The Quality of the Aspect Solution

The aspect data are redundant in many ways. Therefore, the quality of the reconstructed aspect solution can be measured. However, at the current stage, many of the quality measurements are not in place yet. Describing only the quality measures which are calculated by the present software release, this section will evolve over time. Setting the control level to 4 or higher, the quality measures are calculated and stored in the info structure of the aspect solution object. The following command lines show how to access this information.

IDL> o->set,aspect_cntl_level=4
IDL> data=o->getdata()
IDL> info=o->get(/info)
IDL> help,info.as_quality,/struct
** Structure <40697188>, 3 tags, length=752476, refs=2:
   RADII           FLOAT     Array[26874, 6]
   TRIANGLE        FLOAT     Array[26874]
   RAS_RESIDUALS   POINTER   <NullPointer>

Reduced Triangle. For each SAS integration time, three pairs of Solar limbs are measured. Reconstructing the Sun center in the SAS coordinate system, the three mid-perpendiculars of the three pairs of limbs do not intersect in one point but form a triangle. The size of this reduced triangle is a measure for the quality of the SAS solution. Setting the control level to 6, the size is calculated, the moments of the size are displayed on the log window and the data versus time is plotted. Currently, a mean value $<$ 0.5 arcsecond and a variance of $\approx$ 0.5 arcsecond$^2$ are reasonable values.