Ok, I rarely post to this forum because I am a visual observer, but had dabbled in CCD a while ago.
The purpose of this thread came to my mind due to the recent problem of substantial offsets observing the same variable (CH Cyg) by different CCD observers. Something like several tenths of a magnitude! Thats even worse than typical visual observers. This problem has been noted with several other variables in the recent past as well (NSV 1436).
It would seem to me that gross errors like this could be caught by the software before the results were published, if more than one comp star is in the field? The software should check the expected value of each of the comp stars based upon the others, using some kind of good algorithm. Any anomalies should then be red flagged as a problem somewhere in the reduction, comps or technique. The variable's observation should then be withheld until these internal/systematic errors are resolved and the algorithm computes the correct estimate for all comps within a certain error level.
Is this something thats already available, but not used by observers, or does this feature need to be added?
Seems like this kind of internal check of all available comps against each other would resolve most of these issues of grossly aberrant CCD observations. Of course, this implies several comps should always be used. Submitting any observation using a single comp star can be quite dangerous!