Quick Reference

  1. Login and check instrument status
  2. Start LRIS software, autocopy, FACSUM, Guider Eavesdropping
  3. Test Bias and Flat
  4. Verify Slitmasks
  5. Identify Alignment boxes for slitmasks
  6. Determine Central Wavelengths
  7. Create Setup files
  8. Focus the instrument
  9. Acquire Arcs and Flats
  10. Create Target List

Contact your Support Astronomer (FN)

  1. If you do not know who is your assigned SA, you can find the name on the observing schedule posted in the Remote Ops room of Keck 1 or available online. Home and cell phone numbers are posted on the cork boad behind the monitors of the instrument observing station.
  2. You should make sure to discuss the following points with your SA:

Login and prepare your workspace

Observers control the instrument from the instrument workstation, a three-headed computer called haleiwa. It is located on the left-hand side of the workbench in Keck 1 remote ops, close to the polycom TV screen.
FN: your SA will help you with the first startup of the system.

Follow these steps to login and prepare your workspace:
  1. Identify your computer account.
    Locate the Keck I observing schedule posted in the Remote Ops room (or online). Find the listing for today's date (see also the upper right corner of this html page). Note that the dates are HST, not UT. The sixth column of the table will indicate the account you have been assigned, such as lris1. There are 20 lris accounts. You use always the same during your observing run. Use your account name when logging into any computers at Keck.
  2. Login into haleiwa and pupukea
    Ask the SA for the password. Make sure that your desktop environment is FVWM, otherwise the instrument Menus will not work. Two items should appear:
  3. Check instrument availability.
  4. Print logsheets.
    If you will need logsheets for note-taking, you can print the preformatted ones:
    right-click on the background pane, select

    Instrument Utilities...Print Logsheets

    A GUI appears and you can enter your choice and the quantity your desire to print.
    Electronic logging for LRIS is still in its experimental phases.

Start up your LRIS session

  1. To start the LRIS Software,select

    LRIS Control Menu --> Start Up All LRIS Controls

    from the desktop menu. An xterm window will pop up with the following message: 
    Welcome to the LRIS initialization script.  You should ALWAYS run this script 
at the start of any observing nights of your run to undo any changes that the previous 
observer made to LRIS and to re-initialize hardware ans software.
    The script is self-explanatory, but in case you want to know more, follow the link.

    When finished, the script will beep and print the message: 

    Instrument initialization completed --- please proceed with observing
    and the xterm window will disappear.

  2. Check that the following windows appear:

      Left hand screen  Center screenRight hand screen
    LRIS widget
    CCD log window
    Motor log window
    Object.tcl window     		blue XPOSE gui
    blue DS9 image display
    blue DS9Relay
    instrument compass rose
    Xbeeper
    ADC Status Gui
    		red XPOSE gui
    red DS9 image display
    red DS9Relay
    instrument compass rose

  3. Launch Autocopy
    The Autocopy program (a.k.a "copymon") will automatically copy new images from your summit data directory to a scratch directory at HQ. To start it, right-click on the background pane and select

    LRIS utilities -> Autocopy(copymon)

    from the desktop menu. The Autocopy program will create a new directory using the HQ scratch disk with the most available space, copy into it any existing images from your summit data directory, and wait for new images to appear.

  4. Turn on sounds with Xbeeper
    After selecting sounds and starting the script, iconify the tool. You can change the sounds every time you wish.

    To silence the tool, press the Quit button.

  5. On pupukea start the following:

Verify instrument's setup

The following elements are loaded on-board LRIS upon request:

Optional: Take test exposures

Test exposures are taken to ensure that everything is fine with the instrument and the light path.
You can skip this part if you are taking afternoon calibrations (bias and dark frames, flat field images, etc.) for your science program.

If you do not want to save the test images, turn off the write to disk option: in the Xpose GUI, click on Disk... and select Disabled for the Disk Write option (left hand side)

Do not forget to enable the write to disk when you take your calibrations.

The steps below assume that you are familiar with the use of the XLRIS, XPOSE, and FIGDISP GUIs. Follow the links if this is not the case or ask your SA.

  1. Take test bias exposures
    2. For both red and blue side, in the XPOSE GUI:
    1. Close the trapdoor.
    2. Set exposure time to 0.
    3. Click on the Start Dark button.
    4. Once the frames are readout, inspect the frames.
    5. If you see something unusual, contact your SA.
  2. Take test illuminated exposures
    3. Configure for imaging on both side. This can be done via a script: in the punaluu window type

    take_test_flat

    and hit Enter.

