Keck LRIS¶
Overview¶
This file summarizes several instrument specific settings that are related to the Keck/LRIS spectrograph.
Longslit¶
If reducing data with a longslit, we recommend that you specify that only a single slit is desired, i.e.:
trace slits number 1
See Number of Slits for further details.
Taking Calibrations for LRISb¶
Default Settings¶
Here are the deviations from the default settings for LRISb:
settings trace dispersion direction 0
settings trace slits tilts method spca
settings trace slits tilts params 1,1,1
settings trace slits pca params [3,2,1,0]
settings trace slits sigdetect 30.0 # Good for Twilight flats; faint dome flats might fail miserably..
The last setting is fine for a relatively bright frame taken on the twilight sky, but we suspect a faint dome flat on the blue side will require a lower sigdetect (and is likely to be very challenging overall).
Internal flats, meanwhile, may be too bright and need to be tested.
Pixel Flat¶
It is recommend to correct for pixel-to-pixel variations using a slitless flat. If you did not take such calibration frames or cannot process them, you may wish to use an archival. If so, copy the file into your MasterFrame folder (should be named MF_lris_blue and you may need to create it yourself) and set the following in the _reduce-block of the PypeIt file:
reduce flatfield useframe MF_lris_blue/PypeIt_LRISb_pixflat_B600_2x2_17sep2009.fits.gz