LRIS START UP AND OPERATIONS PROCEDURES on Keck II (December 1997)

from Lori Lubin

LRIS Start Up Procedure

  1. Activate "Start Up ALL LRIS Control" utility under LRIS Control Window in left display. This starts XLRIS, Xpose, CCD Log, object.tcl (to edit image header), and Figaro.
  2. Click SET in XLRIS window to get slitmask, grating, filter, and focus parameter window.
  3. Activate LRIS "Telescope Parameters" utility under K2 Telescope Status Parameter in right display. Parameters include LST, UT, HA, Ra, Dec, airmass and telescope focus.
  4. Activate LRIS "Exposure Parameters" utility under LRIS Eavesdropping in right display. Parameters include frame number, elapse time and LRIS temperature.
  5. Activate "Facilities Summary" utility under LRIS Eavesdropping in right display to see OA's information display.
  6. Activate LRIS "Guider Compass Rose (RA/Dec)" utility under Compass Roses in right display. Note that the "guider position angle" is 90 degrees different from the "LRIS position angle" as given in LRIS Summit tools "LRIS Compass Rose (RA/Dec)".
  7. Be sure to define disk area with "DISK..." button on exposure window. Initially disable disk writing until testing is done. Note that the disks are crossed-mounted. You must specify /data before the directory name e.g. /data/sdata200/lris1.
  8. Verify that display section is set correctly by hitting "WIN..." button on exposure window. You should have X,Y binning equal to 1 and window W,H equal to 2048 (unless you want to readout only part of the chip). Note here that X,Y indicate the start row,column while W,H indicate the TOTAL number of rows,columns.
  9. Set exposure number ID with "m frameno=NNNN" from UNIX window, verify ID with "s frameno". Note that you must be in a window on Makuna.
  10. Set object name with "m object=name" from UNIX window on Makuna, verify with "s object". Note that you can now also do this by editing the name and description in the object.tcl window. This window is brought up automatically when you start "ALL LRIS Control". You can also get this window by clicking CMD in the XLRIS window and specifying "object.tcl".
  11. Set gain setting with "m ccdgain=low" from the UNIX window, verify with "s ccdgain". This gives a gain of 2 e-/DN. The gain is also shown on the XPOSE window display.
  12. For Oke et al. distant cluster project, set sky position angle to 180 deg (and track at this PA throughout). This is done by a request to the OA. This means that North is down, and East is to the right.
  13. In the daytime, do test exposures (e.g. R band filter, 1 sec, slitmask in, mirror in, trap door open, dome lights on) to verify slitmasks are correct.
  14. Enable disk writing!

Calibration Procedures

  1. Taking domeflats for photometric claibrations : Open trap door. Direct mirror in. For imaging flats, use low lamps.

    DOME FLAT EXPOSURE TIMES
    B 20 sec
    V 10 sec
    R 6 sec
    I 3 sec

  2. Spectral standard star : longslit + GG495 + 300g/mm. Exp time = 10 sec. Wavelength = 6900 Ang. Set this wavelength using the "W" next to the Wavelen display on the XLRIS window. Note the wavelength offset from the central wavelength in multislit mode.
  3. Arcs : Close trap door. Ne, Ar lamps on. Exp = 2 sec.
  4. Spectral flats : Ne, Ar lamps off. Halogen on. Exp = 2 sec.

Multislit Operations

  1. Open trap door.
  2. Convert to imaging mode but with GG495 filter. Note that this filter cuts off the second order wavelength - important so that the second order blue lines do not overlap your first order red ones.
  3. Go to star and have AO run align procedure. (This will align the mirror segments).

    Slit mask alignment procedure:
    NOTE - use TWO AMP mode to do the slitmask alignment as the readout is faster. Remember to change back to ONE AMP mode to take the spectra. Click CMD on the XPOSE window to change from ONE to TWO AMP mode. Notice that as of 4/96 the image displayed in the Figaro display window in NO LONGER flipped in X in ONE AMP mode!

