Troubleshooting guide

printed to the screen. Do not hit the Update All Items button on the UFSTATUS GUI during execution of either
of these scripts. It is, however, a good idea to update the GUI after the script has successfully completed.
NOTE:
• It is not possible to move more than one wheel at a time.
• The only useful dark position is on the Grism wheel; there is a dark position on the Decker
wheel, but it does not provide a truly dark condition, since it is not directly in front of the detector.
• Once the script has started moving a wheel, do not attempt to abort it. Just wait for it to finish
moving, and run the script once again.
C. Configuring an Exposure
Several parameters need to be set before taking an exposure. The script config.exposure.pl [Configure Exposure]
described in § III.A.5 will print out a list of exposure parameters, and query if you wish to change any of them.
If you do, you can step through each of the modifiable parameters; enter the new value or return to keep the old
value.
If you wish to change just the exposure time or the filename, and don't want to run through the entire list of
parameters, then use set.exposuretime.pl [Set Exposure Time] or set.filename.pl.
D. Taking Images at a Single Pointing
The most useful script for quickly looking at an image with the present telescope pointing and instrument
configuration is singleimage.pl [Take Image]. This takes an image immediately upon hitting return and displays
in ds9.
E. Taking Dithered Images
FLAMINGOS also has the ability to take a sequence of images using a set of pre-determined dither patterns. In
order to configure the dither pattern, run config.dither.kpno.pl [Set Dither Pattern]. This allows you to change the
following parameters:
DPATTERN The desired dither pattern. Your choices are 2×2, 3×3, 4×4, 5×5, 5box, 5plus, and
45rot_5×5 pattern rotated by 45 degrees. The offsets always are in the form of (δRA,
δDec). The 5box pattern is the 2×2 pattern with the central pointing; 5plus is the 5box
pattern rotated by 45 degrees.
D_SCALE Additional scale factor for the offsets. The default of D_SCALE = 1 will add a border to
your images of 15", for a net increase of 30" to the total field of view of the final stacked
image, for any of choice of DPATTERN.
D_RPTPOS Number of times to repeat each dither position.
D_RPTPAT Number of times to repeat the entire dither pattern.
STARTPOS Starting position in the dither pattern, where 0 is the first position of the pattern. This is
very useful if the system crashes or hangs mid-sequence, however do not forget to reset it
back to 0.
USENUDGE Nudge pointing center on pattern repeats; 0 = do not nudge, 1 = perform nudge.
NUDGESIZE Radial size in arcseconds of nudge, randomly chosen in one of the cardinal (ra, dec)
directions.
THROW Radial length in arcseconds to other nod beam (not functional in imaging mode).
THROW_PA PA of other beam for nodding (not functional in imaging mode).
After you have configured your dither sequence, run dither.source.kpno.pl [Execute Dither] to execute the dither
pattern and take images. Immediately after hitting return this script prints out information about the requested
FLAMINGOS@4-m, Ver. 2.39, 2013 April 23 Page 20 of 47