position and attitude.
Example of a RESIDUALS.TXT File
..................................................
IA1_01 T 0.0200 56.5481 140.8124 13.6146
..................................................
A1_01 8.139 -6.853 10.640 0.01091
A2_05 -28.427 49.215 56.835 0.04250
B1_01 -3.517 52.347 52.465 0.04857
B1_03 -18.475 -57.091 60.006 0.05509
IA1_01 42.78
..................................................
IA1_03 T 0.0200 36.4771 136.8269 11.4593
..................................................
A1_03 -29.498 -12.161 31.906 0.04002
A2_03 -71.840 23.961 75.731 0.07142
A2_04 -3.885 -4.689 6.089 0.00643
A2_05 -34.754 95.249 101.392 0.10527
B1_01 64.895 -21.470 68.354 0.07337
B1_03 11.000 59.329 60.340 0.06832
B2_04 97.637 29.005 101.855 0.11002
B2_05 42.109 41.562 59.165 0.07455
IA1_03 75.45
.........
Observation # = 360180
RMS Residual (m) = 0.78928860594347106