LBC Quick Review

Night Prep

Connect to one of the mountain workstations. For details on connecting to the mountain workstations remotely, see the Remote Observing Software/Setup page.

Ensure that your scripts have been uploaded. Note that the home directories of obs1 ,obs2 and robs are not cross-mounted.

• The home directories on the old computers (obs4, now called obs-32bit) are available on obs1, obs2 under /lbt/data/old_homes/.
• Scripts to take biases are available at /lbt/lbto/lbc/Calib_OBs/BIASDARK/

Beginning-of-Night Setup

 Turn on the TMS lasers and set up to run the TMS system following the guidelines under the Observing with TMS – Quick Review.

On the robsN and obsN machines, all of the windows and sessions that are needed to observe with the LBCs can be launched by running $ lbc in the terminal window. This script basically checks and launches only the windows that aren’t open yet.  The individual commands it runs are:

• lbc_cmu: a chromium browser window of the LBC User Interface
• lbc_iraf: an IRAF session
• lbc_fpia_monitor: a Focal Plane Image Analysis monitor session

In addition running $ lbc_idl will launch an IDL window if needed for using dofpia or dohybrid.  Starting in 2023B, we have modified our observing machines so that dofpia and dohybrid can be run directly from the terminal.  See Observing with LBC -> Collimating for details on the syntax.

Turn on the LBCs & establish the TCS connection

The LBC User Interface has 5 panels: House Keeping, Power Control, OB Execution, Log Analyzer and Information. By default, it comes up with the House Keeping screen displayed. Go to the Power Control page:

• The House Keeping should be on (“ready”). If not, turn it on.
• The “Other Systems” (Cameras, Trackers, Filters and Rotator) should be off, but “enabled” (meaning ready to be turned on). Click the button “Turn On” to turn these on.
  Note: If the ambient temperature is less than 0 C, then click the “Warm Up” button first and wait ~10-min for each degree below 0. Then click the “Turn on” button.
• Once the operator says that the LBCs are authorized, click the “Connect LBC” button at the top (both sides for binocular, left or right to use LBCB or LBCR only).

RB_Science

In another terminal window run RB_Science to launch the program which will open a ds9 window and display incoming LBC images: LBCB images in one frame and LBCR images in another. If you need to restart RB_Science, use the command, RB_Science --starttime -1, to display the last pair of Blue/Red images and wait for subsequent ones. Type RB_Science --help (or --howto) for brief (or extensive documentation), or see the LBC Software page for useful command line options.

IDL

If you need to run dofpia or dohybrid in IDL, then use the command $ lbc_idl (not just idl). Starting in 2023B, you may also run dofpia and dohybrid from the terminal window, using the syntax described in Observing with LBC -> Collimating.

IRAF

The LBC application will have launched an xgterm window and started an IRAF session in it. If you need to restart it, you may do so from any terminal window by typing the command lbc_iraf.

• In IRAF, epar LBTtools and set the
• camera to LBC
• archive to /lbt/data/new/   (/lbt/data/new)
  
• utdate to the UT date for the night in the format, YYYYMMDD
• :wq to save parameters and exit
• type LBTtools to load the LBTtools package
• type Observe to load the Observe package, which contains lbcrangebal
• type LBC to load the LBC package, which contains allseeing
• create a working directory. obs1 and obs2 do not have a /scratch disks, so you’ll have to work under your partner account (suggest working under ~/Scratch/<utdate>).
  
• cd /home/<partner>/Scratch/<utdate>. Do any IRAF work in this directory, since it is local and you have write permission to it.
• type prepdir to create the subdirectories under /home/<partner>/Scratch/<utdate> that are needed by LBTtools tasks.

Take test biases

• • • On the OB Execution Page, upload and play the script /lbt/lbto/lbc/Calib_OBs/BIASDARK/2Bias_Bino_Checkout.ob. 

Open ancillary tools

LBTplot: In a terminal window, type LBTplot to launch this tool.

Twilight Sky Flats

• Twilight flats are necessary (dome flats are not possible).
• Recent flats can be found at this table
• Use mkskyflat to create OBs, choose a blank field based on the current conditions.
• mkskyflat creates (1) a SkyFlatTest_*.ob to check counts and (2) a SkyFlat_*.ob to obtain a series of 5 dithered flats. On the User Interface, you can pause and change the scaling factor for the exposure time.

Observing with the LBCs

1. Collimate and Co-point

   • Upload the script to take the pair of co-pointing images for the first field.
   • Play this script, count to 3 and stop it in order to slew to the field but not take any images there.
   • In the shell or IDL, run dofpia (dohybrid, if the first collimation of the night or the first collimation after active optics has been cleared). Wait until it has finished. If TMS is unavailable, the –bypasstms (or in IDL /bypasstms) option needs to be used.
   • Once again, upload the co-pointing script and this time, play it to the end
   • Run lbcrangebal on the resulting LBCB/LBCR image pair to correct pointing and copointing
     • lbcrangebal Btime=bhmmss Rtime=rhmmss where bhmmss and rhmmss are the timestamps of the LBCB and LBCR images, respectively.
     • When prompted, position the cursor over the co-pointing star indicated on the finding chart and click the spacebar. The task will direct you to do this first on the blue image, then on the red image.
     • Enter “Y” to send the corrections if they are reasonable (few mm, 10’s of arcsecs)

2. Run the Science Observation

   • Upload and play the science script which corresponds to the co-pointing script just executed.
3. Repeat steps 1 and 2 for each target.
4. To estimate seeing, in IRAF use imexam, and multiply the pixel width by the pixel scale (0.2255) to get the seeing in arcsec.

End of Night Shutdown

• Run one or two series of 25 biases after closing and with the dome dark.
• Click the “Disconnect” button near the top of the User Interface to disconnect the LBCs from the TCS
• Turn off “Other Systems”
• Leave “HK” on