    Alternatively you can configure the instrument and manually take the images:

    Set grating = mirror
    set red filter = R     		Set dichroic = 560
    set grism = clear
    set blue filter = G
    1. Set slitmask = direct.
    2. Switch on the neon lamp.
    3. Set red and blue exposure time to 1 sec.
    4. Take one red and one blue frame (Click on START in the XPOSE GUIs)
    5. While images are reading put switch off the Neon lamp.
    6. Check that light is seen in the frames.
    7. If you see something unusual (e.g. no light), contact your SA.

MOS: Verify instrument's slitmasks

    Verify Slitmasks with the LRIS Slitmask Imaging Tool"
  1. From the desktop menu, select LRIS Utilities --> Image Slitmasks to launch the LRIS Slitmask Imaging Tool
  2. Use the check boxes on the GUI to select all masks to be observed.
  3. Click GO to acquire direct images of the masks.

Users who are using LRIS in Multi Object Specroscopy (MOS) mode, should take images of their masks and verify that they correspond to what was requested. Although errors are rare, they do occur. If an error is caught early enough in the afternoon, there is usually time to correct it. If you discover any problems with your masks, contact your SA.

A script called LRIS Slitmask Imaging Tool" may be used to obtain direct images of all of your slitmasks so that you can verify them and calibrate the xbox routine. Note: Since the blue side is faster to reconfigure than the red side, most slitmask observers prefer to do slitmask alignment on the blue CCD. The script will reconfigure the blue side for imaging and acquire the slitmask images, then return the instrument to your original configuration. Alternatively, you may manually cycle through the slitmasks.

The following instructions for manually verifying slitmasks assume use of the blue side.

  1. Configure the lris blue side in imaging mode:

    • Close the trapdoor.
    • Set dichroic = 560.
    • Set grism = clear.
    • Set filter = G.
    • Switch on the Argon lamp.
    • Insert the slitmask you wish to image.  
    • Set exposure time to 1 sec.
  2. Take one exposure.
  3. Verify slits: verify that all slits and alignment holes are in their expected positions and that all slits appear clean. If dirty slits are suspected, they can be removed and cleaned if summit personnel are alerted soon enough.
  4. Repeat: repeat the preceding steps for your remaining slitmasks.

MOS: Identify Alignment Boxes

In this step, we define the positions of the alignment boxes and create coordinate files for use during the night.
  1. Start IRAF:
  2. load the keck package and the lris sub-package
  3. cd to the data directory.
  4. epar either check_boxes
  5. Run check_boxes imagename on each image of a slitmask where alignment boxes need to be identified. maskname.box needs to be set to the mask name as it appears in XLRIS appended with a .box (e.g. COSMOS.box). This will enable the do_lbox and do_check_boxesb to run with default file names.
  6. After creating coordinate files reset "doxbox" back to yes.

MOS/Longslit: Determine a Central Wavelength

If this is your first night or the gratings have been swapped, you will need to determine the central wavelength for spectroscopic observations.

The wavelength range on the blue side is set by the choice of the grism, while, on the red side, it can be tuned as desired by tilting the grating. Check the dispersive elements web page if you want to know more on the possible wavelength ranges.

The following instructions assume use of the red side.

  1. Configure the red side in spectroscopic mode, as required by your science program
    • Select one of your slitmasks or the chosen longslit.
    • Select the grating you will be using for your science.
    • Select the filter you will be using for your science.
    • Specify your desired central wavelength.
    • Close the trapdoor.
    • Turn on the desired arc lamps.
    • Set exposure time to 1 sec.
  2. Take an exposure.
  3. Make a row plot in FIGDISP and check the peak counts. If needed, increase the exposure time and take another exposure to get sufficient signal.
  4. Compare a row plot from your image to the plot displayed by ARCPLOTS for the same instrument setup. Identify key features and estimate the central wavelength. If the wavelength coverage is not optimal, adjust the Wavelen or MSWavelen settings as required and take another exposure.
  5. Repeat the procedure for each slitmask/grating combination needed for your science program.

Each grating can be inserted in any one of the 4 available ports. Since the ports have slightly different zeropoints, the central wavelength selected by means of the XLRIS GUI can be off the mark by a few hundred Å. Moreover, the use of grating angle settings from previous runs will not yield the correct setup, unless you are sure that the grating of interest is installed in the same port.

It is therefore recommended to take some test arc lamps frames and check that the wavelength range is as expected. The ARCPLOTS tool can be useful for lines recognition and comparisons.

Optional: Create setup files

If your science program requires multiple instrument setups during the night, it is recommended to create setup files.

