search

desihub / desispec

DESI spectral pipeline
BSD 3-Clause "New" or "Revised" License
33 stars 24 forks source link

update pixmasks for warm columns -> disconnected masked pixels? #2212

Open sbailey opened 3 months ago

sbailey commented 3 months ago

Check cases where there appears to be a vertical pattern of not-quite-connected masked pixels that might indicate a hot column that isn't quite triggering the automatic masking (credit @schlafly for noticing), e.g. from https://data.desi.lbl.gov/desi/spectro/redux/daily/nightqa/20240330/nightqa-20240330.html (DARK pulldown) -> z7 (lower left) and r3 (lower middle):

image image

If these appear on multiple nights with different pixels they might disappear from median masks and might need a by-hand update to force a mask. There is some #survey-ops Slack discussion where @Waelthus inspected individual preproc files, but I'm transferring the issue here for tracking longer term.

Alternately, it could be useful to identify which fibers overlap these potentially problematic columns to see if they are causing any real problems in redshift distributions.

Waelthus commented 3 months ago

just for keeping the position of the Slack discussion which inspections: https://desisurvey.slack.com/archives/C01HNN87Y7J/p1711827311297459. Will have a look at the masks later.