Procedure Index

• A. Preliminaries
• B. DM/WLS registration
• C. LBWFS calibration I
• D. Image sharpening
• E. LBWFS calibration II
• F. WFS calibration

Procedure

A. Preliminiaries

Bring up the AO tools

1. Open VNC viewers k2aoserver-new:2 and k2aoserver-new:3.
2. Right-click in the background of any of the VNC desktops and select LGS-AO Control → Start LGS Calibrations.
3. Wait for a few minutes until all GUIs are up.

Verify the following GUIs are present

• On k2aoserver-new:2
  • ao2 SC GUI
  • LBWFS Img Acq
  • Low-Bandwidth Manager GUI
  • LUI
• On k2aoserver-new:3
  • MAORI
  • TT graphs
  • STRAP Status GUI
  • Calibration tools GUI (Keck II calib)
  • ACAM tool (ACAMTOOL) (available on the second workspace)
  • LBWFS calibration GUI
  • AOAcq (SIM mode)
  • LUI

Launch NIRC2 GUIs

On k2aoserver-new:2, VNC pulldown menu:

• NIRC2 Menu → NIRC2 waikoko-new terminal
• NIRC2 Menu → Start Quicklook
• NIRC2 Menu → Start NIRC2 Status GUI

Optional: On the waikoko-new terminal, type newdir if you would like to save the NIRC2 images in a new data directory. If the directory for user nirc2eng and current UTC date already exists, no new directory will be created.

Run calibrations setup

Start setting up for calibrations:

• Keck II calib → Calibration setup. When prompted:
  • Select NIRC2
  • Select LGS-AO
  • Select sodiumDichroic
  • Select STRAP/LBWFS
• Turn HEPA off:
  • Keck II calib → Light Source Control
  • If HEPA still on, hit Click for HEPA OFF

Take a test image with ACAM

1. Keck II calib → Light Source Control → 0.1% = ND3
2. ACAMTOOL check that Tint(s) is 1.0
3. ACAMTOOL → goi
4. Verify that SFP is within 5 pixels of the OPT_AXIS pixel in qfix/acampo.dat; (982.2, 1040.5) in March 2025

B. DM/WLS registration

Run DM/WLS registration

1. Keck II calib → DM Control → Clear Voltages
2. Keck II calib → DM WLS Registration
3. After Null Centroids, if needed, run fsmoffload from the Calibration toolbox IDL terminal until Cx,Cy in the Keck II - WFS Intensity GUI are less than 0.030

Once the registration is completed (with error ≲ 0.3%), Dismiss the DM/WLS Registration window.

C. LBWFS calibration I

On the LBWFS Calibration Tool:

1. Click on Setup for Cals.
2. Select Yes if you want to calibrate the 5x5 array in addition to the 20x20 array.
3. When prompted, select Sodium Dichroic
4. Wait until the IDL prompt is back and the STRAP display shows STRAP OK and TSS: INPOS.
5. Click on Align TSS
6. Click on DM/LBWFS Reg
• Correlation of recinstructed wavefront with actuator pattern should be between 0.92 to 0.95.

D. Image sharpening

The purpose of this step is to set the DM actuators (hence shape) in a static mode (open loop) so that they correct the non-common path aberrations. The best image quality is achieved via the image sharpening algorithm. If needed, one may also load a previously saved phase map onto the DM via the WYKO.

Establish the initial shape of the DM

You can select one of the following options:

• Clear DM voltages: Keck II calib → DM Control → Clear voltages
• Rough correction of the astigmatism introduced by IR dichroic: Keck II calib → DM Zernike Control → 0 deg astig → -0.6

Both options above are equally valid although option2 tends to converge faster than option 1.

Check health of NIRC2 alad server

Before running the image sharpening, check that the NIRC2 alad server is not crashed. This can be done by simply changing the NIRC2 integration time and check that the time actually changes in the NIRC2 status GUI. In the NIRC2 control terminal type itime 1.