There are various ways to create setup files. We present here the two simplest ones:

  1. Instrument State files
    It is possible to save and restore snapshots of the LRIS status using the scripts save_state and restore_state.

    These scripts are run from the punaluu window.

    For a complete description of the options see the save_state and restore_state scripts.

    Note:
    1. The script save_state generates ASCII files which can be easily edited.
    2. The snapshot may also include CCD keywords and other parameters, unlike the XLRIS scripts
    3. The restore_state script can generate error messages in case of failures.
  2. XLRIS setup files
    The XLRIS GUI allows saving the current state of LRIS to file for later recall:
    1. Configure the instrument as desired.
    2. Click on WRITE (lower left).
    3. Type in the name of the setup and click on WRITE
    4. Click on DISMISS
    To recall the setup:
    1. Click on GO
    2. Select the desired setup
    Note:
    1. These setup files are saved in the ~/setups/ directory and can be edited at will. This is particularly useful if you want to change one value without having to recall the setup and save it again (e.g.:you want to change the camera focus values).
    2. The files do not save the trapdoor status or the lamp settings.
    3. The files do not include the CCD parameters.

Determine Instrument Focus

Both the red and the blue camera need to be focussed daily.

There are now three different methods for focusing the instrument. Please use the focus procedure that best suits your science program.

As the observer, you're responsible for determining the nominal focus of the red and blue cameras using the above procedures.
Remember that if the camera are not properly focussed, the telescope focus may also be determined incorrectly.

Note 1:

Large focus variations on both cameras have been observed. Thus, it is important to focus the instrument each night.

Take afternoon calibrations: Arcs and Flats

    Acquire arcs to determine the wavelength solutions
  1. Congigure the instrument for spectroscopic observations
  2. Close the trapdoor.
  3. Turn on the desired arclamps.
  4. Acquire spectra for each longslit or multislit setup
  5. Acquire internal halogen lamp flats if desired
    Acquire dome flats
  1. Wait for the telescope to be released an in the dome flat position.
  2. In the XLRIS GUI click on CMD...
  3. Select Dome Lamp Control.
  4. Aftr 10 seconds or so a widget appears: select imaging or specroscopic lamps.
  5. Configure LRIS as desired and take images.
  6. Do not forget to switch off the lamps when you are done by selecting Quit
Until the telescope has been released, it's not possible to take dome flats. While waiting (usually the telescope is released before 4:00 PM), you can take bias and dark frames. Note that the dark current on the CCD is quite low, so most observers do not bother with darks. Also, the LRIS bias is basically featureless, so bias frames are generally not necessary either. Remembet that LRIS is not light tight. USeful dark calibrations can be taken only of the dome is completely dark. Check with your SA if this is possible.

Prepare the target list

  1. Create and format your target list (starlist) as described in the instructions.
  2. Validate and install your starlist by selecting the item Instrument Utilities -> Install Starlist from the desktop menu. This script will check the syntax of your starlist and copy it into the appropriate directory. See install starlist.
  3. If the accuracy of your coordinates is suspect, use SKY to display the Digital Sky Survey image of your LRIS field.

Coordinate with the OA

Observing Assistants customarily arrive at the summit around 5:30pm in winter and 6:00pm in summer. Once they arrive, you can do one or more of the following:
  1. Greet the OA.
    Introduce yourself to the OA and alert them to any immediate needs that you will have. Tell them if you are taking calibrations and inform them about your calibration plans.
  2. Wait for the OA to get settled.
    Setting up computers and bringing up all of the telescope control systems requires some time, and things go wrong much more often than we would prefer. Be patient while the OA prepares the telescope for operation.
  3. Inform the OA about your starlist.
    Now would be a good time to let the OA know where your starlist is, so they can verify that they have access to it.
  4. Informthe OA of your plans for the night
    It is always good practice to inform the OA of your science plans: depending on the LRIS modes you plan to use (longslit, MOS, imaging), the OA will make decisions on how and when is best to focus the telescope. The OA can also be asked about specific observing techniques you are interested into (e.g dithering, offset pointing, etc). Just before opening, your SA will also be available to help with these issues. Do not be shy and ask.

Dinner

If you are reading this, you're probably very tired and hungry. Moreover, the real work is still ahead of you. Now it is a good idea to go get dinner and all other sources of sustainment you may need during the night.
In each remote ops room there is a folder labelled Restaurant Guide for you to consult. Please also note that Starbucks (acroos the road, in the Foodland food court) closes, mercilessly and irrevocably, at 9:00 pm.