WFS focus to match the Luci best focus position.

The focus check can be done after any intervention on luci/WFS or just to follow any trend summer/winter.

Instrument setup.

Start Luci.

Luci setup:
  • Filter H.
  • Mode cube.
  • Dit:2.5
  • Ndit 10.

Start WFS.

  • Deploy ARgos cal unit.
  • Light source shutter full open.
  • load a disturbance with 0.8 arcsec seeing for 1700Hz.
  • Close loop.
  • Optimize.
Sent PresetAO through AOS for mag 10.

close loop and optimize to have a well corrected PSF.
  • Check Luci images to identify the PSF position x and y.
  • Luci setup a subwindow of 250,250 in the PSF position.
  • Take a luci image with the subwindow on.
  • Note the pixel position that it is going to be used in the AutoFocus Gui.
For a good PSF estimation a background can be taken, also it works as a reference for posteriori checks with the same configuraiton.

To per form the background:
  • AOS pause.
  • Turn Off Argos light source.
  • From WFS control Gui take 2x Luci darks (acquire luci dark); same number of frames; 10 (default).
  • After the darks taken,
  • Turn ON Argos light source.
  • AOS resume.
Screen Shot 2024-03-13 at 11.02.27 AM.png

launch script:
  • Setup Gui:
  • Focus range:2.
  • Focus step:0.2
  • Images to average: 10 (default)
  • PSF position on Luci Frame.
Screen Shot 2024-03-13 at 10.50.40 AM.png

The script will step 2 mm of focus in steps 0.2mm.

The elab will process the images identifying the PSF center and computing the FWHM vs focus steps. Fitting a parabola and determining the minimum where the focus position should go.

Pop up a small gui to accept the new value. Note: The Gui come up with no yes/No button. (left button is yes, right is No)

Fitting curve:


Update configuration File.

Once a new focus is found the WFS configuration file shas to be updated.
  • File is LUCIFER_ACE-AO found in: /home/AOeng/live/aoroot/calib/wfs/current/setups/
  • Change the value in: self.stagez.moveTo(51.5).
Example for SX:
  • self.flowerpot.setOperatingState(0)
  • self.stagez.moveTo(51.5)
  • self.lens.moveTo(0,0)
  • self.adc._motor1.moveTo(-208)
  • self.adc._motor2.moveTo(-0)
  • self.stagez.waitTargetReached(checkStatus= True)
  • self.adc._motor1.waitTargetReached(checkStatus= True)
  • self.adc._motor2.waitTargetReached(checkStatus= True)

Current values.

date Side Focus[mm]
20240312 SX 51.5
20240312 DX 55.9

-- JuanCarlosGuerra - 13 Mar 2024
Topic revision: r1 - 13 Mar 2024, JuanCarlosGuerra
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