CD16 tasks (revised 10/22)

First Second pass at CD16 tests.  This reflects discussion on 10/22  This is posted mostly so people can comment and we can revise.  What else?!?

• would like to run as much as possible from GUI.  
• Should have bias we expect to fly with (2 V?).  If we need to adjust bias when higher photon fluxes, we can do it, but that would mean we need to get bias board installed for commissioning.  
• Would like to run with short frame time as much as possible.  ctdelay = 13 will give us 493 msec.  Do lots of Ns (and use lots of memory).  

1. verify focus across array with flat focal plane
1. medium mode
2. hi-med mode (slit 3 should give < 3 km/s at 14 microns)
2. Check for leaks in BBP_4700_5615 + MgF2 blocker.  
3. Calibration testing - ideal is to be able to do calibrations in the lab before/after mounting to SOFIA, but that probably won't happen.  We'd need to be able to use a model for dividing out the sky for this to work.  More likely is to do a blackbody and sky at start of each leg for the calibrations with eventual goal of only needing to do it once per flight per setting.
1. flatfield - how repeatable are blackbody images.  Good to do at wavelength with little/no atmosphere.  1230 cm-1 is one possibility (N07904 filter).  Or medium mode long slit near 1160 cm-1 (Ocli Q in decker).
1. in time series (differences with no change to setup)
2. after lunch or overnight (leave setup as is, but let time change)
3. after returning to an old setup
4. Note: want to check flatfield counts vs predictions.  
2. darks (will be subtracted from blackbody):
1. how dark is mirror in lens wheel compared to dark at slit wheel and to unilluminated parts of cross dispersed and long slit.
2. how variable is it (various time scales).
4. Linearization data - repeats of multi-Ns with D such that we can see ADU change as a function of linear increase in time.  Vary illumination by using slit width?  Have orders just slightly overlapping in hi-med mode.  
5. Check to see if ellipsoid shimming is good.
6. Check pupil imaging focus, if needed.
7. Get throughput for filters without them.  Also need throughput for at least one previous filter to see if bias has impact.
8. Noise data: verify noise floor with new fanout using series of identical darks (lens wheel mirror) at several biases.
9. Measure input angle using heat source at distance of secondary mirror.  TAAS SCHP with no SI plate (or SI plate still connected to EXES) might work.  Might use travel of SCHP to determine acceptance angle.  Distance between EXES window and secondary is (from KRS5 zemax file) 6.66 meters or 21 feet 10 inches.  Secondary diameter is 352 mm or 13.86 inches.   I think we'd like to have SCHP travel be larger than 70 mm (20% of secondary diameter) to get an accurate enough idea of our acceptance angle.  More travel is better.
10. Mount to TAAS
1. Compare alignment to SCHP on TAAS to previous iterations.  Ted Dunham says he's seen 1.5mm difference in TAAS FCLS locations.  Absolutes are, therefore, questionable.  Relative motions should, I think, be ok.    
2. Look for change of SCHP in cold stop as a function of letting EXES sag on its plate.