AuxTel Lost Pointing Accuracy#

Overview#

This procedure should be used when the AuxTel loses pointing accuracy, causing targets to not appear centered in the detector during the first acquisition.

Error diagnosis#

  • Targets are not centered in the detector, appearing at the edge of the field or not in the field at all.

  • The issue might occur if the auxtel/correct_pointing.py script has not centered the right star.

  • This can arise when two or more similar magnitude stars are present in the field, potentially confusing the script.

  • The issue should be mitigated by using the bright star catalog, but sometimes SIMBAD returns a field with two or more bright stars that may cause mispointing.

  • See OBS-88 for some off-centered images examples.

Procedure Steps#

  1. Pause the LOVE ATQueue.

  2. If the pointing is completely lost and no bright star is seen in the detector, the absorbed zero-point pointing offsets need to be reset.

    In order to reset the absorbed pointing offsets, recycle ATPtg CSC by sending it to STANDBY, and then back to ENABLED.

  3. Add a auxtel/correct_pointing.py script to the queue and move it to the top of the waiting scripts.

    Leave the configuration empty (defaults are az: 90, el: 60) or you can choose an area (az, el) of the sky by introducing new values. You could also launch a wider target search by modifying the mag_limit, mag_range, or the search radius.

    auxtel/correct_pointing.py#
    az: 180
el: 35
mag_limit: 6.0
mag_range: 4.0
radius: 5.0

  4. Play the ATQueue and while the script is running, confirm in the incoming RubinTV images that the right target is being centered.

  5. If the pointing is lost again, repeat steps 1-3 with a different configuration, different location of the sky, or widen the search to ensure the target is appropriate for the auxtel/correct_pointing.py script.