• If the terminal prompt comes back and the itime changes in the NIRC2 status GUI, then proceed to run the image sharpening.
• If the terminal prompt does not come back and/or error messages appear on the terminal, then you need to follow the NIRC2 alad crash recovery procedure:
  • Open a new NIRC2 control terminal: VNC background menu → NIRC2 Menu → NIRC2 waikoko-new terminal.
  • Type recover on the new terminal.
  • At the prompt, answer y and hit Enter.
  • You may need to restart the NIRC2 Quicklook GUI once the recovery procedure is completed
  If the recovery procedure is successful, then you can proceed to run the image sharpening.

Run image sharpening

Image sharpening for NIRC2 takes about 10 minutes.

1. Keck II calib → Image Sharpening to start the Image Sharpening Tool
2. Image Sharpening Tool → CAMERA → NIRC2
3. Image Sharpening Tool → Auto Image Sharpen

Note the values of the SFPZ position in mm and the RMS of the WF in nm shown in the IDL terminal where image sharpening runs. As a reference, a RMS of the WF less than 35 nm represents a good image sharpening.

Two pop-up windows will appear when the image sharpening is completed:

1. Check image quality of sharpened image. In the NIRC2 Quicklook GUI:
   1. Zoom and pan until the image of the fiber source is well centered on the display.
   2. Plot → Gaussian Fit.
   3. Note the XFWHM and YFWHM.
   The PSF of the sharpened image should look approximately circular and have an average FWMM better than 3.5 pixels.
2. Hit Dismiss in the Image Sharpening Tool GUI.

Protect NIRC2 detector: In a waikoko-new terminal, type shutter close and hit Enter.

Save DM voltages file on disk (optional)

• Keck II calib → DM Control → Save voltages to file
• Please use the following notation for file names: YYYYMMDD_nirc2.dm

E. LBWFS calibration II

In the LBWFS Calibration GUI:

1. Click on Setup for Cals
2. Select Yes if you want to calibrate the 5x5 array in addition to the 20x20 array
3. Select Sodium Dichroic when prompted
4. Click on Record Image
5. Examine the image and verify that all subapertures are evenly illuminated and at least 1000 counts
6. Click on Save as cog
7. Check that the DM shape is the expected one
8. If the DM shape looks right, answer Yes to the prompt
9. Select NIRC2 as the PO

Check the health of the LBWFS cog files, which are stored in /net/k2aoserver-new/usr/local/kroot.2024.02/rel/ao/qfix/data/Lbwfs/CentOrigins. Launch IDL in a k2obsao@k2aoserver-new terminal:

IDL> lb = readlbcog("NIRC2-L.cog")
IDL> print, minmax((lb)
    -0.778075     0.642462  
IDL> lb5 = readlbcog("NIRC2-L5x5.cog")
IDL> print, minmax(lb5)
    -0.909949     0.295984

If any of the values are outside the [-1, 1] interval, then you need to rerun Setup for Cals and Save as cog.

F. WFS calibration

First run WFS calibration in LGS mode

1. Keck II calib → WFS Calibration
2. Choose instrument → NIRC2-L
3. If the DM shape looks right, answer Yes to the prompt
4. Select → 2.4
5. After Clear Centroids, if needed, run fsmoffload from the Calibration toolbox IDL terminal until Cx,Cy in the Keck II - WFS Intensity GUI are less than 0.030

Run WFS calibration again in NGS mode

1. Keck II calib → WFS Calibration
2. If the DM shape looks right, answer Yes to the prompt
3. Choose instrument → NIRC2-N
4. Select → 2.4
5. After Clear Centroids, if needed, run fsmoffload from the Calibration toolbox IDL terminal until Cx,Cy in the Keck II - WFS Intensity GUI are less than 0.030

Once all the steps in the WFS calibration procedure have been completed, hit Dismiss in the WFS Calibration window.

IMPORTANT: Proceed to the daily image quality check procedure.