Troubleshooting guide

If you need to take many darks at several different exposure times, consider writing a cshell (csh) script which
consecutively calls config.exposure.pl and more.singleimages.pl multiple times, each time passing the proper
keystrokes into each script. An example, based on a script written by Anthony Gonzalez (UF), appears in
~2mguest/bin/Example.many.scripted.darks.csh
Note that the blank lines are very important!
Also, be very certain to check later that the script completed successfully; cf. § VIII. Troubleshooting for
possible failure modes, such as bad reads, scrambled images, zero frames, and MCE4 hangs.
H. Dome Flats
Although most observers use sky flats generated from the target observations, one may take dome flats as a
backup. These can be taken at the end of the night or during the afternoon, although one may have to wait until
1600 hr when the spotlights for the Visitor Gallery turn off. During the daytime, one should open the mirror
covers only with the telescope at zenith, then use Go to White Spot from the shortcut menu. Naturally, do not
open the mirror covers if the weather is questionable or the dome is wet.
Instead of taking darks for bias and dark current subtraction, we recommend taking a series (10 – 20) of flats
with the lamp at the proper intensity to yield signal levels in the 10000 – 15000 ADU range and a second series
with the lamp turned off. These two sets are then averaged and subtracted to eliminate the bias and dark
current, as well as any ambient background light and thermal emission.
I. Custom Scripts
Various user scripts are located in the directory ~/bin and have the general format <scriptname>.csh. To create
a custom script, cd ~/bin and copy an existing script to a new name:
cp <scriptname>.csh <newscriptname>.csh
After editing the new script, you may execute it from the command window with
~/bin/<newscriptname>.csh
FLAMINGOS@2.1-m, Ver. 2.39, 2011 May 13 Page 23 of 46