Beginning of Night Procedure
Note: You may want to repeat this procedure with 8x mode if looking at fainter guide stars, skipping the telescope focus and Fold1X and Y mirror adjustments.
- Load appropriate Instrument setup into ShaneAO loop control GUI, e.g. ngs16cog.
- If you have a good measurement of seeing, you should make an appropriate onSky refcent file by using genSkyRefcents:
- As user@real: genSkyRefcents 16x refcentfile seeing
- Example: genSkyRefcents 16x hs-2020-10-27-COG_16xLGS.fits 1.2
- If doing 8x mode, substitute 8x for 16x
- Load in new sky refcent file: e.g. refcent('data/hs-2020-10-27-COG_16xLGS_onSky.fits')
Performance is often improved by taking into account the seeing, but not always.
- Move to bright (6.5 mag) star near zenith.
- Focus star on guide camera.
- Send light to SAO (diagonal mirror position 3).
- Move telescope 30 arcsec N (or some other direction to get sky).
- Take WFS camera dark: dark()
- Take TT camera dark if TT Dichroic is Splitter: ttdark()
- Move telescope 30 arcsec S (or undo previous move).
- Close loops: gain(.3)
- Adjust telescope focus until foc reading in peeko is close to zero or
the value when loops are closed on the internal source.
- Adjust Fold1X and Fold1Y mirror to fine tune centering, making sure lr and ud in the peeko display are close to zero. Typical move is 0.5mm (500 encoder counts), though you may want to do moves as small at 0.2mm (200 encoder counts) for fine tuning.
- Run /u/user/observers/lgs/saocon_setups/seeing-logging.sh script if you have time.
- Adjust gain until happy with performance, taking images on ShARCS to evaluate Strehl.
- Open loop: open()
- Repeat gain tuning for other modes (e.g. ngs16bq, ngs8cog, etc.).
- Move to science target.