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Tricks for calibration on-sky

  • Loop Closed on a bright NGS star with FLAO only 36 modes to keep proper collimation
  • VibrationCompensation ON
  • Optimise asterism to avoid beam vignetting during actuator steps
  • Disable OffloadToLM1
  • Close Guider (if any) to start from a well-centered condition.
  • setJitterStailizerGain(0.001) on Blue, Yellow and Red.
  • Create the proper object BCUJitterStabilizer in the argos terminal and tweak it: nIterInt=1, nIterExt=5, nMeasures=1000, deltaExt=5m
  • stop the Guider and start measurement. If lasers drift away too much during the measurement tweak nIterExt
  • repeat the measurement several times (5-10) and then check and average reconstructors

New Procedure from March 2017

  • open an argos terminal
  • generate the FastGuider Calibration object
from argos.terminal.sandbox import FastGuidingCalibrator
fgc = FastGuidingCalibrator(argos)

  • Loop Closed on a bright NGS star with FLAO only 36 modes to keep proper collimation
  • VibrationCompensation ON
  • Optimise asterism to avoid beam vignetting during actuator steps
  • Disable OffloadToLM1
  • Close Slow Guider (if any) to start from a well-centered condition.
  • acquire data in push pull with the function "_acquireInPushPull" and in the meanwhile acquire a snapshot (with the GUI). Use the procedure for both pupilMirror axis.
fgc._acquireInPushPull(self, howManyCycles, howManyStepsUp, commandOffset)
  • assign the two snapshot's tracking numbers to two variables stexTn and steyTn
  • analyze the data:
from argos.snapshot.analyzer.argos_snapshot_analyzer_terminal import ArgosSnapshotAnalyzerTerminal
terminal= ArgosSnapshotAnalyzerTerminal(argos._indexFile, argos._telescopeSide, argos._logger)
newGreenRec= fgc._analyzeSnapshot(terminal, stexTn, steyTn, commandOffset)
  • save the new rec
rec= argos.lgsw.calibrationManager.jitterStabilizerReconstructor('oldRecTag')
rec['GREEN']= newGreenRec
argos.saveJitterStabilizerReconstructor(rec, 'newRecTag', None)

History of experiments

When Rec NotesSorted ascending
20161214 20161214_062600 Measured on-sky on SX. It works OK
20160312 measured on sky (?) No snapshots available, not working
20160313 measured on sky (?) No snapshots available, not working
20160316 See presentation of TM of MPIA Jul 2013 - 20160313_231000 (1) Rejection of ~10 < 5Hz
20161021 See fast_guiding.pdf Test with the 2 actuator axes controlled independently (2)

20160313_231000    [[-0.0004051  -0.00113072], [-0.00163311  0.00084793]]
20161021_105800    [[ 0.18196794,  0.30437769], [ 0.6339633 , -0.39368591]]
20161021_115300    [[ 0.18196794,  0.30437769], [ 0.,  0.]]
20161021_115400    [[ 0.,  0.],[ 0.6339633 , -0.39368591]]
20161214_062600    [[-0.00113842, -0.0060764 ],[-0.00345469,  0.00238202]]

(2) Rec 20161021_105800 is Rguider * Rec 20161021_115300 controls only PM axis 0 and has no rejection Rec 20161021_115400 controls only PM axis 1 and has some rejection of ~10 < 5Hz (?)

-- LorenzoBusoni - 14 Dec 2016
Topic revision: r4 - 01 May 2017, TommasoMazzoni
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