Calibrating the NGS AO system

A. Preliminaries

A0. Notes on this page:

• X: Indicates steps done once, X can be N2 for NIRC2, O for OSIRIS, or NS for NIRSPAO
• XNS: Indicates steps done once per instrument being calibrated, X can be N2 or O, NS is NIRSPAO

A1. Bring up the AO tools:

1. Log in as "kNobsao", where N can be 1 or 2
2. Select kNao VNC Menu -> Check VNC Server Stat and check that four VNC servers are running. If not, start the servers (ask for assistance if needed).
3. Start the VNC viewers
   Off the desktop menu select:
   • k2 AO VNC Menu -> Start Acquisition Viewer (center) on your favorite center display.
   • k2 AO VNC Menu -> Start Telnets Viewer on your favorite display.
4. Right-click in the background of the VNC desktop--> NGS AO Control Menu --> Start NGS Calibrations

A2. Verify Tools:

After startup, the following guis should be present:
• MAORI
• TT graphs
• The SC GUI (continously check SC GUI for faults (indicated in red))
• The IDL "Calibration tool" titled "Keck I calib" or "Keck II calib"
• The WFS intensity display
• K2 only: NIRC2 instrument software (For OSIRIS/NIRSPAO, run the software in the appropriate instrument VNC sessions)
• Firefox -> WYKO display

A3. Reboot WFC

1. MAORI -> Scripts -> Reboot WFC
2. A new window will launch to reboot and go away when complete (about 4 min utes)

N2/O NS   A4. Run the calibration setup: on the Calibration Tools Gui, select Calibration setup

Keck 1:

1. Select OSIRIS
2. Select NGS AO
3. Set SND to 0.1%, note original value
4. Take 1 sec exposure on ACAM
5. Verify that SFP is within 3 pixels of the OPT_AXIS pixel in qfix/acampo.dat (currently 449.75,503.40 in 2016)
6. Return SND to original value

Keck 2:

When prompted
1. Select NIRC2 or NIRSPAO
• If calibrating for two instruments, calibrate for NIRC2 first
2. Select NGS AO
3. Finish Calibration Setup
4. Set SND to 0.1%, note original value
5. Take 1 sec exposure on ACAM
6. Verify that SFP is within 3 pixels of the OPT_AXIS pixel in qfix/acampo.dat (currently 511.7, 491.7 in 2016)
7. Return SND to original value

N2/O NS   A6. Run the DM WLS registration on the Calibration Tool Gui: DM WLS Registration

• N.B.: If after the "Null Centroids" step the Centroid averages as reported on the WFS Intensity Display are greater than 0.02, please type "FSMOFFLOAD" from the Calibration Tools IDL prompt.

Discussion:

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. Image sharpening is currently available for NIRC2, OSIRIS, and NIRSPAO. As of September 2013, NIRSPAO data must be taken manually. An automated script is forthcoming.

If needed, one may also load a previously saved phase map onto the DM via the WYKO.

B1. Establish best shape on the DM

N/O

1. Click DM Zernike Control on the Calibration GUI to bring up the zernike control gui.
2. Change the "0 deg atig" to -0.6 . If entered in the text box remember to press enter.
3. Select from the Calibration GUI: Image Sharpening.
4. Click Auto Image Sharpen
5. When completed, proceed to next section (C. WFS Calibration)

   NOTES: NIRC2 image sharpening algorithm describes the routine. This automated process requires approximately 10 minutes on NIRC2 and 15-20 minutes on OSIRIS. After it completes, you may get the "junk.opd" error message, indicating a wyko problem. See Twiki troubleshooting page for guidance.

Backup (auto image sharpening does not work)

• To shape the DM directly as follows:

  Loading the phase map
  
  

  Click on DM control on the WFC IDL widget. Click on Clear voltages button. Click on Load phase using WYKO Select the last saved file for the instrument: NIRC2 nirc2_yyyymmdd.ph NIRSPAO ddmmyy_nirspec_h.ph IF zeros.ph OSIRIS zeros.ph If you get the "junk.opd" error message, a wyko problem is likely. See Twiki troubleshooting page for guidance.

  Check the returned Wyko phase map (see below)
  Repeat Steps 3, 4 and 5 three more times.
  Judge on Wyko display that that the fringes are reasonably straight (for the case of zeros.ph). If it is not the case, iterate steps 3, 4 and 5.
  If zeros.ph was selected and you are happy with the fringes, redefine the DM origin file by clicking on click on Save voltages as DM origin .
  Dismiss DM Control
  
  Checking the Wyko phase map:
  
  The Wyko interferometer that we use to measure the shape of the DM surface is very sensitive to vibrations. It is necessary to check any phase measurement. Under quiet conditions, the returned phase will look very smooth and does not present any phase discontinuity. Examples of thoses instances are shown on the left in the table below. The user would click on accept button for such cases
  On the other hand, the returned phase may show the presence of phase discontinuities, and the user would click on redo. If you are having difficulty in making the measurement due to the presence of vibrations, you may ask the summit crew to turn telescope oil off.

  Examples of good returned phase map	Examples of bad returned phase map

  VERY IMPORTANT!!!

  Define the phase on the DM as the DM origins by clicking
  
  Save voltages as DM origins.
  
  If this does not yield adequate image quality, move the SFP-z and change the DM Zernikes until the image quality is good.
  Remember to Define and Save the SFP position (for OPTOSIRIS, OSPEC and OSIMG) and the new DM shape using Save voltages as DM origins.
  

Notes

• Problems with the WYKO:
  If you have problems with the WYKO software (e.g., no phase map is returned), then you may want to check that the software is running. You can VNC onto wykopc or k1wykopc (the password is the same as for the k2ao account) and check that the "WYKO-Vision" program is running. If not you may (re)start the program. If this fails, you can ask someone on the summit to reboot the WYKO PC.

• For IF:
  If there is no optimized phase map, we just assume the flat shape is the best one... One can optimize the image quality on KAT by adjusting the focus (SFP z) and loading DM zernikes (from the DM zernike widget) until the best image is found on KAT.