Cal. Acq. Tool The Calibration Acquisition Tool (CAT) provides a GUI for observers who wish to take more than the one flat and one dark provided by the EFS "Lamps Only" option.

    Notes:

  • There are two modes for the CAT: Specify exposure time and coadds or specify total counts per flat field.
  • The flat lamp will be set to give a flux of about 3000 DN/sec in all modes except some AO modes.
  • Non-linearity on the SPEC detector starts above 20,000 DN per coadd
  • Detector persistance has not been observed with this new chip
  • The desired filter, slit, echelle angle, and cross disperser angle must set prior to taking cals with the CAT (see the EFS page to learn about a "setup only" script).
  • Low-res observers often take 1 Neon and 1 Argon lamp; High-res observers often take 1 arc with all lamps on.
  • The minimum integration time for SPEC is 1.5 seconds.
  • Argon has some very strong lines that will saturate even at the minimum exposure time.


    To start the CAT:

  • Right-click in the background --> Click "NIRSPEC GUIs Menu" --> Click "Calibration GUI"

    There are two ways to use the CAT:

  1. Set the exposure level (total counts) per flat field
    1. Setup NIRSPEC using a "Setup Only" script from the EFS
    2. Click on "Counts"
    3. Enter the number of darks (lamps off) and flats (lamps on) frames that you want
    4. Enter the counts (total ADU) that you want per flat. Do not worry about reaching non-linearity, as the CAT will simply add coadds to attain your desired count level.
    5. Select which arc lamps you want
    6. Enter the integration time and coadds for each arc frame (we recommend 1.5 seconds with 10 coadds)
    7. Click "GO"
  2. Set your own integration time and coadds
    (N.B. The flat lamp will give about 3000 DN/sec in most modes)
    1. Setup NIRSPEC using a "Setup Only" script from the EFS
    2. Click on "Exp. Time"
    3. Enter the number of darks (lamps off) and flats (lamps on) frames that you want
    4. Enter the integration time and coadds for each flat/dark frame
    5. Select which arc lamps you want
    6. Enter the integration time and coadds for each arc frame (we recommend 1.5 seconds with 10 coadds)
    7. Click "GO"