Checking array performance

Check noise level by taking a dark.

To check the noise performance of CSHELL, take a dark frame and compare to previous results.  Let staff at the IRTF know when substantial differences are noticed.  The following set-up should give a mean value < 10 and a standard deviation < 5:

1. Itime of 1 second

2. Shutter closed

3. Direct Imaging Mirror (DIM) in

4. Obs Mode in Stare(A)

5. Take exposure (push GO)

6. Draw a box in DV display 0 (drag middle-mouse button) in area with minimal bad pixels

7. Box size can be adjusted in DV

8. Set display 1 to active and display type to stats

Check signal level by taking a spectrascopic exposure of a known line.

To check the signal performance of CSHELL, take a spectroscopic exposure of a known line and compare to previous results.  The following set-up uses the 2.19085 μm Kr line, which should have a peak count of approximately 500 near column 130 ± 10 and a FWHM of approximately 2.5.

1. Itime of 1 seconds

2. Slit set to 0.5 arc seconds and shutter open

3. Direct Imaging Mirror (DIM) out

4. Put in Kr lamp

5. Set filter to CVF/Wlen Open

6. Enter wavelength of 2.19085 μm and click Wavelen (μm) button

7. Take exposure (push GO)

8. Draw a line (shift middle-mouse button) in DV display 0 perpendicular to Kr line

9. Set display 1 to active and display type to xlinecut

10. Click on Set Endpoint from Line

11. Click on Gaussian fit

Check slit position by taking an image of the illuminated slit.

The slit position should be verified anytime the slit wheel is moved or after large changes in telescope position.  It should fall near column 110 ± 10.  The following setup uses the Kr lamp to illuminate the slit, but any lamp will work.  However the continuum lamp would be too bright for the setup below.

1. Itime of 1 seconds

2. Slit set to 0.5 arc seconds and shutter open

3. Direct Imaging Mirror (DIM) in

4. Put in Kr lamp

5. Set filter to CVF/Wlen Open

6. Enter wavelength of 2.19085 μm and click Wavelen (μm) button

7. Take exposure (push GO)

8. Draw a line (shift middle-mouse button) in DV display 0 perpendicular to the slit

9. Set display 1 to active and display type to xlinecut

10. Click on set endpoint from line

11. Click on Gaussian fit