Quick Review

1. Focus the telescope using MIRA: recomended
2. Acquire the target
3. Coarse Alignment
• Image the target field
• Image the mask: or use images of the mask acquired in the afternoon
• Identify stars
• Offset telescope to comple coarse alignment
4. Fine Alignment:
   • Image the mask: stars are now in the alignment boxes
   • Run check_boxesb/xboxb (blue side) or check_boxes/xbox (red side) for fine alignment
   • Repeat Fine Alignment if necessary.
5. Start Spectroscopic Observations .

Slitmask Alignment

• alignment boxes in the multiobject slitmasks.
• pickoff mirrors for coarse alignment are NOT being used.
• LRIS IRAF routines will be used for alignment.

Focus telescope

• Tell the OA the name of your target as listed in your starlist file and also the position angle for the instrument rotator.
• Ask to OA to run MIRA in the neighborhood of your target.
  • If you plan to observe the field for two hours, you may ask the OA to run MIRA one hour ahead of of your target field.
  • MIRA on the blue side should usually be run to focus the telescope because it requires less time to re-configure the instrument.
  • MIRA on the red side should be run only if a good focus is critical to science observations on the red side.

Acquire target

• Target name and coordinates
• Position angle (skypa)
• Pointing origin (should be LRIS)

Coarse Alignment

1. Configure the appropriate side of the instrument for imaging:
   • Set slitmask to direct
   • Set dichroic to any position except clear
   • Set grism to clear
   • Set blue filter appropriately (if you will be taking spectra in the red, use either the clear position or the G filter; using U or B filter could result in problems due to differential atmospheric refraction)
   • Set blue camera focus as appropriate for the selected blue filter.
2. Set exposure time to 10-20 seconds, as desired.
3. Take an image.
4. When image starts reading out, insert the slitmask
5. Acquire second exposure (direct with slitmask) after the first image has read out.
6. Identify one alignment star on the first image and measure the pixel coordinates. Call these x1 and y1. Usually, FIGDISP is used to identify stars
7. On the second image (or if you decide, an image of the mask acquired in the afternoon), identify the corresponding alignment box for the alignment star and note the coordinates of the box center. Call these x2 and y2.
8. Move the telescope by issuing a move command.

   Display tool	move command	where
   FIGDISP blue side	movb x1 y1 x2 y2 movb_f2d x1 y1 x2 y2 NOTE: x2 y2 are measured coordinates using IRAF/DS9 when using movb_f2d	punaluu window
   FIGDISP red side	mov x1 y1 x2 y2	punaluu window
   SAOInage ds9 blue side	movb_iraf x1 y1 x2 y2 mshiftb x1 y1 xref=x2 yref=y2	punaluu window IRAF window
   SAOInage ds9 red side	mov x1 y1 x2 y2 mshift x1 y1 xref=x2 yref=y2	punaluu window IRAF window

   
   The alignment stars should now be in their boxes; proceed with fine alignment.

Fine Alignment

1. Start Guiding:
   Have the OA select a guide star on the movable guider and begin guiding. Ensure that the guide star selected is not too close to the edge of the guider field, since small offsets may still be required.
2. Take an image.
3. Start IRAF:
   Select from the desktop menu:
   IRAF and IDL --> IRAF --> cl + ds9
4. load the keck package and the lris subpackage
   While in the IRAF xterminal, load the keck package and the lris subpackage. This should load the routines checkboxes, checkboxesb xbox, xboxb, and other routines.
5. cd to the data directory.
   • If you do not know the data directory, type "s outdir" in a punaluu window.
     outdir = /sdata240/lris1/2000feb07 (unix path name)
   • In the iraf terminal type:
     cd /s/sdata240/lris1/2000feb07
     The "/s" is required to access a summit directory from headquarters.
6. Run either check_boxesb and/or xboxb
   As an example, to start check_boxesb for blue side data

        check_boxesb image coordfile

   or for red side data

        check_boxes image coordfile

   where image is the name of the FITS image you took, and coordfile is the name of a file containing the coordinates of the guidestar boxes (or the name of a new file in case you measure the boxes in real time). The routines xbox and xboxb have the same calling sequence.
   Note: it takes seven seconds for an image to be written to the data directory after the image is read out by the software.
7. Repeat steps 2 and 6 if necessary.
   Until the translation and rotation are within your tolerances, repeat steps 2 and 6. Typically, a mask is aligned when the translation and rotation are within the measurement errors given in parenthesis.
   • The xbox and xboxb routines will report suggested moves in rotation and position, as well as the uncertainties (in parenthesis).
   • Perform another alignment iteration if:
     • a rotator move was required
     • either the north or east offset was > 0.2 arcsec (or whatever your personal tolerance is!)

Spectroscopy

• Reconfigure the instrument for spectroscopy:
  • Set dichroic and gyrism to the appropriate position for spectroscopy
  • Set blue filter to clear position
  • Set blue camera focus as appropriate for the clear position.
• Set exposure time as desired for spectroscopy.
• Expose...phew!