Discrepancy between starcheck P2 and preview P2

[taldcroft]

In the FEB1819B products I noticed a small but not insignificant difference between the P2 values in starcheck 13.0 and aca_preview. Specific example is 48379. Ref email thread "ACA preview of FEB1819" for links. Starcheck reports P2=4.2580 while preview shows 4.02. (BTW, only two digits of precision are warranted in that number in starcheck.).

I suspect a diff in T_ccd being used but haven't tried to track it down. Slightly OT, but are both the acq and guide temps reported in 13.1?

[jeanconn]

I think 13.1 doesn't really exist but my plan was to cut the N100 fraction and get both T_ccds in there.

[jeanconn]

I don't know if I put it anywhere but I was also wondering about putting the "call_args" for the starcheck get_acq_catalog call somewhere; but wasn't sure if that was overkill in a quest to be useful for just this kind of mismatch debugging.

[taldcroft]

I can't reproduce this now and am taking this off the 4.1 milestone (with checking below), but leave open for now in case something similar comes up again.

The original FOT MP directories are gone or changed and the breadcrumb trail I left isn't enough to get me back. What I did was double-check again (similar to the original validation for proseco promotion) that the guide and acq t_ccd in sparkles output matches the starcheck t_ccd temperature plot (visually) for a obsid 21263 in the production FEB1819B (pickle taken from /data/mpcrit1). In addition the P2 values are consistent to the printed precision of 0.01, and the guide t_ccd is good to within 0.1 C.

sparkles:

Probability of acquiring 2 or fewer stars (10^-x): 5.97
Acquisition Stars Expected: 7.51
Guide Stars count: 5.00
Predicted Guide CCD temperature (max): -11.1
Predicted Acq CCD temperature (init) : -12.2

starcheck:

Probability of acquiring 2 or fewer stars (10^-x):	5.9739	
Acquisition Stars Expected  : 7.50
Predicted Max CCD temperature: -11.0 C 	 N100 Warm Pix Frac 0.268

[jeanconn]

I thought this was a starcheck 13.1 issue and not a sparkles 4.1 milestone issue anyway but maybe I was confused on scope.