GROND daily/weekly calibration procedures

Daily calibration (by LS staff)

Execute the OB "GROND_cal.obd".
This OB sequentially takes a series of bias and dark frames for all 7 GROND detectors.
The OB can be launched at any time during the day at the convenience of the operators. It takes 1:20 hrs to finish.
It does not depend on TCS status (the earlier bug has been fixed). Yet, make sure that the TCS is off (and the red lamp on) on the main GROND panel.
It can run in parallel to any WFI/FEROS activity, i.e. any WFI/FEROS calibration will not disturb the GROND data of this OB. Exception: do NOT move the telescope while the OB is running (this causes noise in the detector read-out)!
In principle, also light in the dome (including opening the main door) can be tolerated, but this should not be the default option. Also, we would like to informed post facto, if the dome was not dark while the OB was running.

With telescope in Zenith: open Main Mirror Cover
Preset to "FFScr"
Make sure that WFI skyflat lamp is off.
Execute the OB "GROND_img_cal_flat.obd".
No need to switch on any lamp - this is done within the OB.
This OB sequentially takes a series of dome flats separately for (i) the g-band, (ii) for the riz-bands, (iii) for JHK, and all the above for normal and fast read-out speeds.
The OB can be launched at any time during the day at the convenience of the operators. It takes 30 min to finish.

There are two skyflat OBs:
- GROND_img_cal_skyflat.obd for evening twilight
- GROND_img_cal_skyflat2.obd for morning twilight
Each of those executes three subsequent exposures with rising (evening) or decreasing (morning) exposure times.
Evening skyflats should be started when the Sun is at -6 deg.
Morning skyflats should be started when the Sun is at -10 deg.
Each of the OBs takes 25 min, thus they span the -6...-10 deg (evening) or -10...-6 deg (morning) Sun angle range.

Jochen Greiner (jcg@mpe.mpg.de), last update: 27-Jun-2008 [Disclaimer]