Useful guider finder charts are a crucial item to have at hand
when starting the slitmask
alignment process on a DEIMOS slitmask. Dan Magee of
UCO/Lick has generously donated his excellent Python-based utility for
creating excellent DEIMOS guider finder charts from DSS images.
The software, installed now on all DEIMOS numbered accounts at
Keck, requires only the DSIMULATOR
output files as input, and generates not only a set of guider
finder charts, but also a starlist
file which you can simply copy into your directory in
/kroot/starlists.
Procedure
Log into a machine at Keck Headquarters using your DEIMOS
numbered account.
Transfer (via ftp or scp) your
DSIMULATOR output files (the TEXT file, not the
FITS file) from your home institution to Keck.
Run the software via
deimos_guider_dss file1 file2 .. fileN
where fileN are the names of your
DSIMUALTOR files.
Wait a few minutes for the software to create the finder
charts. When completed, the software will respond with
Point your browser to -> address
Use your browser to open this URL, which serves as an
index to your finder charts and to the starlist file.
Use the browser to access and print out each of the
finder charts.
Important sanity check: verify that the finder
chart shows stars in the locations of the markers where guide
stars are expected. If not, then the mask may have an
astrometry problem!
Copy the starlist file into your directory in
/kroot/starlists.
Troubleshooting
The script will fail to read the input file properly if
the mask name contains any spaces. If your mask name contains
spaces, simply edit the output file and replace spaces with
underscores, then re-run the script.
The script will fail if the list of guide stars
(code = -1) in the "Selected Objects" section of
the mask design file does not match the list of guide stars in
the "Selected Guide Stars" section of the mask design file.
If the script fails, simply edit the file and re-run the
script. [And thank Dan Stern for this fix!]
The script will fail if the list of guide stars
(code = -1) in the "Selected Objects" section of
the mask design file contains two or more objects with
duplicate target names. Edit the output file to ensure that
all targets are uniquely named and re-run the script.