  4. Take picture of mask on sky (30 sec).
  5. Measure x,y positions of where reference stars should go.
  6. Take picture of same field without mask and measure actual reference star locations.
  7. Run Bev's slit_alignment program by typing "sla" in the directory with the executable. Move telescope accordingly. Repeat step 6 until moves are small.
  8. Put mask back in and take picture. Verify objects are centered in slits. Make final alignment as needed.
  9. Re-assemble spectrograph: set Wavelength to 6900 Angstroms using the "M" next to the MSWavelen display on the XLRIS window. Put the 300g/mm grating back in. You can now change directly the grating angle by clicking on the "A" by the Angle display in the XLRIS window.
  10. Notice that the central wavelength of the slitmask is approximately 600 Angstroms higher for the 300g/mm (140 Angstroms higher for 1200 g/mm) than the longslit as the longslit is NOT at the center of the field (for mechanical purposes). Therefore, when using the longslit, you must set the wavelength using the "W" by Wavelen in the XLRIS display, and when using multislits, you must use the "M" by MSWavelen in the XLRIS display. This will make the appropriate Angstrom offset.
  11. Begin science observation. Note: if doing multiple slitmasks on a common cluster with a common central pointing, one can usually get by with performing just step 8 above to test alignment for the additional masks (NOT the first mask). If all is well, the alignment will already be adequate for a long exposure.

Focusing the telescope

  1. Set exptime to 10 sec
  2. mirror in, clear mask in.
  3. Filter to GG495
  4. Spectrograph focus to 2640
  5. type (in UNIX window): focusloop tel_focus (where tel_focus is the central telescope focus value, e.g., 12.9). Notice that this can now be done by clicking CDM in XLRIS window and specifying starting focus.
  6. To change telescope focus type (UNIX): modify -s dcs telfocus=NEWVALUE

Changing the Slitmasks

  1. Place slitmask wheel in position 1 - normally DIRECT
  2. Replace appropriate slitmasks
  3. Check slitmask names by typing "configure slitname" in a Manuka window. Output to screen should look something like :
  4. Value aliases for slitname:
    long_1.5 = 4
    7_774 = 3
    7_796 = 7
    direct = 1
  5. Delete names of removed slitmasks by typing "configure -d slitname name1 name2 etc". Confirmation of deletion should appear on screen.
  6. Put in names of new slitmasks by typing "configure slitname name = #" Confirmation of name change should appear on screen.
  7. Quit the SETUP and restart to refresh names on slitmask window.

Checking Grating Positions

  1. Check grating names by typing "configure graname" in Manuka window. Output to screen should look something like :

    Value aliases for graname:
        mirror = 1
        600/5000 = 5
        1200/7500 = 2
        300/5000 = 3

  2. Show grating port number by typing "s grating" and show corresponding grating name by typing "s graname" in a Manuka window.

Writing Setup Procedures

  1. Set up the mask, the grating, and the grating angle. Note that the position of trap door and the status of lamps are NOT included in setup.
  2. Click WRITE in XLRIS display window. Give filename for setup file which is written to "setups" directory on (e.g) /home/manuka1/lris18.
  3. To enable, click GO in XLRIS window. Note that this can change grating and slitmask simultaneously and that the Angle changes NOT the central wavelength.

Remote Observing From Waimea

  1. Bring up camera display under "Guider Eavesdropping" by specifying the guider window of the OA's display at the summit and the window where yours will be displayed in the remote observing room. Your display should not be the window where you are running LRIS.

LRIS FOCUS SETTINGS (as of December 1997 on Keck II):

Imaging: Clear 2060
B 2060
V 2230
R 2080
I 2060

Spectra: Longslit GG495 2080
clear 2080
Slitmask GG495 2110
clear 2060

Note that a new V Filter was installed after 4/96; previous focus was 2080.

Figaro Display Notes

General Notes:

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