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chara:discussion_of_alignment_procedures

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Discussion of Alignment Procedures

Old Alignment Sequence

At stow:

  • M7 to default
  • Make sure red beacon goes into the ACQ hole, fine tune into boxes —move beacon flat
  • Make sure that the laser from the lab, with m2 corner cube goes into the hole —move dichroic
  • Turn off laser and red beacon and turn on blue beacon, to fine tune spots into labao —move dichroic
  • Focus blue beacon on labao — then focus red beacon on telescope
  • Repeat until convergence and small errors.

Slewing to star:

  • At star, the red beacon on telwfs likely won't have moved much, blue beacon on labao may need significant adjustment.
  • M7 to default
  • Red beacon - TelWFS - beacon flat
  • Blue beacon - Labao - dichroic
  • Blue beacon focus - Labao - “focus beacon button” - lab parabola
  • Red beacon focus -TelWFS - “focus WFS ” button scope parabola.
  • Turn off red beacon.
  • Lock star - TT
  • Close TELWFS DM loop
  • Close LABAO DM loop
  • AUTOM7 - to offload tilt in lab to M7
  • Star acquired
  • When slewing to next star, send M7 to default position and repeat.

New Alignment Sequence

Implemented January-July 2023

At stow:

  • M7 to default. Load default boxes on tel WFS. Load default flats on telAO and labAO.
  • Move Beacon flat to center beacon in ACQ hole.
  • Align TelWFS boxes to center on the red beacon.
  • Align blue beacon to labAO using dichroic.
  • Focus blue beacon on labAO and red becaon on TelWFS.
  • If aberration terms are high, ZERO CENTROIDS to adjust relative positions of the boxes.

Slewing to Star:

  • On first slew only, align red beacon to TelWFS boxes using beacon flat.
  • Align blue beacon to lab WFS using M7.
  • Focus blue beacon on labAO and red becaon on TelWFS.
  • Turn off red beacon.
  • Turn off blue beacon and lock star (TT only) - move TelWFS boxes to get star centered and evenly illuminated on ACQ hole.
  • Lock star on Tel AO - DM servo
  • Turn on blue beacon - lock LABAO servo
  • Turn on DM AUTO - use DM to correct tilt and offload to M7 when needed.
  • If coma and astigmatism high, create sky flat on bright star - Turn off [DM], [SV FLT], [FLATEN], then relock the [DM].
  • For IR combiners, move beacon flat to align star to STST.
  • For SPICA, move beacon flat to align star on SPICA FTT.
  • Star Acquired.
  • When slewing to the next star, DO NOT send M7 to default. If next star is bright align beacon flat to center star on STST/SPICA FTT. If star is faint, keep beacon flat fixed or align beacon flat to center red beacon in offset beacon boxes on TelWFS when repeating sequence.

Proposed Revisions to Current Alignment Sequence

chara/discussion_of_alignment_procedures.1710979687.txt.gz · Last modified: 2024/03/20 20:08 by gail_stargazer